Yong-Soo Hwang

Two Species of Penicillium Associated with Blue Mold of Yam in Korea

During 2007 survey of post-harvest diseases of yam performed in May and June, severe tuber loss caused by blue mold was observed in Iksan, Cheonbuk Province. Two species of Penicillium were isolated from the infected tubers. Based on β-tubulin gene sequence analysis, and cultural and morphological characteristics, the isolates were identified as Penicillium sclerotigenum and P. polonicum. P. sclerotigenum, which is a novel to Korea, is presently described and illustrated.

Effect of Postharvest High CO 2 Treatment and Anti-moisture Pad on the Quality of Fresh Oyster Mushroom during Export Simulation

This study was aimed to find factors responsible for export potential of oyster mushroom through postharvest treatments including high pressure and anti-moisture pad. Temperature fluctuation during export simulation induced the condensation of excess moisture resulting in the quality loss due to browning and decay. Anti-moisture pad was effective on inhibition of browning occurrence in part. High temperature exposure () as retail simulation greatly offset the positive effect of anti-moisture pad. Short term treatment of high pressure delayed the surface color changes as hunter L, a, and b values. There was no consistent tendency in total sugar and phenolics between treatments. In general, the export potential of small size mush-room (export size) at harvest was higher than large ones (domestic size). The major factors asso-ciated with the quality decrease of oyster mushroom during export were moisture condensation in packages and temperature fluctuation. Further research is required to improve mushroom export procedures.

수확 후 고농도 CO₂ 단기처리가 ‘매향’ 딸기의 저장에 미치는 영향

This experiment was conducted to examine the effects of a short-term treatment of high pressure CO2 on shelf-life of strawberry fruit. A short-term treatment (12 hr) of 100% CO2 resulted in the increase of fruit firmness up to 71.9% compared to that at harvest. The firmness of CO2 treated fruit remained a significantly higher than that of control (air) up to 15 days. The alteration of pectic polymers was observed by CO2 treatment such as an increase of EDTA soluble pectins and decrease of water soluble ones. The CO2 treatment resulted in the increase of total amount of wall bound calcium. Pectate lyase activity, an important agent of strawberry fruit softening, was also significantly reduced by CO2 treatment.