Properties Of Maillard Reaction Products Research Articles

Antioxidant and antibrowning properties of Maillard reaction products in food and biological systems.

Oxidative damage refers to the harm caused to biological systems by reactive oxygen species such as free radicals. This damage can contribute to a range of diseases and aging processes in organisms. Moreover, oxidative deterioration of lipids is a serious problem because it reduces the shelf life of food products, degrades their nutritional value, and produces reaction products that could be toxic. Antioxidants are effective compounds for preventing lipid oxidation, and synthetic antioxidants are frequently added to foods due to their high effectiveness and low cost. However, the safety of these antioxidants is a subject that is being discussed in the public more and more. Synthetic antioxidants have been found to have potential negative effects on health due to their ability to accumulate in tissues and disrupt natural antioxidant systems. During thermal processing and storage, foods containing reducing sugars and amino compounds frequently produce Maillard reaction products (MRPs). Through the chelation of metal ions, scavenging of reactive oxygen species, destruction of hydrogen peroxide, and suppression of radical chain reaction, MRPs exhibit excellent antioxidant properties in a variety of food products and biological systems. Also, the capacity of MRPs to chelate metals makes them as a potential inhibitor of the enzymatic browning in fruits and vegetables. In this book chapter, the methods used for the evaluation of antioxidant activity of MRPs are provided. Moreover, the antioxidant and antibrowning activities of MRPs in food and biological systems is discussed. MRPs can generally be isolated and used as commercial preparations of natural antioxidants.

Characteristics and Functional Properties of Maillard Reaction Products from α-Lactalbumin and Polydextrose.

The characteristics and the functions of Maillard reaction products (MRPs) produced by polydextrose (PD), a new type of prebiotic, and α-lactalbumin (α-LA) were valued. PD and α-LA were incubated at 60 °C and 79% relative humidity for up to 72 h to prepare MRPs. The results showed that the absorbance and fluorescence intensity of heated α-LA-PD increased, and the amount of free amino groups reduced as the reaction progressed, which confirmed the formation of different stages of MRPs. Electrophoresis revealed an increase in molecular mass and the degree of covalent cross-linking. The secondary structure of MRPs experienced no significant changes with the measurement of circular dichroism (CD), while the tertiary structure gradually unfolded, exposing hydrophobic groups. Furthermore, a significant increase was detected in the radical-scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the ferric reducing/antioxidant power (FRAP) of MRPs. The findings offer a foundation for understanding the structural and functional features of MRPs in formula milk powder.

Sensory attributes and functional properties of maillard reaction products derived from the crassosotrea gigas (Ostrea rivularis gould) enzymatic hydrolysate and xylose system

To improve the flavor of Ostrea rivularis Gould, enzymatic hydrolysis was conducted and xylose-OEH Maillard reaction products were prepared. Then, their physicochemical properties and metabolites were determined by UHPLC-MS-MS, and volatile compounds were determined by GC-MS to investigate the changes. The results showed that His, Gln, Lys, Asp, and Cys were the major amino acids consumed. After being heated at 120 °C for up to 150 min, the DPPH (2,2-Diphenyl-1-picrylhydrazyl) was 85.32 ± 1.35% and the reducing capacity was 1.28 ± 0.12. Both were the highest in the groups. Additionally, 45 volatile compounds, including 2-ethyl-5-methyl-pyrazine and 2-ethyl-3,5-dimethyl-pyrazine, and 678 compounds were identified. We also found that 18 metabolites with significant differences (VIP ≥2) were differential metabolites, which involved lipid oxides and amino acid derivatives. The content of lipids favored the regulation of Maillard products and affected the lower threshold of the flavor of aldehydes, which contributed to the flavor and antioxidant activity. These results suggested the potential of xylose-OEH MRPs as a natural antioxidant for further processing oysters.

Characterization and functional properties of Maillard reaction products of β-lactoglobulin and polydextrose

The Maillard reaction products (MRPs) between polydextrose (PDX), a popular polysaccharide in formula powder, and β-lactoglobulin (β-LG), a major whey protein, were studied in aggregation degree, structure, hydrophobic, antigenic and antioxidant activity changes of β-LG. Incubation of PDX and β-LG (60 ℃, 79% relative humidity) for up to 72 h yielded MRPs with increases in furosine, UV absorbance, fluorescence intensity and loss of free amino groups. High molecular weight β-LG-PDX MRPs were observed by SDS-PAGE. Circular dichroism spectroscopy revealed negligible change in β-LG secondary structure. Changes in the tertiary structure of β-LG were detected by tryptophan fluorescence spectroscopy consistent with an increase in surface hydrophobicity of heated β-LG-PDX. Antigenicity reduction of β-LG in β-LG-PDX reached its peak when heated for 24 h. After heating for 72 h, DPPH radical-scavenging activity of β-LG-PDX increased by 7.4-fold, and the ferric reducing antioxidant power reached 61.1 µmol ascorbic acid/g protein.

