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1.
Thermal degradation studies of food melanoidins 总被引：1，自引：0，他引：1
Adams A Borrelli RC Fogliano V De Kimpe N 《Journal of agricultural and food chemistry》2005,53(10):4136-4142
Food melanoidins were isolated from bread crust, coffee, and tomato sauce and their composition was investigated by thermal degradation. Among the generated volatiles, important food flavor compounds were detected: in particular furans, carbonyl compounds, 1,3-dioxolanes, pyrroles, pyrazines, pyridines, thiophenes, and phenols. The results indicated that the isolated melanoidin fractions mainly consisted of compounds formed from carbohydrates and their degradation products. Besides proteins, other food constituents were incorporated in the melanoidin structure as well, such as lipid oxidation products in tomato melanoidins and phenolic compounds in coffee melanoidins. A comparison of the thermal generation of volatiles between these food-derived melanoidins and model melanoidins prepared from a single carbonyl compound and an amino acid showed that the degradation pattern of food melanoidins is quite different from that obtained from a glucose-glycine model system. 相似文献
2.
Adams A Abbaspour Tehrani K Kersiene M Venskutonis R De Kimpe N 《Journal of agricultural and food chemistry》2003,51(15):4338-4343
Different types of model melanoidins were thermally degraded, with subsequent identification of the volatiles produced, to obtain and compare the thermal degradation profile of various melanoidins. At first, the volatiles produced from heated glucose/glycine standard melanoidins were compared with glucose/glutamic acid and L-(+)-ascorbic acid/glycine standard melanoidins. In the headspace of heated glucose/glycine melanoidins, mainly furans, were detected, accompanied by carbonyl compounds, pyrroles, pyrazines, pyridines, and some oxazoles. Heating of L-(+)-ascorbic acid/glycine melanoidins resulted in relatively more N-heterocycles, while from glucose/glutamic acid melanoidins no N-heterocycles were formed. In a second part, a chemical treatment was applied to glucose/glycine melanoidins prior to the thermal degradation. Acid hydrolysis was performed to cleave glycosidically linked sugar moieties from the melanoidin skeleton. Nonsoluble glucose/glycine melanoidins were also subjected to an oxidation. The results indicate that the thermal degradation profile is a useful tool in the characterization of different types of melanoidins. 相似文献
3.
We followed the contribution of released glucose to the formation of melanoidins in the maltose-glycine reaction by adding (14)C glucose to the maltose-glycine mixture, after it already had undergone some reaction. This approach allowed us to confirm the turnover of glucose in this reaction and hence the role of glucose in forming melanoidins. A comparison of the total amount of glucose converted into the melanoidins with the total concentration of melanoidins formed from maltose and glycine showed that the concentration of melanoidins originating from the released glucose was relatively small in comparison to the total melanoidins concentration. Hence, the parallel glucose-glycine reaction is considered to be only a minor pathway in the formation of maltose-glycine melanoidins. The incorporation of glucose into the nondialyzable melanoidins in the maltose-glycine reaction was in excellent agreement with the amount estimated from a kinetic model for the reaction of maltose with glycine. The rate constants were estimated by nonlinear regression, via multiresponse modeling. 相似文献
4.
Tehrani KA Kersiene M Adams A Venskutonis R De Kimpe N 《Journal of agricultural and food chemistry》2002,50(14):4062-4068
Nondialyzable and water-insoluble melanoidins, isolated from a glucose/glycine model reaction mixture, which was prepared in a standardized way according to the guidelines of the COST Action 919, were heated at different temperatures ranging from 100 to 300 degrees C. Among the volatile compounds, which were analyzed by SPME and GC-MS, pyrazines, pyridines, pyrroles, and furans were detected. In general, total amounts of volatile compounds increased with the temperature. When water-insoluble melanoidins were heated, especially at higher temperatures, this resulted in a higher diversity of isolated compounds. For furans, pyrroles, pyrazines, and carbonyl compounds a maximum was observed in the case of high molecular weight melanoidins around 200-220 degrees C. Pyridines and total oxazoles, however, were generated in higher yields with increasing temperatures. These results demonstrate the possibility of producing some flavor-significant volatiles from heated standard melanoidins at temperatures relevant to food preparation and contribute to the flavor aspects originating from melanoidins. 相似文献
5.
