• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.1
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• pp.6-13
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• 2001

The study was conducted to investigate the effect of the browning inhibitors such as PVPP(polyvinylpoly-pyrrolidone), A.A.(ascorbic acid) on nonezymatic browning factors [free sugar, total amino acid, organic acid, A.A., HMF (hydroxymethylfurfural)] and enzymatic browning factors [PRO (polyphenoloxidase) activity, polyphenol compounds] in concentrated apple juice during 90 days storage. Considering color value (L value, $\Delta$E), absorbance at 420 nm, concentrated apple juice during 90 days storage. Considering color the effect of browning inhibition. According to the storage period, the changes of nonenzymatic factors in concentrated apple juice added with browning inhibitors were similar to those in control (concentrated apple juice without browning inhibitors), which were the decreased of sucrose(0.24~0.35% at 90 days), the slight increase of glucose and fructose, the decrease of total amino acid (530.4~573.1 mg/10g at 90 days), same value of A.A. at 90 days (38.5~78.6 mg/100g), and the increase of HMF (27.8~30.6 mg/100g at 90 days). On the contrary, enzymatic browning factors were significantly inhibited in concentrated apple juice added with PVPP, judging from the slow increase of PRO activity and the significant decrease of initial value in polyphenol compounds (especially chlorogenic acid). These results suggest that PVPP plays an important role as enzymatic browning inhibitor, that is, a scavenger of polyphenol compounds by adsorption in concentrated apple juice.

• Journal of the Korean Society of Food Culture
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• v.23 no.4
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• pp.489-498
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• 2008

The objectives of this study were to provide fundamental information on how individual phenolic compounds form on the inside of apple slices during cold storage, the changes in the content of four types of phenols, ingredient variation of individual phenolic compounds and the influence of phenolic compounds on enzymatic browning. This study measured the changes in the content of soluble solids, pH and vitamin C in order to investigate the correlations between these variables. HD and FA were the main phenolic compounds found in the apple slices, and HD was the most prevalent phenol. Furthermore, comparison of the CG and EP content revealed that there were more CGs than EPs. The phenol content tended to decrease considerably in the fresh apple slices and water-dipped apple slices but only slightly in the CP from sucrose-dipped apple slices and 0.5% ascorbic acid solution-dipped apple slices. The degree of browning increased in the following order: fresh apple slices, water-dipped apple slices, 0.5% ascorbic acid solution-dipped apple slices and CP from sucrose-dipped apple slices. The vitamin C content tended to decrease in the fresh apple slices, water-dipped apple slices, 0.5% ascorbic acid solution-dipped apple slices and CP from sucrose-dipped apple slices. The pH tended to increase in all sample groups, but the pH of the water-dipped apple slices was lower than that of the comparison group. The CP from sucrose-dipped apple slices had the lowest value of pH. The change in soluble solids tended to increase in all treatment groups, but this increase was less in the CP from sucrose-dipped apple slice. Correlation analysis revealed a high degree of correlation between browning and chlorogenic acid content. The results of the present study show that, when stored in the fridge, the change in phenol ingredient content in apple slices influences the browning of the slices. The results also showed that HD and FA were the main phenolic compounds, while CG was shown to have the greatest influence on browning.

• Applied Biological Chemistry
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• v.25 no.3
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• pp.161-165
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• 1982

In order to find out pertinent methods for the acceleration of browing during ginseng processing, various treatments were made or fresh ginseng (Panax Ginseng C.A. Meyer) with sugars, amino acids and inorganic nitrogenous compounds and the extent of browning was measured. Among sugars tested, maltose resulted in the greatest acceleration of browning followed in decreasing order by glucose and lactose, whereas pentoses, fructose, sucrose and raffinose had negligible effect. A marked browning occurred in ginseng treated with basic amino acids, while the extent of browning was not greatly increased when ginseng was treated with aliphatic amino acids, hydroxy amino acids, or acidic amino acids used in the experiment. Among treatments with sugar-amino acid mixture, a mixture of glucose with glutamic acid gave the greatest acceleration. The brown color intensity gradually increased with an increase in glucose concentration for up to 0.5M. inorganic nitrogenous compounds enhanced the browning in general, and the effect varied greatly with the different compounds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1087-1091
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• 1999

Microwave extraction system equipped with closed vessels, which is known to rapidly extract target compounds from natural products, was applied to monitor the changes in phenolic compounds, browning color intensity and electron donating ability by using response surface methodology(RSM). Maximum content of phenolic compound was 21.65mg/100ml in 67.88% of ethanol concentration, 145oC of extraction temperature, and 6.24min of extraction time. The phenolic compounds in extracts are dependent on the increase of the extraction temperature and the ethanol concentration. Browning color intensity, which was maximized in 67.21%, 147oC, and 6.02min, was proportional to the increase of the extraction temperature. Maximum value of electron donating ability was 24.50units in 54.33%, 147oC, and 6.11 min. The electron donating ability of extracts was dependent on the increase of extraction temperature and maximized in the range from 50 to 65% of ethanol concentration.

