Enterobacteriaceae in unpackaged ice cream: Implications for microbial safety and methodological concordance between ISO and TEMPO®

Ice cream, a widely consumed dairy product, especially during summer, can pose serious microbiological risks when produced and sold under unhygienic conditions. This study evaluated the microbiological quality of unpackaged plain ice creams sold in the Kocaeli region of Türkiye between April and September 2024, focusing on Enterobacteriaceae contamination and comparing two enumeration methods: the ISO 21528-2 standard and the TEMPO® system. A total of 118 samples were analyzed. Enterobacteriaceae were detected in 41.5 % of samples, with mean counts around 2.3 log CFU/g by both methods. No statistically significant difference was observed between methods (p > 0.05), confirming the TEMPO® system as a rapid, reliable, and ISO-compliant alternative for routine monitoring. Staphylococcus aureus was isolated in 4.2 % of samples, with a mean count of 2.67 ± 0.15 log CFU/g, while Salmonella spp. and Listeria monocytogenes were not detected, suggesting effective pathogen control likely due to pasteurization and hygiene measures. The high prevalence of Enterobacteriaceae indicates lapses in hygiene during production and vending, posing a risk to public health. This is the first study in Türkiye to validate the TEMPO® EB system against ISO 21528-2 in unpackaged ice cream, demonstrating both excellent concordance and operational advantages. These findings underscore the critical need for stringent hygiene practices, cold chain maintenance, and HACCP implementation in street-vended ice cream production to ensure consumer safety.