Cayot N Pretot F Doublier JL Meunier JM Guichard E 《Journal of agricultural and food chemistry》2004,52(17):5436-5442
The release of isoamyl acetate from starch-based matrices was studied on the basis of a cumulative dynamic headspace analysis. Two corn starches were compared, which are known to yield pastes and gels differing in their structures and properties. These properties were assessed by viscometry and viscoelastic measurements. Aroma release was discussed as a function of the structure and texture parameters of the matrix.The release curves obtained from water and from the various starch-based matrices at 25 degrees C showed similar patterns but differed in their initial slopes and in the final plateau values. The lowest initial slopes were obtained for the normal starch dispersions that formed gels due to amylose gelation. The aroma compound was entirely released from water and from the waxy starch pastes. A significant amount of isoamyl acetate remained trapped in the normal starch dispersions. 相似文献
6.
The browning of glucose-fructose-glycine mixtures involves parallel glucose-glycine and fructose-glycine reactions, which share a common intermediate, the immediate precursor of melanoidins in the kinetic model. At pH 5.5, 55 degrees C glucose is converted into this intermediate in a two step process where k(1) = (7.8 +/- 1.1) x 10(-)(4) mol L(-)(1) h(-)(1) and k(2) = (1.84 +/- 0.31) x 10(-)(3) h(-)(1) according to established kinetics, whereas fructose is converted into this intermediate in a single step where k(4) = 5.32 x 10(-)(5)()()mol L(-)(1) h(-)(1). The intermediate is converted to melanoidins in a single rate limiting process where k(mix) = 0.0177 h(-)(1) and the molar extinction coefficient (based on the concentration of sugar converted) of the melanoidins so formed is 1073 +/- 4 mol(-)(1) L cm(-)(1). Whereas the value of k(mix) is the same when the individual sugars undergo browning, the value of the molar extinction coefficient is similar to that for melanoidins from the glucose-glycine reaction (955 +/- 45 mol(-)(1) L cm(-)(1)) but it is approximately double the value for melanoidins from the fructose-glycine reaction (478 +/- 18 mol(-)(1) L cm(-)(1)). This is the reason that the effects of glucose and fructose on the rate of browning are synergistic. 相似文献
7.
Retention of aroma compounds in starch matrices: competitions between aroma compounds toward amylose and amylopectin 总被引：1，自引：0，他引：1
The retention of three aroma compounds-isoamyl acetate, ethyl hexanoate, and linalool--from starch-containing model food matrices was measured by headspace analysis, under equilibrium conditions. We studied systems containing standard or waxy corn starch with one or two aroma compounds. The three studied aroma compounds interact differently: ethyl hexanoate and linalool form complexes with amylose, and isoamyl acetate cannot. However, in systems containing one aroma compound, we observed with both starches a significant retention of the three molecules. These results indicate that amylopectin could play a role in the retention of aroma. In systems containing two aroma compounds in a blend, the retentions measured for isoamyl acetate and for linalool were either equal to or less than those in systems where they were added alone. This phenomenon was attributed to competition between aroma compounds to bind with starch. The retention of aroma compounds blended in starch-based systems gave us additional information which confirmed that interactions occur not only with amylose but also with amylopectin. 相似文献
8.
Headspace solid-phase microextraction method for the study of the volatility of selected flavor compounds 总被引：4，自引：0，他引：4
Changes in the volatility of selected flavor compounds in the presence of nonvolatile food matrix components were studied using headspace solid-phase microextraction (HS-SPME) combined with GC-MS quantification. Time-dependent adsorption profiles to the SPME fiber and the partition coefficients between different phases were obtained for several individual volatiles, showing that HS-SPME analysis with a short sampling time can be used to determine the "true" headspace concentration at equilibrium between the headspace and a sample matrix. Equilibrium dialysis followed by HS-SPME/GC-MS was carried out to confirm the ability of HS-SPME extraction for monitoring the free volatile compounds in the presence of proteins. In particular, a short sampling time (1 min) avoided additional extraction of volatiles bound to the protein. Interactions between several selected flavor compounds and nonvolatile food matrix components [beta-lactoglobulin or (+)-catechin] were also studied by means of HS-SPME/GC-MS analysis. The volatility of ethyl hexanoate, heptanone, and hexanal was significantly decreased by the addition of beta-lactoglobulin compared to that of isoamyl acetate. Catechin decreased the volatility of ethyl hexanoate and hexanal by 10-20% and increased that of 2-heptanone by approximately 15%. This study indicates that HS-SPME can be a useful tool for the study of the interactions between volatile compounds and nonvolatile matrix components provided the kinetic and thermodynamic behavior of the volatiles in relation to the fiber chosen for the studies is carefully considered. 相似文献
9.
