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A series of Amadori compounds of glucose were prepared from glycine (G-ARP), diglycine (DiG-ARP), and triglycine (TriG-ARP), and identified by UPLC-MS/MS and NMR. The formation rate of ARPs was TriG-ARPDiG-ARPG-ARP, and their activation energies were 63.48 kJ/mol (TriG-ARP), 72.84 kJ/mol (DiG-ARP), and 84.76 kJ/mol (G-ARP), respectively, suggesting that ARP was formed more easily from small peptides than from amino acid. Although 1-DG was formed much more difficultly than 3-DG, the same order of the formation of 1-DG, 3-DG, and browning was DiGlyTriGlyGly. It was also confirmed that more methylglyoxal and glyoxal would be formed from small peptides than equimolar amino acids. Compared with free amino acid, ARP, deoxyglycosones, and their secondary degradation products were more easily formed from dipeptide and tripeptide, thereby stronger browning occurred and higher reactivity was exhibited in Maillard reaction of di- or tripeptide.

Acrylamide (AA) is a potential carcinogen formed in food rich in carbohydrate during heating. Recently, AA has been found in several fruit products, such as prune juice, sugarcane molasses and canned black olives. This study focused on the role of galacturonic acid (GalA), the main acid hydrolysis product of fruit pectin, in AA formation in three model systems - asparagine (Asn)/glucose (Glc), Asn/GalA, and Asn/Glc/GalA - during heating under different pH values (pH 3.8-7.8), Glc concentration (0-0.1 mol LThe results suggested that the addition of 0.1 mol LThe results suggested that Maillard reaction between Asn and GalA might contribute to AA formation. This study is significant in elucidating the contribution of interaction between components for AA formation in fruit products. © 2022 Society of Chemical Industry.

The present study aimed to investigate the effects of fructo-, inulin-, and galacto-oligosaccharides (FOS, IOS, and GOS) on forming the Maillard reaction products such as browning, α-dicarbonyl compounds, and advanced glycation end products (AGEs). The model solutions at pH 6.8 containing each carbohydrate (mono-, di-, and oligosaccharides) and whey protein were incubated at 50 °C for 8 weeks. In the IOS model, sugars of DP3 or larger were significantly decreased at 4 weeks, whereas at 6 weeks in the FOS model. The residual amount of GOS after 8 weeks was higher than FOS and IOS; however, a large amount of 3-deoxyglucosone was formed compared to the other models.

Pyrrole-ligated 1,3,4-oxadiazole is a very important pharmacophore which exhibits broad therapeutic effects such as anti-tuberculosis, anti-epileptic, anti-HIV, anti-cancer, anti-inflammatory, antioxidant, and antibacterial activities. A one-pot Maillard reaction between D-Ribose and an L-amino methyl ester in DMSO with oxalic acid at 2.5 atm and 80 °C expeditiously produced pyrrole-2-carbaldehyde platform chemicals in reasonable yields, which were utilized for the synthesis of pyrrole-ligated 1,3,4-oxadiazoles. Benzohydrazide reacted with the formyl group of the pyrrole platforms to provide the corresponding imine intermediates, which underwent I2-mediated oxidative cyclization to the pyrrole-ligated 1,3,4-oxadiazole skeleton. The structure and activity relationship (SAR) of the target compounds with varying alkyl or aryl substituents of the amino acids and electron-withdrawing or electron-donating substituents on the phenyl ring of benzohydrazide were evaluated for antibacterial activity against Escherichia coli, Staphylococcus aureus, and Acinetobacter baumannii as representative Gram(–) and Gram(+) bacteria. Branched alkyl groups from the amino acid showed better antibacterial activities. Absolutely superior activities were observed for 5f-1 with an iodophenol substituent against A. baumannii (MIC < 2 μg/mL), a bacterial pathogen that displays a high resistance to commonly used antibiotics.

Black garlic has many beneficial effects, and it has a less spicy flavor. However, its aging conditions and related products still need to be further investigated. The present study aims to analyze the beneficial effects under different processing conditions and utilize high-pressure processing (HPP) in the production of black garlic jam. The highest antioxidant activities, including the DPPH scavenging, total antioxidant capacity, and reducing power (86.23%, 88.44%, and A700 = 2.48, respectively), were observed in black garlic that had been aged for 30 days. Similarly, the highest total phenols and flavonoids were observed in black garlic that had been aged for 30 days (76.86 GAE/g dw and 13.28 mg RE/g dw, respectively). The reducing sugar in black garlic was significantly increased to about 380 (mg GE/g dw) after 20 days of aging. The free amino acids in black garlic were decreased time-dependently to about 0.2 mg leucine/g dw after 30 days of aging. For the browning indexes of black garlic, the uncolored intermediate and browning products were increased in a time-dependent manner and reached a plateau at day 30. Another intermediate product in the Maillard reaction, 5-hydroxymethylfurfural (5-HMF), was observed in concentrations that increased to 1.81 and 3.04 (mg/g dw) at day 30 and 40, respectively. Furthermore, the black garlic jam made by HPP was analyzed for its texture and sensory acceptance, showing that a 1:1.5:2 ratio of black garlic/water/sugar was the most preferred and was classified as “still acceptable”. Our study suggests suitable processing conditions for black garlic and outlines the prominent beneficial effects after 30 days of aging. These results could be further applied in HPP jam production and increase the diversity of black garlic products.

This article belongs to the Special Issue Processed Food: Nutrition, Safety and Public Health., Chia seed (Salvia hispanica L.) is a food rich in protein, fiber, polyunsaturated fatty acids and antioxidants. Consequently, its incorporation in food formulations may be desirable from a nutritional and healthy point of view. However, there is concern regarding the formation of process contaminants when they are subjected to thermal processing. The objective of this study was to incorporate different amounts of ground chia seeds in a biscuit model to evaluate the effect on the antioxidant capacity and formation of acrylamide and furfurals. Seven standard “Maria-type” biscuit formulations were prepared, replacing wheat flour with different amounts of ground chia seeds (defatted and non-defatted), from 0% (control biscuit) to 15% (respect to total solids in the recipe). Samples were baked at 180 °C for 22 min. Compared with the control biscuit, chia formulations increased the content of nutrients, antioxidant capacity (ABTS) and phenolic compounds (Folin–Ciocalteau method) but also doubled acrylamide levels and even raised more than 10 times furanic compound concentrations. Results indicate that the use of chia seeds as ingredients in new cereal-based formulations would improve the nutritional profile but also increase the occurrence of chemical process contaminants. This paradox should be carefully considered in the context of risk/benefit analysis., This research was funded by the Community of Madrid and European funding from FSE and FEDER programs (project S2018/BAA-4393, AVANSECAL-II-CM).

