Study On Tenderization Of Beef By Sodium Chloride And Polyphosphates

Semitendinosus muscle obtained from 2-year-old beef carcasses was treated with sodium chloride solutions of 2%,4%,6%,and desodium pyrophosphate, sodium tripolyphosphate, tetrasodium pyrophosphate and hexametaphosphate solutions of 1%,3%,5% respectively, the marinating periods was 1d,2d,3 d. The tenderization of these salts on beef semitendinosus muscle was studied. The main results were given as followed.l.NaCl and polyphosphates decreased the shear force of semitendinosus muscle, the shear force decreased with increse of concentration of salts and prolongation of marinating time.The moderate conditions of each salt was that 4% NaCl,5%DSPP,3%STPP,3%TSPP,3%HMP marinade 3days at 4 .respectively.2. Compared with control, NaCI, STPP, TSPP, HMP increased the percentage net weight increase at different concentration and different marinating time, DSPP solution of 5% increased the meat weight slightly after marinating 3 days, the samples treated with the DSPP solutions of 1% and 3% had lower meat weight than the control, irrespective of marinating time.3. DSPP solution decreased the cooking loss at the concentration of 5% and had no impact on cooking loss at other concentration, but other salts decreased the cooking loss at different concentration.4. Compared with control, the pH of meat samples treated with NaCI solution had no distinct difference (P>0.05). The meat samples treated with DSPP had lower pH than the control. The solution of STPP, TSPP, HMP increased the pH of beef (P<0.05).5. After the semitendinosus muscle treated with NaCI,STPP,TSPP and HMP respectively, the shear force had negative correlation with the percentage net weight increase and pH value, had positive correlation with cooking loss (P<0.01). the shear force of the samples treated with DSPP had negative correlation with percentage net weight increase, had positive correlation with cooking loss and pH value (P<0.01).6. The samples treated with NaCl solution of 4%, DSPP solution of 5%, STPP,TSPP.HMP solution of 3% respectively, the collagen solubility of these samples was markedly raised (P<0.01). No significant difference between NaCl treatment and STPP treatment as well as between STPP treatment and HMP treatment (P>0.05).7. The changes of shear force at various temperature was determined, the curves trend ofall treatments was similar. There were two peaks at 60 and 80 in every curve, and the curves slightly declined at 90 .8. The myofibrils of control and DSPP treatments remained integrity, the structure of sarcomere was intact and clear. The sarcomere of NaCl treatment remained original structure basically except that it seemed less pronounced and had slightly weakening at Z disk. The structure of STPP treatmenet and TSPP tueatment was disrupted and the weakening occurred at Z disk ,even the rupture was found. The sarcomere struture of HMP also remained basic structure except the weakening at Z disk.9. The structure of collagen fibrils in the perimysium of control had no obvious alteration, it seemed like as compact rope. The collagen fibrils of NaCl and STPP treatments disassociated more thinner tropocollagen fibrils which liked disordered silk thread and separated from each other. Except that the fibrils occurred loose, the structure of DSPP treatment had no distinct alteration and was similar with control. The collagen fibrils of STPP treatment and HMP treatmen disassociated tropocollagen fibrils, but they closed with each other.