PREPARATION OF MAHUWA (Madhuca longifolia) FLOWER WINE FROM ISOLATED NATIVE YEAST

Abstract

Mahuwa (Madhuca longifolia) flowers and murcha samples from Gadhawa Gaunpalika, Ward No. 08 (followed by a brief survey) were screened for fermentative yeast to study the effect of different yeasts and pH levels on the chemical and sensory quality of mahuwa wine. Yeasts were screened by culturing on MYPG and molasses agar media at 30°C for 2-3 days. The isolates that could ferment molasses broth at a low pH were utilized for must fermentation, while the others were rejected. Yeast isolates were characterized based on colony morphology, microscopic characteristics, fermentative capacity. Furthermore, mahuwa juice was subjected to a 21-day of the fermentation period at room temperature (25±2°C), nine (9) treatment combinations were used, each including three varieties of yeasts, viz., Fy1 (mahuwa flower yeast), My2 (murcha yeast), and Wy3 (commercial wine yeast) at three pH values (3, 3.5, and 4). Fermentation kinetics for total soluble solids (TSS), titratable acidity and yeast growth were also studied. The quality of wines prepared using Fy1, My2, Wy3 were assessed and compared by chemical analyses (ethanol, higher alcohols, esters, aldehydes, total phenolic content, and acidity) and sensory evaluation (7-point hedonic rating for the attributes appearance, odor, mouthfeel, finish, and overall acceptance). The survey showed engagement of 53% of the households of Gadhawa Gaunpalika, Ward No. 08 in mahuwa spirit production, with an annual income of ~ NRs 40000.0 per household. Variations in yeast strain and pH of mahuwa must had a considerable (p ≤ 5%) effect on wine quality and fermentation kinetics. After 21 days of fermentation of mahuwa flower juice, sample E (fermented using isolated murcha yeast at pH 3.5) wine was found to have the best sensory quality. Upon physicochemical analysis, the best sample had the following characteristics: ethanol (12.13±0.23% abv), total titratable acidity (0.97±0.07% as lactic acid), volatile acidity (0.083±0.006% as acetic acid), fixed acidity (0.84±0.08% as lactic acid), total phenolic content (250.7±5.3 mg GAE/L) of wine), esters (236±6.7 g ethyl acetate/100 L), aldehyde (148.8±4.3 g aldehyde /100 L) and higher alcohol 181.7±6.6 mg/L. It can be concluded that all fermentative yeast types can be used to prepare mahuwa wine, but a pH of 3.5 appears to be the best condition. Further, the physicochemical properties (ethanol, methanol, esters, aldehydes, etc., in particular) either do not necessarily relate or are too complex to relate to the sensory quality of mahuwa wines.