Evaluating the nutritional quality and thermal damage effects of gluten-free foods is essential to ensure that people with gluten intolerance or celiac disease can safely meet their needs. In this work, fifteen different commercial gluten-free pasta samples made from cereals, pseudocereals, and pulses, alone or in mixed combinations, were analyzed to assess their nutritional value, essential amino acids composition, and protein chemical score. The occurrence of the Maillard reaction was investigated, and the levels of heat treatment markers (furosine, maltulose, hydroxymethylfurfural, and glucosylisomaltol) were determined. Analysis of the furosine values showed that pasta made with the same raw materials can have different degrees of thermal damage. There was no evidence of the Maillard reaction progressing in the advanced phase in any of the samples tested. Finally, the correlation between maltulose and furosine levels demonstrated the usefulness of combining the two markers to assess the extent of thermal damage

Evaluating the nutritional quality and thermal damage effects of gluten-free foods is essential to ensure that people with gluten intolerance or celiac disease can safely meet their needs. In this work, fifteen different commercial gluten-free pasta samples made from cereals, pseudocereals, and pulses, alone or in mixed combinations, were analyzed to assess their nutritional value, essential amino acids composition, and protein chemical score. The occurrence of the Maillard reaction was investigated, and the levels of heat treatment markers (furosine, maltulose, hydroxymethylfurfural, and glucosylisomaltol) were determined. Analysis of the furosine values showed that pasta made with the same raw materials can have different degrees of thermal damage. There was no evidence of the Maillard reaction progressing in the advanced phase in any of the samples tested. Finally, the correlation between maltulose and furosine levels demonstrated the usefulness of combining the two markers to assess the extent of thermal damage.

Tea as the most consumed beverage in the world has received enormous attention for its promoting health benefits. The deleterious effect of α-dicarbonyls and AGEs formed in Maillard reaction is also a long-term challenge. The connection between the two topics was the main aim of this review, to address and update the antiglycation effect and mechanism of tea and tea polyphenols. By analyzing recent publications, we have covered across chemistry models, cell lines and animal studies. Tea polyphenols, particularly catechins, showed outstanding antiglycation effect by trapping α-dicarbonyl compounds and impeding AGEs formation. Reduction of carbonyl stress brought alleviation to aging, diabetes, and collagen related diseases or complications through regulation of RAGE expression and subsequent MAPK and TGF-β pathway. Therefore, tea polyphenols can serve as promising natural candidates in the treatment and/or prevention of nephropathy, retinopathy, hepatopathy, hyperglycemia and obesity among others, by their potent antiglycation effect. Further studies need to address on aspects like exact mechanisms, solution of detection obstacles, balance of practical usage and harmful effects such as potential flavor damage and toxicity in food, to gain a comprehensive understanding of antiglycation activities of tea polyphenols and its actual application.

Wildfires in forested watersheds dramatically alter stored and labile soil organic matter (SOM) pools and the export of dissolved organic matter (DOM). Ecosystem recovery after wildfires depends on soil microbial communities and revegetation and therefore is limited by the availability of nutrients, such as nitrogen-containing and labile, water-soluble compounds. However, SOM byproducts produced at different wildfire intensities are poorly understood, leading to difficulties in assessing wildfire severity and predicting ecosystem recovery. In this work, water-extractable organic matter (WEOM) from laboratory microcosms of soil burned at discrete temperatures was characterized by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry to study the impacts of fire temperature on SOM and DOM composition. The molecular composition derived from different burn temperatures indicated that nitrogen-containing byproducts were enriched with heating and composed of a wide range of aromatic features and oxidation states. Mass difference-based analysis also suggested that products formed during heating could be modeled using transformations along the Maillard reaction pathway. The enrichment of N-containing SOM and DOM at different soil burning intensities has important implications for ecosystem recovery and downstream water quality.

The possibility to reduce the acrylamide (AA) formation during cooking by treating pizza dough with L-Asparaginase enzyme was explored. Wheat flour was added with commercial enzyme Preventase® in three formulations: W, M and XR-BG during mixing to produce pizza doughs. AA content was evaluated in the obtained pizza bases through UHPLC-UV analysis. Enzymes concentration (0.15÷12 U/100 g of flour) and water content (58÷64 g/100 g of flour) during mixing were considered for pizza doughs intended for frying. In the fried pizza base, the untreated sample (without Preventase®) showed an AA level of 3150±554 µg/kgdw. Preventase® treatment was able to reduce AA up to non-detectable levels (M and W) or 89% (XR-BG). The enzymatic treatment up to 3–6 U/100 g did not affect the dough handling. Preventase® W (1.5÷6.0 U/100 g of flour), which showed the best performance in fried pizza samples, with a lower amount of enzyme and optimal dough consistency, was applied in the preparation of the wood oven baked pizza base. In these experiments, the AA level of the untreated pizza base sample was 2210±205 µg/kgdw, and the enzymatic treatment resulted in a maximum AA reduction of approximately 50%, without apparently altering the technological characteristics of the dough. Results showed that the use of L-Asparaginase could possibly play a key role in mitigating acrylamide formation in the cooking process of fried and wood oven baked pizza base.

