Formation Of Maillard Reaction Products Research Articles

Antioxidant and Antibacterial Activities of Indian Marsh Fleabane (Pluchea indica (L.) Less)

Ethanolic extracts of various parts of Pluchea indica (L.) Less were analyzed for DPPH radical scavenging capacities, total phenolic contents and antibacterial activities. The results showed that fresh root extract had the most antioxidant activities (0.16  0.001 mg/mL EC50, 20.02  0.177 mg/g TEAC and 15.79  0.008 mg GAE/g total phenolic content). Antioxidative activities of most fresh samples were significantly higher than that of dry samples (P < 0.05). The low antioxidative activities of dry samples might be due to the effect of drying (60 oC for 2 days). In contrast, tea leaves extract exhibited the high antioxidant capacities (0.28  0.012 mg/mL EC50, 11.86  0.519 mg/g TEAC and 3.18  0.012 mg GAE/g total phenolic content) due to the formation of Maillard reaction products during heating at lower temperature for a shorter period (50 oC for 2 hrs). Antibacterial activities assessed by the disc diffusion method showed that all of investigated bacteria were inhibited by the extract of fresh root, fresh twig, dry stem and tea leaves, while the extract of fresh and dry flower, fresh and dry leaves, and dry root showed the less inhibition potential. The minimal inhibitory concentrations (MICs) of extracts using agar microdilution and disc diffusion method showed significant inhibition activities even at 2 – 16 fold dilutions, with the most effective result in fresh root extract as low as 64 fold dilution. Tea leaves extract also had high inhibitory capacities when the concentrations were 4 - 16 fold dilution. Fresh root extract had the most excellent inhibition potential against Bacillus cereus, Pseudomonas fluorescens and Salmonella typhimurium (0.16, 0.16 and 0.32 mg/mL MICs, respectively). Inhibitory activities against Escherichia coli were very low. The increase in antioxidant activities did increase antibacterial abilities.

Effect of Protease Treatment during Mashing on Protein-Derived Thiol Content and Flavor Stability of Beer during Storage

The ability of a protease added during mashing in a pilot-scale brew to release protein-derived thiols as antioxidants and thereby improve flavor stability during storage was investigated. The protease treatment resulted in increased protein-derived thiol concentrations in fresh beer produced at a pilot scale compared with a control beer without protease treatment, and electron spin resonance lag phase analysis also demonstrated improved oxidative stability of the protease-treated beer. However, the protease treatment also resulted in high sulfite levels and, therefore, it was not possible to conclude that the improvement in oxidative stability was solely a direct effect of increased levels of protein-derived thiol concentrations. The development of papery character and volatile linear aldehydes was inhibited when the protease-treated beer was stored at 35°C but the protease treatment also resulted in increased concentrations of free amino acids in beer, resulting in a more fruity aged or vinous character of the beer during storage due to increased formation of Maillard reaction products. Thiols were found to be irreversibly oxidized during storage, which indicates that thiols cannot be regenerated during storage; and, if thiols are to act as antioxidants in beer, increased concentrations must be present in the fresh beer.

ʟ-Carnitine, pyridoxine hydrochloride, ᴅʟ-α-tocopheryl acetate를 이용한 분유모델시스템의 마이얄반응생성물 저감화 조건 최적화

The Maillard reaction is a non-enzymatic reaction between amino and carbonyl groups. During milk processing, lactose reacts with milk protein through this reaction. Infant formulas (IFs) are milk-based products processed with heattreatments, including spray-drying and sterilization. Because IFs contain higher Maillard reaction products (MRPs) than breast milk, formula-fed infants are subject to higher MRP exposure than breast milk-fed ones. In this study, we investigated the optimization of conditions for minimal MRP formation with the addition of L-carnitine (L-car), pyridoxine hydrochloride (PH), and DL-α-tocopheryl acetate (α-T) in an IF model system. MRP formation was monitored by response surface methodology using fluorescence intensity (FI) and 5-hydroxymethylfurfural (HMF) content. The optimal condition for minimizing the formation of MRPs was with 2.3 μM L-car, 15.8 μM PH, and 20.6 μM α-T. Under this condition, the predicted values were 77.4% FI and 248.7 ppb HMF.

