Total Phenolic, Resveratrol Content, Antioxidant and Antimicrobial Activity in Five Cultivars of Peanut Sprouts

Abstract

Peanut sprout is one of the potential natural sources of bioactive substances. In this study, five different peanut cultivars were conducted to germination, the change in total phenolic compounds, resveratrol content, antioxidant and antimicrobial activity were investigated. The sprouts of five peanut cultivars (Fuhua, Silihong, Dabaisha, Xiaobaisha and Huayu) were extracted using 75% ethanol for 3 h and the crude extracts were collected. When the five peanut kernels were germinated at 25°C for 5 days, the total phenolic compounds increased significantly from range of 0.55 to 0.96 (μg Gallic acid/g) up to the range of 1.97 to 2.44 (μg Gallic acid/g) and the resveratrol contents showed similar trend, from range of 8.94 to 15.62 μg/g up to the range of 31.74 to 46.49 μg/g depending upon peanut cultivar. Among the five cultivars, Xiaobaisha showed the highest phenolic content [2.44 (μg Gallic acid/g)], expressed the highest 2,2-diphenyl-1-picrylhydrazyl scavenging value [(84.86±4.02) mmol/L TE/g dry weight] and ferric ion reducing antioxidant power scavenging value [(92.98±3.71) mmol/L TE/g dry weight] on the fifth day. In the antimicrobial evaluation the five sprout extracts were highly effective in inhibitory zone assay followed by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) analysis against five pathogen microbial. In comparison with other peanut cultivars, the inhibitory effects were strongest in Silihong, the average MIC and MBC values against 5 spoilage bacteria were 10.66 and 28.52 mg/mL, respectively. In summary, this work provides evidences that Xiaobaisha and Silihong might be applied as antioxidant and antibacterial agent in food and pharmaceutical industries.