Parameters involved in the production of lactic acid preserved fish‐starchy substrate combinations

Summary Preliminary studies based on a minced fish‐salt‐glucose system indicated that a rapid lactic acid fermentation i.e., pH decrease to less than 4.5 in the first 48 hr proved difficult to achieve. The use of rice or cassava as carbohydrate alternatives were evaluated with or without a 1‐day prefermentation (prior to admixing with the fish). Different carbohydrate: fish proportions were studied in the range 20–100% w/w of fish mince. The use of prefermented cassava (20% w/w) resulted in consistent, rapid fermentations; the pH decreasing to less than 4.5 and the lactic acid bacteria (LAB):spoiler ratio exceeding four log cycles of growth within 48 hr. The use of added low‐molecular weight sugar (e.g. 2% w/w glucose) in addition to the cassava is necessary to prevent undesirable pH increase after the first 2 days of fermentation. Inoculation studies with the common food pathogens Staphylococcus aureus, Salmonella typhimurium, Clostridium sporogenes and Escherichia coli indicated that these pathogens rapidly disappear during the fermentation.