Influence of fermentation time on anaerobic acidogenic fermentation of soy sauce residue

By optimizing fermentation time in this paper,more organic substrates in soy sauce residue was converted into volatile fatty acid,such as acetic acid.Anaerobic acidogenic fermentation provides one of the most important ways to reutilize soy sauce residue.The results revealed that 8d fermentation was a better choice.The concentrations of soluble proteins and carbohydrates in pretreated supernatant of soy sauce residue were lowest and their degradation rates were 68.01% and 81.21%,respectively.Relatively,carbohydrates were the better substrates for acidogens.The concentrations of total organic acids and acetic acid were highest with 28.82g/L and 22.91g/L.Acetic acid was the dominant component and its percentage in the total organic acids was 79.94%.With soluble substrates gradually consumed,the organic acids produced were reutilized by acidogens as substrates.A certain amount of propionic acid accumulated during the anaerobic acidogenic fermentation.After 8d fermentation,the concentration of propionic acid was highest with around 5.00g/L.