Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.274
Filtrar
1.
Molecules ; 26(5)2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33652771

RESUMO

The aim of this research was to investigate the effect of the number of freeze-thaw cycles (0, 1, 3, 5, and 7) on porcine longissimus protein and lipid oxidation, as well as changes in heterocyclic aromatic amines (HAAs) and advanced glycation end products (AGEs) and their precursors. We analyzed the relationship among HAAs, AGEs, oxidation, and precursors and found the following results after seven freeze-thaw cycles. The HAAs, Norharman and Harman, were 20.33% and 16.67% higher, respectively. The AGEs, Nε-carboxyethyllysine (CEL) and Nε-carboxymethyllysine (CML), were 11.81% and 14.02% higher, respectively. Glucose, creatine, and creatinine were reduced by 33.92%, 5.93%, and 1.12%, respectively after seven freeze-thaw cycles. Norharman was significantly correlated with thiobarbituric acid reactive substances (TBARS; r2 = 0.910) and glucose (r2 = -0.914). Harman was significantly correlated to TBARS (r2 = 0.951), carbonyl (r2 = 0.990), and glucose (r2 = -0.920). CEL was correlated to TBARS (r2 = 0.992) and carbonyl (r2 = 0.933). These changes suggest that oxidation and the Maillard reaction during freeze-thaw cycles promote HAA and AGE production in raw pork.


Assuntos
Tecido Adiposo/metabolismo , Aminas/metabolismo , Compostos Heterocíclicos/metabolismo , Proteínas/metabolismo , Aminas/química , Animais , Galinhas , Culinária , Congelamento/efeitos adversos , Compostos Heterocíclicos/química , Humanos , Reação de Maillard , Carne/análise , Oxirredução , Carne de Porco/análise , Suínos , Substâncias Reativas com Ácido Tiobarbitúrico/química , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
2.
Food Chem ; 352: 129332, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33690075

RESUMO

In order to construct a novel and efficient calcium delivery system, a dextran- casein phosphopeptide (CPP) conjugates as calcium carrier was prepared by Maillard reaction of CPP and dextran. The preparation of the conjugates, construction of calcium delivery system and digestion in vitro were studied. The grafting rate of conjugates, which was confirmed by migration and intensity changes in the characteristic peaks using ultraviolet-visible and Fourier transform infrared spectroscopy, reached 48.88%. The microscopy showed CPP was coated with dextran, the conjugates with a kind of "shell-core" structure had excellent stability. Compared with CPP, the chelating rate of conjugates increased from 6.0% to 13.87%, and the calcium retention rate improved from 1.09% to 7.90% in vitro digestion. The calcium binding capacity and effect of controlled release of the conjugates were superior to those of CPP. Therefore, the conjugates could be used as an effective carrier for new calcium supplements.


Assuntos
Cálcio/química , Caseínas/química , Dextranos/química , Digestão , Portadores de Fármacos/química , Fosfopeptídeos/química , Cálcio/metabolismo , Reação de Maillard
3.
Food Chem ; 352: 129305, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33691208

RESUMO

The effect of potato tuber composition, frying time and temperature on acrylamide formation in potato chips was investigated and a mathematical model of the kinetics of acrylamide formation is provided. Moisture-temperature-time profiles were obtained for potato slices during frying to enable the determination of the 'effective' reaction time by identifying the critical moisture content (6% dwb) for acrylamide formation to commence and using dehydration curves to calculate subsequent frying time to finished product moisture content. The chemical kinetic model conformed to the following rate equation over a one hundred-fold range of acrylamide concentrations: d[acryl]dt=k1glucoseasn+k6[fructose][asn][TAA] where [TAA] represents total amino acid concentration. The timescale of the frying process meant that the chemical reactions were all in their initial rate phase. Kinetic parameters confirm that the fructose-dependent reaction (caramelization) contributes twice as much acrylamide as the reaction of glucose (Maillard reaction).


