Applications of the Maillard reaction in the food industry

Effects of Edible Organic Acid Soaking on Color, Protein Physicochemical, and Digestion Characteristics of Ready-to-Eat Shrimp upon Processing and Sterilization

Soft-packed ready-to-eat (RTE) shrimp has gradually become popular with consumers due to its portability and deliciousness. However, the browning caused by high-temperature sterilization is a non-negligible disadvantage affecting sensory quality. RTE shrimp is processed through "boiling + vacuum soft packing + high temperature and pressure sterilization". Ultraviolet-visible (UV) spectroscopy with CIELAB color measurement showed that phytic acid (PA) + lactic acid (LA), PA + citric acid (CA), and PA + LA + CA soaking before cooking alleviated browning, as well as UVabsorbance and the browning index (BI). Meanwhile, UV spectroscopy and fluorescence spectroscopy showed that organic acid soaking reduced the content of carbonyl, dityrosine, disulfide bonds, surface hydrophobicity, and protein solubility, but promoted the content of free sulfhydryl and protein aggregation. However, in vitro digestion simulations showed that organic acid soaking unexpectedly inhibited the degree of hydrolysis and protein digestibility. This study provides the basis for the application of organic acids as color protectors for RTE aquatic muscle product.

Effect of ultrasonic assisted grafting on the structural and functional properties of mung bean protein isolate conjugated with maltodextrin through maillard reaction

Four different methods of maillard reaction including ultrasound (150 W, 10 min) assisted, classical wet heating (80 °C, 60min), moderate water bath heating (60°C, 12 to 30 h) and dry state method (60 °C, 79 % relative humidity and 48 h) were used to Mung bean protein isolate - Maltodexrtin conjugates (MPI-MD) preparation. The samples prepared under ultrasound and wet heating were chosen for further analysis according to degree of graft and UV-absorbance at 420 nm. Higher glycosylation at short time and lower browning were obtained under ultrasound treatment. Covalent attachment in conjugates confirmed by SDS-polyacrylamide gel electrophoresis. The structural analysis revealed prominent unfolding effect of ultrasound waves on the protein's molecules. The decrease of α-helix content was related to the exposure of buried amino group residues during reaction. Glycation of MPI under ultrasound caused changes in tertiary structure of protein and leads to decrease in the fluorescence intensity compared with native and wet heating treatments. FTIR spectra confirmed the conjugation of the MPI and MD and suggested that protein structure was changed and ultrasound promoted the graft reaction more than wet heating treatment. Conjugated MPI showed higher emulsification and solubility index than MPI, moreover the effect of ultrasonic waves on ameliorated functional properties was impressive than those for wet heating treatment. Overall, this study showed use of ultrasonication in maillard reaction was a suitable method for producing MPI- MD conjugates and improved the efficiency of graft reaction and functional properties of grafts.

Standardized ileal digestibility of amino acids in cottonseed meal fed to pregnant and non-pregnant sows

