Optimization of disinfectant pretreatment conditions for the shelf life extension of fresh cut fruits

The study was conducted to optimize the pretreatment conditions for increasing shelf life of the fresh cut fruits. Five different disinfectants viz. sodium hypochlorite, potassium meta bisulphite, citric acid, acetic acid and benzoic acid were evaluated over three fresh cut fruit (guava, papaya and pear) to check their bactericidal efficacy. Considering residual chlorine levels and microbial load reduction, 100ppm concentration of sodium hypochlorite was selected for further optimization process. Optimization of pretreatment conditions viz. temperature, pH and contact time was statistically designed and analyzed using response surface methodology. Numerical optimization of results revealed a temperature of 10°C; pH 7; contact time of 25-30 minutes was found to be optimized for fresh cut guava, papaya and pear disinfection with a desirability level of 93%, 91% and 93%,respectively. Validation of results was done by scaling up the sample size to 3kg scale under all optimized conditions. Shelf life analysis of pretreated (under optimized conditions) and untreated fresh cut fruit stored under refrigeration conditions (4-7°C) revealed enhancement in shelf life of treated fresh cut fruit from 6, 6 and 3 days to 9, 9 and 6 days of fresh cut guava, papaya and pear, respectively. During shelf life period, all physicochemical parameters of pretreated fresh cut fruit were non-significantly differ along with microbial load under acceptable limits and a good sensory score.