Investigating the Impact of Three Washing Methods on Microbial Reduction, Color, and Texture of Spinach and Tomatoes

ABSTRACT Fresh produce is susceptible to contamination, leading to spoilage or foodborne illness. Effective postharvest washing methods are essential to reduce microbial load and ensure produce safety. Most studies focused on single sample type or the immediate impact of washing methods. However, various washing parameters and product type may affect microbial reduction and quality attributes not only immediately after washing but also during storage. In this study, the effectiveness of three washing methods (tap water, 0.01% sodium hypochlorite, and 1% citric acid) was investigated on spinach and tomatoes. The washing parameters were optimized and the impact of each method on bacterial reduction and product texture and color was evaluated both immediately after washing and throughout the storage period of 7 days. Among the three treatments, 1% citric acid demonstrated the highest microbial reduction for both spinach and tomatoes, particularly during storage. With the same washing method, more bacteria were removed from tomatoes than from spinach. All three washing treatments did not significantly affect the produce texture or color. The study provided a better understanding of the effectiveness of common postharvest treatments of produce and their impact on quality attributes, which will help assure the safety and quality of fresh produce.