| 01 - ASSESSMENT OF WATER MIGRATION IN
MULTI-COMPONENT SNACKS BY MAGNETIC RESONANCE IMAGING |
Pedro Ramos Cabrer, John P. M. van Duynhoven*, Hans Timmer, Gerard van
Dalen, Klaas Nicolay
Utrecht University, Unilever R&D Vlaardingen, Eindhoven University of
Technology
|
Consumer appreciation of snacks is often provided by
contrast in texture between different components of the product. For almost
all of the known multi-component snacks, this implies contrast in water
abundance and activity. Without proper precautions, this inevitably leads to
water migration and loss in texture (quality) during shelf life of the
product. Hence, a major challenge in the development of snacks with ambient
stable texture contrast is to find strategies to control water migration.
When the efficacy of such strategies could be assessed in a non-invasive
manner this could aid significantly in the development of novel snack
products.
Therefore we have developed two MRI protocols that can assess water
transport phenomena in multi-component systems in a non-invasive manner.
Both protocols can be used for systems of realistic dimensions (7 cm), but
differ in their emphasis on molecular mobility information and temporal
resolution.
The first protocol, emphasizing molecular mobility information (at the cost
of temporal resolution) was successfully applied to a snack consisting of a
bread roll filled with cheese and sausages. The slow migration of water in
this system (weeks) could be monitored at three molecular mobility levels,
i.e. glassy/crystalline, semi-solid and liquid like. In order to span the
width of molecular mobility regimes, recourse was taken to a combined use of
Single Point Imaging and ‘conventional’ Spin Echo MRI techniques.
A second protocol, tailored to monitoring relatively rapid (hours/days)
water transport phenomena, was used to study stability of a sandwich snack,
consisting of bread filled with components with high water activity (tomato,
ham and cheese). In order to monitor components with low molecular mobility
(i.e. bread), a Single Point Imaging MRI approach was used.
Both protocols were successfully applied for non-invasive assessment of the
efficacy of experimental ‘water migration control’ technologies, such as
edible barriers. These results were used to enable ‘snack engineering’ in a
rational manner.
 |
| |
| 02 - STRUCTURAL CHARACTERIZATION OF THE
POLYSACCHARIDE PRODUCED BY LACTOBACILLUS HELVETICUS CNRZ32 BY
HIGH-RESOLUTION NMR SPECTROSCOPY: EVIDENCE OF A PHOSPHOETHANOLAMINE
SUBSTITUENT |
Marie–Rose Van Calsteren 1, Danièle Atlan 2 and Christophe Gilbert 2
1 Centre de recherche et de développement sur les aliments, Agriculture et
Agroalimentaire Canada, Saint–Hyacinthe, Québec, Canada
2 Unité de Microbiologie et Génétique, UMR 5122, CNRS, Université de Lyon
1, Villeurbanne, France
|
Strain CNRZ32 of Lactobacillus helveticus was grown in milk
or chemically defined medium, and its exocellular polysaccharide was
isolated from the supernatant or the whole culture and purified by TCA and
acetone precipitations, solvent extractions, dialysis, and lyophilization.
Purity was checked by gel permeation chromatography. Structural
characterization was performed by chemical methods and with 1H,
13C, and 31P NMR spectroscopy. Essentially identical spectra were obtained under all
culture and purification conditions.
Sugar analysis by TLC or GC revealed the presence of rhamnose, galactose,
glucose, and an amino sugar. C, H, N, and P were found by elemental
analysis.
13C NMR spectra displayed 46 signals, seven of which were in the anomeric
region, three could be attributed to rhamnose methyls, two to an acetyl
substituent, one to C2 of an acetamido sugar, and two were found to belong
to phosphoethanolamine. Of the four methylene belonging to C6 of hexoses,
two were nonsubstituted, one was glycosylated, and one was substituted with
phosphoethanolamine.
On the 1H NMR spectra, seven signals were present in the anomeric region,
the methyl region contained signals for three rhamnose and one acetyl, and
two signals could be attributed to phosphoethanolamine. Two rhamnose and one
galactose had the α anomeric configuration, whereas the third rhamnose, the
second galactose, one glucose, and one acetamido sugar were β linked. NOESY,
ROESY and HMBC spectra gave linkage information.
The data were consistent with a multibranched heptasaccharide repeating
unit. Phosphoethanolamine has never been reported to occur in a
polysaccharide produced by lactic acid bacteria. |
| |
| 03 - NMR INVESTIGATIONS OF INDUSTRIAL DOUGH
PROCESSING AND STORAGE BY NMR |
John van Duynhoven, Eddy Esselink, Peter Weegels
Unilever R&D Vlaardingen, The Netherlands
|
It is well recognised that the quality of industrial bakery
products strongly depends on dough processing and supply chain conditions.
The industrial conditions can differ significantly from the artisanal
manufacturing process. Industrial dough processing typically involves
large-scale kneaders, extruders and moulders. Furthermore, in contrast to
the artisanal process, the industrial supply chain of bakery products often
involves the storage and transport of frozen dough to bakers. In order to
enable a rational design of industrial dough processing and storage
conditions, a good understanding of the involved microstructural phenomena
is required. Many microstructural and rheological studies on dough have
already been reported. However, most of them pertain to laboratory scale
processing and storage experiments, using either rheology, microscopy or
spectroscopy. In our studies we have deployed NMR in conjunction with
rheology and microscopy, in order to study the microstructural phenomena as
they occur during processing at industrial manufacturing lines. The same
techniques were also used to study the microstructural effects as they occur
during frozen storage of dough.
In the microstructural assessment of an industrial dough processing line [1]
the impact of industrial kneading, extrusion and moulding was monitored by
NMR relaxometry, rheology and electron microscopy. Also the effect of
proofing and resting steps was studied. These processing steps had a
considerable impact on the structure and cohesiveness of the
gluten/starch/water components of the dough. NMR relaxometry showed how a
molecular biopolymer (gluten) network was being formed, disrupted and
restored during the different stages of industrial manufacturing. These NMR
observations were well in line with results from electron microscopy and
rheology.
During frozen storage of dough, NMR relaxometry [2] indicated that water is
released from the gluten network. This is in agreement with Infrared
spectroscopy, which shows conformational changes in the gluten proteins. In
line with these observations, electron microscopy showed that the released
water migrated to the gas cells in the dough, where ice crystals were
formed. At the macroscopic scale, MRI measurements indicate that these ice
crystals are not evenly distributed over the dough.
[1] Esselink, E, van Aalst, H, Maliepaard, M, Henderson, T, Hoekstra, N, van
Duynhoven, JPM, Impact of dough processing on structure: a rheology, NMR and
EM approach, Cereal Chem 80(4): 419-423 (2003)
[2] Esselink, E, van Aalst, H, Maliepaard, M, van Duynhoven, JPM, Long term
storage effect in frozen dough by spectroscopy and microscopy, Cereal Chem
80(4): 396-403 (2003) |
| |
| 04 - LOW-FIELD NMR T2 RELAXOMETRY APPLIED TO
MONITOR PHASE TRANSITIONS DURING COOLING OF CREAM |
Hanne Christine Bertram, Lars Wiking, Jacob Holm Nielsen, Henrik J.
Andersen
Department of Food Science, Danish Institute of Agricultural Sciences,
Research Centre Foulum
|
Milk fat crystallizes during cooling. The crystallization
temperature depends on the content of saturated and unsaturated fatty acids
in the milk (1-2). Milk fat is very susceptible to compositional changes,
and the fatty acid composition of milk is directly affected by the diet of
the cow. Knowledge of crystallization temperature of milk fat would enable
development of superior cooling strategies in storage and pumping of raw
milk before pasteurisation to preserve superior quality of the milk for
further use. Low-field 1H NMR has shown potential as a future at-/on-line
method in several foods.
Low-field 1H NMR transverse relaxation (T2) was measured during cooling
(31C to 4C) of cream with low and high content of palmitate (C16) induced
by different feeding strategies (3). Distributed analysis of the T2
relaxation data revealed marked differences in the T2 relaxation
characteristics of the liquid fat population (10-100 ms), which could be
ascribed to differences in the size of the fat globules in the two types of
cream. Principal component analysis (PCA) on the obtained T2 relaxation
decays showed clear shifts in NMR relaxation behaviour at 17˚C and 22C in
cream with a low and high content of palmitate, respectively. DSC
measurements on the creams revealed that these shifts are taking place at
the onset of crystallization of fat. Consequently, the present study
demonstrates that potential of low-field 1H NMR can to measure phase
transitions in a medium-fat containing matrix as cream.
1. Shi et al. (2001). Journal of Dairy Science, 84, 2392-2401.
2. Steffensen et al. (2004). Milchwissenschaft, 59, 176-179.
3. Wiking et al. (2003). International Dairy Journal, 13, 799-803. |
| |
| 05 - CHANGES IN CHEMICAL-PHYSICAL PROPERTIES
OF MYOFIBRILLAR PROTEINS AND MYOWATER DURING COOKING OF MEAT- COMBINED
LOW-FIELD NMR RELAXAOMETRY AND FT-IR SPECTROSCOPY |
Hanne Christine Bertram 1), Achim Kohler 2), Henrik J. Andersen 1),
Ragni Ofstad 2)
1) Department of Food Science, Danish Institute of Agricultural Sciences,
Research Centre Foulum, 2) MATFORSK, Norwegian Food Research Institute
|
Meat quality is affected by multiple and mutual interacting
factors from gene to fork. Especially, fresh meat characteristics and the
cooking process are substantial for the sensory perception of meat.
