• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.201-206
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• 1998

The antibrowning effcts of cysteine, citric acid and ascorbic acid on the browning reaction of enzymatic garlic hydrolyzate were investigated at 37$^{\circ}C$ for 12 days. Cysteine was the most effective antibrowning agent followed by citric acid. The antibrowning effects of cysteine and citric acid were greater as concentrations increased, and the optimal concentration of both cysteine and citric acid as antibrowning agents was 0.3%. Ascorbic acid itself contributed to the browning reaction and showed an accelerating effect as the concentration increased. The addition of 0.1% ascorbic acid as synergist either to 0.3% cysteine or 0.3% citric acid did not enhance significantly the antibrowning effect of cysteine or citric acid. When stored at 3$0^{\circ}C$, 4$0^{\circ}C$ and 5$0^{\circ}C$, the browning reaction was accelerated as the temperature increased, especially at 5$0^{\circ}C$. Even though the effects of citric acid and cysteine as inhibitors on the browning reaction decreased as temperature increased, cysteine was more effective in decreasing browning reaction than citric acid.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.979-984
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• 2000

To improve the quality of dehydrated onion, antibrowning agents were screened. Effects of antibrowning agents on the degree of browning and the quality characteristics in dried onions were investigated. Sliced onions were dehydrated in an air drier at $70^{\circ}C$ within 3 percent moisture. Among various antibrowning agents, cyclodextrin and corn starch treatments were selected. Dipping in 4%(w/v) corn starch suspension proved more effective in preventing browning than other treatments. The change of color and the degree of browning showed a correlation. Dried onions treated with antibrowning agents prevented browning at around $24{\sim}32%$ compared to control. The contents of reducing sugar and vitamin C in treated onions had minimally changes.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.278-282
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• 1998

Peeled garlic, soybean sprouts, cut onion and cut green pepper were treated by dipping in solutions of different antibrowning agents, and then stored at $10^{\circ}C$. Surface color and polyphenol oxidase activity of produce were measured through the storage. Tested antibrowning agents include ascorbic acid, citric acid and allyl isothiocyanate. The commodities showed different responses to the antibrowning agent solutions; 1% citric acid for peeled garlic, 1% ascorbic acid for soybean sprouts, 2% citric acid for cut onion, and 1% ascorbic acid for cut green pepper showed better retardation in browning than the other treatments for respective product. For peeled garlic, surface browning was concomitant with increase in polyphenol oxidase activity during storage. On the other hand, there was no positive correlation between surface browning and polyphenol oxidase activity for the other stored products.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.454-458
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• 2002

The effect of antibrowning agents such as PVPP (polyvinylpolypyrrolidone), bentonite, gelatin, celite 545, tannic acid and sodium sulfite in apple concentrate was investigated for the control of enzymatic browning by comparing physicochemical properties (pH, color, turbidity), polyphenoloxidase activity and contents of polyphenol compounds. In color value, apple concentrate containing PVPP showed higher L value (lightness) than control and other antibrowning agents. The turbidity (absorbance at 660 nm) of apple concentrate added PVPP, gelatin celite 545, tannic acid and sodim sulfite were 0.003, 0.038, 0.018 and 0.022, respectively. PVPP was regarded to remove suspended solids effectively. Polyphenoloxidase activity and polyphenolics(catechol, catechin, chlorogenic acid, epicatechin) content of apple concentrate used PVPP significantly reduced. Therefore PVPP was proved to be effective for enzymatic antibrowning agent considering to color, turbidity, polyphenoloxidase activity and polyphenol compounds in apple concentrate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.1
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• pp.151-155
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• 2007

A comprehensive study to evaluate the relative antibrowning activity of 5 known natural juices was conducted. Among the juices tested, rhubarb juice showed the highest inhibitory activity on apple browning (${\Delta}L=0.47$ & ${\Delta}E=1.8$ after 6 storage days at $4^{\circ}C$). Even 50% diluted rhubarb juice was very effective in controlling apple discoloration, showing very limited change in Hunter's L and E values. No significant difference in apple slices browning was observed with respect to the packaging material (LDPE or nylon/PE). However, gas composition inside package was closely related to apple browning.