The release kinetics of l-menthol dissolved in propylene glycol (PG), Miglyol, or 1,8-cineole (two common odorless flavor solvents differing in polarity and a hydrophobic flavor compound) were monitored from a model aqueous system via atmospheric pressure chemical ionization mass spectrometry (APCI-MS). Breath analysis was also conducted via APCI-MS to monitor release of l-menthol from hard candy that used PG and Miglyol for l-menthol incorporation. The quantities of l-menthol released when dissolved in PG or Miglyol from the model aqueous system were found to be similar and overall significantly greater in comparison to when dissolved in 1,8-cineole. Analogous results were reported by the breath analysis of hard candy. The release kinetics of l-menthol from PG or Miglyol versus from 1,8-cineole were notably more rapid and higher in quantity. Results from the sensory time-intensity study also indicated that there was no perceived difference in the overall cooling intensity between the two flavor solvent delivery systems (PG and Miglyol). 相似文献
10.
11.
An apparatus that allows extraction and enrichment of flavor volatiles of rice during cooking using solid-phase microextraction (SPME) was designed and tested in the Japanese rice cultivar Akitakomachi. Because it is a solvent-free technique, no solvent contaminants were extracted during sampling. This technique enables one to place the fiber of SPME in the effluent of the flavor volatiles of the rice during cooking and it can also be used for simultaneous extraction of those volatiles in the course of the cooking process. Therefore, variations in the composition and amount of volatile compounds of rice during cooking can be determined. The overall flavor volatiles of rice during cooking have been analyzed by using this SPME method. Compounds that have been previously highlighted as flavor volatile markers, such as volatiles from oxidative degradation of lipids, products from thermal decomposition, and fatty acids existing in rice, were extracted directly by SPME in conjunction with this apparatus. 相似文献
12.
V Faist M Lindenmeier C Geisler H F Erbersdobler T Hofmann 《Journal of agricultural and food chemistry》2002,50(3):602-606
In the present study, water-soluble nonenzymatic browning products (melanoidins) formed in roasted malt were separated, quantified, and investigated for their effects on detoxifying mechanisms in intestinal Caco-2 cells. The melanoidins were prepared from roasted malt by hot water extraction, and the water-soluble compounds were separated into different molecular weight (MW) fractions by gel filtration chromatography. By monitoring the effluent at 300 nm, seven molecular fractions I-VII were consecutively collected, revealing that approximately 2.3% of the water-soluble compounds had mean MWs between 10000 and 30000 Da. Thus, the bulk of water-soluble malt melanoidins consisted of MW > 30000 Da, among which approximately 58% showed mean MWs between 60000 Da and 100000 Da, whereas approximately 32% exhibited mean MWs of 200000 Da. Biotransformation enzyme activities of NADPH-cytochrome c-reductase (CCR) and glutathione-S-transferase (GST) were analyzed in Caco-2 Cells after 48 h of exposure to the different MW fractions. The low MW fraction of 10000 Da was most effective in activating the CCR and the GST activities (+122 and +33% vs control, respectively). The majority of the mid molecular weight compounds tested showed an activating effect on CCR activity and an inhibitory effect on GST activity. These effects were most pronounced for compounds of up to 70000 Da and >200000 Da but less distinct for fractions of an average molecular weight of 100000 Da. 相似文献
13.