This study determined the apparent ileal digestibility (AID) and standard ileal digestibility (SID) of crude protein (CP) and amino acids (AA) of six cottonseed meal (CSM) samples in pregnant and non-pregnant sows. Two CSM samples were processed by expelling with a CP level of 40.67% (ECSM41) and 44.64% (ECSM45), and four samples were processed by solvent-extracted which contained graded CP levels of 45% (SECSM45), 51.16% (SECSM51), 56.44% (SECSM56), and 59.63% (SECSM60). Landrace ×Yorkshire third parity sows, 7 at gestation and 14 non-pregnant, were fitted with T-cannula in the distal ileum. Pregnant sows were allotted to a 7 × 6 Latin square design with a cornstarch-based nitrogen-free (NF) diet and the six CSM diets, and non-pregnant sows were allotted to a replicated 7 × 3 Latin square design with seven diets and three periods, respectively, resulting in a total of six replicates per treatment. All experimental sows were fed 3.0 kg/d of the experimental diets. The AID of CP in ECSM41 (75.58%) was lower than in SECSM51 (80.42%), SECSM56 (80.50%), and SECSM60 (82.44%) diets for pregnant sows (P < 0.05). The AID of CP in ECSM41 (77.88%) was significantly lower than in SECSM60 (81.87%) diets for non-pregnant sows (P < 0.05). The physiological phase did not affect the AID of CP (P > 0.05). The SID of CP was affected by diets for both pregnant (P < 0.01) and non-pregnant sows (P = 0.06). The physiological phase also affected the SID of CP (P < 0.01). The AID of histidine, leucine, methionine, threonine, and tryptophan significantly differed between different CSM samples in both pregnant (P < 0.05) and non-pregnant sows (P < 0.05). The AID of dispensable AA aspartic acid, cysteine, glutamic acid, serine, and tyrosine differed between different CSM samples of both pregnant (P < 0.05) and non-pregnant sows (P < 0.05). For pregnant sows, the indispensable AA cysteine, glycine, proline, and tyrosine had significantly different SID between different groups (P < 0.05). For non-pregnant sows, the SID of arginine, lysine, methionine, threonine, aspartic acid, cysteine, and serine had different values among different diets (P < 0.05). In conclusion, the current study presented that the ileal AA digestibility of CSM fed to pregnant and non-pregnant sows increased with the decreased of fiber content, and the current findings can contribute to a precise formulation of diets for sows using CSM.

Future foods: Design, fabrication and production through microfluidics

Many delicious foods are soft matter systems with health ingredients and unique internal structures that provide rich nutrition, unique textures, and popular flavors. Obtaining these special properties in food products usually requires specialized processes. Microfluidic technologies have been developed to physically manipulate liquids to produce a broad range of microunits, providing a suitable approach for precise fabrication of functional biomaterials with desirable interior structures in a bottom-up fashion. In this review, we present how microfluidics has been applied to produce gel-based structures and highlight their use in fabricating novel foods, focusing on, among others, cultured meat as a rapidly growing field in food industry. We first discuss the behaviors of food liquids in microchannels for fluidic structure design. Then, different types of microsized building blocks with specific geometries fabricated through microfluidics are introduced, including particles (point), fibers (line), and sheets (plane). These well-defined units can encapsulate or interact with cells, forming microtissues to construct meat products with desirable architectures. After that, we review approaches to scale up microfluidic devices for mass production of the hydrogel building blocks and highlight the challenges associated with bottom-up food production.

Evaluation of the Effect of a Combined Chemical and Thermal Modification of Wood though the Use of Bicine and Tricine

The effects of thermal modification of wood have been well established, particularly in terms of reductions in mechanical performance. In recent years, there has been an increase in studies related to the Maillard reaction. More commonly associated with food chemistry, it involves the reaction of amines and reducing sugars during cooking procedures. This study has attempted to combine the use of amines and thermal modification, with subsequent properties investigated for the treatment of spruce (Picea abies (L.) H. Karst) and beech (Fagus sylvatica L.). In this initial study, the combined effects of chemical treatments by tricine and bicine were investigated with thermal modification. Along with some preliminary data on mechanical properties, the modifications which appeared in the wood structure were evaluated by infrared spectroscopy and biological studies according to EN113 and EN117 methodologies. The hierarchal study interpretation of FTIR suggested interactions between the bicine or tricine and the wood, which was partly supported by the analysis of volatile organic compounds (VOC), though other tests were not as conclusive. The potential of the method warrants further consideration, which will be described.

