Combination treatment including irradiation improved the keeping quality of bitter melon (Momordica charantia L) with retention of functional bioactives while fulfilling phytosanitary requirement for export

Present work dealt with development of a combination process for prolonged extension of shelf life of whole as well as minimally processed bitter gourd samples. In this treatment, GRAS chemicals were used for extension of shelf life while radiation processing was optimized to use as a phytosanitary treatment. The whole process involved dipping the bitter gourd samples in sodium hypochlorite (200 ppm) at 52 degrees C for 10 min (as disinfectant treatment) followed by potassium metabisulphite at optimal concentration (0.5%) for 10 min at 26 +/- 2 degrees C (as an antifungal treatment). Finally, the samples were exposed to low dose (1 kGy) gamma irradiation treatment as a phytosanitary measure. An extended shelf life of 30 days was obtained, while improving the microbiological quality and retaining the colour, textural and sensory qualities. Combination process significantly enhanced the total phenolic content in processed samples during the storage period as compared to unprocessed control. Antioxidant activities of processed samples in terms of FRAP and DPPH radical scavenging activity as well as the antimutagenic activity were also conserved in treated samples. Thus, the treatment developed enhanced the storage life of processed bitter gourd stored at 4 +/- 2 degrees C while satisfying the phytosanitary requirement for export especially to the countries requiring longer voyage time.