Quality and Microbial Assessment of Cooking Oils and Serving Plates Used by Street Food Vendors in District Sialkot, Pakistan

Abstract

Introduction: Street-vended foods are essential for low- and middle-income populations in developing countries, but public health risks arise from unhygienic practices, including the continual reuse of cooking oil. This study aimed to evaluate the physicochemical quality of cooking oils and the microbial contamination of serving plates used by street food vendors in Sialkot District, Pakistan. Materials and Methods: One hundred and fifty composite samples of frying oils and serving plates were collected from vendors across six zones: urban, educational, kachehri (government offices), bazar (market), fast-food, and rural areas. Oil quality was assessed by analyzing moisture content, free fatty acids (FFA), acid value (AV), peroxide value (PV), and total polar compounds (TPC). Microbial load on serving plates was evaluated using total plate count (TPC) and Escherichia coli enumeration. Results: The highest mean values indicating severe oil degradation were found in samples from rural vendors: FFA (1.82%), AV (3.62 mg KOH/g), PV (13.8 meq/kg), and TPC (28.4%). The bazar area exhibited the poorest hygiene, with the highest mean total plate count (3.7×10⁴ CFU/cm²) and the presence of E. coli on multiple serving plates. Discussion: The results demonstrate significant deterioration of cooking oils, particularly in rural settings, and substantial microbial contamination on serving utensils, especially in market areas. This indicates widespread unsafe practices, including excessive oil reuse and poor hygiene, which pose serious cross-contamination risks to consumers. Conclusion: The findings underscore an urgent need for periodic monitoring of street food operations, strict enforcement of national food safety standards, and targeted awareness programs for vendors and consumers to promote safer food practices in Pakistan.