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Ping‐Jun Zhang Zhen‐Gang Zhao Shu‐Juan Yu Shu‐Zhen He 《International Journal of Food Science & Technology》2012,47(3):475-481
The formation and degradation of N‐(1‐Deoxy‐d ‐xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d ‐xylulos‐1‐yl)proline, derived from the secondary amine Maillard reaction in xylose‐amino acid model solutions, were detailed in this study. The identification and quantitative analysis of N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline were carried out using high‐performance anion‐exchange chromatography and high‐performance liquid chromatography. The formation of intermediate and advanced products derived from N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline was also tested using an UV‐Vis spectrophotometer to gain a better comparing of the degradation process of the two important Maillard reaction products using thermal treatment. Results showed that the degradation of N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine was more significant than N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline. Moreover, xylose was tested in the degradation products of both N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline, which indicated that the degradation of N‐substituted 1‐amino‐1‐deoxyketoses was a reversible reaction to form reducing sugar. 相似文献
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Cassava‐starch based polymer films containing glycerol as a plasticizer (1.0‐2.5‐5.0%, w/w) and different lipids as additives (paraffin, stearyl alcohol, and beeswax – 0.25‐0.5‐1.0%, w/w) were produced. Control films were produced by heating a mixture of glycerol, starch, and water, while treated films were produced by the addition of lipids/ ethanol solutions. The solutions were kept at around 70ºC during amalgamation, and once congealed, were placed in a vacuum oven for 1 h at 90ºC. The solutions were then spun on 7‐inch diameter non‐stick disks, allowed to dry, and conditioned at 23ºC and 50% RH before testing. Cassava starch‐glycerol‐beeswax films were successfully produced with a stable film structure at glycerol concentration equal or below 5% (w/w). Addition of glycerol and beeswax did not visually change the color of the films. Increasing glycerol content improved elongation while decreasing tensile strength. Increasing the glycerol concentration from 1.0 to 5.0% increased the water vapor permeability by 150% and addition of beeswax further increased these values by 250%. 相似文献
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Paola Pittia M. Cristina Nicoli Giuseppe Comi Roberto Massini 《Journal of the science of food and agriculture》1999,79(7):955-960
Minimally processed fruit and vegetables are generally more perishable than the original raw materials due to the injury stresses during preparation that greatly increase tissue respiration and lead to deterioration through various biochemical pathways. In this paper, the effects of low intensity blanching treatments on enzymatic and microbiological stability on the fresh‐like quality of ready‐to‐use pear cubes has been evaluated. Blanching treatments as well as packaging were carried out both in aseptic and in non‐aseptic conditions. The combination of low intensity blanching with superficial enzymatic treatments has been carried out. The results confirm that the combination of a mild heat treatment (3 min at 95 °C) under aseptic conditions is enough to enhance the stability of this minimally processed product with an acceptable reduction in the texture. The superficial treatment with lysozyme did not result in an improvement in the stability of the blanched pear cubes during storage under refrigerated conditions. © 1999 Society of Chemical Industry 相似文献
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Gastrointestinal absorption and metabolism of hesperetin‐7‐O‐rutinoside and hesperetin‐7‐O‐glucoside in healthy humans
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Lucas Actis‐Goretta Tristan P. Dew Antoine Lévèques Gema Pereira‐Caro Maarit Rein Alexander Teml Christian Schäfer Ute Hofmann Matthias Schwab Michel Eichelbaum Alan Crozier Gary Williamson 《Molecular nutrition & food research》2015,59(9):1651-1662
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Moisture‐Absorption and Water Dynamics in the Powder of Egg Albumen Peptide,Met‐Pro‐Asp‐Ala‐His‐Leu