Effect of extrusion processing on lipid stability of rye bran

The aim of this study was to investigate under which processing conditions the extrusion of rye bran could produce a material with a long shelf life in terms of lipid chemistry and possibilities to link lipid stability with physical properties of the extrudates. In addition to water content (13–30 %) and temperature (80–140 °C) as variables during extrusion, the effect of rye bran particle size (633 and 15 µm) was studied. Stability of lipids was measured by volatile compounds and the loss of tocopherols and tocotrienols. Of the studied process parameters, the water content had a significant effect both on the physical properties and on lipid stability. Low water content (13 or 16 %) in the extrusion of coarse or fine bran led to the highest expansion and porosity and the most stable lipids during storage. The improved oxidative stability when processed at low water contents in extrusion was connected with a higher formation of Maillard reaction products, which could have acted as antioxidants. In spite of the loss of tocols during grinding, the lipids in the fine rye bran extrudates were at least as stable as the lipids in the coarse rye bran extrudates when processed at low water content. However, the high furfural content in the fine rye bran extrudate at 13 % indicated that Maillard reaction was extensive which could lead to undesirable flavour. Thus, the overall best performance was obtained when the coarse rye bran was processed at the lowest water content.

Glycation of human cortical and cancellous bone captures differences in the formation of Maillard reaction products between glucose and ribose.

To better understand some aspects of bone matrix glycation, we used an in vitro glycation approach. Within two weeks, our glycation procedures led to the formation of advanced glycation end products (AGEs) at the levels that corresponded to approx. 25–30 years of the natural in vivo glycation. Cortical and cancellous bones from human tibias were glycated in vitro using either glucose (glucosylation) or ribose (ribosylation). Both glucosylation and ribosylation led to the formation of higher levels of AGEs and pentosidine (PEN) in cancellous than cortical bone dissected from all tested donors (young, middle-age and elderly men and women). More efficient glycation of bone matrix proteins in cancellous bone most likely depended on the higher porosity of this tissue, which facilitated better accessibility of the sugars to the matrix proteins. Notably, glycation of cortical bone from older donors led to much higher AGEs levels as compared to young donors. Such efficient in vitro glycation of older cortical bone could result from aging-related increase in porosity caused by the loss of mineral content. In addition, more pronounced glycation in vivo would be driven by elevated oxidation processes. Interestingly, the levels of PEN formation differed pronouncedly between glucosylation and ribosylation. Ribosylation generated very high levels of PEN (approx. 6- vs. 2.5-fold higher PEN level than in glucosylated samples). Kinetic studies of AGEs and PEN formation in human cortical and cancellous bone matrix confirmed higher accumulation of fluorescent crosslinks for ribosylation. Our results suggest that in vitro glycation of bone using glucose leads to the formation of lower levels of AGEs including PEN, whereas ribosylation appears to support a pathway toward PEN formation. Our studies may help to understand differences in the progression of bone pathologies related to protein glycation by different sugars, and raise awareness for excessive sugar supplementation in food and drinks.

Study on Sensory Quality, Antioxidant Properties, and Maillard Reaction Products Formation in Rye-Buckwheat Cakes Enhanced with Selected Spices

The effect of selected spices included in the recipe of rye-buckwheat cakes on sensory quality, nutritional value, and Maillard reaction (MR) products formation was addressed in this study. The cakes with cloves, nutmeg, allspice, cinnamon, vanilla, and spice mix addition revealed the highest overall quality values. Cakes enriched with cloves, allspice, and spice mix showed the highest rutin content and almost threefold higher available lysine contents whereas cakes enhanced with mix, cloves, and cinnamon were the richest source of phenolic compounds. The highest antioxidant capacity showed cakes with cloves and spice mix. The furosine, a marker of early stage of MR, was decreased in cakes with cloves, allspice, spice mix, and vanilla whereas fluorescent intermediatory compounds were reduced in cakes enhanced with cloves, allspice, and cinnamon. In contrast, browning index was increased as compared to cakes without spices. The FAST index was significantly lowered in all cakes enriched with spices, especially with cloves, allspice, and mix addition. The presence of cloves, allspice, and vanilla in cake formula was the most efficient in acrylamide strategy. It can be suggested that cloves, allspice, and vanilla might be used for production of safety and good quality cakes.

Food Processing and Maillard Reaction Products: Effect on Human Health and Nutrition.

Maillard reaction produces flavour and aroma during cooking process; and it is used almost everywhere from the baking industry to our day to day life to make food tasty. It is often called nonenzymatic browning reaction since it takes place in the absence of enzyme. When foods are being processed or cooked at high temperature, chemical reaction between amino acids and reducing sugars leads to the formation of Maillard reaction products (MRPs). Depending on the way the food is being processed, both beneficial and toxic MRPs can be produced. Therefore, there is a need to understand the different types of MRPs and their positive or negative health effects. In this review we have summarized how food processing effects MRP formation in some of the very common foods.