Black soldier fly has been proposed as an alternative protein source sustainable for both food and feed due to its nutritional composition. The functional properties of this protein can be improved by inducing the Maillard reaction (MR) in protein-sugar mixtures. This study focused on the conjugation and characterisation of black soldier fly larvae (BSFL) proteins and conjugates. The defatted BSFL larvae were subjected to protein extraction at an alkaline pH. The protein extract was then conjugated with glucose. The BSFL protein and glucose were mixed at (2:1 w/w, pH 9), incubated at 50, 70, and 90 °C for 30, 60, 90 and 120 min. The products obtained were then characterised and compared. The changes were confirmed by universal attenuated total reflectance Fourier-transform infrared spectroscopy (UATR-FTIR), scanning electron microscopy, thermal gravimetric analysis and differential scanning calorimetry. UATR-FTIR combined with principal component analysis monitored the protein-sugar conjugates, to show the structural difference among heated proteins and conjugates. The heating treatments resulted in the unfolding and reduction of the protein molecule aggregation. The protein extract from the larvae was rich in protein content (67±0.78%) and displayed good essential amino acids (EAA) in sufficient quantities to meet the dietary requirements for humans. The EAA quantities of the conjugates decreased due to the MR treatment. The conjugates showed a significant decrease in the lysine content as a function of reaction temperature and time at 90 °C and 120 min, respectively. FTIR indicated that the amide I and II bands of the protein were altered by the MR. The increased Tmax (the temperature at which decomposition is completed) demonstrated that the conjugation of the protein with glucose improved the thermal stability, remarkably. These results suggested that MR with glucose can be a promising way to improve the thermal properties of BSFL protein.

The metabolic perturbations and health impact of the co-accumulation of acrylamide, harmane, and Nε-(carboxymethyl)lysine was investigated via serum biochemical and histopathological examinations as well as metabolomic analysis.

Egg white has high protein content and numerous biological/functional properties. However, the reported allergenicity for some of the proteins in the egg white is an issue that needs to be paid exclusive attention. A consideration on the structure of the IgE epitopes and their sequences as well as a comprehensive understanding of the effects of various processes on the epitopes and the impact of the gastrointestinal tract on them can help target such issues. The current study focuses on the identified IgE epitopes in the egg white proteins and evaluates the effects of gastrointestinal digestion, carbohydrate moiety, food matrix, microbial fermentation, recombinant allergen, heat treatment, Maillard reaction and combination of the various processes and gastrointestinal digestion on the egg white allergenicity. Although the gastrointestinal tract reduces the immunoreactivity of native egg white proteins, some of the IgE epitope-containing fragments remain intact during the digestion process. It has been found that the gastrointestinal tract can have both positive and negative impacts on the IgE binding activities of egg white proteins. Elimination of the carbohydrate moiety leads to a reduction in the immunoreactivity of ovalbumin. But, such effects from the carbohydrate parts in the IgE binding activity needs to be explored further. In addition, the interaction between the egg white proteins and the food matrix leads to various effects from gastrointestinal tract on the digestion of egg white proteins and their subsequent immunoreactivity. Further on this matter, studies have shown that both microbial fermentation and Maillard reaction can reduce the IgE binding activities of egg white proteins. Also, as an alternate approach, thermal process can be used to treat the egg white proteins which may result in the reduction or increase in their IgE binding activities depending on the conditions used in the process. Overall, based on the reported data, the allergenicity levels of egg white proteins can be mitigated or escalated depending on the conditions applied in the processing of the food products containing the egg white. So far, no practical solutions have been reported to eliminate such allergenicity.

β-Lactoglobulin (β-LG) is a major milk protein, making up more than 53% of the total whey proteins, and is seen as a valuable ingredient in food processing because of its high essential amino acid content and diverse functional applications. The Maillard reaction can occur during the storage and processing of food and generate various beneficial effects, including anti-allergenicity, antioxidant, and immunomodulatory effects. The addition of an β-LG-lactose conjugate (LGL) produced by the Maillard reaction was shown to have a strong immune-enhancing effect, increasing both nitric oxide generation and cytokine expression through activation of RAW 264.7 cells, even after in vitro digestion. Furthermore, daily LGL administration resulted in the upregulation of several immune markers in a cyclophosphamide-induced immunosuppressive mouse model, indicating that this treatment stimulates multiple immune cells, including macrophages, natural killer cells, and lymphocytes, enhancing the proliferation and activation of both the innate and adaptive immune responses. Taken together, these findings indicate that consuming LGL on a regular basis can improve immunity by increasing the natural production of various immune cells.

The main objective of the present study was to evaluate the variation of dependency between physical green coffee beans characteristics and thermal effects during roasting. In this work was analyzed coffee roasting process, used differential scanning colorimetry able to describe thermophysical processes inside a coffee bean during the roasting process was developed. For the analysis of thermophysical effects inside the coffee bean were explored six samples of coffee beans with different origins. The scanning colorimetry data obtained showed differences in thermal effects, the transition from an endothermic process to an exothermic one, as well as the amount of heat required for the roasting process. The analyzed humidity and density curves were then compared with the observed data. The analysis showed a direct dependency between the physical characteristics of the grain and the thermal effects during the roasting process. The present study concludes that green coffee with different properties requires the use of different strategies for the use of energy to obtain a quality product.

The model in vitro protein digestion technique has received greater attention due to providing significant advantages compared to in vivo experiments. This research employed an in vitro infant digestive static model to examine the protein digestibility of whey proteins isolate–lactose (WPI–Lac). The polyacrylamide gel electrophoresis (PAGE) pattern for alpha-lactalbumin of WPI at 60 min showed no detectable bands, while the alpha-lactalbumin of the WPI–Lac was completely digested after 5 min of gastric digestion. The beta-lactoglobulin of the WPI–Lac was found to be similar to the beta-lactoglobulin of the WPI, being insignificant at pH 3.0. The alpha-lactalbumin of the WPI decreased after 100 min of duodenal digestion at pH 6.5, and the WPI–Lac was completely digested after 60 min. The peptides were identified as ~2 kilodalton (kDa) in conjugated protein, which indicated that the level of degradation of the protein was high, due to the hydrolysis progress. The conjugated protein increased the responsiveness to digestive proteolysis, potentially leading to the release of immunogenic protein by lactose, and to the creation of hypoallergenic protein.

