LOW‐TEMPERATURE, LONG‐TIME HEATING OF BOVINE MUSCLE 1. Changes in Tenderness, Water‐Binding Capacity, pH and Amount of Water‐Soluble Components

SUMMARY: Relationships between the tenderness of very slowly cooked meat and its waterholding capacity, pH and the amount of water‐soluble components were studied. Beef muscle portions from the longissimus, semitendinosus and rectus femoris muscles were heated under fixed temperature programs with samples from each analyzed at 1‐hr intervals between the 3rd and the 10th hr of heating. Weight losses after holding at the final temperature to the 24th hr were determined. During the first 4 hr of heating there were only minor changes in tenderness. The major decrease in shear values occurred between the 4th and 6th hr, when the meat was warming from 50‐60°C. The weight losses increased rather linearly to the 7th hr and remained constant for the longissimus and the semitendinosus muscle. The pH values gradually increased during heating. During the first 3 hr of heating, up to 45°C, there was only a slight decrease in the amount of the water‐soluble fraction. During the following 3 hr. from 45 to 58°C, the water‐soluble fraction decreased more rapidly and the decrease was only slight during a following 4‐hr holding period. After 6 hr of heating to 60°C there were still uncoagulated water‐soluble proteins. These studies indicate that the final temperature of meat has great influence on tenderness and weight loss. The significance of the shrinkage of collagen in long‐time, low‐temperature cooking is considered.