Protocol development for fresh cut vegetables

Abstract

The present investigation on “Protocol Development for Fresh Cut Vegetables” was carried out at the Department of Processing Technology, College of Agriculture, Vellayani during the period of 2011-2013, with the objective to standardize an efficient and economic protocol for the development of fresh cut vegetables with extended shelf life and to study the acceptability of the standardized technology. Protocol for preparation of any fresh cut vegetable includes surface sanitization of whole vegetable, preliminary preparations like removal of inedible portions and cutting into pieces of required sizes, pre- treatment of cut pieces, air drying, packaging and storage. Hence the investigation was carried out as four different continuous experiments incorporating all these steps. Vegetables like beans, beetroot, cabbage and carrot were used individually for the study. The study on efficiency of the different sanitizing agents revealed that 30ppm sodium hypochlorite solution was effective in reducing microbial population in all four vegetables. Investigation on the effect of different pre storage treatments revealed the superiority of calcium treatments in maintaining the freshness and quality of the fresh cut vegetables. Shredded vegetables treated with one percent calcium chloride and calcium ascorbate showed least physiological weight loss, transpiration loss and hence had highest water potential. Percent leakage was also least in vegetables treated with calcium compounds resulting in better texture. As none of the pre - treatments showed superior performance for all the chemical quality parameters evaluated, the top four pre storage treatments were selected based on discriminal function test and subjected to microbial analysis. Considering the efficiency in reducing the microbial load, economics and other physical parameters, calcium compounds were selected as the effective chemicals for pre storage treatment of fresh cut vegetables. When different packaging materials were compared, modified atmospheric packaging viz, nitrogen and vacuum packaging were superior in maintaining the physical, physiological and chemical quality parameters of the fresh cut vegetables. Polystyrene tray wrapped with cling film was superior compared to unventilated and micro ventilated polyethylene and polypropelene covers. As both the modified atmospheric packaging were equally effective in reducing microbial population, vacuum packaging in laminated pouches was selected considering the economics of the system. Considering all these steps, the most efficient and economic protocol was developed for each fresh cut vegetable which could give a shelf life of one week. Fresh cut beans, beetroot and cabbage can be prepared by surface sanitization using 30ppm sodium hypochlorite solution for 15 minutes followed by treating the shredded pieces with one percent calcium chloride for 10 minutes and refrigerated storage in laminated pouches under vacuum. Carrot could be stored using the same protocol except pre storage treatment with one percent calcium ascorbate. Cost of production and economics was calculated and the BC ratio was profitable for the prepared fresh cut vegetables and the samples were acceptable to the sensory panel even at the end of one week.