A total of 87 kinds of dried sweet potato products from Korea, China, and Japan were collected to compare dried sweet potatoes' quality characteristics for preparing CODEX. The characteristics of Aw, moisture, and reliable soluble content, color, and hardness were analyzed using Principal Component Analysis. The moisture content varied from country to country in order of Korea (21%), China (20%), and Japan (25%). In terms of color, Chinese products were dark and red compare to Korean and Japanese. Chinese products had a wide distribution of quality characteristics in common, so the product quality was not uniform. As a result of the PCA analysis, 67.2% of the total variance was explained. The first component evaluated the degree of the drying progress and the second component evaluated the appearance of the product, how it was bright and yellow. Based on the first component, Japanese, Korean and Chinese products were placed from the left, so the drying degree varied from country to country. Japanese products were the softest, Chinese products were hard, and Korean products were moderately hard. In conclusion, the moisture and reliable soluble content, color, and hardness of the dried sweet potato are essential quality factors, and they are expected to help identify the primary quality elements of sweet potato in neighboring countries.

The aim of this study was to investigate the effect of pretreatments on quality of frozen peach. Pretreatments including steam blanching, water blanching, high pressure, and osmotic dehydration were applied to two varieties (Daeokgye and Hwangdo). Pretreated peaches were frozen and thawed at -20oC and 5oC, respectively. Steam blanching and osmotic dehydration with ascorbic acid reduced ΔE values without change of pH and acidity. Osmotic dehydration with sucrose decreased drip loss and increased brix. Freezing/thawing resulted in an increase of maximum force, while maximum force decreased with increasing time of steam and water blanching. Furthermore, osmotic dehydration with calcium chloride increased maximum force. High pressure decreased maximum force of Daeokgye and increased that of Hwangdo compared with non-treatment. Total polyphenol content, DPPH radical scavenging activity, and ABTS radical scavenging activity were improved by pretreatment including steam blanching, blanching, and osmotic dehydration with ascorbic acid.