南极大磷虾木瓜蛋白酶酶解产物氟浓度及营养成分研究

为了解酶解处理对南极大磷虾木瓜蛋白酶酶解产物（上清干物质KSF,沉淀干物质KS和残渣KR）中氟浓度的影响,采用氟选择电极法对酶解产物中氟进行测定。同时,采用国标方法对KSF和KS中主要营养成分进行测定。结果：KR中氟浓度最高,且KR中氟占酶解前基质中总氟的质量分数为72.94%~79.94%,而KSF和KS中氟浓度得到极大的降低。木瓜蛋白酶加入有利于虾浆中不溶的蛋白质以可溶解的形式进入上清液中。KSF中未检测到粗脂肪,总糖含量为13.91%~21.57%,粗蛋白含量为57.75%~67.13%。而KS中粗脂肪含量高达33.28%~42.90%,总糖10.14%~15.57%,粗蛋白38.00%~44.87%。因此,木瓜蛋白酶酶解南极大磷虾获得的KS和KSF均可以作为优质、安全的饲料添加剂。其中,添加1.5%的木瓜蛋白酶和1.0%葡萄糖,经58℃水浴3 h的酶解方式能使KSF的得率从18.65%上升到20.37%,其粗蛋白含量为65.49%,而KS的粗蛋白和粗脂肪含量分别为39.16%和38.49%,为最佳的酶解南极大磷虾的酶解方式。

On fluoride concentration and nutritional components in hydrolysates of Antarctic krill Euphausia superba by papain

The purpose of the study is to investigate fluoride concentration and nutritional components in hydrolysates（ including krill supernatant fluid,KSF; krill sediment,KS; krill residua,KR） from Antarctic krill Euphausia superba homogenate after different enzymatic treatments. The main nutritional components were analyzed according to Chinese standards,fluoride contents were analyzed by electrode method for selection of fluoride ion. Results showed that the highest fluoride contents were found in KR,which accounted for 72. 94- 79. 94% of total fluoride in krill homogenate,and much lower fluoride contents were found in the other two products（ KSF and KS）. The insoluble protein in homogenate has became soluble polypeptides and free amino acids after adding enzymes. Crude lipid was not found in KSF,and the total sugar contents and crude protein were analyzed to be 13. 91%- 21. 57% and 57. 75%- 67. 13%,respectively. Crude lipid was found to be high in KS,accounting for 33. 28%- 42. 90%,the contents of the total sugar and crude protein were 10. 14%- 15. 57% and 38. 00%- 44. 87%,respectively. These two low fluoride concentration products could be good source of valuable and safe supplements for animal feeds. In conclusion,the optimized enzymatic process was to add 1. 5% papain together with 1. 0% glucose to homogenate,later water bathed for 3h at 58°C. And at this condition,the recovery rate of KSF increased from 18. 65 % to 20. 37 % with a high protein content of 65. 49%,while crude protein and lipid contents in KS were 39. 16% and 38. 49%, respectively.