Low Formaldehyde Binders for Mineral Wool Insulation: A Review

Insulating materials are ubiquitous in a built environment and play a critical role in reducing the energy consumed to maintain habitable indoor environments. Mineral wool insulation (MWI) products, including glass, stone, and slag variants, are the most widely used class of insulating materials in Europe and account for more than 50% of the total market by volume. MWI typically consists of two key components: a mesh of inorganic fibers that are several micrometers in diameter, and an organic thermosetting adhesive commonly referred to as the "binder." Traditional phenol-formaldehyde-urea (PFU) binders used in the manufacture of MWI are increasingly being scrutinized for the formaldehyde released during their manufacture and service lifetime. The recent classification of formaldehyde as a carcinogen by various safety organizations has accelerated a paradigm shift within the industry toward alternative binder technologies that minimize or indeed eliminate formaldehyde emissions. This review examines more recent strategies for achieving low- or zero-added formaldehyde binders for MWI, with a particular focus on the patent literature. The chemistry underpinning traditional PFU binders is presented and compared to new strategies involving scavenging molecules that decrease formaldehyde emissions, as well as zero-added formaldehyde binder technologies such as polyester, Maillard, and epoxide thermosets.

Influence of Storage Time and Method of Smoking on the Content of EPA and DHA Acids and Lipid Quality of Atlantic Salmon (Salmo salar) Meat

Smoking is one of the oldest technologies for processing and preserving raw materials of animal origin. To this day, smoked fish is very popular among consumers. The most popular smoked fish is salmon. The research compared the qualitative changes in the fat fractions of hot and cold-smoked salmon during refrigerated storage. Generally accepted physicochemical methods for assessing the quality of fats, such as peroxide, anisidine, and acid number, were used. First, the smoked salmon was stored, and then, the samples were analyzed to find changes in the fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). It was shown that cold smoking significantly inhibited the increase in the level of lipid oxidation compared to hot smoking and raw samples stored in the same way. In the meat of stored and cold- and hot-smoked salmon, the TOTOX values remained at the level indicated by the Codex Alimentarius. Hot smoking limited the degree of lipid hydrolysis during storage as compared to cold smoking. The smoking process had a protective effect on EPA and DHA acids. In the raw samples, the loss of these acids was three times higher. Summarizing the research, it can be concluded that smoked products are a good and safe source of omega-3 fatty acids in the diet.

The complex of whey protein and pectin: Interactions, functional properties and applications in food colloidal systems - A review

This review describes the mechanism of non-covalent/covalent interaction of whey protein-pectin (WPP) complexes, including electrostatic interaction, steric hindrance, cross-linking and Maillard reaction. The interaction between whey protein and pectin determines the form of the complex in the system, i.e. co-dissolution, precipitation, separation, complex coacervation and compounding. The interaction of WPP is affected by environmental conditions and its own properties, including several factors such as pH, polymer concentration and ratio, temperature, and ionic strength. In addition, the functional properties of WPP complexes are discussed through illustrative examples. The complexes with good emulsification, heat stability, gelling properties and biological activity have promising application prospects. WPP complexes have been widely studied for application in food colloidal systems, including protein beverages, delivery systems for bioactive substances, fat substitutes and food preservation films/coatings. The understanding of the interaction and functional properties of WPP complexes provides theoretical support for the improvement and design of new food colloidal systems.

Soy Protein: Molecular Structure Revisited and Recent Advances in Processing Technologies

Rising health concerns and increasing obesity levels in human society have led some consumers to cut back on animal protein consumption and switch to plant-based proteins as an alternative. Soy protein is a versatile protein supplement and contains well-balanced amino acids, making it comparable to animal protein. With sufficient processing and modification, the quality of soy protein can be improved above that of animal-derived proteins, if desired. The modern food industry is undergoing a dynamic change, with advanced processing technologies that can produce a multitude of foods and ingredients with functional properties from soy proteins, providing consumers with a wide variety of foods. This review highlights recent progress in soy protein processing technologies. Using the current literature, the processing-induced structural changes in soy protein are also explored. Furthermore, the molecular structure of soy protein, particularly the crystal structures of β-conglycinin and glycinin, is comprehensively revisited.

Functional properties of chitosan derivatives obtained through Maillard reaction: A novel promising food preservative

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.

