Maillard Reaction Products Research Articles

Identifying the structures and taste characteristics of two novel Maillard reaction products in tea

Maillard reaction products (MRPs) produced during thermal processing of tea are intimately related to its flavor. Our recent work revealed that both levels of l-theanine and d-galacturonic acid in tea leaves decreased dramatically during drying, whereas the specific MRPs from l-theanine and d-galacturonic acid remain elusive. Here, the MRPs formed from l-theanine and d-galacturonic acid were investigated and their taste characteristics and the involved mechanisms were explored. Two novel MRPs from l-theanine and d-galacturonic acid were identified as 1-(1-carboxy-4-(ethylamino)-4-oxobutyl)-3-hydroxypyridin-1-ium (MRP 1) and 2-(2-formyl-1H-pyrrole-1-yl) theanine (MRP 2). MRP 1 and MRP 2 accumulated in dark tea and black tea and were associated with sour (threshold, 0.25 mg/mL) and astringent tastes and an umami taste (threshold, 0.18 mg/mL), respectively. Molecular docking revealed that the taste characteristics of MRPs may be due to strong binding to umami taste receptor proteins (CASR, T1R1/T1R3) and the sour taste protein OTOP1 via hydrogen bonds and hydrophobic interactions.

Selected Maillard Reaction Products and Their Yeast Metabolites in Commercial Wines.

During beer and wine production, Maillard reaction products (MRPs) are formed, which have a particular influence on the taste and aroma of the fermented beverages. Compared to beer, less is known about individual Maillard compounds and especially corresponding yeast metabolites in wine. In this study, 36 selected wines (Amarone, Ripasso, red, and white wines) were analyzed by HPLC-UV and GC-MS concerning the amounts of 3-deoxyglucosone (3-DG), 3-deoxygalactosone (3-DGal), methylglyoxal (MGO), glyoxal (GO), 5-hydroxymethylfurfural (HMF), and furfural (FF). 3-DG was found to be the dominant compound with values from 3.3 to 35.1 mg/L. The contents of 3-DGal, MGO, GO, HMF, and FF were in a single digit range. In addition to MRPs, the yeast metabolites originating from 3-DG, namely, 3-deoxyfructose and 3-deoxy-2-ketogluconic acid, 2,5-bis(hydroxymethyl)furan and 5-formyl-2-furancarboxylic acid, both formed from HMF, and the FF metabolites furfuryl alcohol and furan-2-carboxylic acid were detected and quantitated in wines for the first time. The amounts were between 0.1 and 53.5 mg/L with especially high contents of the oxidation products. Differences between red and white wines indicate that enological parameters like grape variety, production method, and aging may have an influence on the MRP contents in wines.

Maillard reaction products of pea protein hydrolysate as a flavour enhancer for beef flavors: Effects on flavor and physicochemical properties.

This study evaluated the effects of Maillard reaction products of pea protein hydrolyzates (MRPs-PPH) as salt-reducing and umami-enhancing components on the flavor and physicochemical properties of beef flavors. The addition of MRPs-PPH reduced the brightness of beef flavors, increased the redness and yellowness, as well as changed the texture characteristics of beef flavors. With the addition of MRPs-PPH, the apparent viscosity, storage modulus and loss modulus of beef flavors decreased. Finally, the relationship between taste attributes and flavor compounds of the samples was analyzed by Partial Least Squares Regression (PLSR), and flavor compounds with significant positive contributions to different taste attributes were found. This study showed that MRPs-PPH could be used as a flavor enhancer derived from biomacromolecules with salt reduction and freshness enhancement.

