Study on ability of growth and alcoholic fermentation of yeast strain NM3.6 in leaves extract of Perilla frutescens (L.) Britton

Perilla frutescens (L.) Britton is well known as an herb and also a medicinal plant in Vietnam and many East Asian countries. Perilla juice (Shiso) is a familiar drink of the Japanese; however, there are very few studies on the alcoholic fermentation of perilla juice to produces alcoholic beverages. In this study, we investigated the growth and fermentation ability of yeast strain NM3.6 in perilla leaf extract to produce a low alcoholic beverage. The results showed that this strain grew well in perilla leaf extract supplemented with sucrose 70 g\L, pH 5. The OD610 value of 18.2 was obtained after 24 hours of cultivation at 30 °C and 180 rpm. This strain also performed a good fermentation ability of perilla leaf extract supplemented with 200 g\L of sucrose, pH 4.5, and 10% of seed culture. After 9 days of the main fermentation at 30 °C and 14 days of the secondary fermentation at 10 °C, alcoholic content reached 3.22% (v\v) and fermentation efficiency reached 57.6%, sensory scored 16.7 points. The fermented perilla leaf extract had unchanged flavonoid content, total phenolic content (0.235 mg\mL) was higher compared to that of the original leaf extract (0.196 mg\mL). This alcoholic fermentation juice met a standard of sensory and quality for low alcoholic drinks fermented from fruit and vegetable extracts.