Comprehensive Profiling of the Native and Modified Peptidomes of Raw Bovine Milk and Processed Milk Products

Bovine milk contains a variety of endogenous peptides, partially formed by milk proteases that may exert diverse bioactive functions. Milk storage allows further protease activities altering the milk peptidome, while processing, e.g., heat treatment can trigger diverse chemical reactions, such as Maillard reactions and oxidations, leading to different posttranslational modifications (PTMs). The influence of processing on the native and modified peptidome was studied by analyzing peptides extracted from raw milk (RM), ultra-high temperature (UHT) milk, and powdered infant formula (IF) by nano reversed-phase liquid chromatography coupled online to electrospray ionization (ESI) tandem mass spectrometry. Only unmodified peptides proposed by two independent software tools were considered as identified. Thus, 801 identified peptides mainly originated from α_S- and β-caseins, but also from milk fat globular membrane proteins, such as glycosylation-dependent cell adhesion molecule 1. RM and UHT milk showed comparable unmodified peptide profiles, whereas IF differed mainly due to a higher number of β-casein peptides. When 26 non-enzymatic posttranslational modifications (PTMs) were targeted in the milk peptidomes, 175 modified peptides were identified, i.e., mostly lactosylated and a few hexosylated or oxidized peptides. Most modified peptides originated from α_S-caseins. The numbers of lactosylated peptides increased with harsher processing.

Effects of Maillard reaction on structural modification and potential allergenicity of peanut 7S globulin (Ara h 1)

BACKGROUND

Ara h 1 is a major food allergen in peanuts. Recently, many studies have revealed that the Maillard reaction (MR) affects the allergenicity of food proteins.

RESULTS

To investigate the influence of the MR on the allergenicity of Ara h 1, R-Ara h 1 was processed with glucose in dry heating conditions for different periods. The extent of the MR was assessed by four methods. The changes in secondary and tertiary structures were characterized through spectroscopy assays. Advanced glycation end products (AGE) structures were identified by protein sample dry heating for 60 min, indicating the formation of AGE-Ara h 1. Simulated gastric fluid (SGF) digestion analysis showed that AGE-Ara h 1 has higher resistance to peptic digestion than R-Ara h 1. The BALB/c mouse model was also utilized to explore the effect of the MR on the allergenicity of Ara h 1, and the results showed that the Th2-type cytokines, antibodies, and histamine content increased, and there was a greater degree of degranulation of rat basophilic leukemia (RBL) cells in the AGE-Ara h 1 group compared with the R-Ara h 1 group.

CONCLUSION

During the process of dry heating, proteins participated in the MR with changes in secondary and tertiary structures. The condition applying a temperature of 100 °C for 60 min caused the formation of AGE-Ara h 1. Simulated gastric fluid digestion analysis showed that AGE-Ara h 1 had a greater resistance to peptic digestion than R-Ara h 1. The BALB/c mouse model showed that AGE-Ara h 1 had more allergenicity, indicating that the MR could enhance the allergenicity of Ara h 1. © 2020 Society of Chemical Industry.

Influence of seasonal variation and processing on protein glycation and oxidation in regular and hay milk

Climate and feeding influence the composition of bovine milk, which is further affected by thermal treatment inducing oxidation and Maillard reactions. This study aimed to evaluate season- and processing-related changes in the modified proteome of milk from two different feeding systems. Therefore, tryptic digests of regular and hay milk were analyzed by targeting 26 non-enzymatic modifications using LC-MS. Forty-five glycated, 48 advanced glycation endproduct (AGE-) modified, and 20 oxidized/carbonylated peptides representing 44 proteins were identified with lactosylation, formyllysine, and carboxymethyllysine being most common. The numbers and quantities of glycation- and oxidation-related modifications were similar between regular and hay milk and among seasons. The effects of pasteurization and ultra-high temperature (UHT) treatment were comparable for both milk types. In particular UHT treatment increased the numbers of identified modifications and the relative quantities of lactosylated peptides. The number of identified AGE-modified and oxidized residues increased slightly after UHT-treatment, but the contents were stable.

