Considering the limited availability of technology for the production of rice vinegar and also due to the potential consumer product market, this study aimed to use alcoholic fermented rice (rice wine (Oryza sativa L.)) for vinegar production. An alcoholic solution with 6.28% (w/v) ethanol was oxidized by a submerged fermentation process to produce vinegar. The process of acetic acid fermentation occurred at 30 ± 0.3°C in a FRINGS® Acetator (Germany) for the production of vinegar and was followed through 10 cycles. The vinegar had a total acidity of 6.85% (w/v), 0.17% alcohol (w/v), 1.26% (w/v) minerals and 1.78% (w/v) dry extract. The composition of organic acids present in rice vinegar was: cis-aconitic acid (6 mg/L), maleic acid (3 mg/L), trans-aconitic acid (3 mg/L), shikimic + succinic acid (4 mg/L), lactic acid (300 mg/L), formic acid (180 mg/L), oxalic acid (3 mg/L), fumaric acid (3 mg/L) and itaconic acid (1 mg/L).

O soro de leite fermentado pela levedura Kluyveromyces fragilis, após secagem em spray drier, foi submetido à avaliação da qualidade protéica através de uma análise aminoacídica e de um estudo biológico pelos métodos: Relação da Eficiência Protéica (PER), Relação da Eficiência Líquida da Proteína (NPR) e Utilização Líquida da Proteína (NPU). Na análise aminoacídica, foram utilizadas como comparativo a composição de aminoácidos das proteínas padrão do ovo e da FAO. Os resultados indicaram um alto nível de lisina (65,60mg/g de proteína) e baixos níveis de metionina e valina, respectivamente, 14,90mg e 45,80mg/g de proteína. A avaliação biológica foi conduzida durante 4 semanas, sendo utilizados 24 ratos desmamados aos 23 dias de idade. Os resultados para PER, NPR e NPU foram respectivamente, 19,75%, 46,33% e 26,54%, comparados com os valores obtidos com a proteína padrão caseína. A qualidade da proteína do soro seco fermentado apresentou-se inferior à proteína da caseína.

Kluyveromyces fragilis fermented whey was spray dried and the protein quality of dried product was assayed by aminoacid analysis and three biological methods: Protein Efficiency Ratio (PER), Net Protein Ratio (NPR) and Net Protein Utilization (NPU). Aminoacid analysis using casein and FAO protein as standards had a high level of lysine (65.6mg/g protein) and low levels of methionine (14.9mg/g protein) and valine (45.8mg/g protein). Biological evaluation of dried fermented whey protein, using 24 weaned rats, 23 days of age, during four weeks, using casein as standard protein, resulted in PER, NPR and NPU, 19.75%, 46.33% and 26.54%. Nutritional quality of the dried fermented whey protein was lower than the casein protein.