Consequently, a basic understanding of physical-chemical properties in fresh
meat and during cooking is important to elucidate and optimise perceived
meat quality. In the present study low-field NMR T2 relaxation measurements
were combined with FT-IR spectroscopy during cooking of pork in order to
investigate the changes in water characteristics, protein structures, and
the relationship between the progressions in these two features in two meat
qualities (normal and high ultimate pH).
Measurements were performed during cooking from 28˚C to 81˚C. Pronounced
changes in both T2 relaxation data and FT-IR spectroscopic data were
observed during cooking, revealing severe changes in the water properties
and structural organization of proteins. Upon distributed analysis of the T2
relaxation data the changes during cooking were displayed as broader
populations with faster relaxation times corresponding to water being
confined within smaller more heterogeneous structures upon cooking. The FT-IR
data revealed increases in α-sheet and decreases in β-helix structures of
the myofibrillar proteins upon cooking. Distributed NMR T2 relaxation data
and FT-IR spectra were compared by partial least square regression. This
revealed correlation between the FT-IR peaks reflecting α-sheet and β-helix
structures and the NMR relaxation population reflecting myofibrillar water
and also expelled ‘bulk’ water (T2 relaxation times >500 ms). Accordingly,
the present study demonstrates that structural changes in proteins during
cooking of meat are associated with simultaneous alterations in the
chemical-physical properties of the water within the meat. |
| |
| 06 - IMPROVEMENT OF SPECTRAL RESOLUTION BY
CO-ADDITION OF ALIGNED SPECTRA FROM SELECTED VOXELS OF THE SAMPLE |
Ana Sepe, Igor Serša
Jozef Stefan Institute, Ljubljana, Slovenia
|
| A spectrum from a sample has often limited resolution
because of poor magnetic filed inhomogeneity within the sample. This can
improved by magnet shimming when variations of magnetic field within the
sample are moderate. In many samples the magnetic field is highly
inhomogeneous due to large internal magnetic field gradients that have
origin in susceptibility effects within the sample. If that is the case,
magnet shimming can usually not help to improve magnetic field homogeneity.
This situation is typical also in NMR of food samples when we want to
acquire a spectrum from a part of the sample in an undestructive way.
Standard spectroscopic methods that are based on nonselective excitation or
cubic localization produce poor results because a spectrum is acquired from
a large part of the sample where magnetic field is unhomogeneous.
Spectroscopic imaging (SI) methods allow acquisition of spectra from much
smaller parts (voxels) of the sample with much better magnetic field
homogeneity and the spectra have therefore better resolution. However, the
signal to noise ratio (SNR) may be low. To regain the SNR of the standard
spectroscopic methods and to preserve spectral resolution of the SI method
we propose co-addition of SI spectra with their prior alignment. Spectral
alignment is needed because spectra from an uniform part of the sample look
identical except they are differently shifted because of the magnetic field
variations between different voxels. Our preliminary measurements indicate
that by this method spectral resolution may be improved by a factor up to 3.
 |
| |
| 07 - T1-T2 CORRELATION SPECTROSCOPY OF COMPLEX
FOOD |
N Marigheto, S Benamira, S Duarte, A Costa, K Wright, B Hills,
Institute of Food Research, Norwich Research Park, Colney, Norwich, UK
|
The potential use of NMR two-dimensional T1-T2 correlation
spectroscopy [1-3] is explored for two different aspects of food science,
namely processing effects on raw food materials and quality changes on
storage. The inversion recovery sequence is inserted immediately in front of
a CPMG sequence and by systematically varying the recovery time t1 we arrive
at the two-dimensional T1-T2 pulse sequence. The two independent variables
are the recovery time, t1 and the CPMG acquisition time, t2. The t1 period
is dominated by longitudinal relaxation, whereas t2 is dominated by
transverse relaxation processes. The T1-T2 cross-correlation spectrum of raw
and cooked egg white and yolk showed peaks corresponding to the pools of
exchangeable and non-exchanging protons. Peaks corresponding to the
non-exchanging CH protons of the more rigid gel network formed by the denaturation of major protein components are seen in the spectrum of cooked
egg white and yolk [4]. T1-T2 correlation spectroscopy is also shown to be a
powerful tool for monitoring the effect of high pressure and microwave
processing on the microscopic water distribution and starch chain dynamics
in potato and waxy maize starch [5]. The potential for distinguishing
storage disorders in fruit such as mealiness in apples is explored. Avocado
maturity can also be monitored from the increase in oil content determined
from the relative water and oil peak areas [6].
References:
1. Song, Y.-Q., Venkataramanan, L., Hurlimann, M.D., Flaum, M., Frulla, P.,
and Straley, C., J. Magn. Reson. 154:261-268, 2002.
2. Hurlimann, M.D., and Venkataramanan, L., J. Magn. Reson. 157:31-42, 2002.
3. Godefroy, S., Creamer, L.K., Watkinson, P.J., and Callaghan, P.T., The
use of 2D Laplace Inversion in Food Material, page 85 in Magnetic Resonance
in Food Science, Ed Belton, P. S., Gil, A. M., Webb, G.A. and Rutledge, D.,
The Royal Society of Chemistry, Cambridge, 2002.
4. Hills, B., Benamira, S., Marigheto, N. and Wright, K., T1-T2 Correlation
Analysis of Complex Food, Applied Magnetic Resonance (in press)
5. Hills, B., Costa A., Marigheto, N., and Wright,K., T1-T2 Correlation
Studies of High Pressure Processed Starch and Potato Tissue, Applied
Magnetic Resonance (submitted)
6. Hills, B., Duarte S. and Marigheto, N., An NMR Relaxation Study of
Avocado Quality, Magnetic Resonance Imaging (submitted) |
| |
| 08 - SEPARATION AND IDENTIFICATION OF EXTRACTS
OF TOMATO JUICE PULP BY 1H NMR |
Stefano Tiziani, Yael Vodovotz
Food Science & Technology Department, The Ohio State University, Columbus,
USA
|
| Epidemiological studies have shown the health benefits of
tomato consumption for the preventionof chronic diseases. Antioxidants, such
as lycopene and β-carotene, are the health promoting compounds in tomato
products. In this study, different tomato pulp fractions were analyzed by
1H NMR using a Bruker DRX-600 spectrometer. The hydrophilic components of
tomato pulp were extracted with D2O and analyzed by COSY, TOCSY, HSQC and
HMBC 2D sequences. The combination of these techniques enabled to
distinguish and identify several sugars, organic acids and amino acids.
Hydrophobic compounds, once extracted by 1:1 acetone/hexane and dried by
flushing nitrogen, were dissolved in CDCl3 and analyzed by COSY, TOCSY, and
HSQC 2D spectroscopy. Diffusion ordered 2D NMR spectroscopy (DOSY) helped to
identify different carotenoid isomers. This work confirms that NMR
spectroscopy is a powerful noninvasive technique that allows a
characterization not only of sugars, proteins and organic acids but also the
identifications of minor compounds such as carotenoids. |
| |
| 09 - USING LOW RESOLUTION NMR FOR THE
DETERMINATION OF TOTAL LIPID CONTENT IN VARIOUS TYPES OF ANIMAL FEED |
Geir Humborstad Sørland, Frank Lundby, Chrisitan Jepsen, Anita Rosen
Anvendt Teknologi A/S, Matforsk, DLG-Centrallaboratorium, Felleskjøpet,
Norway
|
An optimized Carr Purcell Meiboom Gill (CPMG) pulse
sequence has been applied for determining the total lipid content in various
types of animal feed. It has been found that even with low resolution
equipment it is not only possible to quantify the total amount of lipids
present in the sample, but also discriminate between two classes of lipids
in samples where the moisture has been dried out; lipids with short T2 (~
0.2 ms) and lipids with long T2 (~100 ms). The NMR results are compared
against chemical extraction methods.
Keywords: Quantification, lipid, phospholipid, animal feed, low field NMR |
| |
| 10 - 1H HR-MAS NMR AND CHEMOMETRIC ANALYSIS TO
STUDY COMMERCIAL PHYTOTERAPIC PLANTS |
Cristina Daolio 1, Antonio Gilberto Ferreira 1, Marcia M.C. Ferreira 2,
1 DQ/UFSCAR-São Paulo-Brazil 2 IQ/UNICAMP-São Paulo-Brazil
|
Catuaba is a commercial phytoterapic product and has a long
history of using in Brazilian popular medicine as physical and mental tonic
and especially as a sexual stimulant. However, there is a big confusion
regarding to the correct species sold commercially as Catuaba. One species
is Anemopaegma arvense (Bignoniaceae) called the “official Catuaba” wich
principal active compounds are the alkaloids. Nevertheless, recent studies
showed that in the herbal commerce today the species Trichilia catigua (Meliaceae)
is the most consumed species and the limonoids are the chemical markers for
this family.
