Ginseng berry contains high amount of ginsenosides, especially Re, which shows various beneficial effects such as anti-cancer, neuroprotective, and anti-inflammatory activities. The amount and kinds of ginsenosides in ginseng berry change according to the extraction and processing methods. The purpose of this study was to establish the optimized extraction process for obtaining ginsenoside Re in ginseng berry. And then, to establish the optimum condition of fermentation by Lactobacillus sp. strain KYH for improvement of bioavailability.
The variations of extraction were the ratio of ethanol to water, (20, 50, 70 and 100%), temperature (50, 60, 70, 80 and 90℃), time (2, 3, 4, 5, and 6 h) and extraction replication (1, 2, 3, 4 and 5 times). The ginsenoside Re, Rg1, Rd and total crude ginsenosides from ginseng berry were evaluated by TLC. Optimized conditions for extraction was 70% to 30% of the ratio of ethanol to water, 80℃ of extraction temperature, 4 h of extraction time and 2 times of extraction replication.
Lactobacillus sp. strain KYH isolated from fermented kimchi was used for fermentation of ginseng berry. Fermentation was performed in a 5 L fermenter containing 3 L of ginseng berry extract at 200 rpm for 72 h according to variations: temperatures, pH and fermentation type (batch and fed-batch). Ginsenosides, antioxidant activity, organic acids, amino acids and sugars contents were analysed. Fed-batch fermentation with 30℃ and pH was set up for optimum condition.
The amounts and compositions of ginsenosides, organic acids, sugars and amino acids in fermented ginseng berry were altered, compared to those in unfermented one. Ginsenoside Re was a major ginsenoside in ginseng berry, regardless of fermentation. However, after fermentation, amounts of ginsenosides Rb1, Rc, and Rd reduced, whereas amounts of ginsenosides Rh1 and Rh2 increased. Total phenol content increased to 43.8%, whereas flavonoid content decreased to 19.8%. The DPPH radical scavenging activity and total antioxidant activity increased to 27.2 and 19.4%, respectively, compared to before fermentation.