FACULTATIVE THERMOPHILIC MICROORGANISMS IN POTATO PRODUCTS IN RETORT PACKAGING

Authors

  • A. Ruzaike Latvia University of Agriculture
  • S. Muizniece-Brasava Latvia University of Agriculture
  • K. Kovalenko Institute of Food and Environmental Hygiene, Faculty of Veterinary Medicine, Latvia University of Agriculture

DOI:

https://doi.org/10.5755/j01.ct.66.1.12363

Abstract

Thermally treated potato products in retort packaging with an extended shelf-life (up to 90 days before opening) at room temperature (20 ± 1 °C) from two Latvian vegetable processing companies (A and B) were analysed in this research. The aim of this research was to determine the presence of thermotolerant microbial contamination in thermally treated potato products in retort packaging, to ensure their safety and suitability for immediate consumption. Samples from three production batches were used.

The total plate count was determined, and a microscopic examination of potato product samples was performed. Microscopic examination of microorganisms showed the presence of microbial vegetative forms in potato products from company B, but the standard investigation did not register them; therefore, Tryptone Glucose Yeast Extract Agar (TGYA), TGYA enriched with 1 % starch solution and TGYA enriched with 5 % starch solution were used for potential microorganism isolation. Samples were incubated at 25 °C; 37 °C; 41.5 °C; 50 °C; 55 °C and 60 °C temperatures under aerobic and anaerobic conditions, incubation time 12, 24 and 48 h. Facultative thermophilic Bacillus licheniformis bacteria which produce thermotolerant spores were isolated from thermally treated potato products in retort packaging from company B. The average colony count in company B samples was 1.27´100 CFU/g (SD = 78.25).

The presence of microorganisms was not detected in potato products produced at company A, while facultative thermophilic and thermotolerant microorganisms were found in potato products produced at company B.

DOI: http://dx.doi.org/10.5755/j01.ct.66.1.12363

Author Biographies

A. Ruzaike, Latvia University of Agriculture

S. Muizniece-Brasava, Latvia University of Agriculture

K. Kovalenko, Institute of Food and Environmental Hygiene, Faculty of Veterinary Medicine, Latvia University of Agriculture

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Published

2015-10-27

Issue

Section

FOOD CHEMISTRY AND TECHNOLOGY