• Journal of the Korean Society of Food Culture
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• v.8 no.3
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• pp.267-274
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• 1993

This study was aimed to investigate the changes in textural properties of Korean radish and relevant chemical, enzymatic activities during salting. During salting, pH was decreased and total acidity was increased. The maximum compression and puncture forces of Korean radish were decreased significantly whereas cutting force was increased. From the force-distance curves, the break point and maximum force point disappeared in salted Korean radish whereas these appeared apparently in fresh one. Also, the number of peak obtained by three types of test from salted Korean radish was decreased. Hot water soluble pectin and 0.4% Na-hexametaphosphate soluble pectin were increased whereas 0.05 N-HCl soluble pectin were decreased significantly. Polygalacturonase activity were increased in Korean radish solid(RS) and Korean radish juice(RJ) until 4 days of salting. Pectin esterase activity were decreased in RS and RJ. Cx-cellulase activity did not appear initially, however, they began to show their activities after 2 days of salting and were increased in RJ although it was low.

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.319-327
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• 2000

This study was conducted to prolong the edible period of Kimchi by adding chitosan (0.25, 0.5%) and sodium salts of various organic acids(0.01~0.04M citrate, malate, lactate) . The edible period was estimated by measuring changes in pH. titratable acidity(TA), PH/TA ratio, ascorbic acid content and pectin fraction during Kimchi fermentation at 2$0^{\circ}C$. The results were compared by estimating the maturity of Kimchi fermentation. Kimchi with the chitosan showed higher pH and titratable acidity throughout the fermentation period than that without chitosan. The pH decreased during the fermentation in the order of control, 0.25% chitosan, 0.5% chitosan, 0.5% chitosan+Na-citrate, 0.5% chitosan+Na-malate and 0.5% chitosan+Na-lactate. But the titratable acidity increased in the order of control, 0.5% chitosan+Na-malate, 0.25% chitosan. 0.5% chitosan+Na-citrate, 0.5% chitosan and 0.5% chitosan+Na-lactate. The PH/TA ratio decreased in the order of control, 0.25% chitosan, 0.5% chitosan+Na-malate, 0.5% chitosan, 0.5% chitosan+Na-citrate and 0.5% chitosan+Na-lactate. Ascorbic acid content in Kimchi was the highest at the 3rd day and then decreased during fermentation. Ascorbic acid content in Kimchi containing 0.5% chitosan and organic acid salts was higher than others. Alcohol insoluble solids( AIS ) in Kimchi decreased during fermentation in the order of control, 0.25% chitosan, 0.5% chitosan, 0.5% chitosan+Na-palate. 7.5% chitosan+Na-lactate and 0.5% chitosan+Na-citrate. During fermentation, hot water soluble pectin (HWSP) of control increased, whereas HCI soluble pectin (HCISP) decreased. By addition of chitosan, however, the results became reverse. Chitosan addition appeared to be effective in improving preservation quality of Kimchi during fermention. The edible period become extended by using chitosan plus organic acids instead of using chitosan only. Overall. addition of 0.5% chitosan+Na-lactate seemed most effective in prolonging the edible periods during Kimchi fermentation.