Reducing Transfer of Salmonella and Aerobic Mesophilic Bacteria on Melon Rinds Surfaces to Fresh Juice by Washing With Chlorine: Effect of Waiting Period Before Refrigeration of Prepared Juice

Dike O Ukuku,Sudarsan Mukhopadhyay,Modesto Olanya

doi:10.3389/fsufs.2018.00078

Dike O Ukuku, Sudarsan Mukhopadhyay + Show 1 more

Open Access

https://doi.org/10.3389/fsufs.2018.00078

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Abstract

Cantaloupes, honeydew melons and watermelons inoculated with Salmonella cocktail at 4.5 log10 CFU/cm2, 3.810 log CFU/cm2 and 3.2 log10 CFU/cm2, respectively were sanitized with 200 ppm chlorine before rinds removal, cutting and juice preparation. Efficacy of 200 ppm chlorine in reducing transfer of Salmonella, aerobic mesophilic bacteria, yeast and mold, and Pseudomonas from the melon surfaces to freshly prepared fruit juice was investigated including the effect of waiting period before refrigeration of the juices. The melon juice filtrates were refrigerated immediately or stored at room temperature (~22oC) for 3 and 5 h before refrigeration. Average Salmonella bacteria recovered in fresh melon juice prepared from unwashed whole cantaloupes, watermelon and honeydew melons was 1.4 log10 CFU/ml, 0.5 log10 CFU/ml and 0.4 log10 CFU/ml, respectively. Juices from unwashed inoculated melons had the highest bacterial populations and storage at an abusive temperature of 10oC led to proliferation. Holding these juices at room temperature for 5 h before refrigeration allowed Salmonella bacteria to increase by 0.5-0.8 log in cantaloupe juice and 0.3-0.5 log in watermelon and honeydew juices. No Salmonella bacteria was determined in fresh juices prepared from melons washed with chlorinated water. The results of this study showed that washing melons with 200 ppm chlorine before juice preparation and immediately refrigerating the juice will minimize the chances of Salmonella proliferation.

Highlights

Consumers are becoming health conscious and are demanding food products that are fresh and safe, and fresh cut fruits and juices are among the foods that are in high demand
Whole cantaloupe surfaces and cantaloupe fresh-cut pieces had the highest populations of aerobic mesophilic bacteria and the populations for each class of these organism was significantly (p < 0.05) higher in cantaloupe surfaces and fresh-cut pieces than whole watermelon and honeydew including their respective fresh-cut pieces (Table 1)
Ukuku and Fett (2004) reported higher microbial populations on whole cantaloupe than honeydew melon rind surfaces and the results of this study agrees with our earlier report

Summary

Introduction

Consumers are becoming health conscious and are demanding food products that are fresh and safe, and fresh cut fruits and juices are among the foods that are in high demand. Food manufacturers are responding to consumers’ demand for safe juice or fruits which may be improperly processed and/or contaminated with human bacterial pathogens. Foodborne illnesses due to consumption of fresh fruit and vegetable produce contaminated with bacteria is food. The authors reported that consumption of bacteria contaminated fresh fruit and vegetable produce leads to 1.2 million illness per year, leading to 7,100 hospitalizations, and 134 human deaths. In a survey of imported 151 cantaloupe melons from Mexico, Costa Rica and Guatemala, FDA indicated that 5.3% of these melons was positives for Salmonella and 2% for Shigella (FDA, 2016) and several salmonellosis outbreaks has been associated with consumption of contaminated fresh-cut melon pieces (Ukuku, 2004) and fresh fruits and vegetable juices (Danyluk et al, 2012). Survival and growth of bacteria on fresh-cut melons was attributed to the nutrient composition of fresh-cut melons (FDA, 2015)

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