The study of the Maillard reaction mechanism is described. Описано дослiдження механiзму реакцiї Майяра. &nbsp

Gluten (Glu) is important to wheat products by forming a three-dimensional matrix. This study aimed to investigate the physicochemical and structural properties of gluten after conjugation with konjac glucomannan (KGM) through the Maillard reaction. The study revealed that the degree of graft increased with the prolonged reaction time. The Glu-KGM conjugates were possessed of increased β-sheet but decreased α-helix and β-turn, as well as unfolding and loose tertiary structures as the reaction proceeded. Among three different proportions, the Glu-KGM 1:1 conjugate was proved to have the most excellent foaming and emulsifying properties, and could form more rigid and firm gelation structures, which could be related to the decreased particle size and increased zeta potential of the conjugate. Overall, the physicochemical and structural properties of gluten were significantly related to the KGM ratios as well as the reaction period.

The white pulp of the Chinese water chestnut (CWC) is crisp and sweet with delicious flavours and is an important ingredient in many Chinese dishes. Phenylacetaldehyde is a characteristic flavoured substance produced in the steaming and cooking process of CWC. The steaming process and conditions were simulated to construct three Maillard reaction systems which consisted of glucose and phenylalanine, and of both alone. The simulation results showed that glucose and phenylalanine were the reaction substrates for the formation of phenylacetaldehyde. The intermediate α-dicarbonyl compounds (α-DCs) and the final products of the simulated system were detected by solid-phase microextraction (SPME) and gas chromatography–mass spectrometry (GC-MS) methods. Through the above methods the formation mechanism of phenylacetaldehyde is clarified; under the conditions of the steaming process, glucose is caramelized to produce Methylglyoxal (MGO), 2,3-Butanedione (BD), Glyoxal (GO) and other α-DCs. α-DCs and phenylalanine undergo a Strecker degradation reaction to generate phenylacetaldehyde. The optimal ratio of the amount of substance of glucose to phenylalanine for Maillard reaction is 1:4. The results can provide scientific reference for the regulation of flavour substances and the evaluation of flavour quality in the steaming process of fruits and vegetables.

To verify the priming effects of Maillard reaction precursors on the microbial decomposition of rice straw at different incubation temperatures, the method of indoor incubation at a constant temperature was adopted. In the process, the addition of glucose, catechol or glycine solution alone or in mixed solution was conducted at incubation temperatures of 10 °C, 15 °C and 28 °C, respectively. The C content of humic-extracted acid (CHLE), humification index (the ratio of C content of humic-like acid to fulvic-like acid, CHLA/CFLA), ∆logK value of humic-like acid (HLA), and C content of humin-like acid (CHLu) were dynamically analyzed at 0, 30, 60, and 90 d, respectively. At the same time, the differences in the atomic ratio and FTIR spectra before and after incubation were systematically analyzed. The results showed that (1) the additions of glucose alone and mixed precursors were both beneficial to increasing the CHLE content at three tested temperatures, especially at two low temperatures (10 °C and 15 °C), and glucose alone manifested the most significant improvement in CHLE. In contrast, following the addition of glycine alone, the CHLE content decreased by 2.4% at 15 °C and 4.6% at 28 °C after incubation. (2) Glucose as the sole precursor was more beneficial to improving the quality of the humic substance (HS) at 28 °C, but only enhanced the condensation degree of HLA molecules at 15 °C. Compared with the results at 15 °C and 28 °C, the HLA molecules had the lowest condensation degree at 10 °C, regardless of whether a single precursor or mixed Maillard precursors were used. (3) After incubation, the amounts of N compounds in the HLA molecules decreased to varying degrees, especially at 28 °C. The O-containing functional groups, such as carboxyl groups, from HLA molecules decreased following the addition of a single precursor, while the mixed precursors resulted in an increase in O-containing functional groups. Increasing the catechol content directly enriched the unsaturated bonds of HLA. With the decomposition of rice straw, regardless of how the precursors were added, the polysaccharide content decreased to different degrees. The decomposition of polysaccharides in HLA was more temperature-sensitive, and an increase in temperature might encourage more polysaccharide consumption. Under each temperature, the molecular structure of HLA was simplified initially and then gradually became complex. Finally, the addition of glucose alone at 15 °C was more favorable for the complexity of HLA molecules, while at 28 °C, it could only alleviate the degree of simplification of the HLA molecular structure to a certain extent. (4) At the three tested temperatures, compared with the CK control, either one precursor or a mixture of three precursors could more effectively promote the decomposition of CHLu. Under the conditions of 10 °C and 15 °C, the addition of mixed precursors was more beneficial to the decomposition of CHLu, causing the CHLu content to decrease by 37.9% and 44.7%, respectively, followed by the addition of glucose alone.

Spirulina protein concentrate (SPC) was extracted from Spirulina biomass and its structure and technofunctional properties were modified through Maillard reaction with maltodextrin (MD). Wet-heating route was adapted and Maillard reaction was controlled within initial to intermediate stage by avoiding or minimising the formation of melanoidins. A glycation degree of up to 29.1 % was achieved after reaction between SPC and MD, and molecular weight of the SPC increased accordingly. The solubility of SPC was improved only in the pH range around its isoelectric point after conjugation. The antioxidative property of the SPC-MD conjugate was also improved as the DPPH radical scavenging activity increased 19.7 to 30.2 %. Oil-in-water emulsion stabilised by SPC-MD conjugate produced at 6 h had significantly reduced droplet size, increased surface charge, and higher physical stability in temperature range 25-60 °C. The outcome of this research will help broaden the application of SPC in food as emulsifier and encapsulating shell material.

Thermal treatment is a key step during infant formula (IF) processing which causes protein glycation and formation of dietary advanced glycation end-products (dAGEs). This study aimed to evaluate the glycation degree in IF in relation to the ingredients of the formula. dAGEs concentrations have been determined by UPLC-MS/MS in a range of commercial cow-based, goat-based, and soy-based IF. Results indicated that the protein source, protein composition, and amount and type of carbohydrates determines the level of protein glycation in IFs. The investigated soy-based formula had significant higher concentrations of arginine and arginine-derived dAGEs than cow-based and goat-based formulas. IF containing hydrolyzed proteins had higher dAGEs concentrations than those containing intact proteins. Lactose-containing formula was more prone to glycation than those containing sucrose and maltodextrin. Data showed glycation degree in IF cannot be estimated by a single compound, but the complete picture of the dAGEs should be considered.