Formation of whey protein isolate–dextran conjugates by Maillard reaction with ethanol-water pretreatment

A simple, efficient, and low-cost Maillard reaction method was developed through ethanol-water pretreatment. The formation of whey protein isolate (WPI)–dextran conjugates was confirmed using the degree of glycosylation, ultraviolet absorbance, browning intensity, color, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The significant conformational changes were illuminated because of the higher wavenumber shift of absorption peaks of FTIR amide I, II, and III bands, the reduction of fluorescent signal, and the decrease of surface hydrophobicity. Scanning electron microscopy revealed the morphological transition of WPI from a smooth sphere to an inhomogeneous block structure with rough and uneven surface before and after covalent grafting of dextran. The strong steric hindrance and abundant hydrophilic hydroxyl groups from covalently conjugated dextran dramatically inhibited the aggregation between conjugate molecules which exhibited low turbidity and good solubility in a wide pH range from 2.0 to 10.0. Emulsifying activity and emulsifying stability of WPI were significantly improved after glycosylation. This work will be beneficial to control the formation of light-colored Maillard reaction products under high substrate concentration, high reaction rate, and low water content at mild temperatures for short processing time, and to facilitate the large-scale preparation of glycosylated protein with desirable physicochemical properties.

Sustainable valorization of pitaya (Hylocereus spp.) peel in a semi-continuous high-pressure hydrothermal process to recover value-added products

This study evaluated the use of a semi-continuous high-pressure hydrothermal process for the recovery of value-added products from pitaya peel. The process was carried out at 15 MPa, a water flow rate of 2 mL/min, a solvent-to-feed ratio of 60 g water/g pitaya peel, and temperatures ranging from 40 to 210 °C. The results show that extraction temperatures (between 40 and 80 °C) promoted the recovery of betacyanin (1.52 mg/g), malic acid (25.6 mg/g), and citric acid (25.98 mg/g). The major phenolic compounds obtained were p-coumaric acid (144.63 ± 0.42 µg/g), protocatechuic acid (91.43 ± 0.32 µg/g), and piperonylic acid (74.2 ± 0.31 µg/g). The hydrolysis temperatures (between 150 and 210 °C) could produce sugars (18.09 mg/g). However, the hydrolysis process at temperatures above 180 °C generated Maillard reaction products, which increased the total phenolic compounds and antioxidant activity of the hydrolysates. Finally, the use of semi-continuous high-pressure hydrothermal process can be a sustainable and promising approach for the recovery of value-added compounds from pitaya peel, advocating a circular economy approach in the agri-food industry.

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.

Effect of amino compounds on the volatile compounds and antioxidant activity of Maillard reaction products of enzymatic hydrolyzed cabbage leaves

Different Maillard reaction model mixtures based on hydrolyzed cabbage leaves waste protein supplemented with different amino compounds (cysteine, thiamine and / or alanine) were used to explore the effect of each amino compound on the characteristics of the generated Maillard reaction products (MRPs). A comparative study was carried out between MRPs of the model mixtures in terms of odour sensory characteristics, SPME-GC–MS analysis of the headspace volatiles, browning intensity and antioxidant activity. The results revealed that omission of one amino compound from the model mixtures led to significant variations in the volatile compounds, browning intensity and odour profile of the MRPs. Omission of cysteine resulted in 25.00% and 30.83% decrease in the thiol containing compounds and antioxidant activity, respectively. While, omission of alanine led to a significant decrease in pyrazines and furans (75% and 100%, respectively), browning intensity and an increase in content of the thiol compounds and antioxidant activity of MRPs.

Evaluation of different sugars for glycation modifications of chitosan to improve its functionality for food preservation

The modification of chitosan's amino groups through the Maillard reaction (MR) presents a pioneering approach to enhance its functional and biological properties. The present study aimed to understand the association between sugar-specific glycation-induced modifications and Chitosan-based Maillard Reaction Products (CMRPs) functionality. CMRPs were prepared by treating chitosan (CHO) with different saccharides, namely fructose (Fru), galactose (Gal), glucose (Glc), lactose (Lac), maltose (Mal), and methylglyoxal (MGO) at 80 °C for 6 h. These CMRPs were characterized by assessing 1) glycation markers, 2) structural modifications, and 3) functional properties. CMRPs formation was higher in aldohexoses (Gal, Glc) as compared to ketohexose (Fru) and disaccharides (Mal and Lac). Notably, fructosamine content, carbonyl adducts, and β-amyloid aggregates were highest in Gal CMRPs (46 mM/mg, 52 mM/mg, 6 M/mg) and Glc CMRPs (45 mM/mg, 15 mM/mg, 3 M/mg). Furthermore, MR of chitosan with aldohexoses at 100 °C for 8 h accelerated CMRPs synthesis with improved emulsifying activity, surface hydrophobicity, antioxidant potential, and substantial gel formation. The thermogravimetric analysis assessed the thermal stability and residual weight, while field emission scanning electron microscopy revealed a compact, nonporous morphology compared to chitosan alone. FTIR and HPLC analysis confirmed the structural changes, primarily due to the binding of the carbonyl group of sugars with the NH2 group of chitosan. Differential scanning calorimetry of CMRPs indicated shifts in peak temperatures and endothermic transitions in terms of enthalpy. Overall, Glc CMRPs exhibited improved functional, thermal, antioxidant, and emulsifying properties indicating their potential application in food preservation and packaging.