Assuntos
Acrilamida/química , Culinária , Modelos Químicos , Solanum tuberosum/química , Acrilamida/análise , Temperatura Alta , Cinética , Reação de Maillard , Tubérculos/química
4.
Food Chem ; 351: 129361, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-33662905

RESUMO

This study evaluated the chemical changes in five types of whole-milk powders (WMP) with different heating loads during storage. The WMP was preheated using low-heat [low-temperature long-time (LTLT), high-temperature short-time pasteurization (HTST)] and high-heat process [ultra-pasteurization (ESL), ultra-high-temperature (UHT) treatments, and in-bottle sterilization (BS)]. Furosine increased by 2.5-3.0 times in high-heat WMP and 5.7-8.4 times in low-heat WMP during storage. 5-(hydroxymethyl)furfural (HMF) content in high-heat WMP was on average 1.4- to 2.4-fold higher than in low-heat WMP during storage. The increases in the amount of Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL) in high-heat WMP were more than that in low-heat WMP (CML, 3.4-4.9 vs 3.1-3.4 times; CEL, 3.4-4.2 vs 2.7-3.0 times). Pyrraline in high-heat WMP increased by 1.8- to 2.1-fold. 2-Furaldehyde, CML, and CEL increased slowly with 12 months of storage and then accelerated. Storage time significantly contributed to more furosine, HMF, CML, and CEL contents in high-heat WMP.


Assuntos
Armazenamento de Alimentos , Temperatura Alta , Reação de Maillard , Leite/química , Animais , Produtos Finais de Glicação Avançada/química , Pasteurização , Pós
5.
J Environ Sci (China) ; 103: 43-49, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33743917

RESUMO

The occurrence of the Maillard reaction and melanoidins formation during the hydrothermal treatment of food waste can reduce the yield of volatile fatty acids (VFA); however, few studies have investigated the adverse effects of the Maillard reaction. This study identified the impact of hydrothermal treatment parameters on hydrolysis and melanoidins formation and optimized the hydrothermal treatment conditions to enhance VFA production by minimizing the impact of the Maillard reaction. A response surface methodology was employed to optimize the hydrothermal treatment parameters and VFA production was evaluated. Results showed that temperature, reaction time, and pH were significant interacting factors with respect to hydrolysis and melanoidins formation while the C/N ratio and moisture content of food waste had little impact. The optimal conditions for hydrothermal treatment (temperature of 132 °C, reaction time of 27 min, and a pH of 5.6) enhanced VFA production by 22.1%. Under optimal hydrothermal treatment conditions, a higher initial C/N ratio further increased VFA production.


Assuntos
Alimentos , Eliminação de Resíduos , Reatores Biológicos , Ácidos Graxos Voláteis , Fermentação , Concentração de Íons de Hidrogênio , Reação de Maillard
6.
Food Chem ; 348: 129132, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-33524691

RESUMO

Enzymatic browning is considered a critical factor that adversely decreases the quality of fresh-cut products. Although many individual physical or chemical methods have been explored to control browning, there are few approaches combining these technologies. In the present study, Sonchus oleraceus L. extract (SOLE) and ultrasound treatment efficiently controlled the activities of polyphenol oxidase, peroxidase, phenylalanine ammonia-lyase, lipoxygenase, soluble quinones, and intermediate and advanced products, and a lower malondialdehyde content and higher antioxidant capacity were observed in fresh-cut potato slices. More than 50 phenolics and flavonoids were identified in SOLE by liquid chromatography-tandem mass spectrometry. In conclusion, the combined SOLE and ultrasound treatment could serve as a promising method for attenuating enzymatic browning.


Assuntos
Extratos Vegetais/química , Solanum tuberosum/química , Sonchus/química , Sonicação , Antioxidantes/química , Catecol Oxidase/metabolismo , Cromatografia Líquida de Alta Pressão , Flavonoides/análise , Reação de Maillard , Malondialdeído/metabolismo , Fenóis/análise , Fenilalanina Amônia-Liase/metabolismo , Solanum tuberosum/metabolismo , Sonchus/metabolismo , Espectrometria de Massas em Tandem
7.
Food Chem ; 349: 129072, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33556729

RESUMO

This review provides an insight about the functional properties of chitosan obtained through Maillard reaction to enhance the shelf life and food quality. Maillard reaction is a promising and safe method to obtain commercial water-soluble chitosan's through Schiff base linkage and Amadori or Heyns rearrangement. Likewise, chitosan derivatives exert an enhanced antimicrobial, antioxidant, and emulsifying properties due to the development of Maillard reaction products (MRPs) like reductones and melanoidins. Additionally, the application of chitosan-MRPs effectively inhibited the microbial spoilage, reduced lipid oxidative, and extended the shelf life and the quality of fresh food products. Therefore, understand the potential of chitosan-MRPs derivatives as a functional biomaterial to improve the postharvest quality and extending the shelf life of food products will scale up its application as a food preservative.


