Development of pea protein-based films and coatings with haskap leaf extracts
Kar Yeen Chong, Marianne Su‐Ling Brooks
Abstract
Haskap (Lonicera caerulea) leaves are an agricultural residue from haskap farms, where haskap berries are cultivated commercially. The leaves are rich in bioactive compounds that could be beneficial for food packaging and preservation. In this study, pea protein-based films and coatings were studied as renewable packaging options for grape tomatoes and Cavendish bananas. The effect of haskap leaf extracts in the films and coatings on weight loss of the tomatoes and bananas was investigated. The bioactive leaf extracts were obtained from prior extraction experiments using either aqueous two-phase extraction (ATPE) or aqueous two-phase flotation (ATPF). The leaf extracts contained bioactive compounds, ethanol, water, and residual salt. The tomatoes and bananas were monitored for changes in weight, °Brix, and pH values over the storage time. Pea protein isolate films containing sodium phosphate/ethanol ATPE extract had the best result for tomatoes with a smaller weight loss (1.81%) compared to those stored with pea protein films containing no extract (1.92%) and without films (2.51%). However, the pea protein concentrate coatings, both with and without extracts, had no significant effect on weight loss for the bananas.