In this work we analyse samples with official botanical classification of
both species and eight commercial samples by using 1H HR/MAS and liquid
1H NMR. The spectra data showed that after PCA analysis the samples sold in
commercial market are not from Anemopaegma arvense like we will spect. We
can also saw that most of them are very close with Trichilia catigua and few
one are completely different from this two species. In this case, probably
it will be a mixture of differents plants species. The spectral analysis
indicated that both methods, líquid and HR/MAS, lead to the same results. In
1H HR/MAS NMR technique we used the crude bark tree without any pretreatment
and for liquid experiments a crude methanol extract.
The 1H NMR data were acquire in BRUKER 9.4 Tesla equipment and all
measurements were done in triplicate using a 4 mm rotor and 5 mm inverse
detection probe, respectively and we use the PCA for chemometric analysis.
|
| |
| 11 - CORRELATION OF POROUS AND FUNCTIONAL
PROPERTIES OF FOOD MATERIALS BY NMR RELAXOMETRY AND MULTIVARIATE ANALYSIS |
Adrian Haiduc, A.A. Reska, John van Duynhoven
Unilever R&D Vlaardingen, The Netherlands
|
The porous properties of food materials are known to
determine important macroscopic parameters such as water-holding capacity
and texture. The measurement of these macroscopic and functional parameters
stands as a considerable challenge. In conventional approaches,
understanding is built from a long process of establishing
macrostructure-property relations in a rational manner. Only recently,
multivariate approaches were introduced for the same purpose.
We tested this approach for model systems consisting of oil in water
emulsion gels stabilised by protein, form complex structures built from fat
droplets, protein aggregates, dispersed water droplets, all of which have an
influence on the final product properties. NMR time domain decay curves were
recorded for emulsions with varied levels of fat, protein and water.
Hardness, dry matter content and water drainage were determined by other
means and analysed for correlation with the NMR data with multi variate
techniques. Partial Least Squares (PLS) can calibrate and predict these
properties directly from the continuous NMR exponential decays. Orthogonal
Signal Correction filters from the overlapping signals the uncorrelated
information and yields regression coefficients higher than 95%. The PLS
coefficients themselves belong to the continuous exponential domain and
explain the connection between NMR data and emulsion properties after
multiexponential fitting. Transformation of the NMR decays into a discreet
domain with non-negative least squares permits the use of multi linear
regression (MLR) on the resulting amplitudes as predictors and hardness or
water drainage as responses. |
| |
| 12 - USE OF SNIF-NMR IN
VINEGAR ANALYSIS |
Elisangela Fabiana Boffo 1, Antonio Gilberto Ferreira 2
1 UNIVERSIDADE FEDERAL DE SÃO CARLOS, 2 UNIVERSIDADE FEDERAL DE SÃO
CARLOS, BRAZIL
|
In Brazil one of the most use of vinegar is in the
industrial foods but we also use with a bactericidal propose. In this case
we do not need to care wich is the sugar source to start the fermentation
process but the final product change dramatically if it is from sugar cane
or grapes for instance.
This work describe the use of SNIF-NMR techniques to classified vinegar
comercial samples using the 1H/2H isotopic relation by NMR. All the eighteen
comercial sample were obtained from the local shopping and submited a
liquid/liquid extraction using 80/150 (v.v. vinegar/diethyl ether) during 24
hours. The 1H/2H NMR spectra were recorded in a BRUKER 9.4 Tesla equipment
without fluorine lock and all measurements were done in triplicate in a 5 mm
probe at 298K.The internal reference was TMS for 1H NMR spectra and TMU for
stablish the isotopic relationship.
The results show that it is possible to predict unequivocally the isotopic
1H/2D relationship in the comercial vinegar samples wich were originated
from plants that they use the C3 and C4 but not clearlly from CAM
biossinthetic metabolism. The 1H/2D relationship founded are: C3 (99 –112 ppm), C4 (aprox. 130 ppm) and CAM (aprox. 106 ppm). We can also distinguish
acetic acid from C3 (grapes) and C4 (sugar cane) when they are mixture
togheter in a agrins comercial sample. The isotopic relationship for others
vinegars originated from: apple (C3), rice (C3), orange juice (C3), pineaple
(CAM), honey (C3) and sinthetic acetic acid were also found. |
| |
| 13 - GM SOYBEAN CROPS RECOGNIZE BY
1H HR-MAS NMR AND CHEMOMETRIC ANALYSIS |
Andersson Barison 1, Glaucia Braz Alcantara 2, Antonio Gilberto
Ferreira 2, José Franciso Feraz de Toledo 3, Marcia Miguel Castro Ferreira
4
1 Universidade Estadual de Mato Grosso do Sul – UEMS, 2 Universidade
Federal de São Carlos – UFSCar, 3 Empresa Brasileira de Pesquisa
Agropecuária – Embrapa, 4 Universidade Estadual de Campinas - UNICAMP
|
In the last few years genetically modified (GM) crops,
mainly herbicide tolerant soybean, had a rapidly acceptance by producers in
several places in the world. Because genetic modification in food crops is a
relatively new technology we must to concern about its environmental and
human beings impact. Moreover, the use of GM crops in many countries, mainly
in European Union, must follow regulations and it is very important to have
tools for this.
In this work we show a new methodology to recognize GM soybean crops by 1H
HR-MAS NMR and chemometric analysis. For this propose we use two samples of
GM and one of “conventional” soybean varieties with identical origin and
cultivated at the same conditions. The 1H HR-MAS NMR spectra, and the PCA
allowed to distinguish the GM samples from their traditional specimens with
a good results. This data also were used to built a classify model which was
able to classify some unknown samples. This results show us that NMR could
be a very attractive analytical technique because its permits to obtain a
fast spectra with resolution enough to distinguish samples with small
differences without sample pretreatment. Moreover, 1H NMR interpretation of
observed differences in the spectra of GM and no GM crops could give
important informations about the compounds involved in this discrimination.
The 1H NMR data were acquired in BRUKER 9.4 Tesla equipment and all
measurements were done in triplicate using a 4 mm rotor at 298K and we use
the PCA for chemometric analysis. |
| |
| 14 - LOSS OF MOISTURE FROM HARVESTED RICE
SEEDS ON MRI |
Nobuaki Ishida, Shigehiro Naito
National Food Research Institute, Japan
|
The drying process of harvested rice seeds greatly affects
the rice grain quality. In rice seeds, water content is already very low at
harvest, just over 20 %. Therefore, it has been difficult to trace water
distribution in a seed by ordinary MRI measurement. The recently developed
SPI (single point mapping imaging) method can detect water in a seed with
low water content. In this study, the decrease of water in rice seeds after
harvesting at various drying temperatures was traced by the SPI method, and
the decrease of image intensity, which is proportional to removable water
content, was compared with the results of the oven method.
Most of the water was present in the embryo and endosperm. The water
reduction rate was larger on the outside than in the central position of the
rice seeds at 50oC, although this discrepancy was not obvious at 40oC. Water
reduction was brought about with time according to the kinetics of the
multiple components, for both MR imaging and the ventilated-oven method.
Images were continuously measured (10 min per image for 100 min). The
reduction rate of water from rice kernels increased rapidly with temperature
near 60oC then rose slowly above 60oC. Latent heat was calculated as 15
kcal/mol•deg from the changes of drying rate at temperatures below 60oC. |
| |
| 15 - 77SE NMR USING A 1 MM PROBE - A NEW HOPE |
Claus Cornett a, Bente Gammelgård a, Till Kühn b
a Danish University of Pharmaceutical Sciences, Department of Analytical
chemistry
b Bruker Biospin, Fällenden, Switzerland
|
| A selenium metabolite previously isolated from rat urine is
for the first time shown to be found in human urine also. The metabolite was
"purified" from 15 L human urine yielding what corresponds to about 10 mg of
selenium and idenfied using ICPMS, LC-MS and 1H-, 13C-, and
77Se NMR using a
1 mm microprobe. |
| |
| 16 - QUALITY CONTROL OF BEER USING
HIGH-RESOLUTION NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY AND MULTIVARIATE
ANALYSIS |
Dirk W. Lachenmeier, Willi Frank, Eberhard Humpfer, Manfred Spraul
Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Chemisches und
Veterinäruntersuchungsamt (CVUA) Karlsruhe, Bruker BioSpin GmbH, NMR
Division, Rheinstetten, Bruker BioSpin GmbH, NMR Division, Rheinstetten,
Germany
|
NMR spectroscopy is introduced for the quality control and
authenticity assessment of beer in official food control. Measurements were
performed at a F 400 MHz NMR spectrometer using flow injection technology
for automatic sample changing. For preparation of the beer samples, only
degassing and addition of buffer (pH 5.6 in D2O with 0.1% TSP) is required.
Each spectrum was acquired at a temperature of 303K, using various
Pre-Saturation pulse sequences.
