60Co-γ射线辐照对鳝鱼品质及挥发性物质的影响

Effects of 60Co-γ radiation on quality and volatile substances of Monopterus albus

中文关键词:  鳝鱼  储藏  保鲜  辐照灭菌  脂肪氧化  挥发性物质

英文关键词:Monopterus albus  storage  preservation  irradiation sterilization  fat oxidation  volatile matter

中文摘要:

      目的 研究60Co-γ射线辐照对鳝鱼品质及挥发性物质的影响。方法 将鲜活鳝鱼剖杀、切段处理后进行辐照灭菌, 设置2、4、6、8 kGy 4个剂量组, 以未辐照组作为对照组, 真空包装后在4 ℃冰箱中进行储藏。定期取样测定其菌落总数、挥发性盐基氮(total volatile base nitrogen, TVB-N)、脂肪含量、丙二醛(malondialdehyde, MDA)、脂质过氧化物(lipid peroxides, LPO)来研究60Co-γ射线辐照灭菌对鳝鱼冷藏品质的影响, 并利用固相微萃取-气相色谱-质谱法(solid phase microextraction-gas chromatography-mass spectrometry, SPME-GC-MS)研究未辐照、8 kGy辐照鳝鱼的挥发性物质变化情况。结果 第8 d时未辐照组鳝鱼片TVB-N值为20.92 mg/100 g, 菌落总数超过1.0×106 CFU/g, 超过可食用标准限值, 但辐照导致鳝鱼脂肪氧化产物增加, 第6 d时未辐照组的LPO和MDA含量分别为8.64 μmol/g prot和7.64 nmol/mg prot, 而辐照各组均高于未辐照组。挥发性物质检测结果显示, 在鳝鱼中一共检测出62种挥发性物质, 其中胺类6种、醛类15种、烃类25种、酸类5种、酮类5种、酯类2种、醇类1种, 其他化合物3种。结论 辐照能够有效延长鳝鱼冷藏货架期, 结合TVB-N和菌落总数指标, 辐照组鳝鱼的冷藏货架期最长可至15 d, 但辐照也有促使脂肪氧化、产生影响风味的挥发性物质等副作用。

英文摘要:

      Objective To investigate the effects of 60Co-γ irradiation on quality and volatile substances of Monopterus albus. Methods Fresh eels (Monopterus albus) were cut into sections and treated with 4 irradiation dose groups of 2, 4, 6 and 8 kGy for irradiation sterilization, and the non-irradiation group was taken as the control group, then they were stored in a refrigerator at 4 ℃. The total number of colonies, total volatile base nitrogen (TVB-N), fat content, malondialdehyde (MDA) and lipid peroxides (LPO) were sampled regularly to study the effects of 60Co-γ irradiation sterilization on refrigerated quality of eels (Monopterus albus), the volatiles of eels irradiated by 8 kGy and non-irradiated were studied by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). Results On day 8, the volatile base nitrogen value of non-irradiated group was 20.92 mg/100 g, and the total number of colonies exceeded 1.0×106 CFU/g, which exceeded the edible standard limit, but the irradiation resulted in the increase of lipid oxidation products of eels, on day 6, the contents of lipid peroxides and malondialdehyde in non-irradiated group were 8.64 μmol/g prot and 7.64 nmol/mg Prot, respectively, while those in irradiated group were higher than those in non-irradiated group. A total of 62 kinds of volatile substances were detected in eels, including 6 kinds of amines, 15 kinds of aldehydes, 25 kinds of hydrocarbons, 5 kinds of acids, 5 kinds of ketones, 2 kinds of esters, 1 kinds of alcohol and 3 kinds of other compounds. Conclusion Irradiation can effectively prolong the shelf life of eels in cold storage, combining with TVB-N and total number of colonie, the shelf life of eels in the irradiation group can be up to 15 d, however, irradiation also has side effects such as promoting fat oxidation and producing volatile substances, etc.