Edible coating prevents apple decay
doi:10.1038/nindia.2019.22 Published online 21 February 2019
Researchers have prepared a polysaccharide-based formulation that, when sprayed on the surface of apples, prevents their decay during storage and transportation1. The polysaccharides, extracted from wheat straw and oat bran, can be used to make an edible coating for apples.
Of all the fruits, apples rank second in terms of post-harvest losses in India. Existing polymer-based coatings cannot efficiently check moisture loss from apples during storage and transportation. As well, animal-based lipid coatings are harmful to human health.
To invent an efficient and safe coating, scientists from the National Agri-Food Biotechnology Institute in Mohali and from Panjab University in Chandigarh, both in India, synthesised a composite material using polysaccharides isolated from wheat straw, a crop waste, and oat bran, a high-fibre food. They then prepared a formulation using the composite material.
The researchers coated freshly harvested apples with the composite-material-based formulation and compared its efficiency in maintaining apples’ freshness with those of uncoated and lipid-coated apples.
The formulation, when applied as a coating on the apples, was found to significantly reduce weight loss, respiration rate, fruit-softening and fruit-ripening processes, and colour degradation compared with uncoated and lipid-coated ones during a storage period of more than 30 days.
The formulation helped retain the apples’ firmness and prevented the loss of volatile compounds that contribute to apples’ distinct aroma. The coating is non-toxic to specific human cells. It remarkably reduced fruit decay by limiting disease incidence.
The researchers say that the formulation has the potential to be an alternative to animal-based lipid coatings for improving the quality and post-harvest storage life of apples.
1. Ali, U. et al. Effect of arabinoxylan and β-glucan stearic acid ester coatings on post-harvest quality of apple (Royal Delicious). Carbohydr. Polymer. 209, 338-349 (2019)