Abstract:
Guava (Psidium guajava) is one of the popular fruits in Sri Lanka. Due to
high perishability postharvest loses are high as 40 %. Study was designed to
formulate nano edible coat using varying quantities of bee wax (0.005 %,
0.001 %, 0.015 %), nutmeg essential oil (50 µl, 100 µL, 150 µL), with aloe
vera, coconut oil and Tween 20. The nano emulsions were prepared with an
ultrasonic cell crusher (Labtrone, China) at 20Kz for 20 minutes. The
experiment consists with three treatments with positive (Coated guava +
KMnO4 1g sachet) and negative control (Uncoated guava). Guava samples
were placed in perforated corrugated boxes and stored under (25±2 ℃).
Physical (colour, firmness, weight loss, marketability) physiochemical (brix
value, total ascorbic acid content, total acidity) and sensory properties (5-
point hedonics scale) were evaluated with 3 days intervals. The data were
analysed with one-way ANOVA (p=0.05). The result revealed that Treatment
2 (0.001% bee wax+ 100µL nutmeg essential oil) had the lowest brix value
(6.00±0.00) was significantly difference from the positive and negative
controls (p˃0.05). Lowest marketable percentage was observed in the
negative control group, that was significantly different (0.83±0.05%) from
the coated guava (p˃0.05). Lowest weight loss (0.23±0.02g) of Treatment 02
was significantly different between the two controls (p˃0.05). Treatment 02
was exhibited the maximum firmness value (717±186g), the lowest pH value
(4.12±0.02), the lowest acidity (6.00±0.64 mg/100g) and ascorbic acid
content (1.18±0.36 mg/100g). It has recorded highest score for all the sensory
attributes during 15 days of storage period at 25±2 ℃
