Structural and functional qualities of gelatin derived from the skin of the common eland antelope (Taurotragus oryx)

Abstract

Gelatin is a widely used polymer in several industrial sectors, principally in the pharmaceutical and food industries. Its popularity stems from its biocompatibility, biodegradability, colorlessness, and provider of stability and texture in different food systems. In Europe, the primary source of gelatin is pig skin; however, due to religious dietary restrictions, there is an increasing demand for alternative sources. This study analyzed the physicochemical and rheological properties of gelatin extracted from eland skin using alkaline (calcium hydroxide 2 %) and acid (acetic acid at 5 %) treatments compared to commercially available bovine and porcine gelatins. The acid-treated eland-skin collagen more effectively preserved the β and α structures. It showed a higher propensity to form triple helices more effectively than all commercial and alkaline-treated samples. It was evidenced by more intense electrophoretic bands, FTIR spectra peaks in the amide I, II, and II regions, and lower relative intensities of side chains of the amino acid residues quantified by NMR.

Rheological properties (small and large deformation) improved with increasing gelatin concentration (3, 5, and 6.67 %. w/v). Type A eland-skin gelatin resulted in a higher storage modulus (G′) and firmer gels than all samples. Electrostatic hydrogels formed at different ratios of protein: polysaccharides (1:1, 1:2, and 1:3) showed excellent texture and water-holding capacity after lyophilization compared to control samples. Our findings demonstrated that eland skin has the potential to serve as an alternative source of food additives and promise delivery system.