Nitrogen-Containing Hydrochar: The Influence of Nitrogen-Containing Compounds on the Hydrochar Formation

Hydrothermal carbonization (HTC) of fructose and urea containing solutions was conducted at 180 °C to study the influence of nitrogen-containing compounds on conversion and product properties. The concentration of fructose was fixed, while the concentration of urea was gradually increased to study its influence on the formation of nitrogen-containing hydrochar (N-HC). The degradation of urea has an important influence on the HTC of fructose. The Maillard reaction (MR) promotes the formation of N-HC in acidic conditions. However, in alkaline conditions, MR promotes the formation of bio-oil at the expense of N-HC. Alkaline conditions reduce N-HC yield by catalyzing fragmentation reactions of fructose and by promoting the isomerization of fructose to glucose. The results showed that adjusting the concentration of nitrogen-containing compounds or the pH value of the reaction environment is important to force the reaction toward the formation of N-HC or N-bio-oil.

Ribose-induced Maillard Reaction as an Analytical Method for Detection of Adulteration and Differentiation of Chilled and Frozen-thawed Minced Veal

Quality control of meat products is one of the main concerns of consumers, governmental control authorities, and retailers. The purpose of this study was to employ ribose-induced Maillard reaction in detection of meat adulteration and differentiation of fresh-chilled from frozen-thawed minced veal. The browning intensity was assessed through measuring the absorbance at 420 nm with a spectrophotometer as well as the direct analysis of the color and pH. The results showed that CIE b*, CIE a*, and A420* values in the extract of fresh-chilled veal were significantly (p<0.05) higher than frozen-thawed samples. The extract of frozen meat samples stored at -18°C became significantly darker and more yellowish compared to -4°C. The results showed that the A420* value in the frozen-thawed veal stored at -4°C and -18°C was reduced by approximately 17.22±3.53% and 11.68±2.49%, respectively, compared with fresh-chilled veal. The findings also showed that the storage temperature of minced veal and the heating time in this reaction had a significant effect on all tested variables (p<0.0001). The proposed method can be considered as an easy, quick, and inexpensive test for differentiating between the fresh-chilled and frozen-thawed minced veal.

Effect of reducing dietary advanced glycation end products on obesity-associated complications: a systematic review

CONTEXT

Consumption of dietary advanced glycation end products (AGEs) is associated with oxidative stress, inflammation, and other chronic conditions commonly associated with obesity.

OBJECTIVE

To analyze the effects of dietary AGEs on complications associated with obesity.

DATA SOURCES

This systematic review was conducted and reported according to PRISMA guidelines. The PubMed, Cochrane, and Scopus databases were searched, using the terms "advanced glycation end products," "overweight," and "obesity." The last search was performed in October 2018.

DATA EXTRACTION

Six studies that evaluated the effects of low-AGE and high-AGE diets were included in the review. The duration of the studies ranged from 1 day to 12 weeks. A comparison of all the compiled data was conducted by the authors.

DATA ANALYSIS

Circulating and urinary AGE markers, besides soluble receptor for AGEs, were considered as the primary outcomes. The secondary outcomes were cardiometabolic, inflammatory, glycemic, anthropometric, and renal markers.

CONCLUSIONS

AGE-RAGE interactions can activate the NF-κB (nuclear factor kappa B) signaling pathway and inhibit the PI3K-AKT pathway in adipocytes, which may explain their association with chronic diseases. This interaction can be considered as a novel explanation for the pathogenesis of obesity. AGEs can also be used as a biomarker for monitoring responses to dietary interventions in overweight and obese people.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42018082745.