• Food Science and Preservation
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• v.18 no.4
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• pp.584-589
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• 2011

This study was conducted to investigate the effects of Taraxacum platycarpum and Chrysanthemum indicum extracts on the browning of apple slices. The inhibition of the PPO activities, total phenolic contents, and DPPH free-radical-scavenging activities was measured from water and from the 80% EtOH extracts of Taraxacum platycarpum and Chrysanthemum indicum as natural antibrowning agents. Apples were cut into 15-mm-thick slices, and each slice was dipped for 1 min in different treatment solutions (1% Taraxacum platycarpum and Chrysanthemum indicum extracts, 1% citric acid) and was stored at room temperature. The inhibition of the PPO activity in the Chrysanthemumin indicum extract was better than that in the Taraxacum platycarpum extract. The highest DPPH free-radical-scavenging activity (76.10%) was found in the 80% EtOH extract of Chrysanthemum indicum. After 24 h, the ${\Delta}E$ value of the apple slices that were treated in the 80% EtOH extract of Chrysanthemum indicum was at the lowest level (2.22). The total phenolic content was 94.07 mg/g, and the total flavonoid content was 102.60 mg/g, in the 80% EtOH extract of Chrysanthemum indicum. The antibrowning effect of Chrysanthemum indicum was higher than that of Taraxacum platycarpum in the apple slices.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.529-534
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• 1996

Using cystine, ascorbic acid and citric acid, retarding and synergistic effect on the browning reaction of onion juice concentrate was evaluated. Cysteine retarded the browning reaction most effectively followed by citric acid ; on the contrary, ascorbic acid accelerated rather than retarded the reaction at the concentration of 0.1%. The retarding effect of cysteine increased abruptly up to concentration of 0.3% and remained unchanged. Citric acid acted more effectively than ascorbic acid in terms of synergism. The browning reaction of onion juice concentrate exhibited activation energies of 62J/mol with cysteine and citric acid as compared to 73J/mol for control. $Q_{10}$ was determined to be 2.52 and 2.38 for control, 2.2 and 2.09 for treatment in the temperature range of 30~4$0^{\circ}C$ and 40~5$0^{\circ}C$, respectively.

• Korean journal of food and cookery science
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• v.28 no.3
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• pp.319-326
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• 2012

This study was designed to investigate the properties related to browning of hot water and 80% ethanol extracts of green tea (Camellia sinensis) and propolis. The extracts were assessed for polyphenol oxidase (PPO) inhibitory activity and total phenolic and flavonoid contents. In addition, apples were cut into 15 mm thick slices and dipped for 1 min in 0.5% of the green tea extracts and the propolis solutions and stored at room temperature for 24 h. The PPO inhibitory activity of the green tea extracts was better than that of the propolis. The highest DPPH free radical scavenging activity (90.81%), total phenol contents (170.42 mg/mL) and the metal chelating effects (45.93%) were measured in the green tea hot water extracts. The mineral content of the green tea water extracts was 69,328.44 ppm potassium and 2,409.42 ppm magnesium. After 24 h, the ${\Delta}E$ value of the apple slices treated with the green tea water extracts was the lowest (1.35). The antibrowning effects of the green tea extracts were higher than those of propolis in the apple slices.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.183-187
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• 2006

Surface browning, caused by cutting and other wound during minimal processing, is very important quality criterion to consumers. Shelf-life of fresh-cut potatoes was extended using natural antibrowning treatments. Fresh-cut potatoes dipped with licorice and green tea extracts were packed with LDPE film and stored at $4^{\circ}C$ for 14 days. Quality characteristics of fresh-cut potatoes were investigated during storage. During storage, L value decreased and PPO activity increased. PPO showed the lowest activity at around 7 days storage, during which browning was effectively inhibited in licorice- and green tea extract-treated potatoes. Total phenol and chlorogenic acid contents increased for 7 days. Results suggest natural licorice extracts with ascorbic acids are effective antibrowning agents for maintaining quality of fresh-cut potatoes.

• 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.