PhD

The present investigation on ‘Evaluation of selected banana (Musa spp) varieties grown in Kerala for postharvest attributes was conducted in the Department of Processing Technology, College of Horticulture, Vellanikkara, Thrissur, Kerala.
Twenty five accessions of banana belonging to six genomic groups were catalogued as per IPGRI description based on 21 fruit characters. Of the twenty five accessions, maximum value for finger weight, finger length, volume of finger, pulp weight and peel weight was recorded by Zanzibar and lowest by Matti. Other varieties with higher finger weight were Nedunendran, Chengalikodan, Manjeri Nendran, BRS I, Monthan, Batheesa and Kanchikela.
Varieties Zanzibar and Chinali recorded highest value for TSS (32.5°brix). Varieties Chengalikodan, Koompillakannan, Nendunendran, Manjeri Nendran, Matti and Njalipoovan also recorded higher values for TSS (TSS >30°brix). Culinary varieties recorded lower TSS. Nendran clones recorded higher values for total and reducing sugars, vitamin C, ß carotene and starch. Physiological loss in weight was highest in Grand Naine and lowest in Batheesa at the end of storage period. Longer shelf life was recorded by the varieties Bodles Altafort, Chengalikodan, Red Banana, Grand Naine, Manjeri Nendran and Poomkalli. On organoleptic evaluation higher scores for sweetness and taste was recorded by Kadali and Koompillakannan.
The physical, chemical and physiological changes during ripening were recorded in four stages viz., mature green unripe stage, colour changing, full ripe and over ripe stage in eight varieties. Pulp percentage and pulp/peel ratio showed an increasing trend whereas peel percentage and fruit firmness showed a decreasing trend during the postharvest period. TSS, total, reducing and non reducing sugars and moisture content increased progressively in the various varieties from stage I to stage IV, whereas starch, pectin and tannin content decreased during ripening. Acidity in the various varieties increased up to colour changing stage whereas on full ripening decreased. The activity of starch hydrolysing enzymes -amylase, ß-amylase and invertase increased during the postharvest period in the various varieties. The rate of respiration showed a climacteric peak at full ripe stage and after that it slightly decreased.
The effect of different postharvest treatments on enhancing the shelf life varied with different varieties. Precooling with ice flakes and tap water was effective in extending shelf life in Palayankodan fruits. In Njalipoovan and Chengalikodan longer shelf life was obtained for fruits vacuum infiltrated with 1 per cent CaCl2. Maximum shelf life in the case of Robusta was for fruits coated with edible wax at cut ends and precooling with cold water.
Precooling treatments in general improved the TSS and total sugars in Palayankodan, Njalipoovan, Robusta and Chengalikodan. Higher scores for sensory qualities were obtained for precooled fruits in Palayankodan, Robusta and Chengalikodan and for fruits vacuum infiltrated with 1 per cent CaCl2 in Njalipoovan.
Effect of different packaging treatments varied significantly in the various varieties. In Palayankodan, Njalipoovan and Chengalikodan minimum physiological loss in weight and maximum shelf life was observed for vacuum packed fruits. Maximum yellow life was observed in fruits packed in corrugated fibre board boxes and CFB box + polyethylene lining + ethylene absorbent. Higher values for TSS, total sugars and higher scores for taste, flavour and overall acceptability was for fruits packed in CFB boxes.