title: The effect of electrical stimulation on post mortem myofibrillar protein degradation and small heat shock protein kinetics in bull beef.
abstract: This study aimed to determine the effect of electrical stimulation and ultimate pH (pHu) on shear force, myofibrillar protein degradation and small heat shock protein (sHSP) concentrations in M. longissimus lumborum (LL). The LL from both sides of carcasses (n=15) was excised with low voltage electrical stimulation (ES) applied to an LL muscle from one side, while the opposing LL muscle was not stimulated (NS). Muscles were categorised into low (pHu<5.8), intermediate (5.8≤pHu<6.2) and high pHu (pHu≥6.2) and aged for up to 28days post mortem at -1.5°C. High pHu meat tenderised faster which corresponded with the faster degradation of titin and desmin in this group compared with low and intermediate pHu meat. Electrical stimulation significantly affected the variable levels of αβ-crystallin and HSP20 with higher concentrations of these sHSP in ES muscles at later ageing timepoints compared with NS muscles.
authors.affiliation: Department Agri-industry, Food and Nutrition, "Luiz de Queiroz" College of Agriculture, - University of São Paulo, P.O. Box 9, Padua Dias 11, Piracicaba, SP, Brazil. Electronic address: ccastill@usp.br.
authors.forename: C J
authors.initials: CJ
authors.lastname: Contreras-Castillo
authors.affiliation: Plant and Food Research, Food Industry Science Centre, Private Bag 11600, Palmerston North, New Zealand.
authors.forename: D
authors.initials: D
authors.lastname: Lomiwes
authors.affiliation: Food Assurance and Meat Quality, AgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, New Zealand.
authors.forename: G
authors.initials: G
authors.lastname: Wu
authors.affiliation: Food Assurance and Meat Quality, AgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, New Zealand.
authors.forename: D
authors.initials: D
authors.lastname: Frost
authors.affiliation: Food Assurance and Meat Quality, AgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, New Zealand.
authors.forename: M M
authors.initials: MM
authors.lastname: Farouk
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology; D004558:Electric Stimulation; D005511:Food Handling / Q000379:methods; D050888:Heat-Shock Proteins, Small / Q000737:chemistry*; D008297:Male; D008460:Meat / Q000032:analysis*; D009124:Muscle Proteins / Q000737:chemistry*; D018482:Muscle, Skeletal / Q000502:physiology*; D009210:Myofibrils / Q000737:chemistry*
chemical_list: D050888:Heat-Shock Proteins, Small; D009124:Muscle Proteins
keywords: Bull beef; Electrical stimulation; Small heat shock proteins; Tenderness; Ultimate pH