Spotless or Spoiled: Evaluating the Effectiveness of Common Household Cleaning Agents for Bacterial and Fungal Reduction on Apples

Abstract

This study examines the bactericidal efficacy of common household cleaning agents—water, lemon juice, vinegar, and baking soda solution—on reducing bacterial loads on apples. Our hypothesis posited that acidic solutions (lemon juice and vinegar) would disrupt bacterial cell membranes, while baking soda would enhance bacterial removal through its abrasive properties. Apples were swabbed and streaked onto agar plates before and after treatment, with each treatment group including three replicates and a control (unwashed) to establish baseline bacterial presence. Surprisingly, our results revealed that apples with no washing (pre-treatment) harbored the lowest bacterial counts, challenging conventional assumptions about cleaning practices. After treatment, the acidic solutions (vinegar and lemon juice) showed some reduction in bacterial colonies, but all treatments ultimately resulted in higher bacterial counts compared to the untreated apples. For fungal contamination, the opposite trend was observed: vinegar, water, and baking soda solutions resulted in a decrease in fungal CFUs, while lemon juice increased fungal growth. Statistical analysis using p-values of 0.63 and 0.24 indicated no significant differences in bacterial or fungal CFUs between before and after treatments. These findings suggest that common cleaning agents may not be as effective as expected in reducing microbial contamination on apples. Further investigation is needed to explore the mechanisms underlying these results and to refine cleaning practices for produce.