Assuntos
Quitosana/química , Conservantes de Alimentos/química , Reação de Maillard , Qualidade dos Alimentos
8.
Poult Sci ; 100(2): 1308-1318, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33518088

RESUMO

Advanced glycation end products (AGE), compounds formed in meat at the advanced stage of Maillard reaction, are easily exposed to thermal processing. Improving cooking condition and adding antioxidants are 2 common ways for AGE reduction. The present work compared the inhibition of grape seed extract (GSE) on levels of free and protein-bound Nε-carboxymethyllysine (CML) and Nε-carboxyethyllysine (CEL) in chicken breast under deep-frying and air-frying conditions. Efficiency of 5 concentrations of GSE (0.0, 0.2, 0.5, 0.8, and 1.0 g/kg) in retarding oxidation, glyoxal (GO), methylglyoxal (MGO), lysine (Lys), Maillard reaction degree (A294, A420), and Shiff's base were tested. Results showed that 0.5 g/kg GSE before heating significantly (P < 0.05) reduced AGE in fried breast chicken, whereas excessive supplementation of GSE (0.8 and 1 g/kg) was reverse. Air frying was found significantly (P < 0.05) better than deep frying to reduce the precursor substances (GO, MGO, and Lys) of AGE. In conclusion, GSE-derived polyphenols exhibited different inhibitory effects on oxidation and glycosylation at different concentrations. We found that 0.5 g/kg of GSE combined with air frying was the best recommendation for inhibiting CML and CEL.


Assuntos
Culinária/métodos , Extrato de Sementes de Uva/farmacologia , Lisina/análogos & derivados , Carne/normas , Animais , Galinhas , Produtos Finais de Glicação Avançada/análise , Produtos Finais de Glicação Avançada/metabolismo , Glicosilação , Lisina/antagonistas & inibidores , Lisina/metabolismo , Reação de Maillard , Fibras Musculares Esqueléticas/citologia , Oxirredução , Compostos de Sulfidrila/análise , Substâncias Reativas com Ácido Tiobarbitúrico/análise
9.
Food Chem ; 346: 128905, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33401085

RESUMO

This study aims to evaluate the effect of ultrasonic pretreatment combined with glycation on the structural characteristics and antibacterial activity of ovotransferrin (OVT). Firstly, OVT (purity >90%) was isolated from egg white with a simple and efficient method. After the treatment of ultrasound and glycation, the browning degree of OVT increased with the rising power of ultrasound, while the number of free amino groups obviously decreased to 25.4%. Various spectrum detection showed that the structures of OVT have changed significantly, indicating the tertiary structure became more flexible and looser. The minimal inhibitory concentration of ultrasound glycated OVT were 25.0 and 32.1 µmol/L for E. coli and S. aureus, respectively. In summary, ultrasound-assisted glycation is an effective technique to improve the biological activity of OVT.


Assuntos
Conalbumina/metabolismo , Sonicação , Animais , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Conalbumina/isolamento & purificação , Conalbumina/farmacologia , Clara de Ovo/química , Escherichia coli/efeitos dos fármacos , Glicosilação , Interações Hidrofóbicas e Hidrofílicas , Reação de Maillard , Testes de Sensibilidade Microbiana , Estrutura Secundária de Proteína , Staphylococcus aureus/efeitos dos fármacos
10.
Molecules ; 26(1)2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33406782

