Efficacy of Sanitizers on Three Types of Tropical Fruits Having Different Skin Characteristics

The efficacy of removal of known concentrations of E.coli and Staphylococcus aureus from the fruit surfaces by different concentrations of Chlorine Dioxide, Hypochlorite, Hydrogen Peroxide, water and heat treatments were studied on three tropical fruits, star fruit, guava and pineapple. It was found that S. aureus was more difficult to remove than E.coli from the surface of guava than from star fruit but pineapple skin offered the highest resistance. This may be due to the firmer attachment of S. aureus to fruit surfaces than E.coli, due to their ability to form biofilms. Star fruit’s smooth, waxy cuticle, possibly discourage bacteria from adhering to its surface compared to guava. Most of the same treatments were only able to reduce the bacteria cells by <1 log CFU in the case of pineapple. The rough pineapple skin would probably encourage firm attachment of bacterial cells and also shield them from sanitizing agents.