Different stages of infant formula (IF) products differ in their composition in terms of carbohydrate, protein and fat content, which subsequently influences their stability during storage. IF composition and processing conditions influence their physico-chemical properties which can further impact caking, Maillard browning and release of surface free fat. A good understanding of interaction of macronutrients in IF powders during storage is critical to optimize formulations that result in products with a prolonged shelf-life and enhanced bio- accessibility. This review focusses on the physical state of carbohydrates in IF powders and its influence on molecular and macroscopic changes as well as phase transitions during storage.

Presently, many studies assess allergenicity via IgE immunoblotting and IgE binding tests; however, IgE detection does not always signal the manifestation of a clinical allergy. However, the capacity of food allergens to trigger basophils makes it possible to use the in vitro functional basophil activation test (BAT) to assess allergenicity. The effect of the Maillard reaction (MR) on the allergenic potential of processed soy proteins was evaluated by two IgE binding tests (Competitive ELISA and Inhibition ImmunoCAP), a Western Blot and a functional BAT; with the aim to analyze whether the sIgE binding results correspond to the functional assay results. The results between the IgE binding tests and the functional assay were in-line for 2 of the 6 studied patients. For one patient there was no correlation between any of the results. For the raw soy protein extract heated with glucose for 10 and 30 min (SH SPE + Glu and LH SPE + Glu, respectively), the results were in-line for only 3 out of the 6 patients. Thus, the present study shows a discrepancy between IgE binding tests and basophil stimulation when assessing the effect of soy processing on its allergenicity. Since IgE-binding capacity does not always correlate to IgE cross-linking capacity, the conclusions of the allergenic potential based on the IgE binding tests alone should be drawn with care and further studies on this matter would benefit from the inclusion of a functional assay such as the BAT.

The chemical properties and quality of milk powder and reconstituted milk can be changed by preheating treatment during milk powder processing. The effect of preheating conditions (low-temperature pasteurization [LT], high-temperature pasteurization [HT], extended shelf-life [ESL], ultra-high-temperature [UHT], and in-container sterilization [CS]), on furosine, furfural compounds, and advanced glycation end products were investigated in milk powders and reconstituted milk. The results revealed that Maillard reaction indicators were affected by preheating intensity; contents of furosine, 5-hydroxymethylfurfural (HMF), 2-furfural, Nε-(carboxymethyl)lysine (CML), and Nε-(carboxyethyl)lysine (CEL) increased, whereas lysine and 5-methyl-furfural (MF) decreased in both milk powder and reconstituted milk with an increase in the intensity of preheating. CML and CEL contents in reconstituted milk increased by 1.7- to 2.4-fold and 1.3- to 1.6-fold, respectibely. The content of CML and CEL in high-preheating powders was 11%-34% and 18%-123% higher than that in LT samples, respectively. Compared with milk powder, furosine was reduced by 22%-55% and MF by 57%-69% in reconstituted milk; HMF increased by 12%-52%, CML and CEL increased 1.7-2.4 times and 1.3-1.6 times, respectively. A superposition effect was observed between preheating intensity and heat process times, which increased the content of Maillard reaction products. PRACTICAL APPLICATION: Our findings revealed the promotion effect of higher preheating conditions on Maillard reaction indicators in milk powder and reconstituted low-temperature pasteurized milk. The results will help reduce some of the harmful Maillard reaction indicators (e.g., advanced glycation end products) formed during heat processing and assist customers in selecting dairy products with low amounts of Maillard reaction products.

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This study was aimed to investigate the structural and immunological properties of parvalbumin from mandarin fish during the Maillard reaction. The microwave-assisted the Maillard reaction was optimized by orthogonal designed experiments. The results showed that the type of sugar and heating time had a significant effect on the Maillard reaction (p < 0.05). The SDS-PAGE analysis displayed that the molecular weight of parvalbumin in mandarin fish changed after being glycated with the Maillard reaction. The glycated parvalbumin was analyzed by Nano-LC-MS/MS and eleven glycation sites as well as five glycation groups were identified. By using the indirect competitive ELISA method, it was found that microwave heating gave a higher desensitization ability of mandarin fish parvalbumin than induction cooker did. In vitro gastric digestion experiments showed that microwave-heated parvalbumin was proved to be digested more easily than that cooked by induction cookers. The microwave-assisted Maillard reaction modified the structure of parvalbumin and reduced the immunoreactivity of parvalbumin of mandarin fish.

An electronic nose (E-Nose) and gas chromatography-ion mobility spectrometry (GC-IMS) were used to analyze the volatile flavor compounds (VFCs) of the enzymatic hydrolysate of Lanmaoa asiatica and its Maillard reaction products (MRPs). E-Nose sensors have strong response signals to sulfide, nitrogen oxides, alcohols, and aldehyde ketone, and the aroma profile was increased after the Maillard reaction (MR). According to GC-IMS, A total of 84 known compounds were identified. Aldehydes, ketones and alcohols are the main VFCs. After MR, the concentrations of some alcohols decreased, and the concentration of pyrazines and ketones increased. Principal component analysis (PCA) and similarity analysis showed that the enzymatic hydrolysate and MRPs were different and could be effectively distinguished. In conclusion, this study clarified the changes in VFCs before and after the MR. The results can provide a theoretical basis for the quality control and flavor changes during the processing of Lanmaoa asiatica and provide a new method for flavor analysis of edible mushrooms and their products.

Compared to the method of aqueous Maillard reaction at atmospheric pressure tandem vacuum concentration, a coupling dehydration method combining spray drying and vacuum drying was used to increase aspartic acid-xylose conversion to the Amadori rearrangement product (ARP). The water activity and moisture states were found as effective indicators to characterize the degree of dehydration of Maillard reaction intermediates and efficient formation of ARP. During the vacuum drying process, the water activity of the product powder decreased significantly. Because the formation of ARP was accompanied by intramolecular dehydration, combining spray drying and vacuum drying increased the proportion of bound water in the vacuum-dried product. Free water was easily dissipated via dehydration, which then converted the immobilized water continuously to free water, and the decreased immobilized water further converted the bound water to immobilized water. The reduction in bound water contributed to the intramolecular dehydration of N-substituted d-xylosamine, which would further be transformed to be the ARP through an intramolecular rearrangement. The yield of ARP was increased from 1.68 to 21.53% after spray drying. The ARP yield was substantially increased up to 77.9% by subsequent vacuum drying.

