• Korean journal of food and cookery science
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• v.8 no.3
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• pp.241-246
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• 1992

In this study. we measured the degree of browning of 3 potato culitivars harvested in Korea and compositions such as total phenols, tyrosine and polyphenol oxidase (PPO) activity. And we compared the extent of browning and composition factors to investigated which was related to the differences among 3 cultivars in browning. The results are as follows. 1. Among 3 culitivars, Sumi browned most after grinding and showed that browning in Sumi was preceded by significant1y shorter lag time. Namjak and Sumi were rapid to brown compared to Daejima. 2. Among 3 culitivars, Sumi contained significant1y more total phenols than did Namjak and Daejima. On the other hand, tyrosine contents by automatic analyzer of Sumi and Namjak were similar and mat of Daejima was the lowest. PPO activities were higher when catechol was used as substrate and Sumi contained more PPO than did the other culitivars. 3. When we compared me browning behavior and composition of 3 culitivars, significant correlation was obtained between browning extent and total phenols, tyrosine and PPO. For me individual cultivar, Sumi which browned much extensively showed higher correlation between browning and PPO. On the other hand, the other cultivars showed higher correlation with total phenols and tyrosine, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.226-232
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• 1988

Non-enzymatic browning is a carbohydrate dehydration reaction, accelerated thorough the interaction of amino compounds. Reaction depends on several factors including temperature, reactant concentration, pH, water activity and specific ion concentrations, and result in progressive development of brown pigments in the affected food systems. The present study was designed to utilize a kinetic approach to analyze the effect of temperature and water activity on the browning development in green ten. The green tea was controlled at aw of 0.33, 0.44, 0.52 and 0.65 using saturated salt solutions and then stored at 35,45 and $55^{\circ}C$. Author portion of the sample of which the water activities were controlled in the same manner was stored at 35 and $55^{\circ}C$ alternately with 7 days interval. Simplified kinetic models were used to obtain the various kinetic parameters for browning development in green tea subjected to accelerated shelf-life tests(ASLT). The reaction of browning development was zero order. The activation energies calculated from Arrhenius plot ranged $1.5{\sim}2.4kcal/mole$ and $Q_{10}$ values were between 1.07 and 1.12. These kinetic parameters were then used to predict browning development under the nonsteady storage. Assessed from the parameters the shelf-lives at $25^{\circ}C$, the time to reach 1.02 O.D./g solid at which severe brown color change could be detectable, ranged 57 to 113 days and showed decrease with increase in aw. The predicted shelf-lives at different water activities were a little higher than actual values.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.214-219
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• 1993

Properties of the antioxidative fraction isolated from browning reaction product (BRP) that were obtained from 2 M L-ascorbic acid (AsA) solution (adjusted to pH 7.0) by heating for 25 hrs at $85^{\circ}C$ were investigated. Both of dialyzable and nondialyzable fraction isolated from BRP showed antioxidative effect. Dialyzable fraction has stronger antioxidative activity than nondialyzable. Dialyzable fraction was divided into the three fractions (A, B, C) by gel filtration. Among these fractions, the fraction (A) that had the highest reducing power and lowest browning drgree had lowest antioxidative activity. The fraction (C) that had lowest reducing power and highest browning degree showed strongest antioxidative effect. In the UV-visible spectrum of these fractions, the maximum absorption wavelengths of fraction A and B were 266.1 and 257.4nm, respectively, and fraction C showed a weaker absorption peak at 274.8nm. Infrared (IR) spectrum results showed that all fractions (A, B, C) had both hydroxy and carboxylic groups, and fraction B and C had carboxylic ester group.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.480-485
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• 1989