The variability of the spectral profile of beers differing in type and
origin was studied by principal component analysis (PCA) considering the
spectrum as a characteristic fingerprint. For the first time, the high
throughput of a Flow-Injection NMR system allowed the efficient
establishment of a comprehensive database of beer spectra for PCA
classification. Beers made with barley malt and wheat malt could be
distinguished. A clustering of beers from the same brewing sites was
observed. Deteriorated beers with flavour taints or bacterial contamination
could be discriminated from normal products. Using the Partial Least Squares
(PLS) method to correlate NMR spectra with results from reference methods (refractometry/densitometry
and enzymatic analysis), models for calculation of ethanol, original gravity
and lactic acid content of the beer samples were established.
The results obtained suggest that NMR is a useful tool for the quality
control of beer samples, since quantitative determination of all essential
compounds as well as chemometric classification is possible by a single
experiment. Compared to conventional methods, 1H NMR spectroscopy is faster
and requires only simple sample preparation. |
| |
| 17 - ESR AND NMR
SPECTROSCOPY STUDIES ON EMULSIONS CONTAINING Β-LACTOGLOBULIN AND OXIDISED
METHYL LINOLEATE |
Suhur Saeed, Nazlin Howell, D. Gillies
School of Biomedical and Molecular Sciences, University of Surrey,
Guilford, Surrey GU2 7XH, United Kingdom
|
|
Proteins including
β-lactoglobulin (β-LG) contribute to the emulsification and gelling
properties of food products due to their specific structure as well as
interactions with other components during processing. The effect of lipids,
especially oxidising lipids, on the structure and function of -LG has not
been investigated in detail.
Spin label
2-methyl-2-nitrosopropane in 25mM DMSO was incubated with the emulsion
containing β-LG (15%) and oxidised methyl linoleate (ML) (10%) in the
presence or absence of antioxidants. ESR spectra, recorded on a Jeol RE IX
X-band spectrometer indicated a spin trap radical adduct initially in the
lipid phase; this was subsequently transferred to the protein layer. After
24 h this immobilised nitroxide radical reached its maximum intensity and
remained stable at -20˚C, but decreased when stored at 22˚C. Antioxidants
prevented the transfer of the radical to the protein. ESR signals were not
detected in the absence of oxidised ML or with fresh ML, indicating that the
detected nitroxide radical depends on the hydroxyl radical produced from
oxidised ML. Only a three-line ESR spectrum was observed, with no additional
hyperfine coupling, indicating that the radical is centred on a tertiary
carbon. Tyrosine and tryptophan residues provide two likely possibilities
for the formation of a radical adduct that would yield the primary triplet
observed in this study.
2D 1H NMR
spectra showed changes in structural flexibility and amide groups and
interactions between β-lactoglobulin and oxidised ML. Changes in the amide
1 and 111 regions, tryptophan and tyrosine doublet bands were also confirmed
by FT-Raman spectroscopy.
This study highlights the significant
effect of lipid oxidation products on protein structure and function.
Acknowledgements:
BBSRC funding to Prof. Nazlin Howell is gratefully acknowledged. |
| |
| 18 - NUTRITIONAL COMPONENTS IN COD (GADUS
MORHUA) MUSCLE AND CHANGES DUE TO FREEZING AND THAWING EXAMINED BY HR 1H MR
SPECTROSCOPY |
Standal, I.,Gribbestad, I S., Bathen, T., Halvorsen, J, Aursand, M,
Martinez, I.
SINTEF Fisheries and Aquaculture, Ltd, Cancer Clinic, St. Olav Univerisity
Hospital, SINTEF Unimed, Norway
|
Lipids (PUFAs) and metabolites (anserine, carnosine,
taurine, betaine, choline) determine the mouth feel and taste of seafoods.
They also have positive effects on human health. All these components can be
identified by HR 1H MR spectroscopy, a sensitive technique with short
acquisition times that produces a fingerprint with the potential to be used
to identify the sample and its history.
Our group is involved in the development of methods for the (1)
non-destructive compositional analyses and (2) authentication of seafoods.
We present here the results corresponding to the characterization by 1D and
2D 500MHz 1H MR spectral analyses of perchloric acid extracts (PCAE) from
pre-rigor white muscle of cod (Gadus morhua) and the effect of freezing and
thawing on the metabolite content of cod muscle.
We could identify single components including: lactate, alanine, anserine,
TMA, TMAO, creatine, choline, glycine, β-alanine, taurine, hypoxanthine and
formate. The singlet arising from TMAO and the numerous signals from
anserine dominated the spectra. The present study also showed that freezing
and thawing affects the metabolite content in cod fillets as well as the
components lost as "drip-loss".
Currently, a database is being constructed in order to classify unknown
samples according to their biochemical composition: by suitable multivariate
data-analyses of the spectra we intend to extract information such as
species, origin, feed, production method, processing and nutritional value
of seafood products. |
| |
| 19 - SIMULTANEOUS MAPPING OF STRUCTURAL- AND
TEMPERATURE-CHANGES DURING HEATING OF FOOD IN WATER BY MRI |
Kevin P. Nott 1, Andreas Hauri 2, Laurance D. Hall 1
1 University of Cambridge, UK, 2 Swiss Federal Institute of Technology,
Zurich, Switzerland
|
Although, a large amount of research has involved modelling
of the often interrelated heat- and mass-transfer processes associated with
thermal processing [1] as well as the moving boundary associated with
structural- and phase-changes [2], the limited processing power of computers
often requires assumptions to decrease calculation times. Therefore, there
is a need for measurement techniques that can acquire data for processes
that are too complicated to model, as well as to validate the models
themselves. Fortunately, Magnetic Resonance Imaging (MRI) can map
temperature distributions [3] as well as other heat induced changes; as
shown in a previous study of microwave heating off-line [4]. This current
study demonstrates that MRI can be used to acquire multivariate data
associated with heating by water on-line. Specifically, not only to map
temperature, but simultaneously visualise the gelatinisation front during
cooking of potato, or the thawing front during heating of a frozen ‘boil in
the bag’ bolognese sauce. The future prospects for other experimental
studies as well as for using such data are discussed.
1. Wang, L.J. and D.W. Sun, Trends in Food Science & Technology, 14,
408-423, 2003.
2. Singh, R.P., Food Technology, 54, 44-54, 2000.
3. Nott, K.P. and L.D. Hall, Trends in Food Science & Technology, 10,
366-374, 1999.
4. Nott, K.P., S.M. Shaarani, and L.D. Hall, in Magnetic Resonance in Food
Science: Latest Developments, P.S. Belton, et al., Editors, Royal Society of
Chemistry: Cambridge. p. 38-45, 2003.
 |
| |
| 20 - WHEAT FLOUR ENZYMATIC AMYLOLYSIS
MONITORED BY IN SITU 1H-NMR SPECTROSCOPY |
Maria E. Amato a, Giuliana Ansanelli b, Salvatore Fisichella a,
Raffaele Lamanna b, Giuseppe Scarlataa, Anatoli P. Sobolev c, Annalaura
Segre c
a) Dipartimento di Scienze Chimiche Università Viale A.Doria 6 - 95125
Catania, Italy
b) CR ENEA Trisaia UTS Biotec-Agro SS 106 Jonica Km 419.5 - 75026
Rotondella (Mt), Italy
c) Institute of Chemical Methodologies, CNR, M.B. 10, 00016 Monterotondo
Stazione (Rome), Italy
|
| Starch enzymatic degradation caused by endogenous
hydrolases is studied by in situ NMR spectroscopy on a set of hard and soft
wheat flours. The results obtained by two different techniques (HR-MAS and
1H-NMR in solution) are analyzed in term of a Michaelis-Menten kinetic
phenomenological model taking into account the presence of endogenous
enzymes and their eventual inactivation. The parameters resulting from the
best fit of all experimental data to the kinetic model equations are
submitted to a multivariate statistical analysis in order to assess the role
of the oligosaccharides release in distinguishing between hard and soft
wheats. |
| |
| 21 - IDENTIFICATION OF PHENOLIC COMPOUNDS IN
OLIVE OIL BY LIQUID CHROMATOGRAPHY WITH NUCLEAR MAGNETIC RESONANCE (LC NMR) |
Photis Dais*, Stela Christoforidou, Manfred Spraul
NMR Laboratory, Department of Chemistry, University of Crete,
Bruker-Biospin GmbH, Germany
|
| This work describes the first application of LC-NMR to the
direct identification of phenolic compounds in the polar part of virgin
olive oil. This hyphenated analytical technique, which combines the
properties of the most powerful separation technique (HPLC) with the most
information-rich spectroscopic technique (NMR), was able to identify a large
number of phenolic compounds, including simple phenols (hydroxytyrosol,
hydroxytyrosol acetate, tyrosol, tyrosol acetate, p-coumaric acid, vanillic
acid, vanillin), secoiridoids (oleuropein and ligstroside derivatives of
hydrolysis), lignans [(+) pinoresinol, (+) 1-acetoxypinoresinol], and
flavonoids (apigenin and luteolin). Through the time-sliced 1D 1H NMR
spectra, and a few TOCSY and HMQC experiments, a comprehensive assignment of
the various signals was obtained for most of the isomers of the secoiridoids
carboxylated and decarboxylated derivatives, and those of elenolic acid.
