Jin-Woong Jeong

Effect of salinity stress on phenolic compounds and carotenoids in buckwheat (Fagopyrum esculentum M.) sprout

The effect of salinity stress on the nutritional quality of buckwheat sprouts cultivated for 1, 3, 5, and 7d was investigated by analysis of the antioxidant activity and levels of phenolic compounds and carotenoids. Treatment with various concentrations of NaCl (10, 50, 100, and 200mM) resulted in an increase in the amount of phenolic compounds and carotenoids in the sprouts compared with the control (0mM). The phenolic contents of sprouts treated with 10, 50, and 100mM after 7d of cultivation were 57%, 121%, and 153%, respectively, higher than that of the control (0mM NaCl). Moreover, the accumulation of phenolic compounds was primarily caused by an increase in the levels of 4 compounds: isoorientin, orientin, rutin, and vitexin. The carotenoid content of sprouts treated with 50 and 100mM NaCl was twice higher than that of the control. In addition, the antioxidant activity of ethanol extracts of the sprouts was increased by NaCl treatment. Although the growth rate of sprouts decreased with >50mM NaCl, these results suggest that treatment of an appropriate concentration of NaCl improves the nutritional quality of sprouts, including the level of phenolic compounds, carotenoids, and antioxidant activity.

Quality Characteristics of Kimchi Fermented with Abalone or Sea Tangle Extracts

This study evaluated the quality characteristics of fermented abalone-kimchi or sea tangle-kimchi during 28 days of storage at . Abalone and sea tangle were added as extracts compared to a control. We analyzed lactic acid bacteria, pH, acidity, salinity, reducing sugars, free sugars, organic acids, free amino acids, and sensory characteristics. The lactic acid bacteria levels were 4.4~5.3 log CFU/g on day 0, 6.8~7.1 log CFU/g after 7 days, and continued to rise during the fermentation period. The salinity increased slightly over time. As fermentation progressed, pH and reducing sugars, free sugars, and organic acid contents decreased. Free sugars, in particular, dramatically decreased about 70% compared to the initial day. The total free amino acid content was higher in abalone-kimchi. In terms of free amino acid contents, taurine was high in abalone-kimchi, while glutamic acid and aspartic acid content was high in sea tangle-kimchi. The sensory evaluation results show that abalone-kimchi and sea tangle-kimchi had higher scores for their savory taste and overall acceptance compared to the control.

Characteristics Evaluation and Development of Peach Washing System

This study was conducted to find condition of improving the quality of peach by using surfacing washing system. The rate of weight loss of A,B groups were showed slower decreasing trend than CT group and the value of soluble solid degree was not different significantly among all groups from the results of stored peach treat with surface washing system of peach in the first experiment. The colory value of surface were increased with increasing storage period in all treatments. Browning pace of A,B groups were slower than control. Emission of carbon dioxide was increased from the results of respiration rate, 6-10 mL/kg/hr and 32-41 mL/kg/hr . In second experiment with surface washing system of peach, the value of soluble solid was showed with similar value from 10 to 13 . The pace of soft rot of EW groups were lower than CT groups from the results of hardness during storage period. The results of colory value was not showed with significant difference in and storage temperature but changed to browning in EW groups. The moisture contents was from 85% to 90% in all groups. And the count of total microorganism of EW groups were lower than control. Also total coliform of EW groups were negative. In sensory evaluation, washing peach was showed higher value with significant difference in all acceptability.

Removal Effects of Microorganism and Pesticide Residues on Chinese Cabbages by Electrolyzed Water Washing

This study investigated the washing efficiency of electrolyzed water for the removal of microorganisms and pesticide residues from Chinese cabbage. Initial total bacteria and coliform counts were 6.64 and 3.56 log cfu/g respectively. After washing, total bacteria count of tap water (TW) were 5.97 log cfu/g and low alkaline electrolyzed water (LAlEW) and strong acidic electrolyzed water (SAcEW) were 1.63-4.67 log cfu/g. Especially SAcEW-100 was found to the most effective method of washing the cabbages. After washing, the coliform count was dramatically reduced. The removal rate of pesticide residues by NaClO treatment (36.93-50.13%) was greater than that of TW treatment (32.28-38.46%). The removal rate of LAlEW-100 and SAcEW-100 was 63.79 and 78.30% respectively, and was higher than those of TW and NaClO treatments. The vitamin C content of the Chinese cabbages after all treatments did not differ significantly. Consequentially, the electrolyzed water was found to be effective to remove bacteria and pesticide residues from Chinese cabbage without affecting quality.

Analysis of hazard on fresh and salted baechus (nappa cabbage, Brassica rapa L. subsp. pekinensis) in Korea

Risk factors, such as microorganism, parasite eggs, pesticide residues, and heavy metal in fresh and salted baechus (napa cabbage, Brassica rapa L. subsp. pekinensis) were analyzed once a month from April 2010 to March 2011. Total bacterial population of salted baechu in summer (2.08–5.11 log CFU/g) was higher than that in winter. Also, coliform population in salted baechu during winter decreased by 2 log CFU/g as compared with that in summer. Pesticide residues and parasite eggs were not detected in any salted baechu. Pb was detected at 0.06 ppm in the winter salted baechu, but the lever was lower than the residue tolerance of the Korea food code. The pH of salted baechu during a 1-year period showed the lowest level at 4.76–5.22 in August and then gradually increased. The microbe results showed a high correlation with the pH of the salted baechu.

Study on Process Development of Ginseng's Surface Washing System

This study was attempted to develop surface washing-system of ginseng. The effect of sterilization, washing and keeping freshness of ginseng through analyzing unit process were examined to establish optimal condition for washing system. Surface washing method of fresh ginseng used two way and full cone spray type. Sterilization was used at water with electrolysis water of 50 and 80 ppm. Ginseng was sterilized with electrolysis water during 30 and 60 s, dehydrated during 1 min and dried during 1min at 30 and . Hardness of surface-washed ginseng showed good result on 1 min spraying time with 80 ppm electrolysis water at storage. Ginseng with 80 ppm electrolysis water was sterilized better with . There are no changes with 0% on appearance quality at 80 ppm electrolysis.