Development and Evaluation of Apple Peel- and Carboxymethylcellulose-Based Biodegradable Films with Antioxidant and Antimicrobial Properties

Antioxidant and antimicrobial biopolymer films were developed by combining apple (Malus domestica Borkh.) peel (AP) and carboxymethylcellulose (CMC) with 1% apple peel extract and (+)-tartaric acid. Total phenolic and flavonoid contents of AP were found to be 24.94 mg gallic acid and 8.85 mg catechin equivalents/g dried weight, respectively. 1,1-diphenyl-2-picrylhydrazyl/2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) scavenging activity were found be 9.86 mg ascorbic acid and 26.30 mg Trolox equivalents/g dried weight, respectively, demonstrating the strong antioxidant activity of AP. Tartaric acid showed great inhibitory effects against the four bacteria. The addition of the antioxidant/microbial agents to the developed films resulted in biodegradable films with great antioxidant activity and antimicrobial effects. CMC/AP films showed a more efficient release rate of antioxidant compounds and stronger antimicrobial capacity than the CMC-only films. Results showed that the developed films efficiently inhibited microbial growth on chicken breast meat. These results suggest the potential applicability of the biopolymer films as an eco-friendly and antioxidant/antimicrobial packaging material for the food industry. Practical Applications: Development of such films has broad potential applications in the food industry. Antioxidant power of the films can effectively prevent oxidation of food product, and antimicrobial activity of the films can inhibit growth of the foodborne pathogenic bacteria. Therefore, application of the AP-CMC films can ensure food safety and quality and extend shelf life of food product.