Moreover, new chromatographic peaks were identified and attributed to
homovanillyl alcohol, syringaresinol and maslinic acid. |
| |
| 22 - APPLICATION OF FTIR AND NMR SPECTROSCOPY
FOR THE DETERMINATION OF ORIGIN AND DATE OF PRODUCTION OF BEER |
Cláudia Almeida, Iola F. Duarte, António Barros, Ana M. Gil
Department of Chemistry, University of Aveiro, Portugal.
|
In this work, Principal Components Analysis (PCA) is
applied to the FTIR-ATR and 1H NMR spectra of a set of beers manufactured in
3 different countries, at different dates, in order to find out if the
spectral parameters of beer may be consistently correlated to origin and
date of production.
PCA of FTIR data separated beers from site 1 from the remaining ones, this
separation being based mainly on differences in alcoholic content. No
significant differences were found as a function of production date, with
the exception of the beers of site 2 which seem to differ slightly in terms
of dextrins composition.
Performing PCA on separated NMR regions, the scores scatter plot of PC1 vs.
PC2 of the aliphatic spectral region indicates very good separation of all
samples according to their production sites. The corresponding loadings
indicate that such clear distinction is due to changes in some amino acids,
alcohols and organic acids, thus indicating these compounds as exquisitely
dependent on variables related to the production sites. Secondly, the PCA of
the sugar region shows that the average number of dextrins branching
points/molecule also correlates to production site and, in some cases, to
manufacturing date. Finally, PCA of aromatic region is successful in
separating beers according to both their production site and date.
These results open the interesting possibility that tandem use of
chemometrics and spectroscopy may provide rapid information about the origin
of beer (geographical and production date), which may be of great value in
accessing the reproducibility (and thus for quality control) within
different brewing sites.
ACKNOWLEDGEMENT
The authors thank Bruker BioSpin GmbH for funding support. |
| |
| 23 - STUDIES OF FISH FREEZING USING MR IMAGING |
A. Borge 1, T. Singstad 1, V. Hardarson 2, L. Jørgensen 3, I. S.
Gribbestad 4
1) Dept of Radiology, St. Olavs Hospital, Trondheim, Norway.
2) Dept of Energy and Process Technology, NTNU, Trondheim, Norway.
3) SINTEF Energy Research, Trondheim, Norway.
4) The Cancer Clinic, St. Olavs Hospital, Trondheim, Norway.
|
| MR imaging offers a unique tool for calibrating
mathematical models and numerical simulations of thermal processes in food
products. A quantitative understanding and the development of on-line
measuring methods of freezing and thawing, are of crucial importance for the
fish farming industry. Dynamic MR temperature and ice content maps will
facilitate this and may thus lead to optimised production parameters and
improved quality and processing properties of the fish. The aim with this
study was to map the feasibility of MRI as a method for producing this kind
of images. A home-made nitrogen cooling device for small fish samples was
used inside a Bruker Biospec 2.4 T scanner. Thermoelements were used to
registrate sample and cooling temperatures. We stepped through a range of
temperatures to take MR pictures at stationary temperature conditions. Also
one big temperature step was performed to “film” an ordinary transient
freezing procedure. Samples of cod and Atlantic salmon were studied in the
typical ranges (+10ºC,-10ºC/-20ºC), respectively. In the stepwise regime an
image with very short echo time (2-3 ms) was obtained and T1 and T2 maps
made (ROI-level). Spin density and ice fraction maps were calculated (cod).
Both T1, T2, and spin density drop in a hyperbolic way when reducing
temperature beyond freezing. Probably this is connected to gradual freezing
point depression due to increased concentration of salts and macromolecules.
Correspondingly, a more or less sharp “ice-front” is seen moving in our
transient measurements. For salmon the MR fat signal component survives very
cold conditions. |
| |
| 24 - BLENDS ANALYSIS OF ARABICA AND ROBUSTA
RAW COFFEES SPECIES THROUGH 1H NMR AND CHEMOMETRIC METHODS |
Leila Aley Tavares 1, Elisangela Fabiana Boffo 1, Antonio Gilberto
Ferreira 1, Márcia Miguel Castro Ferreira 2, Luiz Henrique Capparelli
Mattoso 3, Alessandra Alves Corrêa 3
1 UNIVERSIDADE FEDERAL DE SÃO CARLOS, 2 UNIVERSIDADE DE CAMPINAS, 3
EMBRAPA, BRAZIL
|
The drink coffee is prepared from arabica or robusta
variety grain, or even from blends of them. Arabica variety presents flavor
more pronounced and refined, so it can get a best price than robusta in the
international trade. This increase the chance of frauds and require
techniques that have power to discriminate both varieties in a blend.
In this work was used chemometric methods and 1H NMR spectroscopy data to
discriminate arabica and robusta blends as much as classificatory and
quantitative analysis.
The 1H NMR data were aquire in BRUKER 9.4 Tesla equipment and all
measurements were done in triplicate. Were used eleven coffee samples
without roast and with different contents of arabica and robusta specie. The
chemometric methods used were: PCA and HCA for exploratory analysis, KNN and
SIMCA for classificatory analysis, PCR and PLS for quantitative.
Results obtained showed that the methods of exploratory and classificatory
analysis can group the blend samples correctly in two groups, one content
less and the other high proportion of arabica specie. However the method KNN
shows be better than SIMCA because it can discriminate the samples in two
groups (arabica and robusta) without any error using ten neighbours. To
predict the proportion of each variety in the coffee blend were used PLS and
PCR methods and PLS showed better than the PCR . The same were done with
roast coffee sample but the results were not so good because the roast
degree made a strong influence in the chemometric analysis. |
| |
| 25 - SODIUM AND FAT DISTRIBUTION IN SMOKED
SALMON IN RELATION WITH WATER DYNAMICS ACCESSED BY 1H AND 23Na MRI |
L. Foucat 1, R. Ofstad 1, 2, J.P. Donnat 1, J.P. Renou1
1 INRA Theix. STIM. 63122 Saint-Genès Champanelle. France.
2 MATFORSK, Oslov1, 1430 Ås, Norway.
|
1H and 23Na MRI offer a unique opportunity to access
non-invasively and concomitantly the distribution of fat and sodium. The aim
of this work was to investigate the incidence of the fat distribution on the
heterogeneity of the salt content in smoked salmon filet. To characterize
the water dynamics in function of the salt distribution, parametric images
of the transverse relaxation time T2 of water proton were also recorded.
MRI experiments were performed at 53 MHz (23Na) and 200 MHz (1H) on a Bruker
Biospec imager (4.7 T). A homemade 105 mm 23Na/1H double tune NMR probe was
specially designed for this investigation. Fat selective images were
acquired with a pulse sequence based on the difference of longitudinal
relaxation time T1 and chemical shifts between fat and water signals1.
Because the rapid decline of the NMR sodium signal due to the very short
relaxation time T2 (in the order of the ms), a gradient echo imaging
sequence was used. 23Na MRI approach was preliminary validated on a phantom
constituted by a series of tubes containing NaCl solutions of known salt
concentration (ranging from 0 to 5 % w/w).
Study on smoked salmon filets with different salt and fat contents are
reported, and relationships between fat, salt and T2 distributions are
discussed.  |
| |
| 26 - INVESTIGATION OF MARINE BIVALVES
MORPHOLOGY BY IN VIVO MRI. FIRST ANATOMICAL RESULTS OF A PROMISING TECHNIQUE |
L. Foucat 1, S. Pouvreau 2, M. Rambeau 3, J.P. Renou1
1 INRA Theix. STIM. 63122 Saint-Genès Champanelle. France.
2 IFREMER. Laboratoire de Physiologie des Mollusques Marins. Site
Expérimental d'Argenton. Presqu'île du Vivier. 29840 Argenton en Landunvez.
France.
3 Association pour les Technologies Nouvelles en Radiologie. Département
de Radiologie et Imagerie Médicale. Hôpital Sud. 16, bd de Bulgarie. BP
90347. 35203 Rennes cedex 2. France.
|
Marine bivalves and especially the Pacific Oyster,
Crassostrea gigas, are economically important in the French aquaculture.
Now, its production has become a major industry with a production above 100
000 metric tons in 2002. Nevertheless, the ecology and the physiology of
this bivalve are not really well known and consequently their growth and
reproduction in field but also in hatcheries remain still empirical. Several
scientific projects aim to improve this basis knowledge but new tools need
to be discovered in order to take a step in knowledge acquisition rate.
Classically, the investigation of soft tissue in marine mollusks and
especially in marine bivalves relies on destructive methods, since a
hermetic shell protects the animal. These common techniques give precious
information in marine mollusks biology and ecology but present two main
inconveniences which may constitute a limiting step in specific studies:
these methods are (1) really time consuming and (2) necessarily destructive.