Changes of color intensity and components during browning reaction of water extracts from white tail ginseng were investigated. Temperature dependence was described by the Arrhenius relationship with an activation energy of 16kcal/mole. Temperature sensitivities$(Q_{10}\;value)$ for water extracts of ginseng was 1.90 between $70^{\circ}C\;and\;80^{\circ}C$, 1.57 between $80^{\circ}C\;and\;90^{\circ}C$ and 1.46 between $90^{\circ}C\;and\;100^{\circ}C$. pH value of the solution treated at $90^{\circ}C\;and\;100^{\circ}C$ slightly increased with an increase in reaction time. Among ginseng saponins ginsenoside-Re was most unstable against heat-treatment, white diol group saponins were more stable against heat-treatment. Hydrogen donating activity (reducing activity for ${\alpha},\;{\alpha}'-diphenyl-{\beta}-picrylhydrazyl$) and 3,5-dinitrosalicylic acid(DNS) positive substances of browning reaction products increased in proportion to the length of browning reaction time and temperature, whereas folin positive substances decreased by heat-denaturation of ginseng protein at initial reaction time and then increased thereafter.

• Journal of Life Science
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• v.14 no.3
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• pp.501-508
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• 2004

A bacterial strain CJ-3 which produced chitinase was isolated from Korean traditional soy sauce. Using 16S rDNA analysis, the strain CJ-3 was identified as Bacillus atrophaeus. The approximate molecular weight of the putative chitinase enzyme was 31.0 kDa and the enzyme activity was remarkably induced by addition of colloidal chitin (0.5, 1.0, 2.0%). The antioxidant activity was increased 53% by the browning reaction products of B. atrophneus CJ-3. Escherichia. coli lipopolysaccharides (LPS)-induced production of nitric oxide(NO) was reduced up to 45% by the browning reaction product in RAW264.7 macrophage. Inhibition of cell viability in the presence of LPS was recovered to normal level by the browning reaction product. These results suggest that browning reaction of B. atrophaeus CJ-3 plays an important role for activation of immune system. B. atrophaeus CJ-3 exhibited optimum temperature and pH of 37$^{\circ}C$ and pH 7.0∼8.0, respectively. The major intracelluar free amino acid was determined to be glutamate.

• Preventive Nutrition and Food Science
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• v.8 no.3
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• pp.230-234
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• 2003

Mass transfer characteristics during osmotic dehydration of carrots were studied as functions of immersion temperature and time, and sugar and salt concentrations. The effect of osmotic dehydration on the degree of browning of air-dried carrots was also evaluated. Increasing the immersion temperature and time, sugar concentration, and salt addition increased water loss, sugar gain, molality and rate of dehydration. The water loss and increases in solids, and molality were rapid in the beginning of the process and then increased slowly during remainder of the process. Increasing 1 or 2% salt concentration in the 40$^{\circ}$Brix sugar solution at 6$0^{\circ}C$ increased water loss and solid gain. Salt addition was not able to significantly affected on water loss and solid gain compare to temperature (40～8$0^{\circ}C$) and sugar concentration (20～60$^{\circ}$Brix) changes due to the low salt concentration. A minimum degree of browning of the air-dried carrots (O.D. = 0.048) could be achieved using binary solutions (40$^{\circ}$Brix sugar solution with 2% salt addition) with 24 min of immersion time compared to control (O.D. = 1.308) or blanching with 24 min of immersion time (O.D. = 0.174).

• The Korean Journal of Food And Nutrition
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• v.11 no.5
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• pp.499-505
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• 1998

The purpose of this study was to ivestigate the structural characteristics of waste soulble browning reaction prodcuts (WS-BRPs) isolated from Korean red ginseng. They all showed the maximum absorbances at near 280 nm. Their IR spectra suggested the presence of hydroxyl, amide carbonyl and aliphatic methine groups. From sugar analysis it was identified that L and S-1 contained two kinds of suggar, glucose and xylose, and S-2, a fructose together with glucose and xylose. Thirteen different amino acids were identified in L. Ten amino acids from S-1 and seven amino acids from S-2 were identified using Auto Amino Acid Analyzer. Glycine, serine and glutamic acid in S-1 and one unknown amino acid and glycine in S-2 were detected as the major amino acids, respectively. From the 1H-and 13C-NMR spectra, it was identified that a number of sugar moieties, carbonyl and carbon double bonds (only in S-2) were contained in the three WS-BRP components. Approximate number of sugar moiety of L, S-1 and S-2 was determined to be 8∼10, 9∼11 and 4∼5, respectively. Contents of nitrogen, carbon and hydrogen showed L>S-1>S-2.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.1
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• pp.63-68
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• 1987

