Jung-Min Sung

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.

Quality Characteristics and Microbial Hazard Analysis of Commercial Garlic

This study investigated the quality characteristics and microbial hazards of commercial garlic available in supermarkets, traditional markets, and online shopping malls. Total bacterial counts were 2.55 log CFU/g in whole garlic and 5.20~7.40 log CFU/g in processed garlic, possibly due to contamination during processing. The total bacterial count from garlic purchased in supermarkets was below 5 log CFU/g, while garlic purchased in traditional markets and online shopping malls had counts of 3.87~6.34 and 3.73~6.11 log CFU/g, respectively. Thus garlic purchased at supermarkets appears to be more hygienic than garlic from traditional markets or online shopping malls. Some garlic purchased from supermarkets also had a lower pH (4.96~5.17) compared to fresh chopped garlic (7.4~7.5), likely due to the addition of citric acid and ascorbic acid, to reduce microbes and prevent browning. The moisture content of chopped garlic was 61.92~89.32%, with moisture content in imported garlic from China above 75%. The L, a, and b color values were 52.63~64.47, -3.74~8.75, and 10.67~ 17.88, respectively. The a and b values of supermarket garlic (-3.74~-3.20 and 10.67~13.90) were lower due to the addition of citric acid.

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.