Quality Evaluation and Fourier Transform Infrared (FTIR) Spectroscopy Characterization of Vodka Produced from Malted and Un-malted Potatoes Using Saccharomyces cerevisiae (MK680910)

The present study aims to evaluate the suitability of un-malted (raw version) and malted (sprouted) potato variety Kufri Pukhraj for the production of vodka using the brewing yeast strain Saccharomyces cerevisiae (MK680910). Both un-malted and malted potatoes were subjected to 72 h of fermentation and valuated for changes in total sugars, reducing sugars and ethanol conversion. Results showed that with an increase in fermentation time from 24 to 72 h, the content of total and reducing sugars decreased significantly (p < 0.05), resulting in a significant increase in the ethanol concentration. After 72 h of fermentation, malted potato produced the best results, with a greater substrate-to-product conversion (0.47 g ethanol g⁻¹ reducing sugars), a higher fermentation yield (91.97%), and higher ethanol content (9.82 percent v/v). Following fermentation, double distillation, clarification with activated charcoal, blending, and sensory analysis with different flavours were conducted. Vodka with ethanol concentration of 41.3% v/v was produced having 82.6 proof. Vodka blended with lemon was found to be more preferred with mean score of 8 and was of standard quality. The structural characterisation of the FTIR spectrum band at 1000 cm⁻¹ analysis correlates to C-O stretching in the volatile components and showed the presence of ethanol in the vodka.