Development of Tamarind Seed Polysaccharide-Derived Edible Films for Postharvest Grape Preservation

ABSTRACT

Tamarind seed polysaccharide (TSP) was successfully prepared as edible film without xyloglucan extraction. The protein and fat content in TSP positively affected the film's water barrier properties. Glycerol (Gly) was added to improve the plasticity behavior of the TSP film. The concentrations of TSP and Gly were optimized via response surface methodology (RSM). The film prepared from 7% TSP and 5% Gly (TG7-5) exhibited high mechanical strength and good elasticity. It was also suitable for wrapping objects. The shelf life of postharvest grapes wrapped with the TG7-5 film or coated with the TG7-5 solution was prolonged without spoilage for up to 14 days. In contrast, the grapes wrapped with a PVC film were darkened and rotten by day 10. The production process of the TG7-5 film was simple, without chemical use, utilizing tamarind seed (waste) as a raw material, contributing to low production costs and eco-friendliness. Therefore, the TG7-5 film is an excellent candidate for replacing petroleum-based plastic in food packaging applications.

Practical Application

The shelf life of postharvest grapes was extended by at least 14 days when coated or wrapped with a tamarind seed polysaccharide (TSP)-based solution or film, respectively. In contrast, grapes wrapped in PVC film initially spoiled on day 10. The TSP film is sustainable, cost-effective, and environmentally friendly; hence, it enhances the potential of biopolymers to replace petroleum-based food packaging.