EFFECTIVE ACIDIFICATION OF TRADITIONAL FERMENTED FOODS

This study was carried out to investigate the survival rates of strain s of enteropathogenic Escherichia coli in lactic and acetic acids and to compare them with their survival rates in sour porridge. The fermen ted and unfermented porridges were prepared in the laboratory. The fer mented porridge had both lactic and acetic acids; unfermented porridge was adjusted to the pH of sour porridge with lactic and acetic acids. The sour porridge, the unfermented porridge adjusted to the pH of sou r porridge with lactic and acetic acids and the unfermented porridge w ere inoculated with six strains of enteropathogenic E. coli. The inocu lated porridges had a final concentration of 10(6)-10(7) colony-formin g units (c.f.u.) per ml of food. Few of the strains of enteropathogeni c E. coli were detected 48 hours after inoculation in sour porridge. A ll the strains were detected 48 hours after inoculation in unfermented porridges adjusted to the pH of sour porridge with lactic and acetic acids but decreased in numbers of surviving cells by about 2 log(10) c .f.u. per ml of food. All the strains survived in unfermented porridge for 48 hours and increased in numbers. These results show that lactic and acetic acids have antimicrobial properties but they are not as ef fective as sour porridge in inhibiting the growth and survival of ente ropathogenic E. coli. The inhibitory property of sour porridge is due to a combination of many substances including lactic and acetic acids.