• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.3_4
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• pp.97-100
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• 1973

In the previous work(Kim et al, 1973), the quality of sun-dried Alaska pollack, Theragra chalch-ogramma, was discussed in the aspect of non-enzymatic discoloration as a function of relative humidity during storage at room temperature($20^{\circ}C$). In this paper, sun-dried squid, Ommastrephes steam pacificus was investigated at the same aspect mentioned above. Fresh squid from the whole sale market was dressed, filleted, dried for 48 hours in the open air and finally stored in the humidistat chamber. Lipid oxidation ana development of non-enzymatic browning were tested by the same methods described in the previous paper. The TBA value showed a maximum peak on 30 day storage, hereafter tended to decrease gradually. The rate of browning, however, in water soluble fraction as well as in chloroform-methanol fraction was lower at 0.34 to 0.45 water activity than at any other case, and propagation of lipid oxidation was also diminished at the above level of water activity. From the results, it is recognized that storage at Aw=0.34 to 0.45 provides higher quality stability for sun-dried squid.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.44-49
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• 1990

The quality of garlic powder produced by hot all drying and freeze drying method was evaluated Porapak Q column was comparatively profitable for the separation of flavor components in hexane extracts of garlic. Freeze dried (FD) garlic powder had higher diallyl disulphide, total pyruvic acid and alliin than hot air dried (HD) garlic powder. On the results of color evaluation by color difference meter, garlic powder of HD were more brownish than FD. In microstructure of garlic powder observed by SEM, freeze dried garlic powder was fairly porous.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1301-1304
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• 2001

Deodorizing activity of polyphenol cxidase (PPO) extracted from apples was investigated by measuring the changes of methyl mercaptan as an indicator of halitosis in human mouths. In the studies of apple extracts on deodorizing activity, the deodorizing activity was increased with the amount of apple extracts. In the cases of adding PPO to the low molecular fraction of apple extracts, the deodorizing activities were increased with the amount of the law molecular fraction of apple extracts and the reaction time of the extracts with PPO. Deodorizing activities of PPO is thought that o-quinone as an intermidiate produced by an oxidative reaction of PPO during enzymatic browning reactions may react with methyl mercaptan to form a non-volatile and sulfur-containing compound .

• Korean Journal of Food Science and Technology
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• v.48 no.1
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• pp.15-19
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• 2016

Drying process was applied to increase the antioxidant activity of onion powder: freeze-drying or air-drying at 50, 70, and $90^{\circ}C$ and onion extracts were obtained from each powder using water or aqueous ethanol (50%) at $25^{\circ}C$ and $60^{\circ}C$. In the color analysis, the freeze-dried powders showed higher $L^*$ and lower $a^*$ and $b^*$ values than did the air-dried ones. The browning index of powders air-dried at $90^{\circ}C$ was significantly higher than that of freeze-dried powders or those air-dried at temperatures below $90^{\circ}C$. Phenolic content in the extracts was 4.02-23.12 mg gallic acid equivalent/g sample, and was the highest in the extract from the sample air-dried at $90^{\circ}C$, regardless of the extraction condition. The highest antioxidant activity, measured by 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid and 1,1-diphenyl-2-picrylhydrazyl methods, was found in the powder air-dried at $90^{\circ}C$, which induced browning. These findings indicate that antioxidant activity depends more on browning during drying than on extraction conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.903-907
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• 1998

Mass transfer characteristics during osmotic dehydration of mushrooms(Agaricus bisporus) in sugar solution were studied as a function of sugar concentration, immersion time and temperature, and the effect of osmotic dehydration on browning inhibition of air-dried mushrooms was also evaluated. Increasing the sugar concentration, immersion time and temperature increased moisture loss, sugar gain, molality and rate parameter. The changes of sugar gain and rate parameter were more significantly affected by concentration than by temperature of sugar solutions, while 1$0^{\circ}C$ increase in temperature or 10 Brix increase in concentration had the same effect on water loss. Water loss, sugar gain, molality were rapid in the first period of osmotic dehydration especially in the case of higher concentration and temperature of sugar solutions. Effects of osmotic dehydration in sugar solution(60 Brix, 8$0^{\circ}C$) with 18 min of immersion time(O.D.=0.099) rior to air dehydration on browning inhibition of dried mushrooms were more significant than blanching in water(8$0^{\circ}C$) with the same immersion time(O.D.=0.330) and the control (O.D.=0.559).

