双螺杆挤压对低值海参多肽提取率及抗氧化活性的影响

Effect of twin-screw extrusion on the extraction rate and antioxidant activity of low-value sea cucumber polypeptides

中文关键词: 低值海参  挤压加工  多肽  抗氧化

英文关键词: Low-value sea cucumber  Extrusion processing  Polypeptide  Anti-oxidation

中文摘要:

      海地瓜(Acaudina molpadioides)属低值海参产品，为了提高其使用价值，本研究以海地瓜为原料，利用双螺杆挤压辅助不同浓度亚硫酸钠(Na2SO3)处理，并对挤出物多肽提取率、游离巯基含量和蛋白质溶解度进行测定；利用DA201-C型大孔吸附树脂对挤出物多肽进行分离纯化，并对多肽纯化组分的分子量分布和抗氧化能力进行测定。结果显示，双螺杆挤压辅助3.0% Na2SO3处理组多肽提取率、游离巯基含量和蛋白质溶解度分别为(57.12±0.62)%、(110.32±0.07)%和(28.72±0.13)%，较空白对照组(control check, CK)分别显著提升(7.66±0.35)%、(105.32±0.01)%和(4.91±0.15)% (P<0.05)；粗肽经纯化得到纯化组分Ⅰ(1000~3000 u)和纯化组分Ⅱ(<1000 u)。CK组、双螺杆挤压辅助3.0% Na2SO3处理组及其经分离纯化后得到的的纯化组分Ⅰ、Ⅱ海地瓜多肽的DPPH自由基清除率的IC50值分别为25.51、12.72、6.58和9.02 mg/mL，对超氧阴离子自由基清除率的IC50值分别为25.56、13.51、11.87和8.44 mg/mL。纯化组分Ⅰ在浓度为80 μg/mL时，人正常肝细胞(human normal liver cell, LO2)细胞存活率较损伤组最大提高(20.33±0.41)%；纯化组分Ⅱ在浓度为20 μg/mL时，LO2细胞存活率较损伤组最大提高(17.07±1.18)%。综上所述，双螺杆挤压辅助亚硫酸钠处理海地瓜提高了多肽的提取率，并增强了海地瓜多肽抗氧化活性。

英文摘要:

      The sea cucumber Acaudina molpadioides is a low-value aquatic product of the ocean. To increase its value, in this study, dried body walls of low-value A. molpadioides were selected as research material, from which the polypeptides were extracted by employing twin-screw extrusion with sodium sulfite-assisted treatment. The extraction rate of polypeptides and free sulfhydryl groups, and protein solubility from extrudate of A. molpadioides were determined. Polypeptides were separated from the extrudate and purified with DA201-C type microporous adsorption resin, and the molecular weight distribution and antioxidant ability of the purified components were determined. The results showed that for the A. molpadioides treated with twin-screw extrusion-assisted 3.0% sodium sulfite, the polypeptide extraction rate, free sulfhydryl content, and protein solubility were (57.12±0.62)%, (110.32±0.07)%, and (28.72±0.13)%, respectively, which were significantly higher (P<0.05) by (7.66±0.35)%, (105.32±0.01)% and (4.91±0.15)%, respectively, compared with those of the control check (CK). Moreover, the molecular weights of the purified polypeptides component I and Ⅱ were 1000~3000 u and <1000 u, respectively. Additionally, comparing the A. molpadioides polypeptides with those in the CK group, twin-screw extrusion-assisted 3.0% sodium sulfite extraction group, purified component I, and purified component Ⅱ, the IC50 values of DPPH radical scavenging rate were 25.51 mg/mL, 12.72 mg/mL, 6.58 mg/mL, and 9.02 mg/mL, respectively, and the IC50 values of the superoxide anion radicals scavenging rate were 25.56 mg/mL, 13.51 mg/mL, 11.87 mg/mL and 8.44 mg/mL, respectively. The results of oxidation damage protection test suggested that for purified component I, the optimal concentration for the survival rate of LO2 cells was 80 μg/mL, with (20.33±0.41)% increase compared with that in the injured group; as for the purified component Ⅱ, it was 20 μg/mL with (17.07±1.18)% increase than that in the injured group. In summary, the twin-screw extrusion-assisted sodium sulfite treatment on A. molpadioides improved the extraction rate of polypeptide and the extracted polypeptide possessed enhanced antioxidant activity.