FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY




Quantitative changes of microflora during the storage of frozen chips


The purpose of this study was to assess if the number of microorganisms present in industrially manufactured chips changed during their frozen storage. Two-hundred and fifty samples of frozen chips were subjected to a study. Chips, wrapped in original plastic bags, were stored at -20ºC for 4 months. Total plate count, the numbers of coliforms, coagulase-positive staphylococci, moulds and yeasts and the presence of Salmonella spp. and Listeria monocytogenes were determined directly post production (freezing) and after 1, 2, 3 and 4 months of storage. Initial total plate count ranged from 1.30 to 3.15 log CFU x g-1. Coliforms were detected in 18% (mean 1.67±0.30 CFU x g-1), whereas moulds and yeasts – in 58% (mean 1.74±0.31 log CFU x g-1) of samples tested. Neither coagulase-positive staphylococci nor Salmonella spp. nor Listeria monocytogenes were found in material studied. After 1 month of storage all the microbiological parameters decreased; the changes were insignificant, however. The stabilization of all microbiological counts was noted during consecutive months. Consequently, the level of post-production contamination seems to be the main determinant of the shelf life of frozen chips.


chips, freezing, storing, microbiological quality