Changes in the EPA and DHA content and lipids quality parameters of rainbow trout (Oncorhynchus mykiss, Walbaum) and carp (Cyprinus carpio, L.) at individual stages of hot smoking

The aim of this study was to evaluate qualitative changes in lipids of two most popular freshwater farmed fish (rainbow trout and carp) at particular stages of hot smoking process (brining, drying, smoking and heating). In order to characterize qualitative changes, the amount of peroxides (PV), secondary oxidation products (AsV) and the degree of hydrolysis of lipids (AV) was determined during the smoking process. The studies were carried out both in the fraction of lipids extracted using chloroform-based method (free lipids), as well as the fraction extracted by Bligh and Dyer method of the 1:1 chloroform: methanol ratio (bound lipids). Heat smoking results in loss of fat, especially at the last two stages of the process and the final contents of lipids were about 18% lower in the carp samples and about 10% lower in the trout samples. The dynamics of free lipid oxidation (Ch-lipids) was much smaller than the lipids extracted using B-D method, but the trend of lipid changes was similar. There was no significant difference in the anisidine value between two species, both for free lipids (Ch-lipids) and bound lipids (B-D-lipids), except for the last stage of smoking. No statistically significant differences between the studied species were found also in the case of lipid hydrolysis level, but after the smoking process an amount of free fatty acids increased. Subsequent stages of smoking process resulted in statistically significant losses of EPA and DHA in both fish species and in both types of lipids, i.e. B-D-lipids and Ch-lipids.

Maillard reaction products derived from food protein-derived peptides: insights into flavor and bioactivity

Food protein-derived peptides serve as food ingredients that can influence flavor and bioactivity of foods. The Maillard reaction plays a crucial role in food processing and storage, and generates a wide range of Maillard reaction products (MRPs) that contribute to flavor and bioactivity of foods. Even though the reactions between proteins and carbohydrates have been extensively investigated, the modifications of food protein-derived peptides and the subsequent impacts on flavor and bioactivity of foods have not been fully elucidated. In this review, the flavor and bioactive properties of food-derived peptides are reviewed. The formation mechanisms with respect to MRPs generated from food protein-derived peptides have been discussed. The state-of-the-art studies on impacts of the Maillard reaction on flavor and bioactivity of food protein-derived peptides are also discussed. In addition, some potential negative effects of MRPs are described.

Production of Bone Broth Powder with Spray Drying Using Three Different Carrier Agents

The aim of this study is to determine the some physicochemical (proximate composition, pH and a_w values) and reconstitution (wettability, dispersibility and solubility index (SI)) properties of spray-dried bone broth powder (BBP) along with the effects of the addition of different carrier agents. Subsequently, the powdered products were stored to determine the storage stability (pH, lipid oxidation, color, browning index) for 3 mon at –18℃. For this purpose, firstly marrow-containing bones (Os femur and Os humerus) have been boiled to get the bone broth. Three different emulsions were respectively prepared (1) 20% maltodextrin (MD) added BBP, (2) 20% whey powder isolate (WPI) added BBP and (3) 10% MD and 10% WPI added BBP and the emulsions were dried using a spray-dryer with 185℃ inlet and 95℃ outlet temperature. The proximate composition and reconstitution properties of BBP were found statistically different (p<0.05) depending on the use of different carrier agents. MD added BBP showed uniform and smooth morphology. The color, browning index, thiobarbituric acid reactive substances (TBARS) and pH values of BBP significantly changed (p<0.05) during storage. In conclusion, both the results of physicochemical and storage period analyses showed that the most suitable encapsulation material in the production of the bone broth powder is MD.

Fragrance Formation in the of Cocoa Roasted Process (Theobroma cacao) with Roaster Temperature Variation using a Vacuum Drying Oven

Chocolate is cacao nib processed product which is favorite commodity in the world, nevertheless, many of consumer have not known about the process. Notable stage in cacao processing is roaster process. Cacao roasting process currently uses conventional methods, which have weaknesses like energy wastage and bioactive compounds damage. Vacuum drying oven is new roasting method which uses low pressure and temperature. Through this research, the difference of aroma development between roasting process on conventional and vacuum drying oven method was investigated. Roasted cacao was extracted by water distillation, then distillate was separated by diethyl ether partition. The extract was characterized with GC-MS. The Characterization result shown that temperature 70°C contained 11 volatile compounds and temperature 80°C, 90°C and 140°C contained 7 volatile compounds. The higher roasting temperature, the more diverse of volatile compound. The best result in cacao roasting was on vacuum drying oven at 90°C, which has similar aroma with 140°C as control sample.