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Moisture absorbed into the powder of Met‐Pro‐Asp‐Ala‐His‐Leu (MPDAHL)—a novel egg albumen antioxidant peptide—profoundly affects its properties. In this study, we elucidated water dynamics in MPDAHL using DVS, DSC, and low‐field 1H NMR. Based on the DVS data, we found that MPDAHL sorption kinetics obey a parallel exponential model. DSC results indicated that both water and heating could change the microstructure of MPDAHL. The T2 parameters of NMR reflected the different phases of moisture absorption revealed that there were 4 categories of water with different states or mobility in the MPDAHL during the moisture absorption process. The fastest fraction T2b mainly dominated the hygroscopicity of MPDAHL and the absorbed water significantly changed the proton distribution and structure of MPDAHL. Thus, this study shows that DVS, DSC, and low‐field 1H NMR are effective methods for monitoring water mobility and distribution in synthetic peptides. It can be used to improve the quality assurance of functional peptides. 相似文献
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Jennifer M Gee Monika A Wroblewska Richard N Bennett Fred A Mellon Ian T Johnson 《Journal of the science of food and agriculture》2004,84(11):1341-1348
Rats were meal‐fed a semi‐synthetic diet, with or without quercetin 3‐O‐glucoside (Q3G; 100 mg per meal) and groups of three were killed either fasting, or at 2, 5 and 24 post‐feeding. Flavonoids and their metabolites in the diet, stomach contents, small intestinal lumen and mucosa, caecal contents and plasma were determined by LC/MS. Q3G was not hydrolysed in the stomach, but deglycosylation and further metabolism occurred in the small intestinal mucosa. At least 17 flavonoid glucuronides were identified in the lumen and mucosa, with evidence of time‐dependent changes such as de‐ and re‐glucuronidation. Quercetin mono‐sulphate was also detected in the small intestinal contents. Metabolites were still present in tissue and plasma 24 h after feeding. There was also evidence of complex microbial processing of Q3G in the caecal lumen with the appearance of at least one methylquercetin‐mono‐glucuronide, mono‐sulphate unique to this site in the gut, together with phenolic acid derivatives. Intestinal flavonoid metabolism is thus a very complex process in mammals, involving both enterocytes and bacteria. Copyright © 2004 Society of Chemical Industry 相似文献
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Bárbara Nieva‐Echevarría María J. Manzanos Encarnación Goicoechea María D. Guillén 《Comprehensive Reviews in Food Science and Food Safety》2015,14(1):67-80
2,6‐Di‐tert‐butyl‐hydroxytoluene (BHT, E‐321) is a synthetic phenolic antioxidant which has been widely used as an additive in the food, cosmetic, and plastic industries for the last 70 y. Although it is considered safe for human health at authorized levels, its ubiquitous presence and the controversial toxicological data reported are of great concern for consumers. In recent years, special attention has been paid to these 14 metabolites or degradation products: BHT‐CH2OH, BHT‐CHO, BHT‐COOH, BHT‐Q, BHT‐QM, DBP, BHT‐OH, BHT‐OOH, TBP, BHQ, BHT‐OH(t), BHT‐OH(t)QM, 2‐BHT, and 2‐BHT‐QM. These derived compounds could pose a human health risk from a food safety point of view, but they have been little studied. In this context, this review deals with the occurrence, origin, and fate of BHT in foodstuffs, its biotransformation into metabolites, their toxicological implications, their antioxidant and prooxidant properties, the analytical determination of metabolites in foods, and human dietary exposure. Moreover, noncontrolled additional sources of exposure to BHT and its metabolites are highlighted. These include their carryover from feed to fish, poultry and eggs, their presence in smoke flavorings, their migration from plastic pipelines and packaging to water and food, and their presence in natural environments, from which they can reach the food chain. 相似文献
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Hiroyuki Kataoka Mina Miyake Sachiko Nishioka Tomoko Matsumoto Keita Saito Kurie Mitani 《Molecular nutrition & food research》2010,54(7):1039-1048
Heterocyclic amines (HCAs) are mutagenic and carcinogenic compounds found in cooked meat and fish. Although HCAs are known to form adducts with protein after metabolic activation, adduct formation during cooking has not been elucidated. In this study, we showed that 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) is released from high molecular weight compounds by acid or enzymatic hydrolysis of cooked foods. Formation of free and protein adduct forms of PhIP was dependent on cooking temperature and time, and PhIP–protein adducts were estimated to form after formation of free PhIP. We also demonstrated that PhIP–protein adduct is formed by heating of PhIP and albumin as a model protein. A new adduct peak including [M+H]+ (m/z=225) of PhIP as a fragment ion was detected in the high molecular weight fraction of heat‐treated protein by LC–MS analysis. From model experiments by heating of PhIP and amino acids, the adduct was estimated to be produced by condensation of the amino group of PhIP and the carboxyl group of protein. PhIP–protein adducts were detected in several cooked meat and fish at ng/g food level as PhIP content. These results suggest that food‐borne protein adducts of HCAs may influence human HCA exposure and carcinogenic risk. 相似文献