Model melanoidins from monomeric, oligomeric, and polymeric carbohydrates, and amino acids formed under aqueous as well as water-free reaction conditions, were submitted to acidic catalyzed hydrolysis. Their degradation products were detected qualitatively and quantitatively by HPTLC and HPLC-DAD. A considerable amount of monomer carbohydrates from hydrolysis of model melanoidins formed under water-free reaction conditions was detected. It can be seen clearly that the amount of carbohydrates released increased with increasing degree of polymerization of the carbohydrates used as starting material. In comparison, the hydrolysis of melanoidins formed in aqueous condition resulted in only a small glucose release. It seems that in the Maillard reaction under water-free conditions, a significant amount of di- and oligomer carbohydrates were incorporated into the melanoidin skeleton as complete oligomer with intact glycosidic bond, forming side chains at the melanoidin skeleton. Additional side chains could be formed by transglycosylation reactions. With increasing water content, hydrothermolytic as well as retro-aldol reactions of the starting carbonyl components became significant, and therefore the possibility of forming side chains decreased. The results are consistent with the postulated melanoidin structure being built up mainly from sugar degradation products, probably branched via amino compounds. 相似文献
14.
Napa Gamay grapes were fermented with four different strains of the yeast Saccharomyces cerevisiae (VL1, MI16, Fermirouge, and RA17). Petite Sirah grapes were fermented with seven different strains of the same yeast (BM45, Fermirouge, RA17, NI, CX3079, A350, and A796). Volatile compounds formed in the wines were analyzed by gas chromatography/mass spectrometry. Volatile compounds found in both wines were alcohols, esters, and acids, as well as some miscellaneous compounds. Isoamyl alcohol was the compound found in the highest relative amount with all four yeast strains in the Napa Gamay wines, followed by 2-phenyl ethanol, monoethyl succinate, and hexanoic acid. The relative amounts of isoamyl alcohol ranged from 30.84% (VL1) to 43.28% (RA17). Major volatile compounds found in Petite Sirah wines were isoamyl alcohol, 2-phenyl ethanol, 2-hydroxy ethyl propanoate, monoethyl succinate, and octanoic acid. The several esters, including 2-hydroxyethyl propanoate, may contribute to the fruity flavor of Petite Sirah wines. Overall, the S. cerevisiae yeast strains used to ferment Napa Gamay grapes and Petite Sirah grapes produced the same major components, with certain variations in formation levels. 相似文献
15.
The retention of the aroma compounds in a multicomponent medium like the food matrix is influenced by their affinity with the protein when lipid is present at a low level (0.5%). The effect of the structure of the media is also studied by using two media with the same composition; one was emusified, and the other was not. Among the studied aroma compounds, 2-nonanone and isoamyl acetate present opposite behaviors: the volatility of isoamyl acetate is not affected by the change of the medium structure whereas that of 2-nonanone increases. The decrease of retention of 2-nonanone in an emulsified system would be due to a modification of the fixation site for this compound on the protein or to a competition between the lipid and the aroma compound while the protein is adsorbed at the lipid-water interface. 相似文献
16.
In a roasted Arabica coffee brew, the potent roasty odor quality compound was identified as 3-mercapto-3-methylbutyl acetate by comparison of its Kovats gas chromatography retention index, mass spectrum, and odor quality to those of the synthetic authentic compound. 3-Mercapto-3-methylbutyl acetate has been identified for the first time in the coffee, and according to the results of the aroma extract dilution analysis, the contribution of this compound to the flavor of the roasted coffee brew varied depending on the degree of the coffee bean roasting. The concentration of this compound in the coffee brews as with 3-mercapto-3-methylbutyl formate increased with an increase in the degree of roasting. However, the slope of the amount of both esters was different, and 3-mercapto-3-methylbutyl acetate hardly increased with a low degree of roasting at more than a 21 luminosity (L)-value, but it rapidly increased when the roasting degree of the coffee beans reached the L-value of 18. These results suggested that the contribution of 3-mercapto-3-methylbutyl acetate to the overall flavor is peculiar to the flavor of the highly roasted coffee. 相似文献
17.
