Formulation of edible films based on carboxymethyl cellulose, cassava starch, and alginate using high-intensity ultrasound emulsification treatments

Abstract

Biopolymer-based edible films and coatings are useful for preserving the quality in minimally processed vegetables. Although, its use is economical and respectful with the environment, its effectiveness depends on the final formulation and the technological conditions applied. In this work, control films were formulated based on carboxymethylcellulose (CMC-1.0%), cassava starch (CS-3.0%) and alginate (ALG-2.0%) using glycerol (Gly) as plasticizer (30, 20 and 40% polymer, respectively). Then, in order to evaluate the application of high intensity ultrasound (5 min and 40% amplitude power) during several emulsification treatments (sunflower oil concentrations range: 0.15-0.35%), the barrier, mechanical and optical properties and the microstructure of final films (ECMC, ECS and EALG) were assessed. Ultrasound nano-emulsification treatment led to improved barrier properties only for CS based films. Moreover, ECS Film showed undetectable color changes, homogeneous and stable nano-emulsions with the highest hydrophobic behavior which makes it suitable for coating in minimally processed vegetables.