Abstract:
The objectives of this study were to study of fermented vinegar processing from non-glutinous dark purple rice by studying acetic bacteria that are suitable for fermented vinegar production from pigmented rice. In addition, to study nutritional value, chemical composition, total phenolic and total anthocyanin content, and antioxidant activity of fermented vinegar from non-glutinous dark purple rice. Raw material uses through this research was non-glutinous dark purple rice (Mali-Nil Surin rice). Acetobacter aceti TISTR 103 and 354 were used for screening strain of acetic acid bacteria that are suitable for fermented rice vinegar. Folin-Ciocalteu Method and pH Differential Method were used for determination of total phenolic and total anthocyanin content, and antioxidant activities were measured using ABTS assay and FRAP assay. The results found that Acetobacter aceti TISTR 103 and 354 were suitable for fermented rice vinegar. Acetic acid content followed by standard of vinegar in Thailand. The percentage of acetic acid was 4.8% and 4.76%, respectively, and no significant difference was found (P > 0.05). No energy and nutritional value such as carbohydrate, protein and fats were detected in one serving (15 ml). total phenolic and total anthocyanin content in fermented rice vinegar by TISTR 103 (253.33 mg GEA/ 100 ml, 44.39 mg/kg) were higher than TISTR 354 (239.39 mg GEA/ 100 ml, 31.32 mg/kg) and significantly difference in 95% (P ≤ 0.05). On the other hand, antioxidant activities of fermented rice vinegar by ABTS assay TISTR 354 (1.98 mM TEAC) was higher than TISTR 103 (1.98 mM TEAC) and significant difference was found (P ≤ 0.05). However, no significant difference was found in antioxidant activity of fermented rice vinegar by FRAP assay of TISTR 354 and TISTR 354 (P ≤ 0.05).