Lethuaut L Weel KG Boelrijk AE Brossard CD 《Journal of agricultural and food chemistry》2004,52(11):3478-3485
Six model dairy desserts, with three different textures and two sucrose levels, were equally flavored with a blend of four aroma compounds [ethyl pentanoate, amyl acetate, hexanal, and (E)-2-hexenal] and evaluated by a seven person panel in order to study whether the sensory perception of the flavor and the aroma release during eating varied with the textural characteristics or the sweetness intensity of the desserts. The sensory perception was recorded by the time intensity (TI) method, while the in vivo aroma release was simultaneously measured by the MS-nose. Considering the panel as a whole, averaged flavor intensity increased with sucrose level and varied with the texture of the desserts. Depending on the aroma compound, the averaged profile of in vivo aroma release varied, but for each aroma compound, averaged aroma release showed no difference with the sucrose level and little difference with the texture of the desserts. Perceptual sweetness-aroma interactions were the main factors influencing perception whatever the texture of the desserts. 相似文献
18.
A multichannel flavor delivery system, Dynataste, was developed. Controlled amounts of isoamyl acetate (100 ppm) and sucrose (0-3%) solution was administered to experienced and na?ve assessors who used time intensity techniques to record perceived 'fruit' flavor intensity. In-nose volatile delivery was monitored using atmospheric pressure chemical ionization-mass spectrometry. Results indicated that sucrose is a key driver of fruit flavor intensity but that the magnitude of the effect varies between individuals. The combined temporal analysis of chemical stimuli in vivo and sensory data indicate evidence of interactions at a perceptual level. Comparison of experienced and na?ve assessors revealed cross-modal interactions in each group, although a subgroup of experienced assessors was unaffected by changes in sucrose concentration. This raises the question of the selected use of experienced panels in cross modal investigations. 相似文献
19.
Philippe E Seuvre AM Colas B Langendorff V Schippa C Voilley A 《Journal of agricultural and food chemistry》2003,51(5):1393-1398
Physicochemical parameters, such as hydrophobicity, water solubility, and volatility, of four flavor compounds (ethyl acetate, ethyl butyrate, ethyl hexanoate, and 2-pentanone) were determined. The amount of flavor compounds released from different model matrices (mineral water, purified triolein, an oil-in-water emulsion, a carbohydrate matrix, and a complex matrix containing lipids and carbohydrates) into the gaseous phase was determined at thermodynamic equilibrium, at 37 degrees C, by static headspace gas chromatography. The degree of interaction between the flavor compounds and the matrix components was shown by measuring the percentage retention using the water matrix as the reference. The partition of flavor compounds was principally dependent on their hydrophobicity. Physicochemical interactions that occurred in the different media led to different degrees of flavor retention. An impact of fat on flavor retention was demonstrated when a water matrix and an oil-in-water matrix or carbohydrate and complex matrices were compared. A carbohydrate impact on flavor compound retention was also detected, which was evident even in the presence of lipids. 相似文献
20.
S Rocha V Ramalheira A Barros I Delgadillo M A Coimbra 《Journal of agricultural and food chemistry》2001,49(11):5142-5151
The application of headspace solid phase microextraction (SPME) for flavor analysis has been studied. Headspace SPME sampling was tested for nine common wine flavor compounds in 10% (v/v) aqueous ethanol: linalool, nerol, geraniol, 3-methyl-1-butanol, hexanol, 2-phenylethanol, ethyl hexanoate, ethyl octanoate, and ethyl decanoate. The chemical groups (monoterpenoids, aliphatic and aromatic alcohols, and esters) showed specific behavior in SPME analysis. SPME sampling parameters were optimized for these components. Relative response factors (RRFs), which establish the relationship between the concentration of the compound in the matrix liquid solution and the GC peak area, were estimated for all compounds. Log(10)(RRF) varied from 0 (3-methyl-1-butanol) to 3 (ethyl decanoate), according to their molecular weight. Quantification by SPME was shown to be highly dependent on the matrix composition; the compounds with higher RRF were the less affected. As a consequence, the data obtained with this methodology should be used taking into consideration these limitations, as shown in the analysis of four monovarietal Bairrada white wines (Arinto, Bical, Cerceal, and Maria Gomes). 相似文献