MSc

The present investigation on “Protocol development for fresh- cut fruits and fruit mix preparation” was carried out at the Department of processing Technology, College of Agriculture, Vellayani, during the period of 2010-2012, with the objective to standardize an efficient and economic protocol for development of fresh- cut fruits and fruit mix with extended shelf life and to study the acceptability of the standardized technology.

Protocol for any fresh- cut fruit preparation includes surface sanitization of whole fruit, removal of inedible portions and cutting into pieces of required sizes, pre- treatment of cut pieces, air drying, packaging and storage. The investigation was carried out as four different continuous experiments viz., evaluation of different sanitizing agents, pre-storage treatments, development of packaging system followed by testing the acceptability of standardized technology. Mango, papaya, pineapple and pomegranate were used individually and in combination.

Investigation on the efficacy of different sanitizing solutions on surface decontamination of fruits revealed that highest concentration of 120 ppm is effective in reducing the bacterial population in mango, papaya and pineapple. All concentrations of sodium hypochlorite solution were equally effective in pomegranate.

Studies on the effect of pre storage treatments on physical, physiological and chemical quality parameters of fruit pieces and arils revealed superiority of calcium treatments. One per cent calcium chloride or calcium ascorbate had least percent leakage, physiological loss in weight and osmotic potential, making the pieces and arils firm in texture. Combination of preservative and acidulant also maintained the freshness and quality of fresh-cut samples. Pre storage treatment with 0.1% KMS or sodium benzoate and 0.1% citric acid or ascorbic acid was considered superior. Fruit pieces with superior physical and chemical parameters scored high in sensory analysis too. None of the pre- treatments showed superior performance for all the chemical quality parameters evaluated.

Among the chemicals evaluated, calcium ascorbate was very costly and sodium acid sulphate imparted acidic taste to the product, though they were superior in maintaining the quality of fresh- cut fruits.

When different packaging materials were compared, all the fruit pieces and pomegranate arils kept in aluminium tray with or without KMnO4 sachet and polystyrene tray had lowest physiological loss in weight and percent leakage, indicating their superiority. They could maintain the quality parameters such as increased total soluble solids, reduced phenol of all four fresh- cut fruits. Unventillated or microventillated packages, with or without an ethylene absorbent, were not always good in maintaining physiological quality parameters of fresh- cut fruits. All unpacked fruit pieces had highest physiological loss in weight. The packaging materials did not have influence on microbial population. Addition of ethylene absorbent could not make any added advantage on the microbial control.

The most efficient and economic protocol was developed for each fruit, which could give a shelf life of five days.

Fresh- cut mango can be prepared by surface sanitization using 60 ppm sodium hypochlorite for 15 minutes followed by treating ≈ 2 cm cube pieces with 0.1% KMS and citric acid for 10 minutes and refrigerated storage after packaging in aluminium tray. Papaya could be stored using the same protocol, except sanitization using 90 ppm sodium hypochlorite. In pineapple, surface sanitization using 90 ppm sodium hypochlorite and pre storage treatment with 1% calcium chloride was effective.

Pomegranate arils could be stored using the same protocol, except sanitization using 30 ppm sodium hypochlorite. Fruit mix could be stored in similar packaging material under refrigerated condition after giving the corresponding sanitization and pre treatment selected for individual fruits.

Quality parameters and cost of production of the prepared fresh- cut fruits and fruit mix were analysed and the samples were acceptable to the sensory panel even at the end of fifth day.