Edible collagen coatings from chicken skin for longer shelf life of meat and dairy food systems

Collagen is a popular component of edible coatings that protect food products during storage. This article introduces a new antioxidant and antibacterial edible coating made from broiler chicken skin as a source of collagen. The coating was tested on meat and dairy products with high moisture and fat content, namely sausage, jellied beef, and soft cheese. A set of standard research methods made it possible to determine the physicochemical, sensory, and microbiological properties of broiler chicken skin and the experimental edible coating, as well as to compare the coated and uncoated meat and dairy products. A digital micrometer and a DVT Devotrans GPUG model revealed the structural and mechanical properties of the test products. The protein fraction was described using a method based on the extraction of sarcoplasmic proteins from muscle tissue in a low-ionic-strength buffer solution to produce fractions of water-soluble, salt-soluble, and alkali-soluble proteins. The water activity coefficient was obtained using an Aqualab 4TE analyzer with a dielectric humidity sensor. Alcalase (Novozymes, Danmark) was chosen as the optimal enzymic preparation available on the Russian market for the hydrolysis of collagen-containing raw materials. Its optimal concentration was 0.3% of the raw material weight after preliminary swelling in water. The optimal hydrolysis conditions were as follows: heating medium temperature – 52°C, exposure time – 5 h. The research resulted in a production algorithm and a formulation modeled in the MultiMit automated expert system. The new technology for edible coating from chicken skin collagen can be used in the meat and dairy industries to extend the shelf-life of final products due to antibacterial and antioxidant effects.