• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2522-2527
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• 2010

The aim of this study was to investigate the tyrosinase inhibitory activity and antimicrobial activity by mixtures of ultrasonicated chitosan and Maillard reaction products. Analysis of tyrosinase was purified from potato and confirmed by active staining after SDS-PAGE. Maillard reaction products (MRPs) were formed from various sugars (glucose, fructose, galactose, xylose, arabinose or ribose) and cystein. MRPs inhibited the tyrosinase purified from potato. The highest tyrosinase inhibitory activity was shown by MRP from glucose and cystein. Ultrasonicated chitosan (over 1 hr) showed antimicrobial activity at the concentration of 1% against E. coli and S. aureus. For the development of antibrowning agent with antimicrobial activity, tyrosinase inhibitory and antimicrobial activity by the mixtures of ultrasonicated chitosan and MRP were tested. 1:1 mixture of ultrasonicated chitosan and MRP from glucose and cystein was the best antibrowning agent having antimicrobial activity.

• Preventive Nutrition and Food Science
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• v.22 no.3
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• pp.211-215
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• 2017

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

• Preventive Nutrition and Food Science
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• v.15 no.4
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• pp.297-303
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• 2010

The present study compared the Maillard reaction products (MRPs) derived from aqueous and ethanolic fructoseglycine and its oligomer (dimer and trimer) solutions. The pH was lower in glycine (G) than in diglycine (DG) and triglycine (TG) in both aqueous and ethanolic solutions, but the pH difference between the DG and TG was not significant. MRPs derived from the DG had a greater absorbance at 294 and 420 nm in ethanolic solution than in an aqueous solution. In particular, the loss of sugar was higher in ethanolic solution than in aqueous solution. Enolization of fructose was observed in both aqueous and ethanolic MRP solutions; however, enolization was not observed for the G in aqueous MRP solutions. The glycine oligomer content in ethanolic MRP solutions remained higher than that in aqueous MRP solutions. Furthermore, neither diglycine nor triglycine were detected in the G aqueous or ethanolic MRP solutions, while triglycine was detected in both the DG aqueous and ethanolic MRP solutions. Absorption in the ultraviolet-visible (UV-Vis) spectra was higher with MRPs derived from the ethanolic solution than with those derived from the aqueous solution. MRPs derived from the DG in an ethanolic solution showed the highest absorption intensity.

• Membrane and Water Treatment
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• v.9 no.2
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• pp.105-113
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• 2018

Maillard reaction products like melanoidins present in industrial fermentation wastewaters are complex compounds with various functional properties. In this work, novel ultrafiltration (UF) mixed matrix membrane (MMM) composed of polysulfone (PSF) and nanocomposites was prepared through a phase inversion process for the recovery of melanoidins. Nanocomposites were prepared with acid functionalized multiwalled carbon nanotubes (MWCNTs) as the reinforcing filler for chitosan-thermoplastic starch blend. Higher nanocomposites content in the PSF matrix reduced the membrane permeability and melanoidins retention indicating tighter membrane with surface defects. The membrane surface defects could be sealed with dilute polyvinyl alcohol (PVA) solution. The best performing membrane (1% nanocomposites in 18% PSF membrane sealed with 0.25% PVA coating) resulted in uniform melanoidins retention of 98% and permeability of 3.6 L/m2 h bar over a period of 8h. This demonstrates a low fouling PSF membrane for high melanoidins recovery.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.309-313
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• 1997

Maillard reaction products (MRPs) added into a culture and the resultant bacterial growth were investigated using response surface methodology. The coefficients of determination $(R^{2})$ of response surface regression equations for bacteria were 0.9544 and 0.9578 in Bacillus subtilis and Bacillus natto, respectively. The MRPs produced at higher reaction temperature and for longer reaction time showed greater antimicrobial effect for Bacillus subtilis. Especially, the MRPs produced at temperature above $150^{\circ}C$ for 8 to 12 hrs showed the strongest antimicrobial effect. The MRPs produced at lower reaction temperature and for shorter reaction time showed greater microbial growth effect for Bacillus natto, but those produced at the reaction temperature higher than $160^{\circ}C$ showed the greatest antimicrobial effect. In the ridge analysis, the growth of Bacillus subtilis was the most significantly inhibited in the presence of MRPs prepared at $159.10^{\circ}C$ and pH 12.21 for 9.67 hrs, and the growth of Bacillus natto was the most significantly inhibited in the presence of MRPs prepared at $169.94^{\circ}C$ and pH 9.66 for 9.22 hrs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.2
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• pp.133-139
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• 1994

