Modifying the properties of whey protein isolate edible film by incorporating palm oil and glycerol

Abstract

This study aimed to improve the properties of whey protein isolate (WPI) films by incorporating palm oil (6, 7, and 8% w/w) and glycerol (40, 50 and 60% w/w). The lightness of the films increased as glycerol levels increased, but the redness increased with the increased amount of oil content. Increasing the amounts of palm oil and glycerol improved flexibility (P<0.05), but reduced the strength of the film (P<0.05). Films with higher levels of palm oil and lower amounts of glycerol were less permeable to water vapor and oxygen, but more thermally stable. The size of particles and air bubbles in the films reduced with increased palm oil content, regardless of glycerol level. Among all formulae, the film prepared with 8% palm oil and 40% glycerol showed the best overall results. Modifying WPI films with palm oil and glycerol offers a simple technique for producing packaging with better environmental barrier properties.

Keywords

• palm oil
• glycerol
• whey protein isolate
• edible film
• biodegradable packaging