Spray Drying of Blue Shark Skin Protein Hydrolysate: Physical, Morphological, and Antioxidant Properties

The objective of this work was to evaluate the influence of inlet air temperature and maltodextrin concentration on the physical, morphological, and antioxidant properties of powdered blue shark skin protein hydrolysate. Higher inlet air temperatures led to lower moisture content and bulk density, whereas higher maltodextrin concentrations led to lower moisture content and hygroscopicity, higher bulk density, and larger particles size. Antioxidant capacity was mainly affected by maltodextrin concentration, which was attributed to two possible reasons: the protection provided to the peptides fractions and/or the formation of Maillard reaction products with antioxidant activity. In addition, maltodextrin itself showed a slight antioxidant capacity, which may have contributed to the higher antioxidant capacity of powders compared to the liquid hydrolysate.

The effect of steam pelleting of a dry dog food on the Maillard reaction

During processing of pet foods, the Maillard reaction (MR) can occur, which reduces the bioavailability of essential amino acids like lysine and results in the formation of advanced Maillard reaction products (MRPs). This study examined the effect of conditioning temperature (65 and 90°C) and die hole length (ø 5×45, 65, and 80mm) during pelleting processing of a standard dry dog food on selected indicators of the MR (total lysine, reactive lysine, fructoselysine, ɛ-N-carboxymethyllysine, (5-hydroxymethyl)-2-furfural, lysinoalanine), browning development and CIE-Lab color. Steam pelleting variables did not cause a significant loss of lysine or change in color and absorbance values. Analyzing the unprocessed ingredient mix suggests that the choice of the ingredients used in the ingredient mix, rather than the pelleting process applied, is responsible for the RL/TL ratio observed in the dry standard dog food used in this study. MRP content increased during steam pelleting (fructoselysine: 366.2 to 538.8mg/kg DM; ɛ-N-carboxymethyllysine: 12.6 to 14.8mg/kg DM; lysinoalanine: 5.7 to 7.7mg/kg DM; P<0.05). Increasing conditioning temperature from 65 to 90°C increased fructoselysine (475.9 to 601.6mg/kg DM; P<0.01) and ɛ-N-carboxymethyllysine (14.3 to 15.1mg/kg DM; P=0.003). An increased die hole length of 80mm decreased fructoselysine content compared to 45 and 65mm (461.3 vs. 573.3 and 581.6mg/kg DM; P<0.01) but increased lysinoalanine content (8.8 vs. 7.4 and 6.8mg/kg DM; P=0.002). Analyzing total and reactive lysine and absorbance values are not accurate enough to predict the MR and formation of MRPs during processing.

Optimization of roasting conditions as an useful approach for increasing antioxidant activity of carob powder

Antioxidant activity, gastrointestinal solubility of polyphenols and formation of different classes of Maillard reaction products (MRPs) that occurs during thermal processing of carob powder was investigated in relation to different roasting time-roasting temperature combinations applied. Principal component analysis (PCA) was used to group carob powders with the aim of proposing optimal roasting conditions for obtaining the one with the highest biological activity that can be expected after undergoing the simulation of gastrointestinal digestion. Results showed that antioxidant activity of carob powder can be significantly increased by roasting due to improved polyphenol solubility and formation of the early-stage MRPs. Fluorescent MRPs, HMF and furfural, known for their toxic properties, were the most abundant in samples roasted under more severe time/temperature conditions. Carob powder roasted at 130 °C for 30 min yielded the highest antioxidant activity and the lowest toxic MRP formation.

Bioactive compounds, in vitro antioxidant capacity and Maillard reaction products of raw, boiled and fried garlic (Allium sativum L.)

SummaryGarlic is used in many dishes but some of its bioactive compounds are lost when exposed to heat. This study evaluated bioactive compounds, antioxidant activity and Maillard reaction products of raw (RG), boiled (BG) and fried garlic (FG). Total phenolic compounds, flavonoids, allicin and phytosterol were quantified as well as dietary fibres and mineral content. Antioxidant activities of RG, BG and FG were evaluated by oxygen radical absorbance capacity (ORAC), oxidation of β‐carotene/linoleic acid and Rancimat methods. The main results were the following: thermal processing of RG decreased both bioactive compounds and antioxidant capacity, boiling was found to be less aggressive than frying, and strong correlations were obtained between total phenolic compounds and the antioxidant assays. However, phytosterol content was higher in FG than in RG and BG and higher temperatures increased the formation of Maillard reaction products. It was concluded that RG and BG should be preferred for human consumption as they present higher antioxidant capacity.

Does microwave sterilization of growth media involve any non-thermal effect?

Fast reactions mediated by microwaves are often attributed by many to non-thermal effect. We show here that rapid formation of Maillard reaction products during microwave sterilization of growth medium results from concentration effect and not any non-thermal effect. This leads to an improved method for microwave sterilization of growth media.

