Microbial spoilage of pre‐cooked potato‐topped pies

Abstract

The ecological succession of bacteria which developed in pre-cooked potato-topped pies stored at two different temperatures was examined. Bacillus, Streptococcus and Staphylococcus-Micrococcus spp. were the predominant organisms isolated from freshly prepared pies and those stored at 4 degrees and 37 degrees C. None of these groups of bacteria caused significant biodeterioration of pies held at 4 degrees C, but all groups grew well in pies stored at 37 degrees C and achieved counts of ca 10(8)/g of sample. Bacillus spp. were the first group to grow, followed by Streptococcus and Staphylococcus-Micrococcus spp. Growth which occurred at 37 degrees C did so at the expense of glucose, lactate accumulated and the pH of pie components decreased. Amylase activity detected in all pie components during storage was associated with the growth of Bacillus spp. and probably supplemented glucose already present in pies, by hydrolytic cleavage of potato, flour or binder starches. Spoilage caused by growth and activity of the bacteria isolated was not associated with visual signs of biodeterioration, nor production of 'off' odour usually associated with spoilage of meats. These results suggest that pre-cooked potato-topped pies held at inappropriate temperatures represent a potential public health risk.

Minimally Processed Refrigerated Fruits & Vegetables

“…A study of the microflora of potato-topped meat pies showed that both cooked and uncooked pies contained S. aureus (Thomas and Masters 1988). When the pies were stored at either 4 or 37' C, outward signs of spoilage were not evident.…”

Evaluation and Control of the Risk of Foodborne Pathogens and Spoilage Bacteria Present in Awa-Uirou, a Sticky Rice Cake Containing Sweet Red Bean Paste

“…subtilis is also distributed widely in the environment and foods. Contamination with the organism and its rapid growth in starchy foods is associated with spoilage or quality loss (Thomas and Masters, 1988;Sorokulova et al, 2003). Rice flour and beans can be contaminated with Bacillus spores as a result of soil contamination (Watanabe and Hayano, 1993).…”

“…However, during our experiments, S. aureus cell and B. cereus spore contamination of Uirou-Tane was not detected even after 7 days of storage at 308C (data not shown). The decimal reduction time at 588C (D 58 ) of S. aureus cells in buffer solution at pH 7.0 was reported as 0.32 AE 0.33 (0.09-1.1) minutes (Thomas and Masters, 1988). Dufrenne et al (1994Dufrenne et al ( , 1995 reported the D 90 value of B. cereus to be 23.0 AE 41.6 (2.2 to > 200) minutes.…”