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.

Fermented halla gold kiwifruit (FHK) was prepared with Lactobacillus plantarum CK10, a bacterium derived from kimchi. We investigated the quality characteristics and antioxidative activity of madeleine added with FHK. The madeleine dough was prepared by mixing flour, sugar, baking powder, and then followed by adding salt, rum, different amount of the FHK (0, 1, and 3%) and butter. The total titratable acidity of madeleine increased significantly with the amounts of added FHK (p<0.05), while the pH value and total soluble solids showed the reverse trend. The color of madeleine became substantially redder with increasing amounts of FHK (p<0.05), and it appeared darker and less yellow at the same time. The total polyphenol contents of madeleines increased significantly with increasing amounts of FHK (p<0.05), but there was little difference in the total flavonoid content. When the antioxidant activities were measured in terms of 2,2-diphenyl-1-picrylhydrazyl (DPPH)- and 2,2’-azino-bis-3-ethylbenzothiazoline- 6-sulfonic acid-diammonium salt (ABTS)- radical scavenging, both measured activities of madeleines increased dramatically with added FHK in a dose-dependent manner. Our results suggested that the acidity, color, polyphenol content, and antioxidant activities of madeleines can be improved by adding the fermented gold kiwifruit.

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.

In this study, antioxidant activities and physicochemical properties of chocolate fermented with Lactobacillus plantarum CK10 were investigated. The pH level decreased from 5.26±0.02 to 3.98±0.06 during fermentation while titratable acidity increased from 5.36±0.19 to 13.31±0.34. The total polyphenol and flavonoid contents slightly increased during fermentation, but it was numerically negligible. Slight increase and decrease in the radical scavenging activities of chocolate, against DPPH-, ABTS-, and alkyl- radical, were observed during 32 hr of fermentation, but the changes were not statistically relevant. Composition ratios (% area by GC analysis) of lactic acid, xanthosine, and theobromine increased with fermentation time while hydroxymethylfurfural (HMF) and caffeine decreased after 32 hr of fermentation, in the order of xanthine (22.7%), theobrome (20.0%), lactic acid (14.9%), HMF (9.1%) and caffeine (9.0%). However, there was no remarkable changes in theobromine and caffeine contents in chocolate during fermentation.