The Effects of Seasonal Variation on Bioethanol Yield from Fermented Bamboo Juice Supplemented with Scant mango Fruit at the Verge Stage

Objective The study examined the impact of seasonal variation on the quality of bioethanol produced from bamboo juice through fermentation and distillation, focusing on differences between dry and rainy seasons. Bamboo juice samples were supplemented with small amounts of mango fruit at the verge-stage to enhance enzymatic hydrolysis and fermentation efficiency. Methods Fresh bamboo juice was collected from bamboo farms using “ mbeta ” and allowed to ferment at room temperature. To enhance hydrolysis and fermentation efficiency, the fermenting juice was supplemented with mango fruit at the verge stage. The fermented juice was distilled at a controlled temperature of 78 °C to obtain high-quality bioethanol. Results The total soluble solids (TSS) of bamboo juice were significantly higher in the dry season (10.01 ± 0.04 °Brix) than in the rainy season (5.30 ± 0.08 °Brix), reflecting a higher concentration of fermentable sugars during the dry period. The results demonstrated higher fermentation efficiency in the dry season, achieving a maximum alcohol by volume (%ABV) of 5.15%, compared with 4.14% during the rainy season. The findings showed bioethanol concentrations of 39% (v/v) in the dry season compared with 35% (v/v) in the rainy season for the first 100 mL aliquot from distillation. Subsequent redistillation increased bioethanol purity to 87% (v/v), rendering it suitable for fuel-grade applications. Conclusion These results demonstrate that bamboo juice harvested during the dry season contains higher levels of fermentable sugars and yields superior bioethanol quality, highlighting seasonal timing as a critical parameter for optimizing bamboo juice-based bioethanol production.