Effects of pH on headspace volatiles and properties of Maillard reaction products derived from enzymatically hydrolyzed quinoa protein-xylose model system

The enzymatically hydrolyzed quinoa protein (E-HQP) was used as a main precursor of a wide range of thermal process flavours. Identification of the volatile compounds generated from the reaction of E-HQP-xylose model mixture at different initial pH values (5, 6, 7, 8 and 9) was performed using a solid phase microextraction - GC-MS technique. The content of free amino acids, colour intensity and radical scavenging activity of the Maillard reaction products (MRPs) formed at each pH were determined. The results revealed a great influence of the pH values on chemical composition and odour profile of the generated volatiles. The studies showed that low pH favoured formation of furans, furanones and cyclopentanones. In contrast, the pyrazines comprised the highest yield of the total volatiles at pH 9. A positive correlation was found between increasing the pH values and browning intensity of MRPs. The antioxidant activity of MRPs and total content of free amino groups showed a gradual decrease by increasing the pH. A correlation was found between the antioxidant activity of MRPs and the volatile compounds generated at each pH. Principle component analysis clearly elucidated a distinct separation among the investigated E-HQP-xylose model mixtures based on the volatile compounds generated at different pH.

Structural and antimicrobial properties of Maillard reaction products in chicken liver protein hydrolysate after sonication

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.

Physicochemical and functional properties of Maillard reaction products derived from cod (Gadus morhua L.) skin collagen peptides and xylose

To improve the utilization of cod skin collagen peptides (CSCP), we heated them with xylose at 80 °C, 100 °C, and 120 °C for up to 150 min to prepare xylose-CSCP Maillard reaction products (MRPs), and then investigated their physicochemical and functional properties. The results showed that Arg, Lys, Phe, and Asp were the major amino acids involved in the Maillard reaction. After being heated at 120 °C for 150 min, the ABTS scavenging activity and reducing power of xylose-CSCP MRPs were 99.59% and 0.887 absorbance units, respectively. Xylose-CSCP MRPs had better emulsifying properties and foaming properties than CSCP. Furthermore, 26 volatile compounds, including 2,5-dimethyl-pyrazine and 2-ethyl-3,5-dimethylpyrazine, were identified from xylose-CSCP MRPs by gas chromatography-ion mobility spectrometry. Newly formed heterocyclic compounds might be responsible for the flavor and antioxidant capacity of xylose-CSCP MRPs. These results suggest the potential for xylose-CSCP MRPs to serve as functional food ingredients.

A model system based on glucose-arginine to monitor the properties of Maillard reaction products.

An arginine-glucose mixture (1:2mol ratio) with pH 9 was heated at 53-100°C for 10-350min, and the effects of process parameters were determined during the Maillard reaction (MR). The heating temperature and time were selected as process conditions and were studied with central composite design. The model system was tested based on the values obtained from antioxidant capacity, browning intensity, pH, acrylamide (AC), and hydroxymethylfurfural (HMF) concentrations. Higher temperatures and longer time resulted in higher antioxidant capacity and browning intensity while lowering the pH values. HMF concentration of MR products was found higher in lower temperatures with longer processing time, whereas AC concentration was found higher in high temperatures.

Effects of ultrasound pretreatment on the extent of Maillard reaction and the structure, taste and volatile compounds of chicken liver protein.

To make better use of chicken liver, a byproduct of meat processing with rich proteins, the influence of ultrasound pretreatment on the extent of Maillard reaction (MR) and the properties of MR products (MRPs) of chicken liver protein (CLP) and its hydrolysate (CLPH) were investigated. The extent of MR of sonicated CLPH (SCLPHMs) was significantly higher than that of the other two MRPs. The decreased fluorescence intensity (FI) of the SCLPHMs indicated adequate reaction of d-xylose with sonicated CLPH (SCLPH). The particle size of the three MRPs was significantly larger than that of CLP, CLPH, and SCLPH, respectively. Ultrasound treatment increased the utilization of amino acids and enriched the variety of volatile compounds in all groups. Furfural was the main heterocyclic compound in the MRPs. Therefore, ultrasound pretreatment and enzymolysis of chicken liver may be a foundation for high-value development in flavors for the food industry.

