Some effects of residual glycogen concentration on the physical and sensory quality of normal pH beef

Abstract

The aim of this study was to assess the effects of residual glycogen concentration on the physical and sensory quality of normal-pH beef. Longissimus thoracis et lumborum muscles ( n=42) having ultimate pH (48 h) between 5.50 and 5.75 were excised, assayed for residual glycogen concentration and divided into three categories according to the residual glycogen concentration. The categories were ⩽25 mmol/kg, 25.1–49.9 mmol/kg and ⩾ 50 mmol/kg. One half of every LTL muscle was aged for 28 days. All samples were evaluated for fresh meat colour, drip loss, shear force, thawing and frying losses and fried steak colour as well as sensory attributes of tenderness, juiciness, flavour and overall palatability. The independent significant effects of increasing residual glycogen concentration on the physical and sensory quality of normal-pH-beef were, although numerous, quite modest in magnitude. The water holding variables in the form of decreasing drip loss ( p<0.061), increasing thawing loss ( p<005), increasing sum of losses in thawing and frying ( p<0.05), and decreasing sensory juiciness ( p<0.05) were somewhat affected as were decreasing fresh meat redness (Minolta a*) ( p<0.005), decreasing shear force ( p<0.05) and increasing yellowness (Minolta b*) of the steak ( p<0.0001). Beef of the lowest and highest glycogen category were the ones behaving slightly differently from each other, the intermediate category mostly followed the pattern of one or the other.