inosinic-acid and tetrapotassium-pyrophosphate

Water-holding capacity (WHC) of heat-induced pork gels was examined. The heat-induced gels were obtained from meat homogenates prepared by adding nine volumes of 0.3-0.5 mol/L NaCl solutions containing 9-36 mmol/L disodium inosine-5'-monophosphate (IMP) or 9 mmol/L tetrapotassium pyrophosphate (KPP) to minced pork. IMP at 36 mmol/L enhanced the WHC to the same level as attained by KPP. Physical and sensory properties of heat-induced gels were also examined. The heat-induced gels were prepared from porcine meat homogenates containing 0.3 mol/L NaCl and 9-36 mmol/L IMP or 9 mmol/L KPP. IMP at 36 mmol/L enhanced the values of hardness, cohesiveness, gumminess and springiness, measured with a Tensipresser, and several organoleptic scores to the same level as the score attained by KPP. Thus, it is concluded that IMP is expected to be a practical substitute for pyrophosphates to improve the quality of sausages.

Topics: Animals; Diphosphates; Gels; Hot Temperature; Inosine Monophosphate; Meat; Meat Products; Potassium Compounds; Swine

We examined the mode of IMP and pyrophosphate enhancement of myosin and actin extraction from porcine meat. Extractabilities were determined after homogenates, prepared by adding 9 volumes of 0.3, 0.4, or 0.5 M NaCl solutions containing 0 to 36 mM IMP and 0 to 9 mM tetrapotassium pyrophosphate (KPP) to minced pork, were incubated at 4 °C for 0 or 12 h. Irrespective of the NaCl concentrations, IMP-induced extraction of both proteins increased with increasing extraction time. In contrast, that of KPP did not. When 0.3 M NaCl solutions containing both IMP and KPP were used, the solutions with 1.5 mM KPP showed marked enhancement of IMP-induced myosin and actin extraction. Incorporating these results with our previously published data (Nakamura et al., Biosci. Biotechnol. Biochem., 76, 1611-1615 (2012)), we hypothesized that IMP and KPP have the ability to release thick and thin filaments from restraints in myofibrils, in addition to the ability to dissociate actomyosin into myosin and actin, and that the restraint-releasing ability of IMP is dependent on reaction time and NaCl concentration while that of KPP is not.

Topics: Actins; Actomyosin; Animals; Diphosphates; Inosine Monophosphate; Meat; Myofibrils; Myosins; Potassium Compounds; Sodium Chloride; Swine

We examined the effects of nucleoside monophosphates on the dissociation of actomyosin into myosin and actin. GMP was effective only among GMP, CMP, dTMP, and UMP. Hence we concluded that purine-based nucleoside monophosphates such as GMP, AMP, and IMP are effective, incorporating this with our previous results (Okitani A et al., Biosci. Biotechnol. Biochem., 72, 2005-2011 (2008)). Then we examined whether IMP enhances the extraction of myosin and actin as well as pyrophosphate (KPP), using homogenates of pork with 9 volumes of 0.3, 0.4, and 0.5 M NaCl solutions containing 0-36 mM IMP or 0-9 mM KPP. Maximum extractability, about 70% for both proteins, was attained by means of NaCl solutions containing 36 mM IMP. These values were comparable to the maximum values, about 90% for myosin and 50% for actin, attained by means of solutions containing 9 mM KPP. Hence we concluded that IMP enhances the extraction of myosin and actin from porcine meat.

Topics: Actins; Actomyosin; Animals; Diphosphates; Electrophoresis, Polyacrylamide Gel; Inosine Monophosphate; Liquid-Liquid Extraction; Meat; Muscle, Skeletal; Myosins; Potassium Compounds; Sodium Chloride; Swine