Effect of sugar types on structural and flavor properties of peony seed derived Maillard reaction products

Due to limited utilization of peony seed meal in the food industry, the effect of different sugars on the structural and flavor properties of Maillard reaction products (MRPs) from peony seed meal hydrolysates (PSH) was investigated. It was noticed that the influence of ribose, xylose, and glucose on the structure of MRPs was greater than maltose and xylooligosaccharide. The MRPs prepared by ribose and xylose showed the greater browning intensity, degree of substitution (DS), and fluorescence intensity. The molecular weight (MW) distribution of 500–1,000 Da, 1,000–3,000 Da, and >3,000 Da was significantly increased in all the MRPs. Partial least squares regression (PLSR) showed that MW distribution, free amino acids, and volatile compounds contributed remarkably to the sensory attributes of MRPs. The sugars that provided the stronger meaty and umami tastes to the MRPs were ribose and xylose. Practical applications The peony seed meal is accumulated as a main ecological pollutant during the production of peony seed oil; however, it is an excellent source of plant protein. In the modern food industry, there is an increasing demand for plant proteins over animal derived proteins in various health foods. Therefore, we aimed to prepare flavor agent using peony seed meal protein via Maillard reaction (MR). The effects of sugar types on the color change, structure characteristics, and flavor generation of MRPs were investigated. The improvement of MRPs after the conjugation with various sugar types can increase their industrial potential as flavor enhancers.

Antimicrobial, antioxidant and sensory properties of Maillard reaction products (MRPs) derived from sunflower, soybean and corn meal hydrolysates

Nowadays, proteins from different plant materials are used to produce Maillard reaction products (MRPs). In this study, antimicrobial, antioxidant and sensory properties of Maillard reaction products (MRPs) derived from three plant materials namely sunflower (SF), soybean (SB) and corn (CN) meals were investigated. These MRPs were prepared by mixing each protein hydrolysate (60 g), with xylose (0.595 g) and cysteine (0.372 g) at pH of 7.4, and then heated at 120 °C for 2 h. Results revealed that only SF-MRPs show an antimicrobial effect against tested strains (Staphylococcus aureus and E. coli). SF-MRPs showed greater antioxidant activity followed by SB-MRPs and CN-MRPs. Additionally, CN-MRPs showed higher umami, continuity and mouthfulness sensory attributes compared to SF-MRPs and SB-MRPs. It is therefore deduced that SF-MRPs could be used as potential food ingredients in food products due to their relatively high antimicrobial and antioxidant activities. On the other hand, SF-MRPs could potentially be used as functional food, which could be of great potential for food industries.

Antioxidant Properties of Maillard Reaction Products Derived from Shrimp Shell Chitosan and Xylose, Fructose or Glucose

Under certain conditions, chitosans can react with different types of reducing sugars to form various final Maillard reaction products (MRPs). In this study, the optimal reaction conditions were selected, and three different final MRPs (xylose-MRPs, fructose-MRPs, glucose-MRPs) were analyzed. The structure of the three MRPs was analyzed using fluorescence, ultraviolet, and infrared spectroscopic methods, and then the antioxidant activities of the three MRPs were determined. The results showed that the three MRPs have similar structure and function, and the antioxidant activities between them have certain regularity. Antioxidant activities were ranked as follows: xylose-MRPs>fructose-MRPs>glucose-MRPs, and this order was inversely proportional to their reaction time, that is, shorter the reaction time, higher the antioxidant activity, while longer the reaction time, lower the antioxidant activity.

In vitro antioxidant and cytoprotective properties of Maillard reaction products from phloridzin-amino acid model systems.

The aim of this study was to investigate in vitro antioxidant activities and cytoprotective effect of Maillard reaction products (MRPs) from phloridzin (Pz)-amino acid model systems. Their structures were also characterised by Fourier transform-infrared spectroscopy (FTIR). MRPs were prepared from the Pz-methionine (Met), Pz-lysine (Lys), Pz-isoleucine (Ile), Pz-histidine (His) or Pz-glutamic acid (Glu) model system. The Pz-Lys MRPs, rich in antioxidant potency, were subjected to ultrafiltration to yield four MRPs fractions with different molecular weights (Mw). The fraction with Mw 30-50 kDa had significantly (P < 0.05) higher antioxidant activity than other fractions. Moreover, it significantly (P < 0.05) attenuated the 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH)-elicited decrease in cell viability in HepG2 cells in a concentration-dependent manner. FTIR analysis indicated that the fraction with Mw 30-50 kDa had the strong stretching vibration for the OH, NH, CH, CO and CC groups, suggesting the formation of intermediate MRPs during Maillard reaction. The results obtained in this study may provide some basis for the purported health-promoting effects of MRPs and their potential application as antioxidant agents in food industry. Also, it is important for our understanding of the variation of bioactive substances in food during thermal processing. © 2017 Society of Chemical Industry.