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.186-189
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• 1993

The effect of soybean oil on frying time and number of frying treatment on quality of Yu-kwa (Korean traditional rice cookie) were examined. As the frying time increased, acid value and POV were increased from 0.08 to 0.23 and 1.78, respectively. But the quality of Yu-kwa was not influenced by the frying time. And as the frying time increased, unsaturated fatty acid (oleic and linoleic acid) was decreased, while saturated fatty acid (palmitic acid) was increased. The color was drastically changed on frying oil which showed a dark brown color, but there was no difference in Yu-kwa. As the frying time increased, acceptability was decreased on sensory evaluation, but significant difference among samples tested within significant level 5 % was not revealed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.1013-1016
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• 2004

The inhibitory effect of MRPs (Maillard reaction products) on enzymatic browning of taro was investigated. The MRPs prepared by heating glycine and glucose at 9$0^{\circ}C$ for 7 hr exhibited a strong inhibitory effect on taro polyphenol oxidase (PPO). The maximum inhibitory activity of MRPs against taro PPO was detected toward (＋)-catechin, catechol, 4-methylcatechol followed by L-$\beta$-3,4-dihydroxyphenylalanine (L-DOPA) and pyragallol as a substrate. The MRPs synthesized from fructose and glucose with glycine as a amino acid significantly reduced the taro PPO activity. MRPs prepared by higher glycine or glucose concentration showed stronger inhibition against taro PPO. Increasing reaction time of the glycine and glucose promoted the inhibitory effect of MRPs against the PPO activity of taro, whereas the color formation was gradually increased.

• Journal of Ginseng Research
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• v.10 no.1
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• pp.94-100
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• 1986

Korean red ginseng tails was extracted with solutions having various ethanol concentration at the temperature range of 70-$100^{\circ}C$, Extraction was carried out for 1-5 times of 8 hours at given condition. Sensory properties and color of RG-Ext. were found to be significantly affected by conditions of extraction. Absorbance at 490nm was decreased as the ethanol concentration increased, the increase in ethanol concentration also showed an increase in the Hunter's values of "L" and "b", and a decrease in "a" value indicating the color of RG-Ext. was changed to yellowish with less in darkness. Increase in extraction time and temperature caused darker brown color which is indicates a typical phenomena of non-enzymatic browning reaction. The flavor and bitternes of RG-Ext. were found to be significantly increased as the ethanol concentration increase, the generally responses of acceptance range of ethanol concentration was 30-70%.

• Research in Plant Disease
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• v.18 no.4
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• pp.376-380
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• 2012

A survey of bacterial species associated with Korean isolates of pine wood nematode (PWN) was performed. A total of 110 bacterial isolates were obtained from the PWN isolates that were previously isolated from Pinus densiflora and P. koraiensis. Among the bacterial isolates, Cedecea neteri was most frequent (64 isolates) followed by Ewingella americana (21 isolates), Pseudomonas sp. (15 isolates), Flavobacterium sp. (8 isolates) and Rahnella aquatilis (2 isolates). Both E. americana and Pseudomonas sp. which are assumed to be closely associated with PWN were examined for their phytotoxicity to P. thunbergii seedlings. Ethyl acetate extracts of Psuedomonas sp. (Ba2 strain) cultures were found to induce wilting and mortality in the tested seedlings. The three bacterial species, Pseudomonas sp. (Ba2 strain), E. ameircana (Ba4 strain) and C. neteri (Ba10 strain) were examined in vitro for their sensitivity to 21 kinds of antibiotics. All of the strains were highly susceptible to carbenicillin, doxcycline and tetracycline.