title: [Influence of below-freezing temperatures on the rate of post-mortem metabolism and the water-holding capacity in prerigor frozen beef muscles (author's transl)].
abstract: Prerigor beef is very suitable for the production of "bruehwurst" (frankfurter and bologna type sausages) because of its high waterholding capacity (WHC). This high WHC can be preserved for several months by rapid freezing of prerigor beef either unsalted or salted. In order to elucidate the optimum conditions of frozen storage for the preservation of high WHC, intact beef muscle, ground beef and ground, salted (2% NaC1) beef (neck muscles) were frozen at - 18 degrees or --40 degrees C in a thin layer (0.5-1 cm) 30--60 min after slaugther and stored at various temperatures between --5 degrees and --40 degrees C. The changes of biochemical parameters (content of glycogen and lactate, R-value [it corresponds to ATP concentration] and pH) in the tissue and the WHC of raw and heated muscle homogenates, prepared from the frozen material and containing 2% NaC1, were measured and related to time and temperature of frozen storage. At storage temperature of --18 degrees and --40 degrees C no appreciable biochemical changes occur in intact and ground, unsalted tissue over a period of 10 months. Above 18 degrees C, however, rising temperature causes an increased rate of ATP turnover and glycolysis. In ground muscle higher rates of postmortem metabolism are generally found than in the intact tissue. In prerigor salted and frozen beef a faster drug of ATP concentration (increase of R-value) occurs whereas the breakdown of glycogen to lactate is inhibited. The WHC of raw and heated muscle homogenates depends on time and temperature of frozen storage. As soon as the ATP concentration in unsalted beef falls to a level, at which the onset of rigor mortis occurs, the WHC of homogenates decreases markedly. With beef, ground and salted in the prerigor state and than frozen muscle homogenates are obtained which show always a high WHC even after complete breakdown at ATP during frozen storage. These results have practical consequences with regard to processing of hot-deboned beef.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D005615:Freezing; D006019:Glycolysis; D009132:Muscles / Q000032:analysis / Q000378:metabolism*; D011180:Postmortem Changes; D014867:Water / Q000032:analysis*
chemical_list: D014867:Water; D000255:Adenosine Triphosphate
vernacular_title: Enfluss der Gefrierlagertemperatur auf Muskelstoffwechsel und Wasserbindungsvermögen in prae rigor gefrorenem Rindfleisch.