One-Step Simultaneous Differential Scanning Calorimetry-FTIR Microspectroscopy to Quickly Detect Continuous Pathways in the Solid-State Glucose/Asparagine Maillard Reaction

The stepwise reaction pathway of the solid-state Maillard reaction between glucose (Glc) and asparagine (Asn) was investigated using simultaneous differential scanning calorimetry (DSC)-FTIR microspectroscopy. The color change and FTIR spectra of Glc-Asn physical mixtures (molar ratio = 1:1) preheated to different temperatures followed by cooling were also examined. The successive reaction products such as Schiff base intermediate, Amadori product, and decarboxylated Amadori product in the solid-state Glc-Asn Maillard reaction were first simultaneously evidenced by this unique DSC-FTIR microspectroscopy. The color changed from white to yellow-brown to dark brown, and appearance of new IR peaks confirmed the formation of Maillard reaction products. The present study clearly indicates that this unique DSC-FTIR technique not only accelerates but also detects precursors and products of the Maillard reaction in real time.

Preparation and antioxidant potential of maillard reaction products from (MRPs) chitooligomer

Maillard reaction products (MRPs) were prepared from a chitooligomer solution by heating at 80°C for different times. A time-dependent increase in UV absorbance, browning, and fluorescence was observed upon heating, indicating formation of MRPs with heating of the chitooligomer solution. The formation was also evidenced by Fourier transform infrared and molecular weight distribution, using gel permeation chromatography. 2,2-Diphenyl-1-picrylhydrazyl (DPPH), and 2,2-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS+)-scavenging activities, and MRPs, reducing power increased significantly (p<0.05) with an increase in heating time of the chitooligomer solution. MRPs240 was formed after 240min of heating and showed an inhibitory concentration required for 50% scavenging (IC50) value of 118μg/ml (against DPPH), 266μM ascorbic acid equivalent (AE)/mg MRPs240 (against ABTS+), and 521μM AE/mg MRPs240 (against reducing power). MRPs240 exhibited lipid peroxidation inhibition activity in a linoleic acid emulsion, and the malondialdehyde concentration decreased from 29.6 to 8.4μM. In addition, MRPs showed protection ability against the oxidative stress induced by H2O2 in Chang liver cells.

The Maillard reaction and pet food processing: effects on nutritive value and pet health

The Maillard reaction, which can occur during heat processing of pet foods or ingredients, is known to reduce the bioavailability of essential amino acids such as lysine due to the formation of early and advanced Maillard reaction products (MRP) that are unavailable for utilisation by the body. Determination of the difference between total and reactive lysine by chemical methods provides an indication of the amount of early MRP present in foods, feeds and ingredients. Previous research reported that the difference between total and reactive lysine in pet foods can be up to 61.8%, and foods for growing dogs may be at risk of supplying less lysine than the animal may require. The endogenous analogues of advanced MRP, advanced glycation endproducts, have been associated with age-related diseases in humans, such as diabetes and impaired renal function. It is unknown to what extent advanced MRP are present in pet foods, and if dietary MRP can be associated with the development of diseases such as diabetes and impaired renal function in pet animals. Avoidance of ingredients with high levels of MRP and processing conditions known to favour the Maillard reaction may be useful strategies to prevent the formation of MRP in manufactured pet food. Future work should further focus on understanding the effects of ingredient choice and processing conditions on the formation of early and advanced MRP, and possible effects on animal health.

Influence of Roasting Conditions on the Antioxidant Characteristics of Colombian Coffee (Coffea arabica L.) Beans

We evaluated the effects of the degree of roasting on the antioxidant properties of brewed coffee. Light-roasted coffee beans showed the highest antioxidant activity, and an approximately 40–80% loss of antioxidant activity was observed after further roasting. In addition, light-roasted beans had significantly higher antioxidant activity as compared to unroasted beans, suggesting the formation of Maillard reaction products and the release of bound polyphenols from plant cells. High-performance liquid chromatography analysis indicated that chlorogenic acid was the predominant compound in coffee brews, and that it was degraded with increasing roasting time. Our study demonstrated that light-roasted coffee beans have the most desirable qualities with respect to antioxidative values. Practical Applications Based on our experiments, the light roasting of coffee beans produces antioxidant activity, but further roasting to medium, dark and very dark degrees decreases the antioxidant properties of coffee beans. Therefore, we concluded that light-roasted coffee has better nutritional properties. This study examined the differences in the antioxidant properties of coffee beans roasted for different times.