Structural and functional properties of Maillard reaction products of protein isolate (mung bean, Vigna radiate (L.)) with dextran

ABSTRACTThe objective of this study was to determine the functional and structural properties of Maillard reaction products of mung bean [Vigna radiate (L.)] protein isolate with dextran obtained under the temperature of 80°C or 90°C with different times (0, 1, 2, 3, 4, 5, and 6 h). The mung bean protein isolate–dextran conjugate had better solubility, emulsifying activity, and emulsifying stability than mung bean protein isolate; however, the protein aggregation decreased the solubility, surface hydrophobicity, emulsifying activity, and emulsifying stability of mung bean protein isolate–dextran conjugate. In general, these functional properties of mung bean protein isolate–dextran conjugate obtained at 80°C with lower degree of glycosylation and browning degree were better than mung bean protein isolate–dextran conjugate obtained at 90°C. Both vicilin (8S) and legumin type (11S) globulins both participated in the graft reaction, the subunit with a molecular weight of 21 kDa that contributed to 11S globulin might be the most vulnerable to dextran followed by the 60, 32, and 26 kDa subunits. Maillard reaction between mung bean protein isolate and dextran led to a decreased fluorescence intensity and a bathochromic shift. The fluorescence intensity of mung bean protein isolate–dextran conjugate generally decreased, and λmax of mung bean protein isolate–dextran conjugate first increased and then decreased. The grafted mung bean protein isolates had lower α-helix content but higher β-sheet content. As the Maillard reaction between mung bean protein isolate and dextran proceeded, the α-helix contents of the mung bean protein isolate–dextran conjugates were significantly increased and then decreased, and the β-sheet content generally decreased and then increased. Excessive grafted dextran and more protein aggregation was observed in mung bean protein isolate–dextran conjugate obtained at 90°C, which induced structural changes that might have impaired the functions. Our findings suggest that conjugation of mung bean protein isolate with dextran through the Maillard reaction is an effective way of improving the functional properties of mung bean protein isolate for its application in the food industry.

Effects of ultrasonic pretreatment and glycosylation on functional properties of casein grafted with glucose

Caseins are the predominant proteins in milk. The Maillard reaction is a non-enzymatic reaction between reducing sugars and amino acids. This work investigated the impact of ultrasound pretreatment on the Maillard reaction and functional properties of glycated casein. Casein solution was treated with ultrasound for 0, 10, 20, 30, and 40 min prior to Maillard reaction. Results revealed that the absorbance at 294 nm reached maximum after 20 min of ultrasound pretreatment. Moreover, glycated casein obtained by Maillard reaction coupled with 20 min ultrasound pretreatment had the highest water holding capacity 67.81% ± 1.72%, gel strength 165.05 ± 2.72 g, the emulsifying activity index 91.76 m2/g, the emulsion stability index 20.67 min, reducing power 0.682 compared with other samples. The results of SEM confirmed microstructure of gel improved. Consequently, ultrasonic pretreatment could improve the efficiency of the reaction. Moreover, ultrasonic pretreatment had certain impact on the functional properties of Maillard reaction products. Practical applications Casein solution was treated with ultrasonic pretreatment prior to Maillard reaction. Ultrasonic pretreatment can increase the reaction rate of casein and glucose. Ultrasonic pretreatment had improved functional properties of glycated casein. Therefore, it pointed out the usefulness of ultrasound as an effective method of pretreatment to promote the formation of functional ingredients by Maillard reaction.

Bioactive Properties of Maillard Reaction Products Generated From Food Protein-derived Peptides.

