Search

(1) Background: Recent research on the valorization of agro-industrial waste has attempted to obtain new products. Grape residue is a waste product used in the grape wine industry that is rich in anthocyanins, as well as leaves and waste parts from red cabbage processing. Anthocyanins, thanks to their various functionalities, can be recovered and used as active and intelligent agents in food packaging. Anthocyanins have antioxidant properties that help to prevent cardiovascular disease. (2) Methods: In this study, the process of extracting waste was studied using solvent and supercritical CO2 extraction. The obtained anthocyanins were used in starch-based food film formulations. Several formulations were studied using rheometric techniques and the effect of adding anthocyanins on optimal film formulation was investigated. (3) Results: Solvent extractions resulted in a maximum extraction yield. The extracts obtained were used for the preparation of coating and edible films, optimized in the formulation. (4) Conclusions: The addition of anthocyanins to films resulted in increased sample structuring and mechanical properties that are valid for applications, like dipping using coverage methods. The packaging is also attractive and pH-sensitive.

Anthocyanin is a characteristic nutrient of purple cabbage, and phenylalanine ammonia-lyase (PAL) is the rate-limiting enzyme for the synthesis of anthocyanin by the phenylpropane pathway, which is an important part of plant secondary metabolism. In this research, 7 BrPAL, 8 BoPAL, and 15 BnPAL genes from genomes of Brassica rapa, Brassica oleracea, and Brassica napus, divided into four subgroups, evolved from 4 PAL genes in Arabidopsis. The amplification and evolution of the BrPAL gene are due to segmental duplication and purifying selection. BrPAL genes clustered in the same clade have similar intron/exon structures and motifs. The cis-regulatory elements are divided into four categories: light, growth and development, stress and hormones. The qRT-PCR assays showed that most BrPAL genes were upregulated by UVA, low temperature and MeJA and downregulated by FR, high temperature, salt, PEG, IAA, ABA and GA, and there was a positive correlation between anthocyanin content and gene expression. This study can be used as a source for the function of the cabbage PAL gene and its molecular mechanism of regulating anthocyanin synthesis and provides a theoretical basis for the molecular breeding of cabbage.