Antimicrobial efficacy of household sanitizers against artificially inoculated Salmonella on ready-to-eat spinach (Spinacia oleracea)

Due to health concerns regarding the microbiological safety of fresh produce, consumers frequently wash fresh produce before consumption. Household sanitizers including tap water, vinegar (5.0, 1.5, 1.0%), baking soda, commercial wash, and bleach solutions were evaluated for their effectiveness in reducing counts of Salmonella enterica on spinach leaves. Treatments were carried out at 23 °C for 2 min. An online survey was also conducted in different parts of the United States to collect information on consumers’ practices of washing produce with common household sanitizers. A significantly higher (p < 0.05) bacteria reduction (1.95–2.19 log CFU/g) was achieved using chlorine solution (200 ppm) when compared with other treatments (0.01–1.64 log CFU/g). Running tap water physically reduced bacteria on spinach by 1.52–1.62 log CFU/g. Vinegar solutions at 5, 1.5, and 1.0% promoted reductions of 1.56–1.64, 1.01–1.12, and 0.9–1.02 log CFU/g, respectively. Notably, none of the household sanitizers were capable of entirely removing Salmonella on spinach leaves. With exclusion of chlorinated water and 5% vinegar solution, Salmonella was present in all spend solutions. Our survey showed that three washing solutions were most commonly used by consumers; rubbing produce under running tap water (54.3%), holding produce under running tap water (53.5%), and soaking produce in water (32.9%). Bleached water was the least applied household sanitizer (0.59%). Based on the results of the present work, household sanitizers do not guarantee the complete inactivation of pathogenic bacteria on leafy produce, particularly Salmonella on spinach.