RESUMO

Flavor is amongst the major personal satisfaction indicators for meat products. The aroma of dry cured meat products is generated under specific conditions such as long ripening periods and mild temperatures. In these conditions, the contribution of Maillard reactions to the generation of the dry cured flavor is unknown. The main purpose of this study was to examine mild curing conditions such as temperature, pH and aw for the generation of volatile compounds responsible for the cured meat aroma in model systems simulating dry fermented sausages. The different conditions were tested in model systems resembling dry fermented sausages at different stages of production. Three conditions of model system, labeled initial (I), 1st drying (1D) and 2nd drying (2D) and containing different concentrations of amino acid and curing additives, as well as different pH and aw values, were incubated at different temperatures. Changes in the profile of the volatile compounds were investigated by solid phase microextraction and gas chromatography mass spectrometry (SPME-GS-MS) as well as the amino acid content. Seventeen volatile compounds were identified and quantified in the model systems. A significant production of branched chain volatile compounds, sulfur, furans, pyrazines and heterocyclic volatile compounds were detected in the model systems. At the drying stages, temperature was the main factor affecting volatile production, followed by amino acid concentration and aw. This research demonstrates that at the mild curing conditions used to produce dry cured meat product volatile compounds are generated via the Maillard reaction from free amino acids. Moreover, in these conditions aw plays an important role promoting formation of flavor compounds.


Assuntos
Aromatizantes/análise , Manipulação de Alimentos/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Reação de Maillard , Produtos da Carne/análise , Odorantes/análise , Compostos Orgânicos Voláteis/análise , Animais
11.
Sci Total Environ ; 769: 144798, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33465628

RESUMO

In this study, the molecular transformation of sludge biopolymers during hydrothermal treatment with the temperature ranging from 25 °C to 200 °C was examined and was seen to significantly affect the macrophysical properties (dewaterability and rheological property) of sludge. The results showed that the sludge dewaterability and flow ability under high shear stress deteriorated by a hydrothermal process at 25 °C to 120 °C, but the deterioration alleviated above the temperature threshold of 120 °C. The consistence of changes in sludge dewaterability and rheological property in HT process was mainly attributed to the variation in gel properties of soluble biopolymer. Two-stage changes in biopolymer transformation were identified, beginning with a solubilization stage from 25 °C to 120 °C in which a biopolymer with a gel-like network structure was released into liquid phase, creating flow resistance under high shear stress such that sludge dewaterability deteriorated. The second stage was identified as a conversion stage (120 °C-200 °C) in which proteins and polysaccharides hydrolyzed and experienced a Maillard reaction, leading to the degradation of the biopolymer network structure. The newly formed recalcitrant Maillard products showed weak flow response to high shear stress, allowing for an improvement in sludge dewaterability. The pathways of a Maillard reaction were identified via gas chromatography-mass spectrometer (GC-MS), 1H nuclear magnetic resonance spectroscopy (1H NMR) and two-dimensional correlation spectral analysis (2D-COS) of Fourier-transform infrared spectrometer (FTIR), etc. Three-dimensional excitation-emission matrix (3D-EEM) proved to be an applicable method for tracking Maillard reaction in sludge hydrothermal process due to the distinctive fluorescence characteristics of Maillard products. This study further clarifies the obscure process of sludge hydrothermal treatment and will help improve the accuracy of subsequent research.


Assuntos
Reação de Maillard , Esgotos , Biopolímeros , Proteínas , Temperatura , Eliminação de Resíduos Líquidos , Água
12.
Food Chem ; 346: 128915, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33418417

RESUMO

The study aimed at improving and comparing the nutritional profile of black (BQ) and white quinoa (WQ) through malting at different germination periods (24, 48, 72 and 96 h), followed by drying at 50 °C, decluming, grinding and sieving to obtain malt flour. The changes in protein, reducing sugar, Maillard reaction products (MRPs), minerals, free and bound polyphenols and antioxidant activity were noted. Malting caused significant increase in polyphenolic content, antioxidant capacity and fluorescence of advanced MRP (FAST) index. The highest increment was noted in malts germinated for 48 and 72 h. BQ malts were marked by higher bound hydroxycinnamic acids, flavan-3-ols, magnesium, potassium and antioxidant activity, while, WQ malts had lower saponin, phytic acid but higher protein, iron, calcium, FAST index. WQ exhibited highest increment (27.23%) in antioxidant activity even though it had lower polyphenols than BQ after malting. Major loss in polyphenols and proteins occurred in malt germinated for 96 h.


