Definition of the optimal freezing rate-2. Investigation of the physico-chemical properties of beef M. longissimus dorsi frozen at different freezing rates.

The influence of freezing rate on weight loss during the freezing, thawing and cooking, on water-binding capacity, on sensory and other physico-chemical properties of beef M. longissimus dorsi was investigated. The changes in myofibrillar proteins in muscle samples frozen at different freezing rates were also investigated. The greatest weight losses during the freezing, thawing and cooking were registered at slow freezing procedures (freezing rate of 0·22 cm/h and 0·29 cm/h), when the meat was tougher and less soft. The solubility of myofibrillar proteins was least from those muscles frozen at such freezing rates. The freezing of samples at freezing rates of 3·33 cm/h and 3·95 cm/h had less influence on their physico-chemical characteristics. The solubility of the myofibrillar proteins from such samples was greatest, and the cooked samples were the most tender. From analysis of the results it was concluded that optimal conditions for meat freezing seem to be those when the average freezing rate is 2-5 cm/h.