海参低温处理品质与理化性质研究

Studies on Quality and Physicochemical Properties of Sea Cucumber Stichopus japonicus during Low Temperature Treatment

以新鲜海参为原料,20℃低温处理,考察海参在不同处理时间(0,1/24,1/4,1/2,1,2,3,4,5,6d)下品质和理化性质变化。结果表明,随着低温热处理时间的延长,可溶性胶原的含量随时间的延长呈上升趋势,6d时含量为0d的3.23倍;硬度和咀嚼度在1/4d后都发生急剧下降,最后其硬度和咀嚼度仅为0d状态下的0.92%和0.22%;SDS-PAGE结果表明,分子质量为200.0ku和44.3ku的肌动蛋白条带随着热处理时间的延长发生明显的蛋白降解;与0d相比,组织蛋白酶-L活力在1/2d时增加1.6倍,caspase-3活力在1d时增加3倍,随后随着处理时间的延长而下降;ESR结果表明,在20℃低温热处理1/2d,海参自由基信号强度达到最高水平,是0d的1.67倍。综上所述,在20℃低温热处理下,海参体内自由基生成,氧化促进组织蛋白酶-L和caspase-3被激活,进而导致蛋白质降解,胶原溶出,最终影响海参的品质。

In this study, sea cucumbers were as raw materials, treated at low temperature of 20 ℃, studying on the quality and physicochemical properties of sea cucumber under different treatment conditions at 0, 1/24, 1/4, 1, 2, 3, 4, 5 and 6 d. The study found that the soluble collagen amount increased with the prolongation of time at low-temperature treatment and the content of soluble collagen of 6 d is 3.23 times of 0 d. The hardness and chewiness dramatically decreased after 1/4 d and the hardness and chewiness are only 0.92% and 0.22% of the state of 0d. SDS-PAGE result indicated that the notable proteolysis happened to the protein with molecular weight of 200 ku and 44ku of actin with the heating time extension. Compared with the control group, the activity of cathepsin-L and caspase-3 was increased 1.6 times at 1/2 d and 3 times at 1d and their activity decreases with the prolongation of time at low-temperature treatment. ESR results indicated that the free radicals production of sea cucumber reached the highest level after 1/2 d and compared with 0 d, its value increased by 1.67 times. In summary, at 20 ℃ low temperature heat treatment, free radicals in sea cucumbers were generated and oxidation promotes cathepsin-L and caspase-3 activation, which leaded to degradation of protein, dissolution of collagen, and ultimately morphological and quality changes in sea cucumber.