Therefore, noninvasive and quantitative procedures have recently become of
interest. Among them and after preliminary trials, NMR imaging appears to be
a promising way. The aim of the present study was (1) to provide the first
results in NMR imaging on oyster (2) depict the anatomy with an optimal MR
contrast parameter with the use of two NMR imagers (1.5 and 4.7 T) and (3)
show the feasibility and the potentialities of this technique for future
investigation of metabolism by 1H and 31P localized spectroscopy.
 |
| |
| 27 - COMPARATIVE STUDIES OF FOOD POLYMER
HYDRATION BEHAVIOR |
Catherine Shawl, Bruce Campbell
Kraft Foods R&D, USA
|
| Time domain 1H NMR spectroscopy is used to study a range of
food polymer systems, including flours, meat proteins, and dairy proteins.
NMR relaxation rates are analyzed to determine the kinetics of polymer
hydration. The influence of factors such as temperature, pH, and ionic
strength are investigated. The relaxometry results are compared to
traditional solubility measures as well as rheological data for these
systems. |
| |
| 28 - NUCLEAR MAGNETIC RESONANCE IMAGING (MRI)
– DETECTION OF INTERIOR DEFECTS IN PROCESSED PORK |
Gunilla Lindahl 1, Hans Stødkilde-Jørgensen 2, Margit Dall Aaslyng 3,
Michael Aagard 4, Anders H. Karlsson 5, Henrik J. Andersen 1
1 Department of Food Science, Danish Institute of Agricultural Sciences,
Tjele;
2 Skejby University Hospital MR Research Centre, Aarhus;
3 Danish Meat Research Institute, Roskilde; 4Tulip Food Company, Vejle
4 Department of Food Science, Meat Science Unit, The Royal Veterinary and
Agricultural University, Frederiksberg C. Denmark
|
The ever-increasing demand for high quality products has
made it extremely important for the food industry to be able to supply
products of pre-specified quality. In most food raw materials including
meat, a high biological variation exists both within and between samples.
This results in a high variation in processed products based on such raw
materials. Porosity or a loose structure is often seen in cooked meat
products. These features are important quality defects in the production of
sliced meat products. The reason for formation of holes is far from
understood. Consequently, development of non-destructive methods for
detection of interior quality defects is therefore highly desirable. MRI is
one of the few available imaging techniques, which can identify interior
defects in a non-destructive way.
The present study aimed to clarify the possibility to detect porosity in
cooked cured ham using MRI. Cooked hams (n=76) were scanned in 3 mm slices
with 6 mm distances in a whole body magnet (GE, 1.5 Tesla). The porosity was
detected in T1 weighted images (T1 Flair sequence). The hams were then
sliced in 3 mm slices and the quantity and the size of the pores were
visually judged by a sensory panel. The correlation between the number of
holes assessed by the sensory panel and the MRI images is investigated.
The study is part of the project ‘Characterization of technological and
sensory quality in food by NMR’, which is supported by the research
program ‘Food technology, safety and quality’ and funded by the Ministry
of Food, Agriculture and Fisheries. |
| |
| 29 - HIGH RESOLUTION IMAGING OF FAT
DISTRIBUTION IN MEAT USING 3D-PGSE |
J.M. BONNY, J.P. RENOU
STIM, INRA, France
|
MRI has no equivalent for analyzing the intramuscular fat (imf)
distribution in a non-destructive manner. Imf influences some important meat
quality characteristics e.g. marbling, sensory properties and keeping
qualities as well as diffusion of water and salt in cured/smoked products.
A large number of sequences have been proposed for generating images of fat
distribution which exploit the differences in T1 (e.g. inversion recovery)
or/and resonance frequencies between fat and water (e.g. CHESS or Dixon
phase-sensitive technique) 1.
We propose a new approach which takes advantage of the large difference
between the apparent diffusion coefficients of myofibers and imf 2. Using a
sufficiently large b-value, it is possible to attenuate the signal of water
so that only the one of fat becomes detectable. The manner for selecting the
adequate b-value according to the other MR parameters are discussed and an
example of isotropic high resolution acquisition using a 3D-PGSE sequence is
shown.
1. Laurent, W., Bonny, J.M., and Renou, J.P. Imaging of water and fat
fractions in high field MRI with multiple slice chemical shift selective
inversion recovery. Journal of Magnetic Resonance Imaging 12, 488-496
(2000).
2. Bonny, J.M., and Renou, J.P. Multiexponential modeling of diffusion in
meat at large b-values by MRI. 7th ICAMRFS, Copenhagen (2004).
 |
| |
| 30 - THE USE SOLUTION NMR TO THE STUDY OF
COUMA UTILIS – SORVA FRUIT |
A. M. R. Nascimento a, M. I. B. Tavares a, R. S. Nascimento b
a Instituto de Macromoléculas Eloisa Mano, Universidade Federal do Rio de
Janeiro, Cid. Univer., Ilha do Fundão, Rio de Janeiro, RJ, CP 68525, CEP
21945-970, Brasil
b Universidade do Estado do Amazonas, Manaus, AM, Brasil
|
| Sorva, is a native fruit of Amazons State in Brazil. It has
been very much used in gum industry. In order to maximise the uses of this
fruit it is important to obtain information on chemical components present
in it. Based on it, the main purpose of this work, is to investigated the
fruit components using 13C {1H} solution nuclear magnetic resonance (NMR).
For that, solvents with different polarities were used to extract the
different fruit components at ambient temperature. Interesting and important
data have been obtained to get information on chemical components of this
fruit. We first extracted the components from the during ripening. The total
fruit were put in different separation funnels and the solvents such as
chloroform, water, dimethylsulfoxide and methanol were put in each one to
extract the chemical components. Each extract were analysed by normal 13C
solution NMR and some interesting data were obtained. From dimethylsulfoxide
extract only polysaccharides were extracted. From chloroform extract signal
from triacylglycerols and other components were collected. When water was
used signals related to polysaccharide and triacylglycerol were acquired and
for methanol the signals already detected for water were assigned. |
| |
| 31 - USE OF HR-MAS AND X-RAY TO STUDY THE
GELATINIZATION PROCESS OF FRUIT SEED STARCHES |
Paula de Miranda Costa, Maria Inês Bruno Tavares, Antônio Gilberto
Ferreira, Cristina Daolio, Lucineia Vizzotto, Anderson Barison
IMA/UFRJ, - IQ/UFSCar, BRAZIL
|
| Gelatinization process of native starches is an important
point to understand some of the starches properties for food applications.
The tropical fruits seeds starches gelatinization process has been follow by
HR-MAS, using a 4 mm rotor in 9.4 Tesla Bruker equipment, and by X-ray. The
natives starches as they are heterogeneous amorphous materials they present
domains that are constituted by ordered and non-ordered polysaccharides
chains. As far as we know that fruits seeds starches arrangements and
compositions depend on the regions and clime, the gelatinization process was
carried out after optical microscopic analysis and differential scanning
calorimetry (DSC) measurements. The melting transition of starches crystals
was determined by DSC and the values found for those were about 150°C. The
gelatinization process was carried out at 150°C, which was higher than the
gelatinization temperature used for potato and maize for instance. The
samples were investigated by HRMAS and X-ray before and after being
gelatinized and the HR-MAS showed more detailed information about this
process concerning to the changes in the polysaccharides crystal structure
than was observed by X-ray. The results obtained by HRMAS indicates that
this analysis can be a new technique to be used as a absolute method to
follow the changes in starches structure. |
| |
| 32 - MULTIVARIATE CHEMOMETRIC ANALYSIS OF
MAGNETIC RESONANCE IMAGES IN RELATION TO FOOD QUALITY |
Elisabeth Micklander 1, Frans van den Berg 1, Anette K. Thybo 2, Sune
Jespersen 3, Hans Stødkilde-Jørgensen 3
1 The Royal Veterinary and Agricultural University, Department of Food
Science, Food Technology, Frb. C., Denmark
2 Danish Institute of Agricultural Sciences, Department of food Science,
Plant Food Science, Aarslev, Denmark
3 Aarhus University Hospital, MR Research Centre, Aarhus N, Denmark
|
Water characteristics and the anatomical interior of raw
materials have been identified as the physical/chemical parameters of most
importance for the technological and sensory properties of final (processed)
food products. Magnetic Resonance Imaging (MRI) has potential for
non-destructive determination of the water distribution in food-stuffs and
non-invasive characterization of the inner structures. Accordingly MRIs
contain potentially information on the sensory quality of the products.
In this study multiple MRIs (M0, T1, T2, Dx maps) were obtained on different
potato varieties, which were simultaneously evaluated on 7 sensory texture
attributes. The aim is to investigate the relation between the sensory
qualities of the potatoes as determined by the trained panel and the complex
MRI data using different chemometric factor models.
As often done in more traditional image analysis information is extracted
from the images by estimating different features or intensity-distributions.