In this study, three kinds of Maillard reaction products (MRPs) have been, for the first time, successfully prepared by conjugating soy protein isolate (SPI) with isomaltooligosaccharide, xylooligosaccharide, or galactooligosaccharide at 80 °C for 30 or 60 min and applied for the construction of Lactobacillus casei (L. casei) microcapsules. The results showed that MRPs exhibited enhanced antioxidative activities compared with their physically mixed counterparts. The digested MRPs displayed excellent resistance to pathogenic bacteria and promoted the growth of L. casei. Moreover, MRP-encapsulated L. casei showed a higher survival rate than free L. casei under tested adverse conditions including heat treatment, storage, and mechanical forces. Under simulated digestion conditions, the viability of L. casei decreased from 8.8 log cfu/mL to 1.6 log cfu/mL, while that of MRP-encapsulated L. casei was maintained at 7.4 log cfu/mL. Thus, MRP-based SPI-oligosaccharide conjugates exhibited great potential for microencapsulation of probiotics.

This study integrates the complex research conducted on the sources of brown discolorations that occur on marble statues (fifteenth century) of the Church of Orsanmichele in Florence (Italy). They underwent conservative interventions in the past and the brownish discolorations on their surfaces strongly altered the clear tone of the marble. In this study, Carrara marble model specimens were treated with organic and inorganic substances (non-pasteurised milk; linseed oil; walnut oil; ammonium oxalate; microcrystalline wax; beeswax; milk + linseed oil; and milk + ammonium oxalate + linseed oil) to simulate their effects on the stone. Some of the substances were commonly used in the past (as on the Orsanmichele statues) but most of them are still used in many countries. The treated specimens were exposed to natural and artificial ageing. The main results of the research were (i) the specimens treated with linseed oil, milk + linseed oil, and milk + linseed oil + ammonium oxalate showed a severe change of colour after either artificial or natural ageing; (ii) an extensive polymerisation of the organic substances occurred; (iii) calcium oxalate and several oxidised diacylglycerols (DAGs) and triacylglycerols (TAGs) were the last chemical products of the oxidation processes induced by ageing; (iv) Maillard reaction, producing brownish coloration, likely occurred in specimens containing milk as a result of the interaction between sugars and proteins.

BACKGROUND The consumption of dietary Maillard reaction products (MRPs) might lead to positive or negative effects on health. The digestibility of half-fin anchovy hydrolysates/glucose MRPs (HAHp(9.0)-G MRPs) was therefore determined. The intestinal microbiota modulation of HAHp(9.0)-G MRPs in mice was also evaluated after administration for 14 days (1 g kg-1 •bodyweight). RESULTS Different levels of digestibility of MRPs of fructosamine and advanced glycation products of Ne -carboxymethyllysine were detected in HAHp(9.0)-G MRPs during simulated gastrointestinal digestion. An increased relative proportion of soluble fluorescent melanoidins (SFMs) was observed during gastric digestion as compared to that in the original HAHp(9.0)-G MRPs, followed by decreases in SFMs in intestinal digestion. After feeding with HAHp(9.0)-G MRPs for 14 days, increased goblet cells were observed in the ileum regions of female and male mice. High-throughput 16S ribosomal RNA gene sequencing of fecal samples revealed that HAHp(9.0)-G MRPs administration increased the density of the phylum Bacteriodetes and reduced the density of the phylum Firmicutes in male mice. By comparison, a relatively higher density of members of the phylum Saccharibacteria was observed in female mice. A consistent increase in the abundance of Bacteroidales_S24-7_group_norank was found in female and male groups fed with HAHp(9.0)-G MRPs. Female and male mice treated with HAHp(9.0)-G MRPs also showed higher levels of propionic and butyric acids in feces than their corresponding controls. CONCLUSION Half-fin anchovy hydrolysates/glucose MRPs can be partly hydrolyzed in the simulated gastrointestinal digestion system. Treatment with HAHp(9.0)-G MRPs induced sex-related differences in bacterial abundance and diversity in mice; however, the up-regulation of anti-inflammatory activity was predicted in both female and male mice. © 2021 Society of Chemical Industry.

Oxidative deterioration of vegetable oils is of great importance in the food industry. In China, vegetable oils produced via thermal pretreatment are popular owing to their strong oil flavor and enhanced yield. Here, we review: (i) the currently employed thermal treatment methods of oilseeds before oil extraction; (ii) effects of thermal treatments on the physicochemical properties, contents of minor lipid components, and oxidative stability of vegetable oils; and (iii) Maillard model systems that are related to oil and oilseed chemistry. Among the thermal pretreatment technologies, microwave and infrared radiations are promising, but these are not performed on the same large production scales as roasting. For most oilseeds, thermal treatments increase the yield of extracted oil and content of minor lipid compounds in the oil, such as polyphenols, tocopherols, and phytosterols. In addition, some Maillard reaction products (MRPs) generated by heating oilseeds have been extracted. The presence of both minor lipids and MRPs in the oil confers improved oxidative stability. However, the mechanism or relationship between thermal treatment and oxidative stability is yet to be clearly elucidated because vegetable oil oxidation is dependent on variables such as unsaturation, concentration and types of minor lipid components, MRPs, and the potential synergistic effects of these components. Recently, several Maillard reaction models related to thermally treated oilseeds have been established, suggesting that MRPs play a critical role during oxidation. However, comprehensive identification of antioxidants and the mechanism by which they inhibit oxidation are lacking. Future research can be performed to establish models that would help elucidate the antioxidative mechanisms of MRPs for more oilseeds. Using these models, it will be possible to predict the oil quality after processing, based on the presence of MRPs and oil chemistry.