Application of the Products from the Maillard Reaction of Polyglutamic Acid and Glucose to Prepare Colored and Bioactive Silk

In this work, the Maillard reaction of polyglutamic acid (PGA) and glucose (Glc) was studied, and its functional, polymeric, and colored products were used to dye silk fiber with the aim of imparting bioactivities to silk. The UV–Vis spectroscopic analysis, which was employed to monitor the reaction, revealed the rapid formation of yellowish-brown products at pH 12 and 90 °C, and the great impact of glucose content on the quantity of the products. The FT-IR analysis validated the formation of melanoidin colorants. The silk fiber dyed with the PGA/Glc reaction products at pH 3 displayed a yellowish-brown color, and had very good wash and rub fastness, but poor light fastness. The incorporation of the UV-absorbing moiety into the PGA/Glc reaction products enhanced their light stability. The SEM analysis revealed that the dyed silk fiber was covered by polymeric substances. The dyed silk exhibited durable antibacterial activity against Staphylococcus aureus and Escherichia coli, and good antioxidant activity. This research expands the application field of the Maillard reaction and provides a novel and eco-friendly approach to prepare the colored and bioactive silk materials.

Glycation of whey proteins: Technological and nutritional implications

Whey proteins are globular proteins that have received much attention due to their high nutritional value and characteristic functional properties. In addition to being part of the protein system in milk, they constitute the main proteins in whey and whey protein products. Interaction of whey proteins with reducing sugars and carbohydrates via Maillard reaction have been extensively studied in milk and in model systems. Glycation of individual whey proteins results in variable increases in their solubility, thermal stability, antioxidant activity, and emulsion and foam stabilization. Limited glycation of whey protein products particularly whey protein isolates (WPI) using polysaccharides has been studied with the aim to produce conjugates with modified functional properties and acceptable sensory properties. An overview is presented here on the effect of glycation on individual whey proteins and whey protein products and the potential uses of the glycated whey proteins.

Optimization of Maillard Reaction between Glucosamine and Other Precursors by Measuring Browning with a Spectrophotometer

The individual Maillard reactions of glucose, glucosamine, cyclohexylamine, and benzylamine were studied at a fixed temperature of 120°C under different durations by monitoring the absorbance of the final products at 425 nm. Glucosamine was the most individually reactive compound, whereas the reactions of glucose, cyclohexylamine, and benzylamine were not significantly different from each other. Maillard reactions of reaction mixtures consisting of glucosamine-cyclohexylamine, glucosamine-benzylamine, glucose-cyclohexylamine, and glucose-benzylamine were also studied using different concentration ratios under different durations at a fixed temperature of 120°C and pH 9. Maillard reactions in the pairs involving glucosamine were observed to be more intense than those of the pairs involving glucose. Finally, with respect to the concentration ratios, it was observed that in most instances, optimal activity was realized, when the reaction mixtures were in the ratio of 1:1.

Food Processing: The Influence of the Maillard Reaction on Immunogenicity and Allergenicity of Food Proteins

The majority of foods that are consumed in our developed society have been processed. Processing promotes a non-enzymatic reaction between proteins and sugars, the Maillard reaction (MR). Maillard reaction products (MRPs) contribute to the taste, smell and color of many food products, and thus influence consumers’ choices. However, in recent years, MRPs have been linked to the increasing prevalence of diet- and inflammation-related non-communicable diseases including food allergy. Although during the last years a better understanding of immunogenicity of MRPs has been achieved, still only little is known about the structural/chemical characteristics predisposing MRPs to interact with antigen presenting cells (APCs). This report provides a comprehensive review of recent studies on the influence of the Maillard reaction on the immunogenicity and allergenicity of food proteins.

