MSc

The study entitled “Protocol development for minimally processed jackfruit (Artocarpus heterophyllus L.) bulbs” was carried out in Department of Post-Harvest Technology, College of Agriculture, Vellayani with the objective to standardize an efficient and economic protocol for development of minimally processed jackfruit bulbs with extended shelf life. The work was carried out as four different continuous experiments, viz., evaluation of sanitizing agents, evaluation of pre-storage treatments, development of packaging system and assessment of acceptability.
Fresh, good quality optimum mature fruits of the jackfruit cultivar Muttom varikka were harvested, allowed to ripe and were subjected to four different sanitization treatments viz., immersion in water (400C), 100 ppm sodium hypochlorite solution, 120 ppm sodium hypochlorite solution and 2 ppm ozonized water for 15 minutes each. Untreated fruits were kept as absolute control to evaluate the efficacy of sanitization treatments in controlling total microbial load on the fruit surface.
All the sanitization treatments resulted in reduction in microbial load on the fruit surface. Sodium hypochlorite at both concentrations, 120 and 100 ppm, were equally effective in reducing both the bacterial and fungal load. Untreated fruits had the maximum microbial count, which was comparable with the fruits treated with water at 400C. Considering the efficiency and economics, the lower concentration of sodium hypochlorite, 100 ppm, was selected as the best surface sanitizing treatment and used for the second part of the experiment.
In the second part of the study, after surface sanitization of the fruits with 100 ppm sodium hypochlorite solution, bulbs were extracted and after removal of the seeds, dipped in three different pre-treatment solutions viz, 0.1% ascorbic acid, 0.1% citric acid, 1% calcium chloride for 10 minutes. Untreated bulbs were kept as absolute control and both treated and untreated bulbs were stored under refrigerated conditions in aluminium foil trays wrapped with cling film to analyse the efficacy of pre-storage treatment solutions.
All the pre-storage treatments resulted in better physiological, chemical and sensory quality parameters of the bulbs compared to the untreated ones. However,
all the bulbs except the ones treated with 1% calcium chloride solution had to be discarded by 5th day of storage owing to deterioration.
Pre-storage treatment of the bulbs with calcium chloride (1%) resulted in maximum shelf life (5.00 days), TSS (20.200B), ascorbic acid (23.69) and total carotenoid content (0.83), lowest physiological loss in weight (2.03), percent leakage (79.24), acidity (0.36%) and total phenol content (39.77), after three days of storage, with best sensory scores and hence selected as the best pre-treatment for minimally processed jackfruit bulbs.
In the third part of the study, fruits and bulbs that received the best treatments mentioned above were kept under four different packaging systems viz., laminated pouch, shrink wrapping, cling film wrapping and aluminium tray wrapped with cling film were compared under refrigerated (5-70C) conditions.
Jackfruit bulbs packaged in laminated pouches recorded the maximum shelf life (7 days), TSS (18.920B), total sugar (37.28%), reducing sugar (16.75%), non-reducing sugar (20.53%), vitamin C (27.43 mg100g-1), total carotenoid (0.83) content with maximum sensory scores. They also had least PLW (1.17), percent leakage (65.90), acidity (0.31%) and phenol content (39.50).
Shrink wrapping was the second best in maintaining quality with 6 days shelf life, and bulbs wrapped in cling film showed the least quality parameters with a shelf life of 4 days only. All jackfruit bulbs except those packed in laminated pouch and shrink wrap were found to be spoiled and had to be discarded by 6th day of storage.
Minimally processed ripe jackfruit bulbs of cv. Muttom varikka can have a shelf life of seven days if surface sanitization of fruit are done using 100 ppm sodium hypochlorite for 15 minutes, followed by pretreating de-seeded bulbs with 1% calcium chloride for 10 minutes and stored under refrigerated conditions after packaging in laminated pouch of PP/LDPE.
Minimally processed jackfruit bulbs prepared as per the standardized technology above had acceptable sensory scores for appearance (7.10), colour (6.96), texture (7.26), taste (6.90), flavour (6.60) and overall acceptability (7.43) even at the end of shelf life period. Cost of production of 1 kg minimally processed jackfruit bulbs was estimated to be Rs. 206.89/-.