Our objective was to elaborate lactose-free Dulce de leche (DL) and evaluate the influence of the hydrolysis of this sugar on the attributes of the products. Fluid milk used was divided into two portions and, in one of them, enzymatic hydrolysis of lactose was carried through. Next, the homogenization of milk was performed at 20 MPa. Four different treatments were studied. The final products were evaluated in relation to their composition and physico-chemical characteristics. The main results show that the homogenized lactose-free DL obtained a higher concentration of free 5-Hydroxymethylfurfural (HMF) (133.77 ± 3.42 μmol l−1). Consequently, browning was more intense due to Maillard Reaction. Texture parameters were higher (1611.00 ± 598.78 g hardness and 19.52 ± 2.46 g gumminess) when compared to the homogenized traditional product (28.45 ± 1.16 μmol l−1 free HMF, 437.17 ± 279.3 g hardness, and 406.20 ± 311.69 g gumminess). Lactose-free products are in high demand by consumers; however, the results of this work highlight the challenges to properly control the browning and the texture parameters of DL.

In recent years, a growing number of studies have demonstrated that protein hydrolysates have interesting functional properties and a strong antioxidant capacity, amongst other important bioactivities. In this work, the potential of subcritical water (ScW) to efficiently extract bioactive protein hydrolysates contained in brown crab shell residues was evaluated. Aiming at maximizing the extraction of the target molecules, the impact of operating temperature (150, 200, and 250 °C), solid/liquid ratio (1:5, 1:10, and 1:15 g/mL), and heating rate (3 and 6 °C/min) on ScW extraction performance was assessed. Extracts were then evaluated in terms of total protein content, Maillard reaction products formation, free amino acid profile, and antioxidant potential through oxygen radical absorbance capacity assay. Results have shown that, although an increase in operating temperature allowed a significant increase in global extraction yields, there was a slight decrease (approximately 1.4-fold) in the extraction selectivity towards proteins. Nevertheless, higher temperatures enabled the production of extracts with a higher antioxidant potential, possibly due to an increase of smaller peptides/free amino acids and Maillard reaction products. Therefore, the study reported herein reinforces that ScW represents a viable sustainable alternative extraction media for the recovery of protein hydrolysates from shellfish biomass, with potential to be used as ingredients in industrial applications.

The occurrence of water-soaked brown flesh in pear fruit is closely related to an activated biological Maillard reaction during the latter half of maturation. In this study, samples of immature and mature pear fruits were assessed for the incidence of water-soaked brown flesh (WSBF), sugar content, expression level of sugar metabolism-related genes, and activity of the Maillard and oxidative stress reactions. The occurrence of WSBF disorder was rare in immature fruit, but was pronounced in mature fruit. Glucose content of the flesh was higher in mature fruit with WSBF than in immature fruit without WSBF. Conversely, sucrose content was inversely correlated to glucose content. Higher levels of the neutral invertase gene (PpNIV) were detected in mature fruit compared with immature fruit. Levels of oxidative stress and Maillard reaction products in the flesh of mature fruit were determined. The strongest Maillard and oxidative stress reactions were observed in cells adjacent to the vascular bundle, and these reactions diminished with distance from the vascular bundle. Furthermore, examination of cells near the vascular bundle revealed stronger signal intensity on the phloem side compared to the xylem side. Cellular examination of the phloem side of immature and mature fruits indicated that mature fruit had a stronger signal intensity than immature fruit in both reactions. These results suggest that an increase in the Maillard reaction, attributed to an increased concentration of reducing sugars, during the maturation period may be fundamentally involved in the occurrence of this disorder through oxidative stress.

Glycation and caramelization reactions in malt lead to the formation of 1,2-dicarbonyl compounds, which come in contact with yeast during fermentation. In the present study, the metabolic fate of 5-hydroxymethylfurfural (HMF) and 1,2-dicarbonyl compounds (3-deoxyglucosone, 3-deoxygalactosone, 3-deoxypentosone, 3,4-dideoxyglucosone-3-ene) was assessed in the presence of Saccharomyces cerevisiae. HMF is degraded very fast by yeast with the formation of 2,5-bis(hydroxymethyl)furan (BHMF). By contrast, only 7-30% of 250 μM dicarbonyl compounds is degraded within 48 h. The respective deoxyketoses, 3-deoxyfructose (3-DF), 3-deoxytagatose, 3-deoxypentulose, and 3,4-dideoxyfructose, were identified as metabolites. While 17.8% of 3-deoxyglucosone was converted to 3-deoxyfructose, only about 0.1% of 3-deoxypentosone was converted to 3-deoxypentulose during 48 h. Starting with the parent dicarbonyl compounds, the synthesis of all deoxyketose metabolites was achieved by applying a metal-catalyzed reduction in the presence of molecular hydrogen. In a small set of commercial beer samples, BHMF and all deoxyketoses were qualitatively detected. 3-DF was quantitated in the four commercial beer samples at concentrations between 0.4 and 10.1 mg/L.

The objective of this study was to analyze the effects of phytochemical parameter, physical parameter, color, and sensory analysis in green capsicum by different drying processes (microwave, freeze, and hot air drying). Results showed an increase in microwave output power (600W), decreased drying time, moisture content, Chroma, and bulk density values. The Freeze drying process significantly improved the lightness of dried capsicum. Due to take less time for the Microwave drying technique, phytochemical parameters are intact in capsicum; on the other side, color degradation has been occurred due to the Maillard reaction (L*=29.34±0.08, a*=6.98±0.09,b*=15.36±0.10). Bulk density (0.335±0.01) and dispersibility (40±2.00%) were highest in Microwave drying powder. The capsaicin content of dried capsicum was higher than the fresh capsicum sample, but compared to the different drying techniques, the Microwave drying sample has higher capsaicin content than the Hot air drying and Freeze-drying samples. The lower capsaicin content in fresh capsicum may occur due to the catalytic activity of the peroxidase enzyme. The capsaicin content of all dried capsicum varied between 1.91±0.05 and 3.31±0.16 mg/100 g. In this research, the Microwave drying powder of capsicum was the best product for its highest antioxidant content and other physical properties.

