Utilization of over-ripened fruit (waste fruit) for the eco-friendly production of ethanol

Abstract

This research was carried out to produce ethanol for use as a sanitizer in today’s COVID-19 pandemic situation, via cost-effective and eco-friendly techniques. The waste of seasonal fruit, i.e. apple, grape and Indian blueberry, was used in the study. Saccharomyces cerevisiae (baker’s yeast) was used with KMnO4 (5%), sucrose (47 g) and urea (1.5 g) for the fermentation process. All the selected overripe fruits were analyzed for variations in parameters including specific gravity, pH, temperature and concentration during complete fermentation for ethanol production. After complete fermentation, it was clear that the use of Indian blueberry at a temperature of 33 °C, specific gravity of 0.875 and pH value of 5.2 yielded the highest ethanol concentration of 6.5%. The concentration of ethanol obtained from grape samples was 5.23% at 30 °C with specific gravity of 0.839 and pH 4.3. Lastly, the ethanol concentration obtained from apple waste was about 4.52% at 32 °C with specific gravity of 0.880 and pH of 4.7 pH. The FTIR curve of each sample shows an absorbance peak in a wave number range of 3000 cm−1 to 3500 cm−1, which indicates the absence of alcohol in the samples after fermentation.