Food protein-derived peptides are promising food ingredients for developing functional foods, since various bioactive peptides are released from food proteins. The Maillard reaction, which plays an important role in most processed foods, generates various chemical components during processing. Although changes of amino acids or proteins and reduced sugars by the Maillard reaction have been studied extensively, such changes of peptides by the Maillard reaction are still not resolved enough. Since food protein-derived peptides are widely utilized in many processed foods, it deserves concern and research on the changes of peptides by the Maillard reaction in foods during processing or storage. This chapter initially overviewed food protein-derived bioactive peptides. Then, Maillard reaction products generated from peptides are discussed. We focused particularly on their bioactivities.

Effects of Galactose Concentration on Characteristics of Angiotensin-I-Converting Enzyme Inhibitory Peptides Derived from Bovine Casein in Maillard Reaction

Bovine casein peptide had a strong angiotensin-I-converting enzyme inhibitory activity. The objective of this study was to evaluate the effects of the galactose concentration on angiotensin-I-converting enzyme inhibitory activity, antioxidant activity, and physicochemical properties of Maillard reaction products derived from bovine casein peptide and galactose in aqueous model system. The browning intensities of galactose-bovine casein peptide Maillard reaction products increased remarkably with the galactose concentration increased during heat treatment, while its pH and amino groups decreased significantly. The fluorescence compounds of galactose-bovine casein peptide Maillard reaction products reached the maximum when the galactose concentration was 45 g/L. Compounds with molecular weight between 2941 and 8864 Da were dominant while compounds smaller than 250 Da were also produced during the reactions, as characterized by size exclusion chromatography. Galactose-bovine casein peptide Maillard reaction products lost 14.6% of the original angiotensin-I-converting enzyme inhibitory activity of bovine casein peptide after the addition of galactose concentration ranged from 0 to 12%, but its strong antioxidant activities were obtained. A high galactose concentration could decrease angiotensin-I-converting enzyme inhibitory activity of bovine casein peptide and enhance its antioxidant activities.

Effect of different molecular weight chitosans on the mitigation of acrylamide formation and the functional properties of the resultant Maillard reaction products

Mitigation of acrylamide formation and the functional properties of Maillard reaction products (MRPs) were investigated in a food model system. The system was composed of elements of mixtures and their combination including fructose, asparagine and different molecular weight chitosans. All solutions were heated, and then analyzed for acrylamide content, MRPs absorbance, pH, color, antioxidant capacity, antibacterial activity and kinematic viscosity. The fructose, asparagine and chitosan mixture had more MRPs compared to other mixtures. 1,1-Diphenyl-2-pricrylhydrazy (DPPH) radical scavenging activities, ferrous ion chelating abilities and reducing power results showed that all solutions containing a combination of two or three reactants had antioxidant capacities. Acrylamide content has a positive correlation with absorbance values at OD294 and OD420 but a negative correlation with the CIB L∗ value of a solution (p<0.01). Experimental results evidenced that low molecular weight (50–190kDa) chitosan can be used to mitigate the formation of acrylamide.

Effect of the Reactant Ratio on the Characteristics and Antioxidant Activities of Maillard Reaction Products in a Porcine Plasma Protein Hydrolysate-Galactose Model System

The chemical characteristics and antioxidant properties of Maillard reaction products formed in the Maillard reaction in a model system at 95°C for different lengths of time (0–6 h) were investigated at three mass ratios (1:1, 1:2, and 1:3) of porcine plasma protein hydrolysate to galactose. The results revealed that the pH value and free amino group content decreased (p < 0.05), whereas the browning index, intermediate products, and browning intensity, as well as reducing power and 2,2’-amino-di(2-ethyl-benzothiazoline sulfonic acid-6)ammonium salt radical scavenging activity of the Maillard reaction products increased as the reaction time increased (p < 0.05). Moreover, when the mass ratio of porcine plasma protein hydrolysate to galactose was 1:3, the Maillard reaction progressed easily, which rendered a higher degree of glycation and antioxidant activity (p < 0.05). These results indicated that the Maillard reaction can improve the antioxidant capacity of porcine plasma protein hydrolysate.

Effects of UV-irradiation on tricine impregnated wood

In this work, a method of stabilizing the color of wood by amino acid tricine was studied. Therefore, an aqueous tricine solution was impregnated in oak, maple and walnut and subsequently dried. After the wood samples had been irradiated under artificial light, the color changes as well as the chemical changes were measured using FTIR. The results showed a significantly increased UV resistance due to the treatment with tricine. Spectroscopic studies supported this observation and showed a reduced degradation of lignin after the treatment with tricine. The reason for this increased UV stability can be explained on the one hand by a change in the reflective properties of the treated wood and on the other hand by the radical scavenger properties of Maillard reaction products.