MSc

The investigation entitled “Postharvest treatments for delayed ripening in
Nendran banana (Musa spp.)” was conducted at the Department of Post Harvest
Technology, College of Agriculture, Vellayani, during 2016-2018. The objective
of the programme was to study the effect of postharvest application of different
ethylene inhibitors and to standardize the optimum concentration for delayed
ripening and extended shelf life of Nendran banana.
Nendran banana bunches of uniform maturity were selected from
Instructional Farm, College of Agriculture, Vellayani. De-handed banana fruits
were treated with different ethylene inhibitors at various concentration viz. Benzyl
Adenine (BA) (30 ppm, 50 ppm, 80 ppm - dipping for 10 minutes), Hexanal (0.5%,
1.0%, 1.5% - dipping for 10 minutes), Nitric Oxide (NO) (0.25 mM, 0.5 mM, 0.75
mM - dipping for 5 minutes), Salicylic Acid (SA) (1 mM, 1.5 mM, 2 mM - dipping
for 10 minutes) along with distilled water, ethanol and absolute control (without
any treatment). Treated banana fruits were air dried and stored under room
temperature (30+20C, RH 80-85%) in Corrugated Fiber Board boxes till the end of
shelf life.
Effectiveness of different ethylene inhibitors for delayed ripening of Nendran
banana was evaluated by analyzing physiological, biochemical, physical and
sensory qualities. Nendran banana fruits treated with 50 ppm BA recorded a pulp
percentage of 69.38%, peel percentage of 30.62% and pulp to peel ratio of 2.26 with
the lowest physiological loss in weight (PLW) (13.01%) and respiration rate (97.55
mL CO2 kg-1 h-1) after 15 days of storage. Total sugar (20.82%), reducing sugar
(17.55%), TSS (24.25 0B) and acidity (0.45%) increased with storage and highest
retention of vitamin C (10.74 mg 100g-1) content and antioxidant activity (78.46%)
were also observed at the end of storage.
When fruit firmness, colour and sensory parameters were analyzed, BA 50
ppm treated banana fruits exhibited maximum fruit firmness of 10.55 N after 15
days of storage with optimum ripening (Stage VI). It also exhibited maximum mean
score for sensory parameters viz. appearance, colour, flavour, taste, texture and
overall acceptability and recorded a shelf life of 16.75 days.
Nendran banana fruits treated with SA (2 mM) recorded a shelf life of 15.75
days next to BA (50 ppm) with 13.82 % PLW and respiration rate of 106.23 mL
CO2 kg-1 h-1. When biochemical parameters were analyzed, SA 2 mM recorded a
total sugar content of 21.50%, reducing sugar (18.05%), TSS (25.45 0B), acidity
(0.48%), carotenoid (0.30 mg 100g-1), ascorbic acid content (9.84 mg 100g-1) and
antioxidant activity (76.55%) after 15 days of storage with good fruit firmness,
colour and sensory qualities. Nendran banana fruits without any postharvest
treatment (absolute control) had a shelf life of 11.58 days with higher rate of
physiological, biochemical and physical changes. They also exhibited the highest
PLW of 19.94% and high rate of respiration (128.11 mL kg-1 h-1) which lead to short
shelf life and lowest mean score for sensory attributes after 12 days of storage.
Application of ethylene inhibitors as postharvest treatments reduced the rate
of physiological activities and extended the shelf life of Nendran banana. Based on
physiological, biochemical, physical and sensory analysis, dipping of Nendran
banana hands in 50 ppm Benzyl Adenine for 10 minutes was standardized as the
best postharvest treatment for delayed ripening and extended shelf life up to 16.75
days whereas Nendran banana without any treatment (absolute control) recorded a
shelf life of 11.58 days under room temperature storage. Dipping of Nendran
banana in 2 mM Salicylic Acid for 10 minutes recorded a shelf life of 15.75 days
and was found cost effective as compared to BA (50 ppm).