The output from these image decompositions/transformations is used as input
to chemometric multivariate factor models for comparison with individual
sensory attributes or product maps based on all attributes.
 |
| |
| 33 - METABONOMICS STRATEGY FOR THE DETECTION
OF THE EFFECTS OF THE CHAMOMILE (MATRICARIS RECUTITA L) IN TAKES |
Yulan Wang 1, Huiru Tang 1, Jeremy K. Nicholson 1, Peter J. Hylands 2,
J. Sampson 2, Elaine Holmes 1
1 Imperial College, 2 Oxford natural products, UK
|
We have applied an NMR-based metabonomics technique,
utilising high-resolution 1H NMR spectroscopy in conjunction with advanced
chemometric methods, to study human biological response to ingestion of
chamomile tea. It was found that the biological response to chamomile tea
intake was a weak event and was often obscured by the great diversity in
physiological state and diet of the subjects. Application of Orthogonal
Signal Correction (OSC) data filtration technique was necessary to remove
such variations. A partial least square (PLS) model was subsequently built
using OSC filtered data and the model was validated by successfully
predicting a new dataset, which played no role in OSC filtration or model
construction. The subtle changes induced by chamomile ingestion were
extracted and characterised mainly by the increase in hippurate and the
decrease in creatinine excretion. This study highlighted the benefits of
applying data filtering methods to complex multiparametic biological data
and demonstrated the sensitivities of NMR based metabonomic strategy in the
application of studying subtle metabolic responses to food supplements
Keywords: NMR based metabonomics, chamomile, Matricaria recutita L,
Orthogonal Signal Correction
Abbreviations: PCA: principal components analysis;
OSC: orthogonal signal correction;
PLS: partial least square;
TMAO: trimethylamine N-oxide;
DMA: dimethylamine;
TMA: trimethylamine; |
| |
| 34 - COOKING EFFECTS ON WATER DISTRIBUTION AND
MOBILITY IN POTATOES USING NMR RELAXATION |
Margit C. Mortensen 1, Anette K. Thybo 1, Hanne C. Bertram 1, Søren B.
Engelsen 2, Henrik J. Andersen 1,
1 Dept. of Food Science, Danish Institute of Agricultural Sciences
2 Centre of Advanced Food Studies, Dept. of Food Science, Food Technology,
The Royal Veterinary and Agricultural University, Denmark
|
The purpose of the present study was to follow the changes
in distribution and mobility of water in potatoes during cooking using
continuous low-field (LF) NMR T2 relaxation measurement on two bins of the
potato cultivar Cv. ‘Sava’ with different dry matter content. The continuous
LF-NMR relaxation measurements were carried out during heating (25°C to
99°C) over a period of 20 minutes using 22 temperatures points.
Principal component analysis (PCA) on the obtained NMR relaxation curves
showed that the major changes in water mobility during the cooking took
place at 53.2°C and 59.7°C for potatoes with high and low dry matter
content, respectively. This transition temperature may be attributed to a
softening of cell walls and an initiation of the gelatinisation process. In
contrast changes in water mobility in both potato bins stopped at the same
temperature (70.4°C), which most probably reflect termination of the
gelatinisation process.
A more descriptive interpretation of data was obtained using discrete
bi-exponential fitting on the obtained NMR data. The progress in the two
identified relaxation components T21 and T22 throughout the cooking process
indicated that the slowest relaxing relaxation component (T22) originates
from relatively free water representing the vascular tissue used for water
transport in the potato during growth. In contrast, the more complex behaviour of the fastest relaxing component T21 seems to reflect
intracellular water in the relative non-restricted environment before gelatinisation of the starch (‘raw potato’) and intracellular water in a
more restricted environment after gelatinisation (‘cooked potato’).
In conclusion, the present study demonstrates that continuous LF-NMR
measurements is an excellent and sensitive method to determine changes in
water mobility and water populations during cooking of potatoes, which
moreover allow differentiation of these events in potatoes of different
qualities. This study reveal the potential of LF-NMR to obtain information
of considerable importance for a basic understanding the influence of
processing on gelatinisation and texture of cooked potatoes in relation to
variability in raw material quality. |
| |
| 35 - NON-DESTRUCTIVE DETECTION OF INTERNAL
BRUISE AND SPRAING DISEASE SYMPTOMS IN POTATOES USING MAGNETIC RESONANCE
IMAGING (MRI) |
Anette K. Thybo 1, Sune N. Jespersen 2, Poul Erik Lærke 3, Hans J.
Stødkilde-Jørgensen 2,
1 Dept. of Food Science, Danish Institute of Agricultural Sciences,
DK-5792 Aarslev,
2 Aarhus University Hospital, MR Research Centre, DK-8200 Aarhus N.
3 Dept. of Agroecology, Danish Institute of Agricultural Sciences, DK-8830
Tjele, Denmark
|
| Magnetic resonance imaging (MRI) was applied to detect
non-visible internal bruise and spraing symptoms and to get insight in the
chemical and anatomical cause for such defects. Cv Saturna with internal
bruise and cv Estima with spraing symptoms were investigated by comparison
of different MR images as proton density-, T1 weighted- and T2 weighted
images and T2 maps. Each of the MR images was able to probe the presence of
internal bruise and spraing spots. When combining the information in the MR
images the interior of the internal bruise was characterised as being very
dry (low signal in the proton weighted image) with a small amount of highly
mobile water in the rim around the bruise (high signal in T2 weighted image
and high relaxation time in T2 map). The appearance of the spraing spots
were more diffuse, however a dry interior and presence of highly mobile
water around the spraing dots was somewhat similar to the appearance of
internal bruise but resembled more the appearance of human brain disorders
than bruise disorders in e.g. fruits. In conclusion, this study showed that
MRI detected non-visible internal bruise and spraing symptoms in potatoes,
which has not been published before. MRI may therefore be an appropriate
method for detecting and for studying developmental changes of such
disorders and related disorders during postharvest storage in future
experiments. |
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| 36 - APPLICATIONS OF OLFACTOMETRY IN FOOD SCIENCE |
Isabel O. Lopez 2, Per Møller 2, Lise R. Nissen 2, Ep Köster 1, Frans
van den Berg 2, Magni Martens 2, Wender L. P. Bredie 2
1 (Professor Emeritus) Utrecht University, Utrecht, The Netherlands
2 The Royal Veterinary and Agricultural University, Department of Food
Science, Denmark
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A computer-interfaced dynamic olfactometer has been
developed at the Sensory Science group, KVL. The olfactometer is a versatile
odour mixing machine, with a capacity of 54 odour-intensity combinations,
originating from six channels each at nine different concentrations. The
equipment allows changes in odour composition or intensities to be delivered
instantaneously to human subjects. Examples of on-going research projects
are presented, showing the versatile applications of the olfactometer both
in applied and basic sensory research.
Interaction of memory and perception. This fMRI-study is aimed at localizing
brain areas involved in incidental learning and memory of odours in young
and elderly human subjects.
Odour threshold determination. This study measured odour detection
thresholds for a series of structurally-related monoterpenes by recording
the percentage correct responses from subjects at different odorant
concentrations and by measuring the subject’s time needed to respond.
Quantification of odorant delivery. In this study an odorant trapping GC-MS
method was developed to estimate the concentration of the odorants in the
air-stream reaching the subjects’ nostrils.
Odour adaptation. This study investigated odour adaptation and recovery
after odour stimulation for a series of structurally-related monoterpenes
using a time-intensity method. Large individual differences in adaptation as
well as recovery times were observed. Further work is undertaken to study
the effect of the odorants.
Odorant mixtures. The objective of this study was to investigate the
contribution of six odorants known from lipid oxidation to the total
perceived mixture intensity and their impact on specific sensory attributes.
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| 37 - THE EFFECTS OF EMULSION
FORMATION ON NMR SPECTRA |
Poul Erik Hansen, Philip W. Kuchel
Department of Life Sciences and Chemistry, Roskilde University, P.O.Box
260 DK-4000 Roskilde, Denmark
School of Molecular and Microbial Biosciences, University of Sydney, New
South Wales 2006, Australia
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|
Emulsions are a widely occurring
phenomenon in foods and related to that as compartments of spherical shape
in tissues. The effects of emulsion formation on 1H chemical
shifts will be discussed in terms of differences in magnetic susceptibility
and a simple method describes how to estimate such effects using the Frei-Bernstein
set up.
Effects of changing from a
diamagnetic to a paramagnetic environment are illustrated as this may be of
relevance to measurements of meat.
The use of 19F NMR in
such measurements is discussed.
 (PDF) |
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38-40 - STUDY OF THE BEHAVIOR OF AMINO ACIDS
IN AQUEOUS SOLUTIONS BY TIME DOMAIN-NMR AND HIGH RESOLUTION NMR (3 POSTERS) |
M. Khallouk, D. N. Rutledge*, B. P. Hills
M. Khallouk, D. N. Rutledge*
M. Khallouk, D. N. Rutledge*, A. M. S. Silva, I. Delgadillo
INRA / INA P-G, UMR Ingénierie Analytique pour la Qualité des Aliments (IAQA)
BBSRC Institute of Food Research, Colney Lane, Norwich NR4 7UA, U.K.
Universdad de Aveiro, Departemento de Quimica, 3810-193 Aveiro, Portugal
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Amino acids, peptides and the
proteins are significant components of food. In this study, we concentrated
more particularly on the characterization of the behaviour of amino acids as
a function of pH in aqueous solutions, using Time Domain-Nuclear Magnetic
Resonance (TD-NMR) and High Resolution NMR spectroscopy. The chemical
exchange of protons between water and solutes with labile protons such as
amino acids is a significant mechanism affecting the proton transverse
relaxation of water.