Influence of hot-air and infra-red pretreatments on oxidative stability, physicochemical properties, phenolic and fatty acid profile of white and black chia seed (Salvia hispanica L.) oil

In this research, the effect of hot-air (HAP) and infra-red (IRP) pretreatments at 160 and 180˚C for the time duration of 5, 10, and 15 min on the physicochemical characteristics, phenolic composition, and stability attributes of white (WCO) and black chia seed oil (BCO) were investigated. The WCO and BCO exhibited comparable physicochemical and stability characteristics while the level of phenolic compounds was higher in BCO. The phenolic acids, flavonoids, pigments, oxidative stability, Maillard reaction products, browning index, ΔE and a* value increased significantly while L*, b*, chroma and hue values decreased significantly at higher HAP and IRP exposure duration and temperature. The hydroxybenzoic (protocatechuic, vanillic, and syringic acid), hydroxycinnamic (p-coumaric, chlorogenic, sinapic, and rosmarinic acids) acids and flavonoids (epicatechin, vitexin, rutin, myricetin, luteolin, and apigenin) were highest in oil after HAP at 180°C for 15 min. The infra-red spectral information relates to oxidation and fatty acid composition of pretreated CO. HAP is more effective than IRP for improving oil yield, oxidative stability, and phenolic profile of CO.

The Effect of Free and Protein-Bound Maillard Reaction Products N-ε-Carboxymethyllysine, N-ε-Fructosyllysine, and Pyrraline on Nrf2 and NFκB in HCT 116 Cells.

Maillard reaction products (MRPs) are believed to interact with the receptor for advanced glycation endproducts (RAGE) and lead to a pro-inflammatory cellular response. The structural basis for this interaction is scarcely understood. This study investigates the effect of individual lysine modifications in free form or bound to casein on human colon cancer cells. Selectively glycated casein containing either protein-bound N-ε-carboxymethyllysine (CML), N-ε-fructosyllysine (FL), or pyrraline is prepared and up to 94%, 97%, and 61% of lysine modification could be attributed to CML, FL, or pyrraline, respectively. HCT 116 cells are treated with free CML, pyrraline, FL, or modified casein for 24h. Native casein is used as control. Intracellular MRP content is analyzed by UPLC-MS/MS. Microscopic analysis of the transcription factors shows no activation of NFκB by free or protein-bound FL or CML, whereas casein containing protein-bound pyrraline activates Nrf2. RAGE expression is not influenced by free or casein-bound MRPs. Activation of Nrf2 by pyrraline-modified casein is confirmed by analyzing Nrf2 target proteins NAD(P)H dehydrogenase (quinone 1) (NQO1) and heme oxygenase-1 (HO-1). Studies on the biological effects of glycated proteins require an individual consideration of defined structures. General statements on the effect of "AGEs" in biological systems are scientifically unsound.

Structure and flavor characteristics of Maillard reaction products derived from soybean meal hydrolysates-reducing sugars

In this study, the structure and flavor characteristics of soybean meal hydrolysates-reducing sugars Maillard reaction products (MRPs) were evaluated. Sugars added to the soybean meal enzymatic hydrolysates increased the Maillard reactivity in the following order: hexose < pentose. Results indicated that the intrinsic fluorescence intensity of MRPs increased, whereas the absorption peak intensity of the infrared spectrum changed significantly. Molecular weight analysis results showed that the MRPs were mainly distributed between 128-500 and 500–1000 Da. Furthermore, the bitter amino acid content (9.29 mg/g) and umami amino acid content (3.60 mg/g) were relatively high in ribose-MRPs. The umami, richness and bitterness values of pentose-MRPs were higher than those of hexose-MRPs. Moreover, the analysis of volatile substances showed that the ribose-MRPs presented a stronger caramel aroma, nutty flavor, and grilled meat flavor.

