Characterization and value addition of male buds of banana cultivars

Abstract

India is the largest producer of banana in the world and Kerala is rich with wide array of banana varieties. The banana plant in whole is useful for its fruits, peel, fibre, corm, male bud and pseudo stem. Banana inflorescence also known as navels is removed in commercial banana cultivation, by a practice called denavelling, for quality assurance of fruits. These male buds loaded with lots of nutrients are used as vegetable and also for the preparation of nutraceuticals. The stages of harvest after bunch emergence influence the quality of the male bud. Hence the study was carried out in the Department of Post-Harvest Technology, during 2017-2019,with the objectives to characterize the male buds of banana cultivars and to standardize their harvesting stage, packaging and storage methods and minimal processing techniques .

Palayankodan, Grand naine, Njalipoovan and Nendran varieties of banana were selected for the first experiment. They were harvested at 15, 20 and 25 days after full bunch emergence (DAB) and characterized based on physico-morphological and biochemical parameters. Palayankodan and Grand naine had the highest bud weight, length and diameter when harvested at 20 DAB and Nendran at 25 DAB. The recovery and firmness was found to be highest when harvested at 25 DAB in Palayankodan and at 15 DAB in Grand naine and Nendran. However, Njalipoovan had the highest value for all the four parameters (275 g weight, 19.8 cm length, 20.4 cm diameter, 87.2 % recovery) when harvested at 15 DAB.

Considering the biochemical parameters, in all the four varieties the desirable constituents like carbohydrate, protein, dietary fibre, potassium etc. were found to be highest when harvested at 15 DAB. When subjected to organoleptic evaluation, Palayankodan had the overall consumer acceptance and highest total score under all the three stages of harvest. Also due to its popularity and easy availability, Palayankodan variety was selected for the packaging and storage studies.

In the second experiment, banana male buds were given different packaging treatments (wrapping in shrink film, cling film and perforated polyethylene cover) and stored under ambient, cold storage and refrigerated conditions. Physico chemical changes and organoleptic quality were observed. The studies revealed that banana male buds packed in polyethylene cover of 150 gauge and stored under refrigerated condition had the highest shelf life (43 days) and lower physiological loss in weight along with biochemical parameters like ascorbic acid (11.9 mg/ 100g) and total phenols (0.648 mg/ 100 g). Also it had scored highest in organoleptic evaluation with a total of 36.07.

Third experiment consisted of standardizing minimal processing techniques for banana male bud. An attempt was made by adopting different pre-treatments (0.2 % ascorbic acid, 0.2 % citric acid, 0.2 % turmeric + salt) and packaging methods ( paper plate overwrapped with cling film, polystyrene trays overwrapped with cling film, polyethylene punnets) to enhance the shelf life and to improve the market value of sliced banana buds. Minimal processed buds with 0.2 % citric acid pretreatment packed in polystyrene trays had a shelf life of one week and microbial load within the permissible limit along with better retention of ascorbic acid (6.81 mg/ 100g) and total phenols (0.276 mg/ 100 g).

The present study found that the harvesting stage of buds in Palayankodan and Grand naine was 20 days after full bunch emergence and in Njalipoovan and Nendran it was 15 and 25 days after full bunch emergence respectively. The buds of all four varieties are nutrient rich and organoleptically acceptable with mean rank scores above 6. Packaging in perforated polyethylene cover and storage under refrigerated condition increases the shelf life of whole male bud with retention of desirable qualities. Also 0.2% citric acid pretreatment and packaging in polystyrene trays enhance the market value of minimal processed buds.