Metabolic changes caused by electrical stimulation of carcasses measured by proteomics

In recent years consumers internationally have been more aware of the high variability and inconsistency of beef product quality. A large and significant variability in quality of aged beef has been documented also in Sweden and Norway (i.e. tenderness an d juiciness), both between slaughter animals and between abbatoirs. Although electrical stimulation (ES) of carcasses today is in widespread use to enhance meat tenderness, there is still a large variation in tenderness also when ES techniques (low voltag e) are used as preventive measures in the meat industry. This is crucial, as the use of ES has been implemented at most of the Norwegian abbatoirs as a measure to guarantee meat tenderness. The cellular changes at the protein level related to ES intervent ion is poorly understood. Unravelling molecular changes at the protein level that are induced by electrical stimulation of bovine carcasses, should be useful in understanding both ES and beef tenderisation. In this project, we will use proteomics as a met abolic profiling tool in the study of ES treatment of beef carcasses. To our knowledge this has not been done before. We aim at identifying proteins that are markers for optimisation of ES regarding final quality. In practice, we will collect muscle tiss ues from 2 muscles (LD and SM) from 50 bovine animals before and after ES on the industry slaughter line and compare these with non-stimulated muscles. The effects of ES will be monitored by glycolytic rate, muscle contraction, calpastatin activity and te nderness after ageing, and high-resolution 2D gel electrophoresis maps will be established of the cytoplasmic muscle fractions. The metabolic shift patterns of LD and ST muscles will be compared, and shifts in protein profiles that relate to ES will be ch aracterised by MALDI-TOF based peptide mass fingerprinting and de novo sequencing by MALDI-TOF/TOF analyses. A successful project will create a novel basis for concepts for development of new ES systems for bovine c