Effects of whey protein-polyphenol conjugates incorporation on physicochemical and intelligent pH-sensing properties of carboxymethyl cellulose based films

This study aimed to develop carboxymethyl cellulose films functionalized by whey protein and polyphenols (proanthocyanidins and curcumin) conjugates. The physicochemical properties, freshness monitoring and preservation ability of films with conjugates were evaluated. The results showed that the vapor barrier property, tensile strength and contact angle of films incorporated with conjugates were improved 10 % -31 %, 61 % - 134 %, 4 % -19 % respectively. Furthermore, the incorporation of conjugates improved the ability to indicate the changes of pH value, inhibit the microbial growth and prevent fat oxidation, when the films were applied for beef preservation. The improvement was attributed to the enhancement of intermolecular interactions and higher binding rate, which helped to form the films with more compact and uniform microstructure. This study suggested that films containing conjugates can be applied for monitoring freshness and extending the shelf-life of beef.