Assuntos
Antioxidantes/farmacologia , Chenopodium quinoa/química , Farinha/análise , Germinação , Reação de Maillard , Minerais/análise , Nutrientes/análise , Fenóis/análise , Chenopodium quinoa/crescimento & desenvolvimento , Produtos Finais de Glicação Avançada
13.
J Food Sci ; 86(2): 293-305, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33472280

RESUMO

Interest in plant-based meat alternatives (PMBAs) has been rapidly growing in both the food research community and the food industry due to higher consumer demands in recent years. However, scientific data regarding the health and aroma aspects of PBMA are rare. In this study, the fatty acids (FAs) and volatile flavor compounds (VFCs) were profiled in four types of plant-based burgers (PBs) and compared to beef burger (BB). Over 40 FAs and 64 VFCs were detected and quantified in the samples. Nonsignificant differences (α = 0.05) were observed in the percentages of most FAs between uncooked and cooked PBs. PBs contained lower percentages of saturated FAs and trans-FAs, higher percentages of unsaturated FAs, and lower ratio of n-6 to n-3 FAs comparing to the BB. The FA profiles in PBs are mainly determined by their ingredients. The VFC profile of cooked PBs was different from that of the uncooked ones. The ingredients, thermally induced Maillard reaction, and lipid oxidation had contributed to the formation of the flavor. For uncooked samples, the VFC profiles of PB 3 and PB 4 were similar to that of BB. While for cooked samples, PB 1 had similar VFC profile as BB. This illustrated the importance of the cooking process for aroma formation; however, ingredients, such as spices, remain an important source of VFCs in these burger samples. Ingredient optimization could be an effective strategy to enhance the flavor of PBs to resemble BB. PRACTICAL APPLICATION: This study provides the knowledge of health and aroma-related components in both raw and cooked PBs, including FA and VFC profiles. It also explains the source of those components. This will not only help consumer's decision making in choosing plant-based meat alternatives, but also help the related industry to choose proper ingredients to optimize the final products.


Assuntos
Dieta Vegetariana , Ácidos Graxos/análise , Carne , Paladar , Compostos Orgânicos Voláteis/análise , Animais , Bovinos , Culinária/métodos , Aromatizantes , Manipulação de Alimentos , Temperatura Alta , Reação de Maillard , Odorantes/análise , Especiarias
14.
J Agric Food Chem ; 69(2): 767-775, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33400521

RESUMO

Products of dark brown sugar (DBS) from different production processes and raw materials may bring different risks and benefits to human health. Therefore, this study was aimed to evaluate the quality of natural and commercial DBS products. Results showed that physicochemical properties, including pH value, turbidity, and browning degree have no significant difference between natural and commercial DBS products. Total flavonoid content of natural DBS was found to be significantly higher than that of commercial DBS (p < 0.05). Notably, the levels of harmful Maillard reaction products in natural DBS were significantly lower than that in commercial DBS as evidenced by analyses of methylglyoxal and fluorescent advanced glycation end products (p < 0.05). However, the amount of acrylamide in natural DBS was significantly higher than that in commercial DBS. In conclusion, this study provides useful information for risk-benefit assessment of DBS products, which is helpful for food safety management.


Assuntos
Produtos Finais de Glicação Avançada/química , Fenóis/química , Açúcares/química , Acrilamida/química , Manipulação de Alimentos , Inocuidade dos Alimentos , Temperatura Alta , Humanos , Reação de Maillard , Açúcares/economia
15.
Food Chem ; 343: 128417, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33406574

RESUMO

This study aimed to investigate the structural and antimicrobial properties of Maillard reaction products (MRPs) in chicken liver protein (CLP) and its hydrolysate (CLPH) after sonication (SCLPH). The MRPs of CLP (CLPM), CLPH (CLPHM) and SCLPH (SCLPHM) were analyzed by several spectrometric techniques. The molecular weights of the CLPHM and SCLPHM were primarily between 1.35 kDa and 17 kDa. Moreover, the molecular weights in the CLPHM and SCLPHM below 1.35 kDa were increased, which indicated that cross-linking and thermal degradation occurred during the Maillard reaction (MR). The SCLPHM showed an obvious network skeleton, and the surface had many small crystal-shaped particles after ultrasound treatment and MR by scanning electron microscopy. The SCLPHM had more negative charges than the CLPHM, thus effectively inhibiting the growth of S. saprophyticus and E. coli. MR and ultrasound treatment could be a promising technology to expand the application prospects of low-value meat byproducts.


