title: Shortening and tenderness of pre-rigor heated beef: Part 1 - Effect of heating rate on muscles of youthful and mature carcasses.
abstract: Pre-rigor cooked beef is tender if the cooking produces severe shortening. This study was conducted to compare the effects of different heating rates on shortening and tenderness. Myofibrillar and cooking shortening and related changes were measured with physiograph recordings on pre-rigor M. triceps brachii strips suspended in paraffin oil during heating. Warner-Bratzler shear values were determined on M. triceps brachii samples heated at approximately the same rates at which the muscle strips were heated. Rapid heating (2°C/2min) produced more (p < 0·01) severe myofibrillar shortening that was complete at higher (p < 0·01) muscle temperatures than slow heating (2°C/12 min). Regardless of animal age, rapid heating resulted in a cooked product that was more (p < 0·01) tender than that produced by slow heating in the pre-rigor state and slow heating resulted in a more (p < 0·01) tender product than that achieved by rapid heating in the post-rigor state. Data on muscle shortening and from differential scanning calorimetry suggest that the tenderness produced from pre-rigor rapid heating results from a heat-induced active contraction.
authors: Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA.
authors: H A
authors: HA
authors: Abugroun
authors: J C
authors: JC
authors: Forrest
authors: E D
authors: ED
authors: Aberlee
authors: M D
authors: MD
authors: Judge