The Maillard reaction, a spontaneous 'one pot' reaction between amino acids and reducing sugars that occurs at low reactant concentrations and low temperatures, is a good candidate for having played a role in the origin of life on the Earth. In view of the probability that RNA and DNA were preceded by an evolutionary forerunner with a more straightforward prebiotic synthesis, it is a testament to the prescience of Oro and colleagues that, in 1975, they drew attention to the Maillard reaction, in particular evidence that melanoidin polymers (the end-product of the reaction) contain '…heterocyclic nitrogen compounds similar to the nitrogenous bases' (Nissenbaum in J Mol Evol 6:253-270, 1975). Indeed, reports of the Maillard reaction product, 2-Acetyl-6-(Hydroxymethyl)-5,6-Dihydro-4H-Pyridinone (AHDP), with a structure reminiscent of the pyrimidine nucleobase uracil, suggest the Maillard reaction might have played a key role in the synthesis of components of a proto-RNA polymer, with AHDP and two structurally related products predicted to be similar to uracil in the latter's ability to form non-standard base pair interactions. It is possible that the primary function of these interactions was to allow molecules such as AHDP to separate out of the prebiotic chemical clutter. If this were the case, catalysis, and coding-made possible by the polymerization of proto-nucleoside monomers into linear sequence strings-would have been evolving properties.

Objective: Pork belly is considered as the most commercially important and preferable primal cut by consumers worldwide. Thus, this study was conducted to determine the effects of fat levels on the meat quality characteristics of pork bellies.Methods: Seventy-eight growing-finishing pigs collected from different commercial pig farms were slaughtered and used in the present study. After slaughter 24 h, bellies were fabricated according to the Korean Pork Cutting Specification, and immediately sampled for analysis of their fat content. Based on the fat levels, the bellies were segregated into three different groups: low fat (LF, fat ≤20%, n = 15), medium fat (MF, fat 21% to 30%, n = 30), and high fat (HF, fat ≥31%, n = 33). The bellies were then analyzed for meat quality traits, fatty acids, flavor compounds and eating quality properties.Results: The HF group had lower moisture and cooking loss levels compared to the other groups (p

Limosilactobacillus reuteri was encapsulated using Maillard-reaction-products (MRPs) of soy protein isolate (SPI) and α-lactose monohydrate by freeze-drying. The mixed solution of SPI and α-lactose monohydrate was placed in a water bath at 89°C for 160 min for Maillard reaction, and then freeze-dried to obtain MRPs. The effects of Maillard reaction on functional characteristics of MRPs and the properties of MRPs-microcapsules were studied. SDS-PAGE indicated that SPI subunit reacted with lactose to form a polymer, and the band of MRPs disappeared around the molecular weights of 33, 40, 63, and 100 kDa. Compared with SPI, the emulsion stability, emulsion activity, foaming capacity, foam stability, and gel strength of MRPs were increased by 259%, 55.71%, 82.32%, 58.53%, and 3266%, respectively. The results of Fourier transform infrared spectroscopy, circular dichroism spectroscopy, and scanning electron micrographs confirmed that the protein structure also changed significantly. Then, MRPs were used as wall material to prepare L. reuteri microcapsules. Physical properties and viable counts of L. reuteri during the simulated gastrointestinal digestion and storage period were determined. The particle size of MRPs-microcapsules (68 μm) was smaller than that of SPI-microcapsules (91 μm). The viable counts of L. reuteri in simulated gastrointestinal digestion and after storage for 30 days were improved. The modifications with Maillard reaction can improve emulsification, foaming, and gel strength of SPI, and MRPs could be used as a new type of wall material in the production of L. reuteri microcapsules.

The occurrence of nonenzymaticbrowning in fruit juices during storage is a major quality defect. It negatively affects consumer acceptance and consumption behavior and determines the shelf-life of these products. Although nonenzymatic browning of fruit juices has been the subject of research for a long time, the exact mechanism of the nonenzymatic browning reactions is not yet completely understood. This review paper aims to give an overview of the compounds and reactions playing a key role in nonenzymatic browning during the storage of fruit juices. The chemistry of the plausible reactions and their relative importance will be discussed. To better understand nonenzymatic browning, factors affecting these reactions will be reviewed and several strategies and methods to evaluate color changes and browning will be discussed. Nonenzymatic browning involves three main reactions: ascorbic acid degradation, acid-catalyzed sugar degradation, and Maillard-associated reactions. The most important NEB pathway depends on the matrix. Nonenzymatic browning is affected by many factors, such as the juice composition, the pH, the oxygen availability (packaging material), and the storage conditions. Nonenzymatic browning can thus be considered as a complex problem. To characterize color changes and browning and obtain insight into the browning mechanism of fruit juices, food scientists applied several approaches and strategies. These included the use of model systems with/without the addition of labeled compound and real systems as well as advanced analytical methods. ispartof: COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY vol:20 issue:6 pages:5698-5721 ispartof: location:United States status: published

Despite more than 100 years of research, formation of food melanoidins from carbohydrates and amino acids in the course of the Maillard reaction is still not fully understood. Experiments with relevant precursors are commonly used to limit the pathways of the complex reaction and to elucidate the formation mechanisms of the colored end-products. Here as a simple model, methylglyoxal was incubated with l-alanine or l-lysine in aqueous solutions at 100 °C and pH 5. The reaction mixtures were analyzed for color formation, molecular weight distribution, and conversion of methylglyoxal. High-resolution mass spectrometry was used to characterize the variety of products formed. With the help of Kendrick and van Krevelen analyses, the complex data sets were investigated for common substructures and reaction patterns. This study revealed that methylglyoxal forms oligomers via aldol reaction under involvement of its prevalent reaction products such as formaldehyde, acetaldehyde, acetol, and aminoacetone with amino acids.

The bitterness of foodstuffs is often associated with toxicity, which negatively influences product acceptability. However, bitter compounds have many benefits, and a slight bitter taste is sometimes favored. In this review, we summarize the methods used to isolate and evaluate the taste of bitter compounds in different foods. The chemical structures and threshold concentrations of these compounds are also recapped. Although the structures and thresholds of many bitter compounds have been confirmed, further studies are needed to develop detailed bitter-masking strategies and establish the relation between functional groups (hetero-cyclic substituents and bonding types) and taste quality. Furthermore, a comprehensive bitterness database and chemometric data must be provided in order to quickly assess the bitterness of unfamiliar products.