Assuntos
Antibacterianos/química , Fígado/metabolismo , Hidrolisados de Proteína/química , Animais , Antibacterianos/farmacologia , Galinhas , Escherichia coli/efeitos dos fármacos , Reação de Maillard , Peso Molecular , Hidrolisados de Proteína/farmacologia , Sonicação , Staphylococcus saprophyticus/efeitos dos fármacos , Temperatura de Transição
16.
Food Chem ; 346: 128952, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33421900

RESUMO

Practical application of proanthocyanidins (PAs) as antioxidants is limited because of their hard-to-maintained activities during the processes and storage and in severe gastrointestinal environments. To overcome this challenge, we have developed an easy and green method to encapsulate PAs based on casein-maltodextrin Maillard conjugates. The current work entails the systematic study on the antioxidative potentials of fabricated casein-maltodextrin-PAs nanoparticles (CMPNs). In vitro antioxidant activities of CMPNs remained well during storage in 28 days and treatments under 40-80 °C. In vivo Caenorhabditis elegans (C. elegans) model further showed that the CMPNs could prolong the lifespan of nematodes and protected nematodes from oxidative stress and heat shock. Analyses of intracellular superoxide dismutase and catalase activities also confirmed the existence of an antioxidant protective effect. Besides, in vitro release test showed that the encapsulation enhanced the bioaccessibility of PAs. These results have important implications for the development of novel antioxidants in nutraceutical industries.


Assuntos
Antioxidantes/química , Caseínas/química , Polissacarídeos/química , Proantocianidinas/química , Animais , Antioxidantes/farmacologia , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/fisiologia , Catalase/metabolismo , Longevidade/efeitos dos fármacos , Reação de Maillard , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Proantocianidinas/farmacologia , Superóxido Dismutase/metabolismo
17.
Biochem Biophys Res Commun ; 536: 67-72, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33360544

RESUMO

Proteins or amino acids are subjected to the Maillard (browning) reaction in the presence of reducing sugars and catalyzed by high temperature. The reaction occurs in daily-life cooking and in the human body. Although the reaction is ubiquitous and has been known for over 100 years, it still intrigues researchers across disciplines. Here we report an unexpected finding where proteins and amino acids turn brown in a mixture of two common solvents: dimethyl sulfoxide and acetone. The browning reaction proceeds at room temperature, without the presence of any sugars. This novel browning reaction was confirmed by a series of investigation on a protein-based gel, 3 proteins and 20 amino acids. The browning is spontaneous, regardless of whether the protein or amino acid was dissolved or not. The kinetic study reveals a fast reaction with a formation half-life of about 4 h. Notably, the reactivity is bell-shaped, with the maximal catalytic effect occurring at an acetone-to-DMSO volume ratio of 0.1-0.3. Among the 20 amino acids tested, tryptophan, lysine, and proline are the most susceptible amino acids to the solvent-mediated browning reaction.


Assuntos
Aminoácidos/química , Reação de Maillard , Proteínas/química , Solventes/química , Animais , Bovinos , Galinhas , Liofilização , Humanos , Hidrogéis/química , Muramidase/metabolismo , Espectrofotometria , Temperatura
18.
J Dairy Sci ; 104(2): 1351-1363, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33309364

