Textural modification of Chinese traditional stewed pig trotter: Effect of acid or alkaline-induced degradation of collagen fibers.

Abstract

This study aimed to investigate the effects of acid or alkaline treatments on the textural properties of Chinese traditional stewed pig trotter in relation to the degradation of collagen fibers. Pig trotters were subjected to different pHs of 4, 5, 6, 7, and 8 and then stewed at 95°C for 60 min. Textural parameters (springiness, chewiness, hardness, and gumminess) of pig trotters and Raman spectroscopy, cross-links, decorin, and glycosaminoglycans contents of collagen fibers were assessed. The acid or alkaline treatments at pH 4, 5, 6, and 8 improved the textural properties evidenced by lower chewiness, hardness, and gumminess, and promoted the unfolding of the secondary structure evidenced by a loss of α-helix paralleled with an increase of random coil, as well as induced a breakage to the covalent cross-links evidenced by the reduction of cross-links, decorin, and glycosaminoglycans. This study thus concluded positive effects of acid or alkaline treatments on the textural modification of Chinese traditional stewed pig trotter in relation to the induced degradation of the collagen fibers.