Screening, identification and control of unknown estrogen-like compounds in Maillard reaction products of glucose-arginine/lysine model systems

It was speculated that estrogen-like compounds may be produced by chemical reactions during food processing, such as Maillard reaction, which would disrupt the endocrine system of organisms. Herein, the Maillard reaction in the process of high temperature for long time was simulated by using model system, and unknown estrogen-like compounds produced during Maillard reaction were screened by colorimetric assay based on dual estrogen receptor (ER)-gold nanoparticles (AuNPs) and enzyme-linked immunosorbent assay (ELISA). Possible structures of estrogen-like compounds were inferred by ultra-performance liquid chromatography-quadrupole time of flight tandem mass spectrometry (UPLC-QTOF/MS) in combination with a mass database, and finally the structure of estrogen-like compound, 2, 4-dihydroxy-1, 4-benzoxazin-3-one-2-o-β-D-glucopyranoside (DIBOA-glc), was identified by high resolution orbitrap mass spectrometry (Orbitrap HRMS). This is the first study of the screening and identification of unknown estrogen-like compounds produced in Maillard reaction. Additionally, strategy of controlling the formation of DIBOA-glc by adding vitamin B6 in Maillard reaction was proposed, providing effective proposals for the safety control in actual food processing.

A novel strategy for inhibiting AGEs in fried fish cakes: Grape seed extract surimi slurry coating

This study investigated the effect of different surimi slurry coatings (SS, SSBHT, and SSGSE) on the AGEs of fried fish cakes. Results showed that all surimi slurry coatings significantly reduced AGEs in fried fish cakes, with SSGSE addition being most effective (P < 0.05). The SSGSE group performed a better sensory acceptance, higher moisture content, and denser texture than the other groups. The fat content and TBARS value of fried cakes were reduced by approximately 31% and 29% respectively by the SSGSE coating. Correlation analysis showed a negative correlation of AGEs content with moisture content and a positive correlation with browning, fat content and TBARS value. Conclusively, SSGSE coating reduced the generation of Maillard reaction products by inhibiting lipid oxidation in the fried fish cake. Thus, it was considered that grape seed extract surimi slurry was a promising coating technique to inhibit the production of AGEs in fried fish cakes.

Factors influencing on the formation of dimethyl disulfide and dimethyl trisulfide in model systems

The generations of dimethyl disulfide (DMDS) and dimethyl trisulfide (DMTS) in a binary or ternary model system including lipids, free amino acids and Maillard reaction products (MRPs) were studied. Various factors affecting the formation of DMDS and DMTS indicated that cysteine (Cys) and Cys MRPs could effectively decrease not only the concentrations of methionine (Met), DMDS and DMTS, but also the pH level. Rapid drops in pH limited the formation of DMDS and DMTS during Met thermal degradation. Quantitative analyses of DMDS and DMTS at acidic aqueous solutions revealed that the mixtures of MRPs derived from Cys and xylose (Xyl) had the best inhibition effect on the formation of DMDS and DMTS. The low level of DMDS and DMTS and the increasing level of furfuryl methyl sulfide and 2-thiophenecarboxaldehyde during storage indicated that MRPs derived from Cys and Xyl could effectively not only decrease the concertation of DMDS and DMTS, but also promote the development of thiophene and sulfur substituted furan. Thus, this study implied that MRPs derived from Cys/Xyl could be applied as effective substances to control the formation of DMDS and DMTS and improve the production of volatile compounds with meat-like aroma.

Physicochemical and functional property of the Maillard reaction products of soy protein isolate with L-arabinose/D-galactose.

