Evaluating the feasibility of wine production using sugarcane juice as the substrate

Abstract

Sugarcane juice would be an ideal substrate as it contains 94 – 98.5 % sugars (Sucrose, glucose, and fructose); 1.5 – 6% non – sucrose components (amino acids, proteins, starch). In addition, Vietnam is considered as one of the major sugar producers and consumers in the world. There has been little understanding in feasibility of wine or alcoholic beverage production from sugarcane juice. Therefore, the main object of this research was to evaluate, sugarcane juice utilization and ethanol production of different yeast strains which were previously isolated from sugar enriched fermented fruits. In addition, natural fermentation utilizing the microbial communities in the sugarcane juice was also conducted for comparison. After 7 days of fermentation, samples were collected for the measurements of microbial growth (OD600), ethanol production (by GC), total reducing sugar (using DNS assay), and total soluble solids (Brix). The glucose utilization was used to construct by Excel software at 540nm wavelengths. The first fermentation of reducing sugar after putting different yeast strains into sugarcane juice was 1.519g/L. After 7 days of fermentation, banana yeast peaked at 0.652 g/L, the other strains decreased to around 0.06g/L. In terms of total soluble solids, the first fermentation of the medium was 18 ºBrix. After 7 days of fermentation, banana yeast strains were moderate fallen to 16 ºBrix, which was over triple as much as the amount of ambarella yeast, at around 5 ºBrix. During fermentation, all the yeast strains were able to produce alcohol concentration. The amount of ambarella yeast accounted for the highest alcohol production, at 87 g/L. As a result, strain from ambarella as member of Saccharomyces genus were chosen for the culture combining sugarcane juice with green tea or sugarcane juice without adding green tea. After calculation, every culture was not affected deeply on the growth of ambarella yeast in particular the ethanol made up around 58g/L, sugar concentrations stood at nearly 0.055g/L.