Structure and antioxidant activity of β-lactoglobulin-glycoconjugates obtained by high-intensity-ultrasound-induced Maillard reaction in aqueous model systems under neutral conditions

Sonication is a new processing technology in the dairy industry. The aim of this study was to test glycation of β-lactoglobulin (BLG) in Maillard reaction (MR) induced by high-intensity ultrasound in aqueous solution under neutral conditions at 10–15°C, which is not favourable for the MR. BLG was sonicated in the presence of glucose, galactose, lactose, fructose, ribose and arabinose. Formation of Maillard reaction products (MRPs) was monitored by mass spectrometry, spectrophotometry and fluorimetry. Ultrasound treatment resulted in formation of MRPs with all tested carbohydrates. Ribose induced the highest degree of modification resulting in 76% of BLG modified and an average of three anhydroribose units attached. Circular dichroism spectra analyses indicated only minor alterations in secondary and tertiary structures. MRP obtained by ultrasound exhibited 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and possessed increased iron-chelating activity and reducing power. High-intensity ultrasound efficiently promotes BLG-glycoconjugates formation by MR in aqueous solutions under non-denaturing conditions.

Controlling the Maillard Reaction by Reactant Encapsulation: Sodium Chloride in Cookies

Formation of Maillard reaction products (MRPs) including 5-hydroxymethylfurfural (HMF) and acrylamide has been an intensive area of research in recent decades. The presence of reactants such as sodium chloride may influence the Maillard reaction (MR) pathways through the dehydration of various key intermediates. The aim of this work was to test the potential of ingredient encapsulation to mitigate the MR by investigating the case of sodium chloride encapsulation on the HMF formation in cookies. Thirteen cookies were prepared with recipes containing free or encapsulated NaCl. Increasing NaCl concentration from 0 to 0.65% increases HMF concentration up to 75%, whereas in the presence of encapsulated NaCl the reduction of HMF varied from 18 to 61% due to the inhibition of sucrose pyrolytic decomposition and the fructofuranosyl cation formation. Data demonstrated that the more heat-resistant the lipid-based coating was, the more pronounced the reduction of HMF formation. The results showed that encapsulation represents a useful approach to prevent the formation of potentially harmful compounds in thermally processed foods.

Changes in antioxidant activities and physicochemical properties of Kapi, a fermented shrimp paste, during fermentation.

Changes in chemical composition, physical properties and antioxidant activities of Kapi were monitored during fermentation for 12months. DPPH (2, 2-diphenyl-1-picryl hydrazyl), ABTS (2, 2 - azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) radical scavenging activity as well as ferric reducing antioxidant power (FRAP) gradually increased as the fermentation time increased, particularly during the first 8months (P < 0.05). Thereafter, the decreases in DPPH and ABTS radical scavenging activities were observed (P < 0.05), whereas FRAP remained constant (P > 0.05). The continuous increases in ammonia nitrogen, formaldehyde nitrogen and amino nitrogen contents were noticeable within the first 8months (P < 0.05), indicating the formation of peptides and free amino acids via the hydrolysis of protein by both microbial and indigenous proteases. Browning intensity most likely caused by the formation of Maillard reaction products (MRPs) were concomitantly observed throughout fermentation, as evidenced by the decreases in lightness (L*-value), but the increases in redness (a*-value) and yellowness (b*-value). Low level of thiobarbituric acid reactive substances in Kapi was found during 12months. Antioxidant activities of Kapi were more likely governed by the low molecular weight peptides, amino acids as well as Maillard reaction products generated during fermentation.

Functional properties of Maillard reaction products of rice protein hydrolysates with mono-, oligo- and polysaccharides

The Maillard reaction was carried out under wet reaction conditions using rice protein product from limited hydrolysis to conjugate with various mono-, oligo- and polysaccharides. The Maillard reaction products (MRPs) prepared with rice protein hydrolysates at 5% degree (hydrolysed by Protease N) and dextran T20 (20 min at 100 °C) showed the greatest improvement in functionality. The solubility, emulsification activity (EA), and emulsification stability (ES) of the MRPs increased by factors of 3.5, 5.3 and 7.3 times, respectively as compared to MRPs formed with native rice proteins and dextran T20. Amino acid analysis indicated that lysine and arginine decreased significantly in the MRPs. Formation of MRPs reduced the surface hydrophobicity, which was in agreement with the change of solubility. However, further decreasing of the surface hydrophobicity resulted in lower EA and ES during the late stage of the reaction. Fluorescence analysis suggested that formation of late stage MRPs occurred after 20 min of the Maillard reaction. The molecular weight distributions showed that the functional properties of MRPs and the mechanisms of formation were affected by the peptide chain length.