The interest of this research is to
characterize the phenomenon of proton exchange between the solvent (water)
and the groupings of exchangeable protons of amino acids. This exchange is
controlled by the intermolecular interactions existing between the various
groupings of the molecules and the solvent. These interactions can be very
important in biological processes such as enzymatic catalysis, and in
determining the structure and function of proteins.
Measurements of transverse
relaxation rates of the water protons (R2 = 1/T2) in
aqueous solutions of amino acids such as L-glycine, L-asparagine and L-arginine
were done in order to study the effects of chemical exchange and diffusion
on the amplitude of R2. The relaxation curves were acquired using
a Time Domain-NMR apparatus at a frequency of 20 and on a 100 MHz
spectrometer.
R2 values are measured
using the Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence at different
values of pH, temperature and concentration, using a range of inter-pulse
delays for both magnetic field intensities.
The same samples are used to acquire
the corresponding protons spectra using a 300 MHz NMR spectrometer.
Three posters are presented showing
different results obtained during this series of experiments.
1) Characterization of the
phenomenon of proton exchange and molecular diffusion in aqueous solutions
of glycine by Time Domain-NMR at 20 and 100 MHz.
2) Effect of the pH and the
temperature on chemical exchange and diffusion in aqueous solutions of
glycine by Time Domain-NMR at 20 MHz.
3) Study of the behaviour of amino
acids in aqueous solution by Time Domain-NMR and High Resolution NMR.
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| 41 - CHANGES IN PROTON AND
CARBON-13 NMR OF WHEAT AND SOY BREADS DURING STORAGE |
Stefano Tiziani, Yu Chu Zhang, Yael Vodovotz
Food Science & Technology Department, The Ohio State University, Columbus,
Oh 43210, USA
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| Addition of soy to wheat bread has been shown to affect the
physico-chemical properties of the final product. To better understand the
molecular changes during storage imparted by the addition of soy to bread,
NMR was used. The changes in proton and carbon-13 NMR of a wheat (control)
bread and a soy containing (60% of wheat flour replaced by soy ingredients)
bread during storage at 4°C for 7 days were studied. Bread samples were
placed in 5 mm tubes and 1H Cross Relaxation measurements were performed on
a Bruker 300 MHz liquid NMR and 1H T1 and 13C
measurements were performed on a 600 MHz NMR. There were more solid like
1H’s and decreased 13C mobility in wheat bread than
soy bread. The solid like protons and 13C in wheat bread did not
change during storage while this proton population decreased after 4 days of
storage in the soy bread. Wheat bread had a greater 1H T1
than soy bread and its value did not change much during storage. The soy
bread 1H T1 increased slightly during the first few
days of storage. These results indicate that the addition of soy to bread
significantly influence the proton and carbon-13 mobility and therefore will
impact storage stability. |
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42 -
On the use of low field NMR methods for the determination of total lipid
content in marine products |
Geir
Humborstad Sørland, Per Magnus Larsen, Frank Lundby, Henrik W. Anthonsen,
Bente Jeanette Foss
Anvendt Teknologi A/S, Matforsk, Norwegian University of Science and
Technology, NTNU, Norway
Anvendt
Teknologi A/S, Hagebyv.
32, N-9404 Harstad, Norway
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|
Carr Purcell Meiboom Gill (CPMG) pulse sequences and multi
Pulsed Field Gradient Spin Echo (PFGSE) sequences have been applied to
determine the total lipid content in fish, fish feed, and marine powders. It
was found that with low resolution equipment and the use of an optimized
CPMG sequence it is possible to quantify the total amount of lipids present
in the sample. Further, it is possible to discriminate between two classes
of lipids in dried samples: Lipids with short T2 (~ 0.3 ms) and
lipids with long T2 (~100 ms). We also show that there is a
correlation between the lipids with short T2 and the amount of
lipids bound to the solid matrix in the sample while the lipids with long T2
can be assigned to the amount of lipids in a liquid state.
Keywords: Quantification,
lipid, phospholipid, marine products, low field NMR |
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43 - MRI and NMR
spectroscopy study of post-harvest maturing coconut |
Nikolaus Nestle a, Arthur Wunderlich b, Reinhard Meusinger c
a TU Darmstadt, Institute of solid state physics
b University Ulm, Division of Diagnostic Radiology
c TU Darmstadt, NMR division, department of chemistry
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The coconut (Cocos nucifera) is a major agricultural product of many
tropical regions of the world. It is consumed both in green stage (where the
coconut water provides an excellent refreshing beverage) and in mature stage
(when the fibrous, fatty pulp is the product of interest). Dried coconut
pulp is used for the extraction of its oil which is for nutritional,
cosmetic and other purposes. Despite its economic importance and its
convenient size for MRI studies in clinical MR systems, only very few MRI
studies on coconuts can be found in the literature [1,2] In both cases, only
images obtained on mature coconuts were published. Furthermore, only cursory
remarks on the structure of the pulp layer in coconuts can be found in [1],
and no study of the maturation process on one coconut is known to us.
We have studied the maturation process of green coconuts still contained in
their outer, fibrous pericarp by various MRI contrasts. Notable findings
include the slow and spatially very inhomogenous drying of the pericarp, the
internal structure of the pulp layer and the observation of the deposition
of the pulp layer within the maturing coconut. Furthermore, the onset of the
germination process in the maturing nut could be observed, too.
In addition to MRI studies, coconut water and pulp samples were taken from
two MRI-examined coconuts at different maturation stages and subjected to
1H
and 13C high-resolution and solid-state spectroscopy experiments.
In these experiments, a striking similarity between the spectra of the
young, immature pulp and of the water in a more mature coconut was observed.
The main components in the green coconut water were identified as glucose
and fructose, while the major part of the sugars in the mature coconut’s
water was found to be saccharose.
[1] Jagannathan N.R., Govindaraju V, Ragunathan P 1995 In vivo magnetic
resonance study of the histochemistry of coconut (Cocos nucifera) Magnetic
Resonance Imaging 13 885-892
[2] Schick F 2001 Excitation of narrow frequency bands with reduced
relaxation-related signal losses: Methodology and preliminary applications
Magnetic Resonance Imaging 17 527-536 |
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44 – BALASAMIC VINEGAR AND AGE MARKERS: 1H NMR
STUDIES |
Roberto Consonni1,
Alberto Gatti2
1 Laboratorio di
NMR, ISMAC, CNR Milano, Via Bassini 15, 20134 Milano, Italy
2 Divisione
Sensory & Costumer Analysis, NEOTRON S.p.A. Stradello Aggazzotti 104,
41010 S.MARIA DI MUGNANO – Modena, Italy
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Vinegars are
typically produced by microbiological fermentation of ethanol containing
substrates, whose origin composition characterize different vinegar types.
The Italian traditionally produced balsamic vinegars require specific wine
matrixes and well defined production methodologies.
Due to the nature of
the production, traditional balsamic, balsamic and commercial vinegars
contain substances that can be use as age markers. Here we present the use
of 1H NMR studies combined with statistical approaches for the
age determination. |
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45 – 1H HR–MAS NMR FOR DETECTION OF FISH
MEAL ADULTERATION |
Marc
Bassompierre, Petersen D.G., Nørgaard L., Viereck N., Humpher E. and
Engelsen S.B.
Food Technology,
Department of Food Science, The Royal Veterinary and Agricultural
University, Denmark
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This
study represents a preliminary investigation of the potential of 1H
HR–MAS NMR and NIR for alternative, rapid and objective assessments
for detection of fish meal (FM) adulteration by meat and bone meal (MBM).
Currently, the official method is a cumbersome near-subjective microscopic
analysis of acid-boiled samples aimed at detecting illicit bone fragments of
bovine origin in FM samples. This microscope-based analysis relies on
skilled and experienced technicians, takes hours and its reliability may be
questioned. The BSE crisis resulted in 1999 in a full ban of MBM and a
partial ban concerning the use of FM in plants manufacturing bovine feeds
(99/517/EC). This latest ban was a consequence of illegal practices,
adulterating FM with MBM and the related lack of efficient detection
methods. Consequently, we investigated several analyses in combination with
chemometric analyses as potential control methods. The alternative methods
studied were: 1) Nuclear Magnetic Resonance (1H HR-MAS NMR), 2)
visible and 3) Near Infrared Reflectance Spectroscopy (NIR) and 4) lipid
pattern recognition by GC-FID.
For this purpose, five FM from
different origins (Denmark, Norway and Peru) and five Danish manufactured
MBM were mixed together. The investigated set represented different
combinations of the following concentrations: (0, 0.1, 0.5, 2, 5, 10, 15,
20, 60 and 100% MBM). Interval Partial Least Squares Regression (iPLS) was
employed for screening and evaluation of the different analyses
investigated. In conclusion, it appeared that the main variation between
samples was due to differences in the lipid composition. Moreover, whereas
NIR did not perform as well, 1H HR-MAS NMR appeared to be of
potential interest for detecting adulteration of FM by MBM.
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