• Korean Journal of Pharmacognosy
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• v.31 no.2
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• pp.240-244
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• 2000

Antimutagenicity profiles of the enzymatic browning reaction products(EBRP) were investigated. The rec-assay with Bacillus subtilis strains $H17(rec^+)$ and $M45(rec^-)$ was carried out using their spores. The biological activities were evaluated for seven different enzymatic browning reaction products, which resulted from the reactions of seven polyphenols with polyphenol oxidase isolated from Ginkgo biloba leaves. In the spore $rec^-$ assay, most of the polyphenolic compounds tested were positive, whereas their enzymatic browning reaction products were tested negative. The mutagenicity of enzymic browning mixtures of the polyphenols and the enzymes obtained from Ginkgo biloba leaves showed negative results in the mutagenicity test using Bacillus subtilis strains $H17(rec^+)$ and $M45(rec^-)$. In the case where polyphenol oxidase inhibitors were added in the enzymatic reaction mixtures with polyphenols, the polyphenols showed mutagenic effect in the spore $rec^-$ assay. This suggests that the activity of polyphenol oxidase is decreased.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.433-439
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• 1996

Major components affecting nonenzymatic browning in stored ginger paste were investigated using five synthetic model solutions.　The model systems were stored at $40^{\circ}C$ for 30 days and analyzed for browning, in addition the contents of sugars, organic acids, ascorbic acids, amino acids and gingerols were determined. Among the chemical components, fructose, asparagine and ascorbic acid were the main contributors to the browning development of ginger paste, while gingerol compounds were browning inhibitors.

• Journal of Ginseng Research
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• v.28 no.3
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• pp.143-148
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• 2004

Brown color intensity has been a major factor to estimate the quality of red ginseng and its products. This study deals with the relationship between the browning reaction of ginseng root and two compounds, arginyl-fructosyl-glucose(Arg-fru-glc) and arginyl-fructose (Arg-fru), in the model system of steaming and heat-drying processes for the preparation of red ginseng. During the steaming process, a marked decrease of starch and a considerable formation of maltose occurred in main roots of raw ginseng, but the formation of glucose was scarcely observed. After the heat-drying process, the brown color intensity of the powdered preparation of steamed main roots was 3 to 4 times higher than that of the powdered preparation of raw main roots. Also, when the heat- drying process was done with the addition of L-arginine, brown color intensity of the powdered preparation of steamed main roots was 12 to 13 times higher than that of the powdered preparation of raw main roots. The amount ratios of browning reaction products formed from sugar compounds and amino acids in the model system of steaming and heat-drying treatments in vitro were in order of xylose > glucose > fructose > maltose > dextrin (DE 9) > sucrose > dextrin (DE 8) and soluble starch. Each solution of Arg-fru-glc and Arg-fru that were synthesized chemically from maltose plus L-arginine and glucose plus L-arginine, respectively, changed from colorless to brown color during the heat-drying treatment. Amino acids or sugars were effective on the acceleration of each browning reaction of Arg-fru-gIc and Arg-fru during the heat-drying treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1135-1139
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• 1997

Major factors inhibiting nonenzymatic browning in stored ginger paste were investigated using aqueous model systems with temperature, water activity, pH and sulfur compounds. Browning index and total gingerols were measured during storage. The rate of nonenzymatic browning reactions showed a strong depencence on temperature and pH and a negligible influence on water activity. It was also reduced by the addition of 0.04% N-actyl-L-cysteine(NAcCys), effectively. Activation energies for aqueous ginger model systems with and without 0.04% NAcCys were 29.0 and 25.8kcal/mole, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.148-155
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• 1991

Lipid oxidation and browning during fermentation of domestic Meju and Doenjang were examined in order to elucidate the antioxidative effects of browning products and phenol compounds from Meju and Doenjang. Peroxide values of lipids from Meju were detectable and slightly increased until 3 weeks of fermentation, but started to be decreased after 3 weeks of fermentation and notdetectable after 6 weeks. Peroxides were not detected in Doenjang during the whole fermentation, but started to be decreased after 3 weeks of period of 22 weeks fermentation. Carbonyl value were increased during the whole period of Meju fermentation, but started to be decreased at the early stage of Doenjang fermentation. Hydrophilic fraction of browning products from Meju was much higher than lipophilic fraction and the former fraction was dramatically increased at the early stage of the fermentation. But the both fractions maintained high values during Doenjang fermentation. Hydrophilic browning products and phenol and phenol compound in Meju showed strong antioxidative against linoleic acid.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.271-282
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• 1982

The browning development, mainly through the Maillard reaction, occurring in the dried fish meat products during storage causes reduction of the nutritional value due to the loss of the essential amino acid such as available lysine as well as off -flavor resulting in the deterioration of the food quality thus shortening the shelflife. In the work, the changes in the amount of available lysine, extractable nitrogenous compounds (nonprotein-N, amino-N, trimethylamine oxide, trimethylamine, and free lysine) and development of browning were measured to assess the relationship between the shelflife and the quality loss in dried filefish under the steady state conditions (35,45, and $55^{\circ}C;a_{w}'s$ of 0.44 0.52, 0.65 and 0.75 at each temperature) and fluctuating temperature condition of $35/55^{\circ}C$ will. alternating 7 day periods at each water activity. The results indicated that the amount of available lysine and extractable nitrogenous compounds except TMA decreased rapidly with increasing temperatures and water activities while the rate of available lysine and extractable nitrogenous compounds must be involved in the initial stage of brown pigment formation. The available lysine loss of the dried filefish products stored under the fluctuating temperature conditions was greater than that stored under its fixed mean temperature, $45^{\circ}C$. The activation energies for lysine loss obtained from the Arrhenius plot ranged 6.9 to 4.4 Kcal/mol and $Q_{10}$ values at $40^{\circ}C$ were 1.4 to 1.2. The values for browning were 15.7 to 14.4 Kcal/mol and 2.2 to 2.0 respectively. Shelf-life, defined as the time to reach 0.15 O. D./g solid or the limit of off-color deterioration by browning reaction, was extented longer than the halflife of Iysine loss, actually corresponding $75\%$ loss of available lysine. This suggested that the halflife of lysine loss might not be adequate to assess the shelf-life of the food system with high potential of protein, nonproteinous nitrogen compounds, and lipids.