The desmutagenic effects of seaweed and vegetable extracts were investigated on the mutagenicity of Maillard reaction products (MRP) obtained from equimolar amounts of glucose and amino acid (arginine and lysine${\cdot}$HCl) for Salmonella typhimurium TA 100 without S9 mix. The mutagenicities were inhibited by water-soluble extracts of seaweeds(laver, sea-straghorn, sea-mustard and tangle) and vegetables(ginger, garlic, onion, chinese-pepper, green-onion and cabbage). Cabbage, chinese-pepper, green-onion and sea-straghorn exhibited especially high desmutagenic effects. The desmutagenicities of these extracts(cabbage, green-onion and sea-straghorn) except for sea-straghorn were decreased by heat treatment at $100^{\circ}C$ for 10 min. It is assumed that the desmutagenic effect of seaweed and vegetable extract is due to the reducing power and action of enzyme such as peroxidase and catalase.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.781-786
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• 1994

Meatlike flavors were manufactured using hydrolyzed vegetable protein (HVP) with several reactive precursors at different reaction conditions. Both pH and temperature affected significantly on brown colority of reaction product, whose velocity became fast with increasing pH and temperature. Drastic decrease in residual reducing sugars and free amino acids appeared until 1 hour, being little affected by reaction temperature. Glutamic acid and cysteine were decreased with reaction time, whereas glycine and methionine remained constant. Forty nine aroma compounds formed through Maillard reaction were isolated and identified with GC/MSD, including 3-methyl butanal, 2-methyl tetrahydrothiophen-3-one, 3,4-dimethylthiophene and 2,4-dimethyl thiazole previously known as natural meat flavors. The sensory evaluation showed that one-hour reaction product was the highest in savory taste and the lowest in nasty taste on the level of 5% significant difference among all reaction products tested in this experiment. From the results above, it could be speculated that the initial stage of Maillard reaction in this experimental system occured until one hour, thereafter, savory taste decreased accompanied by increasing nasty taste with elapsed reaction time.

• Food Science of Animal Resources
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• v.40 no.1
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• pp.44-54
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• 2020

The purpose of the present study was to evaluate the sensory and instrumental quality of thawed beef steak prepared by searing and oven cooking. Beef purchased in the local market was divided into two groups; one group was cooked in a 180℃ oven until the internal temperature reached 60℃, and the other group was oven cooked until 35℃, then cooked in a 250℃ pan until the internal temperature reached 60℃. Despite a noticeable change in appearance due to the high temperature of the searing, there was no significant difference in juiciness, water content, and cooking loss between the searing-cooked and the oven-cooked steaks. However, in searing cooking, both scores of overall flavor and roast meat flavor were significantly higher than those of oven cooking. In the searing-cooked steak, the reducing sugar, which is a reactant of the Maillard reaction, was lower and Maillard-reaction products were higher than oven-cooked steak. From our results, it can be concluded that searing does not improve juiciness of the steak, but improves the flavor of beef steak due to higher levels of Maillard reaction products.

• Journal of the Korean Society of Tobacco Science
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• v.10 no.2
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• pp.123-130
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• 1988

The volitile compounds Produced from the Maillard reaction of D-glucose and DL-alanine or DL-$\alpha$-aminobutyric acid using water or propylene glycol as a reaction amdeum were analysed by gas chromatofiraphy and mass spectrometry. From two kinds of reaction products in water 18 compounds were identified. The major compounds in a reaction product of glucose with alanine were 5-hydroxy methyl-2-furfural, 2-acetyl pyrrole and 2-formyl-5-methyl pyrrole, and those in a reaction product of glucose with $\alpha$-aminobutyric acid were 2-ethyl crotonaldehyde and 2-methyl-3, 5-dihydroxy-4H-pyran-4-one including the above 3 compounds. From two kinds of reaction products in propylene glycol solution, 35 compounds were identified. The major compounds in a reaction product of glucose with alanine were alkyl pyraainef, 2-methyl furfuryl alcohol and 2-acetyl pyrrole, and those in a reaction product of glucose with $\alpha$-aminobutyric acid were propionaldehyde PGA, 2-ehtyl crotonaldehyde, 2-acetyl pyrrole and 2-acetyl-5-ethyl furan.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.839-841
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• 2008

The mutagenicity after heating of different sugars (glucose, fructose, galactose, and tagatose) on the non-enzymatic browning reaction in different sugars and glycine model system was investigated. The model system containing 0.2 M glycine and 0.2 M of different sugars in 10 mL water was heated at $150{\pm}5^{\circ}C$ for 30 min. After heating, degree of non-browning reaction intensity and mutagenicity using Salmonella typhimurium TA 98 were examined. Heated glycine model systems containing different sugars increased their mutgenicity ranged from 30 to 372 revertant colonies. After heating for 40 min, mutagenicity was achieved with glycine model systems containing 4 different sugars with by 145, 356, 206, and 369 revertants per plate, respectively. The glycine model systems containing fructose or tagatose were significantly (p<0.05) higher mutagenic activity than glycine model systems containing glucose or galactose after 40 min of heating. The linear regression between Maillard reaction intensity and mutagenic activities (slope=32.38, $R^2=0.93$) indicates that mutagenicity could be fully ascribed to Maillard reaction products.