Fermentative production of rice vinegar using Pichia kudriavzeii and Acetobacter aceti cultures

Rice vinegar was produced using two rice varieties; Basmati (PUSA 1121) and Parmal (PR 116) through submerged fermentation using Pichia kudriavzeii and Acetobacter aceti scaled up to 5 litres. The lab experiments utilizing 8% (w/v) ethanol wine produced 6.51% (w/v) acidity in 28 days for var. PUSA 1121 and 5.08% acetic acid in 25 days for var. PR 116. The scale-up fermentation (5 litres) yielded 5.10% acetic acid in 45 days with 70% recovery (PUSA 1121) and 4.86% (w/v) volatile acidity in 40 days with 74% recovery (PR 116). Elemental analysis (mg/l) showed fermented vinegar to contain Na (527.1 and 183.6), K (323.5 and 379.2), P (227.9 and 450.1), S (670.1 and 761.2), Zn (5.9 and 2.8) and Fe (9.5 and 6.5) for PUSA 1121 and PR 116 vinegar samples, respectively. Qualitatively analysis indicated presence of alanine, leucine, isoleucine, histidine and tryptophan amino acids in the two vinegars.