STRUCTURE AND SOLUBILITY OF COLLAGEN AND GLYCOSAMINOGLYCANS IN TWO BOVINE MUSCLES WITH DIFFERENT TEXTURAL PROPERTIES

Abstract

ABSTRACT Meat samples were collected from two bovine muscles , psoas major and semitendinosus, exhibiting different textural properties as measured by Warner Bratzler Shear Force. The structure and composition of the intramuscular connective tissue was compared by transmission electron microscopy, fibril diameter measurements, statistical analysis, collagen and glycosaminoglycan solubility studies in acetic acid and acetic acid added pepsin. The mean fibril diameter was significantly larger in the tougher muscle and the fibrils were tightly bundled into fibers. The tender muscle exhibited mainly randomly oriented fibrils with more space in between. The biochemical study confirmed the microscopy, showing a higher hexuronic acid/hydroxyproline ratio in the tender muscle, mainly in pepsin digested samples. The content of hydroxyproline after defatting in acetone was 30% higher in ST. No major differences were seen in the proportion of acid labile or stable cross‐links in the collagen of the tough and tender muscle.