This study was designed to investigate the contents of icariin during ripening of Epimedium koreanum with sugar and Soju (25, 30, and 35% alcohol contents) using a homemade method. Contents of icariin of Epimedium wine were examined using high performance liquid chromatography. Icariin levels in Epimedium wine increased during the first 3 days of storage; after 6 days, icariin contents decreased gradually until 30 days. Contents of icariin in Epimedium wine by storage temperature (5 and 20°C) were not different during storage. After 30 days, icaiin was not detected in all tested Epimedium wines. Epimedium wines were assessed for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azinobis( 3-ethylbenzothiazoline-6-sulfonic acid) and (ABTS) radical scavenging activity. DPPH and ABTS radical scavenging activities increased in early storage periods, however, after 6 or 9 days, activities decreased gradually.
This study examined the total glucosinolate (GSL) and isothiocyanate (ITC) contents according to different processing conditions; fresh Kimchi cabbage (Brassica rapa L. ssp. pekinensis), salted Kimchi cabbage and kimchi (storage temperature 4℃ and 20℃) using two different cultivars (Bomatnorang and Chunkwang). Four GSL peaks representing gluconapin, glucobrassicanapin, glucobrassicin and 4-methoxyglucobrassicin were detected in Kimchi cabbage by HPLC and HPLC/MS analysis. The total GSL contents of fresh Kimchi cabbage of Bomatnorang and Chunkwang were 21.37±1.06 μg/g dry weight (DW) and 20.96±3.33 μg/g DW, respectively. After salting, the total GSL contents of salted Kimchi cabbage decreased by 39% and 52% in Bomatnorang and Chunkwang, respectively. Finally, the total GSL contents of kimchi after storage at 20℃ decreased by 83% and 56% in Bomatnorang and Chunkwang, respectively. The extracted ITC contents were analyzed by GC/MS. Three ITC peaks were detected in Kimchi cabbage representing 2-phenylethyl ITC, 3-butenyl ITC and 4-pentenyl ITC. The 2-phenylethyl ITC levels increased during the salting process but this generally fell during storage at 20℃ as kimchi. The 3-butenyl ITC levels of Kimchi cabbage according to processing decreased rapidly due to salting and then decreased slowly during storage as kimchi. The 4-pentenyl ITC of Kimchi cabbage was lost during the salting process. The results for the change in GSL and ITC contents during the kimchi making process will be used in the food industry.