Development of active pH-sensitive biodegradable films based on chitosan and κ -carrageenan biopolymers enriched in beluga black lentil additives

Abstract

Current trends encourage the utilization of food waste for the production of non-traditional food packaging. These novel packages are biodegradable and can be endowed with additional functional purposes. In this work, biodegradable, pH-indicating packages with antioxidant properties were developed. The package films were prepared by using κ-carrageenan (kappa-carrageenan) and chitosan biopolymers incorporated with Beluga black lentil leachate (BBLL) or Beluga black lentil powder (BBLP). Then, antioxidant, mechanical, UV-barrier properties, morphological properties, and pH sensitivity were investigated. The BBLL and BBLP alone showed high antioxidant potential and pH sensitivity with solution color change from bright red to reddish-brown and finally to green color when pH gradually increased from 1 to 13. The κ-carrageenan films showed the best response to pH changes, with color changes being the most pronounced in the films with the BBLL. Both BBL fillers significantly improve film antioxidant properties, and UV barrier properties, and reduce the film's water content. The κ-carrageenan films revealed the highest UV protection and biodegradability. The BBLL provides films with a thickness of > 0.3 mm acceptable for edible films. Moreover, the BBLL enhanced the mechanical parameters of the films and water vapor permeability, although the κ-carrageenan coats revealed significantly better tensile strength. BBLL also worked well as a filler with both biopolymers according to the scanning electronic microscopy images. Considering the color changes as the main factor for this study's purposes the κ-carrageenan film with 20% BBLL represents the best candidate as an alternative to fossil-based packages for keeping and monitoring food freshness.