Microbial Contamination of Delivery Foods and the Reduction of Bacteria Using Grapefruit Seed Extract on Delivery Box

Abstract

Microbial Contamination of Delivery Foods and the Reduction of Bacteria Using Grapefruit Seed Extract on Delivery Box Hyunduk Ryu Dept. of Food & Nutrition The Graduate School of Hanyang University The rapid growth of the food delivery industry, while offering convenience, has also raised concerns regarding hygiene and food safety. Issues such as the sanitary conditions of food delivery establishments, cross-contamination during delivery, inadequate cleaning and disinfection of delivery containers, and poor personal hygiene of delivery personnel have become prominent. Among these, research on the sanitation of delivery containers remains insufficient. Currently, only guidelines for cleaning and disinfecting delivery containers are provided by the Food and Drug Administration, with no specific legal standards or specifications in place. This study conducted microbial experiments on heated foods (chicken, pork feet, and tteokbokki) and complex cooked foods (kimbap, sandwiches, burgers, and naengmyeon) sold in Seoul and Gyeonggi Province to assess the overall microbial contamination of food delivery establishments. To mitigate microbial contamination on the surface of delivery containers, which poses a risk of cross-contamination, a disinfectant was prepared by mixing different concentrations (50, 100, 500, 1000 ppm) of grapefruit seed extract(GSE) with hydrogen peroxide(H2O2) (0, 3, 5%). The surface sterilization effect of the delivery containers was observed at these varying concentrations. The microbial contamination analysis revealed the presence of general bacteria in all food groups, with a notably higher contamination level in the complex cooked food group. The coliform group and S. aureus were predominantly detected in the complex cooked food group, although pork feet in the heated food group also showed significant detection. B. cereus was found in sandwiches and burgers, but no samples exceeded the current standard regulations. Neither Salmonella spp. nor C. perfringens were detected. The antioxidant effects with GSE showed that the highest concentration (1000 ppm) exhibited the greatest antioxidant capacity, with 43.95% in the ABTS method and 654.31 µM in the FRAP method. The antimicrobial activity with the disinfectant made from GSE and hydrogen peroxide showed that samples treated with GSE alone had inhibition zones of 8-12 mm for E. coli and 8-13.5 mm for S. aureus. Although the length of the inhibition zones was not extensive, it increased with higher concentrations of GSE. Samples mixed with hydrogen peroxide at a 5% concentration exhibited larger inhibition zones for E. coli (30-35 mm) and S. aureus (16-18 mm), indicating that higher concentrations of GSE and hydrogen peroxide enhanced the antimicrobial effect. The surface sterilization effect of the delivery containers was highest with 5%, followed by 3%, and 0% hydrogen peroxide. The type of bacteria (E. coli, S. aureus) and surface material (insulation material, HDPE) did not significantly affect the disinfectant's sterilization effect. SDS-PAGE results showed that samples treated with the disinfectant exhibited less distinct bands compared to untreated samples. By evaluating the microbial contamination of various food groups sold in delivery restaurants and confirming the effectiveness of a disinfectant made from GSE and H2O2, this study provides a potential solution to address the risk factors associated with food delivery containers and offers significant insights into the food safety of related services. These results suggest a contribution to the improvement of hygiene and safety in food delivery. Therefore, this research holds value as foundational data for establishing a food safety system for food delivery and related services.