RESUMO

During the thermal processing of milk, Maillard reactions occur between proteins and lactose to generate glycated proteins. In this study, a lactose-glycated caseinate was hydrolyzed by trypsin. The obtained glycated caseinate (GCN) hydrolysate had a lactose content of 10.8 g/kg of protein. We identified its glycation sites and then assessed it for its protective effect against lipopolysaccharide-induced barrier injury using a rat intestinal epithelial cell line (IEC-6 cells) as a cell model and unglycated caseinate (CN) hydrolysate as a reference. Results from our liquid chromatography-mass spectrometry analysis of the GCN hydrolysate verified that lactose glycation occurred at the Lys residues in 3 casein components (αS1-casein, ß-casein, and κ-casein), and this resulted in the formation of 5 peptides with the following amino acid sequences: EMPFPKYPKYPVEPF, HIQKEDVPSE, GSENSEKTTMPL, NQDKTEIPT, and EGIHAQQKEPM. The results from cell experiments showed that the 2 hydrolysates could promote cell growth and decrease lactate dehydrogenase release in the lipopolysaccharide-injured cells; more importantly, they could partially protect the damaged barrier function of the cells by increasing trans-epithelial electrical resistance, decreasing epithelial permeability, and upregulating the expression of the 3 tight junction proteins zonula occludens-1, occludin, and claudin-1. However, compared with CN hydrolysate, GCN hydrolysate showed lower efficacy in protecting against cellular barrier dysfunction. We propose that the different chemical characteristics of the CN hydrolysate and the GCN hydrolysate (i.e., amino acid loss and lactose conjugation) contributed to the lower barrier-protective efficacy of the GCN hydrolysate. During dairy processing, protein glycation of the Maillard type might have a non-negligible, unfavorable effect on dairy proteins, in view of the resulting protein glycation we found and the critical function of proteins for maintaining the integrity of the intestinal barrier.


Assuntos
Caseínas/metabolismo , Células Epiteliais/efeitos dos fármacos , Lactose/metabolismo , Lipopolissacarídeos/farmacologia , Peptídeos/farmacologia , Animais , Sítios de Ligação , Caseínas/química , Linhagem Celular , Claudina-1/metabolismo , Células Epiteliais/fisiologia , Glicosilação , Hidrólise , Intestinos/citologia , Intestinos/efeitos dos fármacos , Reação de Maillard , Peptídeos/química , Permeabilidade , Ratos , Tripsina/metabolismo
19.
Food Chem ; 338: 127715, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32798824

RESUMO

The influence of dough composition on acrylamide, 3-monochloropropane-1,2-diol (3-MCPD) esters, and glycidyl esters (GE) formation during bread toasting was investigated. The doughs differed in added amounts of soy lecithin, salt, and reducing agents (l-cysteine and glutathione). The toasting of bread for 2.5 min considerably enhanced the formation of acrylamide and 3-MCPD esters. The addition of lecithin (1%, w/w) resulted in four times higher content of 3-MCPD esters in toasted bread slices. No distinct relationship between dough composition and GE formation in untoasted and toasted bread was found. The addition of reducing agents (0.05%, w/w) mitigated during toasting not only the formation of 3-MCPD esters (more than six times) but also the extent of Maillard reaction that resulted in three times lower amounts of acrylamide and predominant formation of alcohol-like compounds. Toasted bread without reducing agents contained typical Maillard reaction compounds such as aldehydes, alkyl pyrazines, and derivatives of furan.


Assuntos
Pão/análise , Culinária/métodos , Saccharomyces cerevisiae/metabolismo , Triticum/química , Acrilamida/análise , Ésteres/análise , Cromatografia Gasosa-Espectrometria de Massas , Glutationa/química , Lecitinas/química , Reação de Maillard , Microextração em Fase Sólida , Triticum/metabolismo , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação , alfa-Cloridrina/análise
20.
Food Chem ; 335: 127620, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32739810

RESUMO

A non-enzymatic browning reaction occurs easily in Dongbei Suancai (DS) during storage. Using the method of path analysis, the changes in contents of VC (ascorbic acid), polyphenol, reducing sugar, amino nitrogen, and 5-HMF (5-hydroxymethyl furfural) were investigated to analyze the direct pathways and determinants of browning caused by pre-production blanching at 100 °C (R-100), salt-addition increased from 2% to 6% (Y-6) and fermentation time extended from 30 d to 40 d (T-40), respectively. The results showed that R-100 could delay the browning by inhibiting two direct pathways of oxidative decomposition of VC and oxidation-polymerization of polyphenols, but T-40 could lead to an increase in degree of browning for which primary determinant was the interaction between polyphenol and reducing sugar, while Y-6 had no obvious effect on browning pathway and determinants. R-100 was thus deemed to be a good measure with inhibiting non-enzymatic browning in DS during storage.


Assuntos
Fermentação , Reação de Maillard , Verduras/química , Ácido Ascórbico/análise , Carboidratos/análise , Furaldeído/análogos & derivados , Furaldeído/análise , Nitrogênio/análise , Oxirredução , Polifenóis/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...