The results of previous paper(Lee et al, 1987), indicated that the role of polyunsaturated carbonyls from the polar lipid seemed more important than those of the nonpolar lipid in the browning reaction. In this study, the role of phosphoipid in lipid oxidative browning reaction was investigated. In fatty acid composition of hair tail fish, neutral lipid and glycolipid contained the higher percent of saturated and monoenic acids while phospholipid contained more of polyenoic acids. When this fish was dried and stored, polyunsaturated fatty acids of phospholipid and glycolipid more rapidly decreased than that of neutral lipid. The browning was developed more rapidly in phospholipid than in glycolipid and neutral lipid. In the test of phospholipids, the phosphatidylcholine which fractionated by $CHCl_3-MeOH(1:1)$ solution was the largest in quantity, tut the phosphatidylethanolamine which fractionated by $CHCl_3-MeOH(4:1)$ was more active in the development of browning.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1182-1187
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• 2007

Changes in composition of fatty acids and free amino acids in three differently dried Alaska pollack (sun dried, naturally cyclic freeze-thaw dried, and 1-year-aged cyclic freeze-thaw dried Alaska pollack (Hwangtae)) were investigated to correlate them with browning reactions in drying and aging Alaska pollack. Major fatty acids of the sun dried Alaska pollack were palmitic acid, oleic acid, and eicosapentaenoic acid (EPA), and those in the Hwangtae were palmitic acid, oleic acid, and gondoic acid. Hwangtae showed the lowest amount of polyunsaturated fatty acids among the three types of dried Alaska pollack. Free amino acids content of sun dried Alaska pollack was higher than that of the cyclic freeze-thaw dried Alaska pollack and Hwangtae. Lesser amount of histidine in Hwangtae (0.02%) than that in the cyclic freeze-thaw dried Alaska pollack (0.087%) may indicate the degradation of histidine due to the browning reaction in aging the cyclic freeze-thaw dried Alaska pollack. Significant changes in compositions of fatty acids and free amino acids among the dried products revealed the browning reaction resulted from carbonyl compounds produced by decomposition of lipid hydroperoxides and free amino acids. Aging the cyclic freeze-thaw dried Alaska pollack for a year contributed to the development of browning.

• Applied Biological Chemistry
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• v.24 no.3
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• pp.161-166
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• 1981

Products of ginseng browning reaction were investigated to determine the nature of their antioxidant activity using a model system, White Ginseng and Red Ginseng extracts. In the simulated ginseng model system, the brown color was intensified with an increase in the length of reaction time and the antioxidant activity initially increased in proportion the length of reaction time for up to 17 hrs and then leveled off thereafter. Pararell results were obtained manufacturing of Red Ginseng, Comparison of the antioxidant activity of the inner and outer solutions after dialysis of browning solution showed that the outer solution had a stronger antioxidant activity than the inner one. For further analyses, browning reaction products were fractionated into three peaks on Amberlite CG-120 type I ionexchange resin and designated as fractions I, II and III in order of elution. Partial characterization of the fractions revealed that floe most intense brown fraction (Fraction II) had the strongest antioxidant activity and also exhibited reducing power for Somogyi-Nelson reagents and ninhydrin positive reaction. Both the browning reaction products and Red Ginseng extracts were found to possess potent reactivity with ${\alpha}$,${\alpha}'$-diphenyl-${\beta}$-picrylhydrazyl, whereas White Ginseng extracts showed negligible reactivity.