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ABSTRACT:In order to extend product shelf life while preserving the quality scientific attention focused to biopolymers research that are base for edible films and coatings production. Another major advantage of this kind of food packaging is their eco-friendly status because biopolymers do not cause environmental problems as packaging materials derived from non-renewable energy sources do. Objective of this work was to review recently studied edible films and coatings -their sources, properties and possible application. As sources for edible biopolymers were highlighted polysaccharides, proteins and lipids. The most characteristic subgroups from each large group of compounds were selected and described regarding possible physical and mechanical protection; migration, permeation, and barrier functions. The most important biopolymers characteristic is possibility to act as active substance carriers and to provide controlled release. In order to achieve active packaging functions emulsifiers, antioxidants and antimicrobial agents can also be incorporated into film-forming solutions in order to protect food products from oxidation and microbial spoilage, resulting in quality improvement and enhanced safety. The specific application where edible films and coatings have potential to replace some traditional polymer packaging are explained. It can be concluded that edible films and coatings must be chosen for food packaging purpose according to specific applications, the types of food products, and the major mechanisms of quality deterioration.

Cucurbitin extracted from pumpkin (Cucurbita pepo) oil cake was enzymatically hydrolysed with three different enzymes viz. alcalase, flavourzyme and pepsin. Antioxidative and functional properties of cucurbitin hydrolysates with different degrees of hydrolysis (DH) were investigated. The antioxidant activity of the hydrolysates was strongly dependent on the enzyme used. The hydrolysates obtained by alcalase and pepsin showed antioxidative potential whereas flavourzyme hydrolysates did not demonstrate these activities. Reducing power and 2,2 0 -azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) scavenging activity of cucurbitin hydrolysate were positively related to DH. The highest antioxidant activity was found in the hydrolysate obtained by alcalase at DH 25.6 % [reducing power of 0.25 ± 0.01 A700 nm and ABTS scavenging activity of 3.34 ± 0.02 mmol/L Trolox equivalent antioxidant coefficients (TEAC)]. Hydrolysis by all enzymes increased the protein solubility within the studied pH range. The best emulsion activity and stability index (EAI = 143.28 ± 3.05 m 2 /g and ESI = 87.5 ± 1.96 min) have hydrolysates produced by flavourzyme (DH 9.2 %) whereas alcalase produced hydrolysates with the best foaming capacity (FC = 242 ± 3.21). The results demonstrate that hydrolysates produced in the present study have good functional properties as well as antioxidant activity indicating their possible use in different food systems.

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