Antioxidant and chelating capacity of Maillard reaction products in amino acid-sugar model systems: applications for food processing

BACKGROUND

Maillard reaction products (MRP) have gained increasing interest owing to their both positive and negative effects on human health. Aqueous amino acid-sugar model systems were studied in order to evaluate the antioxidant and chelating activity of MRP under conditions similar to those of food processing. Amino acids (cysteine, glycine, isoleucine and lysine) combined with different sugars (fructose or glucose) were heated to 100 and 130 °C for 30, 60 and 90 min. Antioxidant capacity was evaluated via ABTS and DPPH free radical scavenging assays, in addition to Fe²⁺ and Cu²⁺ ion chelating capacity.

RESULTS

In the ABTS assay, the cysteine-fructose model system presented the highest antioxidant activity at 7.05 µmol mL^-1 (130 °C, 60 min), expressed in Trolox equivalents. In the DPPH assay, the cysteine-glucose system presented the highest antioxidant activity at 3.79 µmol mL^-1 (100 °C, 90 min). The maximum rate of chelation of Fe²⁺ and Cu²⁺ was 96.31 and 59.44% respectively in the lysine-fructose and cysteine-glucose systems (100 °C, 30 min).

CONCLUSION

The model systems presented antioxidant and chelating activity under the analyzed temperatures and heating times, which are similar to the processing conditions of some foods. © 2017 Society of Chemical Industry.

Influence of Quercetin and Its Methylglyoxal Adducts on the Formation of α-Dicarbonyl Compounds in a Lysine/Glucose Model System

Increasing evidence has identified α-dicarbonyl compounds, the reactive intermediates generated during Maillard reaction, as the potential factors to cause protein glycation and the development of chronic diseases. Therefore, there is an urgent need to decrease the levels of reactive dicarbonyl compounds in foods. In this study, we investigated the inhibitory effect of quercetin, a major dietary flavonoid, and its major mono- and di-MGO adducts on the formation of dicarbonyl compounds, such as methylglyoxal (MGO) and glyoxal (GO), in a lysine/glucose aqueous system, a model system to reflect the Maillard reaction in food process. Our result indicated that quercetin could efficiently inhibit the formation of MGO and GO in a time-dependent manner. Further mechanistic study was conducted by monitoring the formation of quercetin oxidation and conjugation products using LC-MS/MS. Quercetin MGO adducts, quercetin quinones, and the quinones of quercetin MGO adducts were detected in the system, indicating quercetin plays a dual role in inhibiting the formation of MGO and GO by scavenging free radicals generated in the system and trapping of MGO and GO to form MGO adducts. In addition, we prepared the mono- and di-MGO quercetin adducts and investigated their antioxidant activity and trapping capacity of MGO and GO. Our results indicated that both mono- and di-MGO quercetin adducts could scavenge the DPPH radical in a dose-dependent manner with >40% DPPH scavenged by the MGO adducts at 10 μM, and the di-MGO quercetin adduct could further trap MGO to generate tri-MGO adducts. Therefore, we demonstrate for the first time that quercetin MGO adducts retain the antioxidant activity and trapping capacity of reactive dicarbonyl species.

Mitigation strategies of acrylamide, furans, heterocyclic amines and browning during the Maillard reaction in foods

The Maillard reaction (MR) occurs widely during food manufacture and storage, through controlled or uncontrolled pathways. Its consequences are ambiguous depending on the nature and processing of the food products. The MR is often used by food manufacturer to develop appealing aromas, colour or texture in food products (cereal based food, coffee, meat…). However, despite some positive aspects, the MR could decrease the nutritional value of food, generate potentially harmful compounds (e.g. acrylamide, furans, heterocyclic amines) or modify aroma or colour although it is not desired (milk, fruit juice). This paper presents a review of the different solutions available to control or moderate the MR in various food products from preventive to removal methods. A brief reminder of the role and influence of the MR on food quality and safety is also provided.