Gold kiwifruit was fermented with Lactobacillus plantarum CK10 derived from kimchi and the fermented products were extracted with ethanol at various fermentation time-points The bacterial cellular density, total titratable acidity, total polyphenol content (TPC), and total flavonoid content (TFC) increased during fermentation, while pH values and total soluble solids decreased. Levels of TPC and TFC were highest after five days, at 1.21±0.13 mg GAE/g dry weight and 0.36±0.04 mg RE/g dry weight, respectively. The antioxidant activities of the fermented gold kiwifruit were analyzed using Fe2+ chelating activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH)-, and 2,2'-azino-bis(3- ethylbenzothiazoline-6-sulphonic acid) (ABTS)- radical scavenging activities, and superoxide dismutase (SOD)-like activity. The Fe2+ chelating activity of gold kiwifruit (125-500 μg/mL) peaked after five days of fermentation at 38.40-78.47%. The DPPH radical- scavenging activity and SOD-like activity were somewhat higher after seven days of fermentation (36.01-86.81% and 54.79-93.83% at 2.5-10.0 mg/mL concentration of samples, respectively). On the other hand, the ABTS radical- scavenging activity of fermented gold kiwifruit was similar to that of the non-fermented form. The polyphenol and flavonoid contents were significantly correlated with the antioxidant activity. In conclusion, our results suggest that TPC, TFC, and antioxidant activity were increased after five and seven days of fermentation, respectively. Therefore, fermented gold kiwifruit with its increased antioxidant activity could be useful in the development of functional foods.

The objective of this study was to compare antioxidant activities of green tea, rosemary, lemon and bamboo leaves extracts using three different extraction methods (80% ethanol sonication extraction, distilled water autoclave extraction, distilled water extraction at room temperature). As a result, green tea and rosemary extracts showed relatively high antioxidant activities compared with those of lemon and bamboo leaves. These green tea and rosemary extracts were subsequently added to soymilk and their mixtures were examined for antioxidant activities. Soymilk added with 10% green tea distilled water autoclave extracts and distilled water at room temperature extracts showed relatively high DPPH, 85.09±2.26%, 84.38±1.97%, and ABTS radical scavenging activities, 73.43±2.78%, 81.34±4.78%, respectively. On the other hand, soymilk added with 10% rosemary distilled water autoclave extracts showed remarkably higher DPPH radical scavenging activity while their ABTS radical scavenging ability was similar to that of non-added soymilk. In conclusion, our results suggest that the addition of green tea distilled water autoclave extracts, distilled water at room temperature extracts and rosemary distilled water autoclave extracts to soymilk could contribute to the development of added value soymilk products with increased antioxidant activities.