Soy protein isolate (SPI) is widely used in the food industry because of its nutritional and functional properties. During food processing and storage, the interaction with co-existing sugars can cause changes in the structural and functional properties of SPI. In this study, SPI-l-arabinose conjugate (SPI:Ara) and SPI-d-galactose conjugate (SPI:Gal) were prepared using Maillard reaction (MR), and the effects of five-carbon/six-carbon sugars on the structural information and function of SPI were compared. MR unfolded and stretched the SPI, changing its ordered conformation into disorder. Lysine and arginine of SPI were bonded with the carbonyl group of sugar. The MR between SPI and l-arabinose has a higher degree of glycosylation compared to d-galactose. MR of SPI enhanced its solubility, emulsifying property and foaming property. Compared with SPI:Ara, SPI:Gal exhibited better aforementioned properties. The functionalities of amphiphilic SPI were enhanced by MR, SPI:Gal possessed better hypoglycemic effect, fat binding capacity and bile acid binding ability than SPI:Ara. MR endowed SPI with enhanced biological activities, SPI:Ara showed higher antioxidant activities, and SPI:Gal exhibited stronger antibacterial activities. Our work revealed that l-arabinose/d-galactose exhibited different effects on the structural information of SPI, and further affected its physicochemical and functional property. © 2023 Society of Chemical Industry.

Comparative study of browning, phenolic profiles, antioxidant and antiproliferative activities in hot air and vacuum drying of lily (Lilium lancifolium Thunb.) bulbs

This study compared the effects of hot air drying (HAD) and vacuum drying (VD) on the physicochemical qualities of lily (Lilium lancifolium Thunb.) bulbs. The results showed that VD treatment effectively reduced the browning of lily scales with a total color difference (ΔE) 42–73% lower than those of HAD group. Two drying treatments enhanced the total phenolic content (TPC) of the lily bulbs effectively. TPC increased with rising drying temperatures, and under isothermal conditions, the TPC of VD group was 1.1–1.6-fold higher than that of HAD group. Five typical phenolic compounds were identified in lily bulbs. As the predominant phenolic fraction, regaloside A of VD group was 51–291% above HAD group. Regaloside B was temperature sensitive and would be destroyed by high temperature. In parallel, VD treatment elevated the antioxidant activity overall, which could be contributed by phenolics and some Maillard reaction products. Furthermore, drying significantly improved the antiproliferative activity of lily bulbs, with samples treated with 120 °C HAD and 60 °C VD exhibiting the strongest antiproliferative capacity. The present investigation demonstrated that VD treatment effectively improved the physicochemical quality of lily bulbs and would provide a theoretical basis for optimizing drying conditions to obtain higher-quality lily bulbs.

Screening and optimization of Manganese peroxidase (MnP) production by Pseudoduganella violacea (SMB4), a bacterial isolate from Similipal Biosphere Reserve, Odisha and evaluation of Maillard reaction products degradation

The Maillard reaction products (Melanoidin) are major environmental pollutants of the distillery and fermentation industries. Manganese peroxidase (MnP) was found to be an efficient ligninolytic enzyme capable of degrading Maillard products. MnP can convert Mn2 ions in wood and soils to the more reactive Mn2+ ions. The current study aims to isolate MnP producing bacteria from Similipal Biosphere Reserve (SBR), Odisha, and determine its biodegradation ability towards millards products. In total 10 ligninolytic bacterial colonies were isolated from the soil sample of SBR and their MnP activity was screened using phenol red dye as an indicator. The isolate, SMB4 was found to be the most efficient MnP-producing bacterium showing the highest MnP activity of 3.89 U/ml/min in un-optimized conditions. The bacterium was identified as Pseudoduganella violacea based on morphological, biochemical and molecular characterization. MnP activity of SMB4 was optimized using response surface methodology. Under optimized conditions SMB4 showed MnP activity of 6.12 U/ml/min which is 1.57 times from un-optimized condition. The isolate SMB4 was found to show significant decolorization of maillards products up to 83.68 % at temperature 37 °C within 192 h of incubation. The degraded product was analyzed using UV–vis and FTIR analyses. The current investigation suggests that MnP produced by Pseudoduganella violacea may be successfully exploited for bioremediation purposes to degrade Maillard products.