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Temporal Check‐All‐That‐Apply (TCATA) is a new dynamic sensory method for which analysis techniques are still being developed and optimized. In this study, TCATA methodology was applied for the evaluation of wine finish by trained panelists (n = 13) on Syrah wines with different ethanol concentrations (10.5% v/v and 15.5% v/v). Raw data were time standardized to create a percentage of finish duration, subsequently segmented into thirds (beginning, middle, and end) to capture panel perception. Results indicated the finish of the high ethanol treatments lasted longer (approximately 12 s longer) than the low ethanol treatment (P ≤ 0.05). Within each finish segment, Cochran's Q was conducted on each attribute and differences were detected amongst treatments (P ≤ 0.05). Pairwise tests showed the high ethanol treatments were more described by astringency, heat/ethanol burn, bitterness, dark fruit, and spices, whereas the low ethanol treatment was more characterized by sourness, red fruit, and green flavors (P ≤ 0.05). This study demonstrated techniques for dealing with the data generated by TCATA. Furthermore, this study further characterized the influence of ethanol on wine finish, and by extension wine quality, with implications to winemakers responsible for wine processing decisions involving alcohol management. 相似文献
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In vitro antioxidant activities of the novel pentapeptides Ser‐His‐Glu‐Cys‐Asn and Leu‐Pro‐Phe‐Ala‐Met and the relationship between activity and peptide secondary structure
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Ruiwen Yang Jia Wang Songyi Lin Haiqing Ye Feng Chen 《Journal of the science of food and agriculture》2017,97(6):1945-1952
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Some starches containing quaternary dimethylalkylammonium groups exhibit an unique phase behavior. A solid phase or gel phase is formed upon cooling, i.e. they are temperature‐responsive polymers. The aim of this study was to investigate the phase and gelation behavior of hydrophobically modified quaternary ammonium starch ethers in aqueous solutions. The mechanisms behind the phase behavior and hydrophobic character were investigated by light scattering (turbidity) and rheological measurements. A relatively large increase in the complex viscosity at higher concentrations was observed when the solutions were cooled to room temperature. The phase angle decreased drastically at a certain critical temperature. The decrease in the phase angle depended on the concentration of starch in solution, higher concentrations showing the greatest decrease and lower concentrations showing no significant change. Turbidity measurements indicated that a solid‐like highly concentrated phase was precipitated. The starch with zero net charge showed a larger increase in turbidity than the starch with a positive net charge, which indicates that particular precipitation is favored by a zero net charge and that the formation of a gel network is favored by charged starch molecules. 相似文献
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The phase behavior of temperature‐responsive hydrophobically modified starches and the interaction between oxidized potato amylose and hydrophobically modified potato amylopectin have been investigated by rheology, turbidity measurements and differential scanning calorimetry. When oxidized amylose was mixed with hydrophobically modified amylopectin, a viscosity peak was observed, indicative of a guest‐host interaction between the oxidized amylose and the hydrophobically modified amylopectin. A series of oxidized and hydrophobically modified potato starches were investigated in the presence of an anionic and cationic surfactant. A coil‐helix transition of the investigated starches was observed in the presence of surfactant, with the exception of a cationic surfactant combined with a hydrophobically modified zwitterionic starch of high positive net charge. The destabilizing mechanism (the phase separation) of the hydrophobically modified starches was studied as well as the difference in stabilizing capacity between the investigated cationic and anionic surfactants. 相似文献
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