Biopolymers Produced from Gelatin and Chitosan Using Polyphenols

Abstract

Chitin, and its derivative chitosan, is an abundant waste product derived from crustaceans (e.g. crab). It has unique properties, which enable its use in, but not limited to, cosmetic, medical and food applications. Chitosan has recently been studied, in conjunction with other waste carbohydrates and proteins, for the purpose of making biopolymer products with unique functional properties. Furthermore use of renewable polyphenols to assist in these reactions is a topic of growing interest. In prior research, we investigated the use of polyphenols, specifically gallic acid and the vegetable tannins quebracho and tara, to modify gelatin. We improved the physical properties of gelatin and were able to demonstrate that these products could be used effectively as fillers. At present, gelatin is scarce and becoming increasingly more expensive so we produced biopolymers from modification of gelatin and whey using the vegetable tannin tara, and made products to augment the gelatin; we further demonstrated that the resulting product could be used as a filler for leather. This present study investigated the preparation of a biopolymer using gelatin and chitosan, modified with the vegetable tannin tara, to make products that could be used either in leather making process, e.g. as fillers or coatings or could have other potential uses such as in film-making or as flocculants. Optimal conditions necessary for polyphenols to react with gelatin and chitosan were determined and physical properties showed that unique products were produced. The gels were examined for thermal stability and for fluorescence. We thus demonstrated that gelatin/chitosan/tara products are feasible and that gelatin products could be supplemented using an inexpensive abundant waste product, chitosan.