title: Optimisation of lactic acid fermentation for improved vinegar flavour during rosy vinegar brewing.
abstract: BACKGROUND
  Rosy vinegar is a well-known traditional Chinese product whose flavour is affected by its lactic acid content. In this study, Lactobacillus bacteria were employed to increase the content of lactic acid during the ethanol fermentation stage.
  
  
  RESULTS
  The optimised fermentation parameters were determined as an inoculation amount of 3% (v/v), a temperature of 30 degrees C and an initial pH value of 4.0. Fermentation under these optimal conditions resulted in an alcohol degree of 6.2% (v/v), a total acidity of 49.5 g L(-1) and a lactic acid content of 4.14 g L(-1). The content of lactic acid (4.14 g L(-1)), which approached the level achieved by solid state fermentation, was 3.56-fold higher than that in vinegar fermented without lactic acid bacteria (1.16 g L(-1)).
  
  
  CONCLUSIONS
  The results indicate that mixed fermentation with Lactobacillus plantarum and Saccharomyces cerevisiae strains greatly increases the lactic acid content and improves the flavour of rosy vinegar.
authors.affiliation: School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, China.
authors.forename: Yujian
authors.initials: Y
authors.lastname: Jiang
authors.forename: Jianna
authors.initials: J
authors.lastname: Guo
authors.forename: Yudong
authors.initials: Y
authors.lastname: Li
authors.forename: Sen
authors.initials: S
authors.lastname: Lin
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Jianrong
authors.initials: J
authors.lastname: Li
mesh_terms: D019342:Acetic Acid / Q000737:chemistry / Q000378:metabolism* / Q000592:standards; D000143:Acids / Q000032:analysis; D000431:Ethanol / Q000032:analysis; D005285:Fermentation; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D005524:Food Technology; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000032:analysis / Q000378:metabolism*; D007778:Lactobacillus; D012275:Oryza / Q000382:microbiology*; D012441:Saccharomyces cerevisiae; D012639:Seeds; D013649:Taste; D013696:Temperature; D055549:Volatile Organic Compounds / Q000032:analysis
chemical_list: D000143:Acids; D055549:Volatile Organic Compounds; D019344:Lactic Acid; D000431:Ethanol; D019342:Acetic Acid