The influence of lingonberry extract on the properties of novel, double-layered biopolymer films based on furcellaran, CMC and a gelatin hydrolysate

In this paper, the procedure is presented of innovative, biopolymer double-layered film synthesis, based on furcellaran (FUR) (1st layer) and carboxymethyl cellulose (CMC) with a gelatin hydrolysate (HGEL) (2nd layer). The double-layered structure of the films can be clearly observed in SEM images. The water extract from lingonberries was added to FUR to reinforce the antioxidant and antimicrobial activity of the films. The films with the greatest lingonberry extract (LBE) additive demonstrated antimicrobial activity against the tested bacteria and antioxidant activity (from 3.01 to 41.89 mM Trolox/mg - via FRAP method, and from 0 to 20.56% - via DPPH method). The films with 40% of LBE showed the highest thermal stability (improvement by up to ∼92%) in comparison to tested films. They were used as active materials in the storage of cherry tomatoes. In the active films, tomatoes lost weight quickly compared to the synthetic ones. However, they were characterised by lower phenol content, which indicated slow ripening. The obtained double-layered films with LBE are an interesting alternative to plastic materials.