Demonstration of microbiological status of fresh fruits and determining the efficiency of different decontaminating agents against the isolated bacteria

Abstract

Consumption of fresh fruits increases along with the promotion of healthier lifestyles. However, many foodborne illnesses have been reported due to the consumption of contaminated fruits. Fresh produces are subjected to various treatments for minimizing these outbreaks. The present study demonstrates the role of various simple household methods including water washing and some other common chemical treatments for the removal of bacterial load. By performing the spread plate technique, total heterotrophic bacteria, Escherichia coli, Staphylococcus spp., Salmonella spp. and Listeria spp. were determined in 60 samples of 6 categories including Apple (Malus domestica); Grape (Vitis vinifera); Guava (Psidium guajava); Strawberry (Fragaria ananassa); Indian jujube (Ziziphus mauritiana); Malabar plum (Syzygium cumini) before and after washing with tap water, hot water, 100 mg/L sodium hypochlorite (NaOCl), 50 mg/L calcium lactate, 4% acetic acid and 2 mL/L CleanAva for 20 mins at room temperature. All the tested solutions were found to be effective and reduced bacterial loads in fruits compared to the unwashed fruits samples (P<0.01). Treatment with NaOCl, calcium lactate, acetic acid and CleanAva was the more effective washing technique rather than hot water wash. Two to three log of the bacterial load was reduced when samples were subjected to treatment with chemical decontaminating agents. The efficiency of washing depends on the purity of water, and the types and concentration of the disinfectant solutions. An appropriate washing technique needs to implicate to diminish bacterial load and the risk of foodborne infections caused by fruits.