Dr. Gurvinder Singh KocherHarmandeep Kaur2024-06-282024-06-282024Harmandeep Kaur (2024). Brewed vinegar production using different varieties of rice (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.https://krishikosh.egranth.ac.in/handle/1/5810211103Brewed vinegar production from black rice was produced by enzymatic saccharification of grounded rice followed by ethanolic fermentation and acetic acid fermentation (both batch and semicontinuous). Enzymatic saccharification of black rice was carried out using optimized amount of commercial amylases. Optimization of enzymatic saccharification parameters (carried out by RSM) revealed that at 45°C with 5.5 pH, the saccharified starch showed brix of 13.5°B with 10.937 g/100ml and 8.602 g/100ml reducing sugars, respectively. The Saccharification validation of 1L based on optimized parameters showed a maximum of 14.2°B, 13.61 g/100ml total sugars and 11.35 g/100ml reducing sugars. The ethanolic fermentation of hydrolyzed starch was carried using Saccharomyces cerevisiae KY069279 under optimized parameters of Brix and inoculum concentration (carried out using RSM). The solutions revealed that 8% inoculum concentration alongwith 13.167°B produces 4.362% ethanol content with 0 g/100ml residual sugars and 1.399 mg/100ml total phenols. The validation of ethanolic fermentation led to 6.89 % v/v ethanol with fermentation efficiency of 96.12% and 0.49 g/g of ethanol productivity. Following ethanol production, the acetic acid fermentation was carried out by two methods- batch and semicontinuous using indigenous acetic acid bacteria, Acetobacter aceti AC1. The Batch fermented vinegar showed 4.23% w/v acidity with 52.9% fermentation efficiency and 0.69 g/g acetic acid productivity. The produced rice vinegar was found to be rich in antioxidants with 77.8% DPPH scavenging activity at 78.48μM concentration. The Semicontinuous fermentation was executed by adsorbing inoculum on wood shavings for 15 h in plastic fermenter with three different packing lengths that lead to maximum of 3.83% acidity (3/4th length) with 57.3% fermentation efficiency. The rice vinegar showed 67.12% of antioxidant activity at 61.07μM concentration. Among both type of vinegars, batch vinegar was found to of standard quality in terms of sensory evaluation by the panelists.EnglishThesis