| Microbiological and chemical changes were evaluated in freshwater prawn stored under refrigeration at 0°C and 5°C during 10 days, with special emphasis on indole production as a chemical spoilage indicator. The total psychrotrophic and indole positive microflora were mainly mesophilic, with indole positive microorganisms being less than 10% of the total microflora after 10 days storage under refrigeration. Bacteria from Enterobacteriaceae and Vibrionaceae families prevailed among the isolated indole positive strains. The use of the Most Probable Number-MPN method, using tryptone broth as culture medium, was the most reliable approach for the quantitative evaluation of the indole positive microflora. The stored samples showed increases in pH, L-tryptophan... |
