辐照处理提高猪肉火腿肠保鲜效果

辐照是一种非常有效的食品杀菌保鲜技术,近年来在即食肉制品保鲜方面的应用逐渐引起了人们的关注。为了探讨γ辐照技术对猪肉火腿肠的杀菌保鲜效果,试验采用1、3、5、7、9 k Gy 5个剂量分别对火腿肠进行辐照处理,辐照结束后样品在4℃条件下冷藏,然后跟踪测定其在冷藏过程中脂肪和蛋白质氧化、颜色、p H值、挥发性盐基氮(total volatile basic nitrogen,TVB-N)以及菌落总数的变化,分析不同剂量辐照处理对火腿肠保鲜效果的影响。结果表明,辐照可以显著降低火腿肠脂肪和蛋白质的氧化稳定性,促进其在储藏过程中的氧化。1 k Gy剂量辐照对火腿肠的色泽影响不显著;3~9 k Gy剂量辐照,可以使样品的红度值(a*值)显著降低、亮度值(L*值)显著升高(P0.05),而在冷藏过程中a*值与L*值均随储藏时间的延长而降低,且高剂量辐照组要比低剂量组降低更快一些。火腿肠p H值受辐照影响不显著(P0.05),且在冷藏过程中所有处理组火腿肠的p H值变化也不显著,均在6.0~6.5范围内。5 k Gy剂量辐照即可对猪肉火腿肠中的微生物起到有效抑制作用。

Improving preservative effect of pork ham sausages by irradiation

Irradiation is a kind of effective food sterilization technology, which can effectively inhibit and eliminate the pathogenic or spoilage microorganisms. Meat and meat products, due to their high level of nutrients, pH value (5.5-7.0) and high water activity, offer a congenial environment for the growth of bacteria. In recent years, the utilization of irradiation in ready to eat (RTE) meat products is gradually getting people’s attention, because many of the ready-to-eat cooked meat products are sterilized by high temperature above 100℃ , which may could cause the nutrition loss and flavor deterioration. Pork ham sausage is a kind of important cooked meat product, which has won good graces of many peoples. Thus, this study mainly used theγ-irradiation for pork ham sausages preservation to investigate the effect of different irradiation doses on the preservative effect of pork ham sausage, and finally chose a suitable irradiation dose for pork ham sausages. The study mainly irradiated the pork ham sausage using theγ ray of60Co at 1, 3, 5, 7 or 9 kGy, respectively. After irradiation, the pork ham sausages were stored immediately at 4℃ for 4 weeks, and the changes of lipid oxidation(TBARs), protein oxidation (carbonyl value), color, pH value, TVB-N content and total microbial counts were measured during the storage. Through analyzing these indices, the effect of different irradiation doses on pork ham sausage was discussed, and a suitable irradiation dose for the pork ham sausage was chosen. The results showed that irradiation could effectively decrease the oxidative stability of the lipid and protein of pork ham sausage, which consequently promote the lipid and protein oxidation of the pork ham sausage during storage at 4℃, and the effect was enhanced with irradiation dose increase. Due to the influence of irradiation on lipid and protein oxidation, the color of the samples was also affected by irradiation. But 1 kGy irradiation had no a significant effect on the color of pork ham sausage. 3 to 9 kGy irradiation could significantly decreased thea* value and increased theL* value compared to the control sample (P<0.05), and both of them decreased gradually with storage time increasing. The decrease rate of high dose irradiation groups was faster than that of low dose irradiation groups. The pH value of samples was not significantly affected by the irradiation dose (P>0.05) and also not changed significantly during the cold storage, which just changed within the range of 6.0-6.5. For all samples, the TVB-N content increased with storage time increase. But for irradiated samples, the increase rate was significantly lower than that of the control sample. And when the irradiation dose increased to 5 kGy, the inhibitory effect of irradiation on the TVB-N formation was not changed significantly with the continually increase of the irradiation dose. This result was very consistent with the microbiological analysis result. These results suggests that 5 kGy irradiation can play an effective inhibitory effect on the microorganisms of pork ham sausages, and will be a very promising ham sausage preservation technology.