Premium
FERMENTATIVE PRODUCTION OF PROPIONIC ACID IN HYDROLYZED COD (GADUS MORHUS) GURRY
Author(s) -
MAHMOUD M.,
LEVIN R.E.
Publication year - 1993
Publication title -
journal of food biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 47
eISSN - 1745-4514
pISSN - 0145-8884
DOI - 10.1111/j.1745-4514.1993.tb00467.x
Subject(s) - fermentation , hydrolysate , chemistry , food science , hydrolysis , acetic acid , incubation , food spoilage , biochemistry , bacteria , biology , genetics
ABSTRACT The fermentative production of propionic acid in cod gurry hydrolysate containing from 2.5 to 4.0% glucose by strains of Propionibacterium was studied. Yields of 1.3 to 1.7% propionic acid plus 0.52 to 0.71% acetic acid with resulting pH values of 4.2 to 4.0 were achieved with steam sterilized hydrolysates after 192 h of incubation. Concentrations of 1.0% propionic acid or more at a pH value at or near 4.0 are considered sufficient to achieve permanent preservation. The rates of the fermentations and resulting rates of reduction of pH were notably slow due to generation times of 6 h or longer. This slow rate of fermentation can be expected to allow the growth of contaminating spoilage organisms during the first 24 to 48 h before inhibitory levels of propionic and acetic acids are produced. The preservation of hydrolyzed gurry by direct propionic acid fermentation is therefore not feasible at this time unless the rate of fermentation is significantly increased .