Application of soy protein isolate-xylose conjugates for improving the viability and stability of probiotics microencapsulated by spray drying.

Production and consumption of probiotics need to meet many adverse stresses, which can reduce their health-promoting effects on humans. Microencapsulation is an effective technique to improve the biological activity of probiotics and wall materials are also required during encapsulation. Application of Maillard reaction products (MRPs) in probiotic delivery is increasing. This work aims to study the effects of soy protein isolate (SPI)-xylose conjugates heated at different times on the viability and stability of probiotics. SPI-xylose MRPs formed after heat treatment based on changes in the browning intensity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Fourier transform infrared spectroscopy. After heat treatment, α-helix and β-sheet contents of SPI-xylose mixture shifted from 11.3% and 31.3% to 6.4-11.0% and 31.0-36.9%, respectively, and the thermal stability slightly changed. During spray drying, except for MRP240@LAB, probiotic viability was higher in the MRP-based probiotic microcapsules (21.36-25.31%) than in Mix0@LAB (20.17%). MRP-based probiotic microcapsules had smaller particle sizes (431.1-1243.0 nm vs. 7165.0 nm) and greater intestinal digestion tolerance than Mix0@LAB. Moreover, the MRP-based probiotic microcapsules showed better storability than Mix0@LAB and adequate growth and metabolism capacity. SPI-xylose Maillard reaction products are a promising wall material for probiotics microencapsulation, which can improve bacterial survivability during spray drying and enhance bacterial gastrointestinal digestion resistance. This study sheds light on preparing probiotic microcapsules with superior properties by spray drying. © 2023 Society of Chemical Industry.

Antioxidant activities and emulsification properties of the new model systems of whey proteins and reduced sugars

The final products formed from the various systems of the Maillard reactions possess different functional properties such as browning intensity, antioxidant activity, and emulsion stability. To study these properties and activities, different systems of whey proteins reaction with glucose and fructose at different concentrations to form a new model system of Maillard reaction products (MRPs) was observed. Results showed that high optical densities (peaks) at 280 and 420 nm indicated the formation of the intermediate stages of MRPs and the formation of advanced MRPs, respectively. Additionally, results showed that these Maillard reaction model systems possessed different antioxidant activities as demonstrated by DPPH and reducing power assays (20 - 93.2% and 40 - 90%, respectively) depending on the type and concentration of sugar, and the incubation time. The whey protein-fructose model system possessed high antioxidant activity (93.2%), and had the highest percentage on the emulsion stability index (75.4%). The whey protein-fructose model systems comprised the highest number of the studied model systems to form MRPs, and had highly powerful antioxidant activity and emulsifying index.

Effects of caramelization and Maillard reaction products on the physiology of Saccharomyces cerevisiae

The thermal treatment the sugarcane juice undergoes during its processing alters the medium's chemical composition through the so-called Maillard reactions and its products, which can affect the alcohol-producing yeast's physiology in steps following the processing. This study aims to describe and characterize the reactivity of the primary amino acids present in sugarcane with sucrose, as well as demonstrate the physiological effects of the reaction's products on the yeast Saccharomyces cerevisiae. The main amino acids in sugarcane (glutamine, asparagine, and aspartic acid) were chosen to be reacted with sucrose under similar conditions to the industrial sugarcane processing (pH 5 and temperature 100–120 °C). The physiological effect of Maillard and caramelization reaction on the S. cerevisiae CEN.PK-122 and PE-2 strains were tested in microplate experiments using a modified mineral media containing both the reacted and unreacted amino acid-sucrose systems and four modified synthetic molasses media. The results have shown that the presence of any amino acids drastically increases product formation. Furthermore, among the amino acids, aspartic acid was the most reactive. Meanwhile, asparagine and glutamine had similar results. In S. cerevisiae physiology, aspartic acid had the most significant effect on culture growth by reducing the maximum specific growth rate and optical density. The increase in the Maillard product concentration for synthetic molasses also evidenced the inhibitory effect on yeast growth compared to media in the absence of these products. We conclude that this initial investigation clarifies the inhibitory effect of the Maillard products on yeast physiology.