南极磷虾木瓜蛋白酶酶解产物的营养学评价

分析了经1.5%木瓜蛋白酶55℃酶解3 h后的南极磷虾(Euphausia superba)蛋白酶解产物(上清和沉淀)的营养组成。结果显示:南极磷虾水解度为44.24%;上清冻干物(FDS)中粗蛋白和总糖含量分别为67.13%和13.91%,其必需氨基酸总量(ΣEAA)、鲜味氨基酸总量(ΣDAA)、牛磺酸Tau含量及F值(支链氨基酸/芳香族氨基酸)较酶解前分别提高了8.96%、6.06%、39.10%和16.67%,表明其氨基酸营养价值较酶解前要高。沉淀冻干物(FDP)中粗蛋白和总糖含量分别为44.49%和10.40%,而粗脂肪含量高达33.28%。FDP中总氨基酸含量(ΣAA)、ΣEAA、ΣDAA、Tau含量及F值均下降,但其ΣEAA在ΣAA中的比例高于40%,且8种EAA含量评分均高于FAO/WHO评分模式要求。脂肪酸分析结果表明,FDP中含有饱和脂肪酸(SFA)8种(44.81%),单不饱和脂肪酸(MUFA)6种(27.55%),多不饱和脂肪酸(PUFA)7种(27.64%),二十碳五烯酸EPA和二十二碳六烯酸DHA含量较丰富。研究认为在本实验条件下通过木瓜蛋白酶酶解南极磷虾得到的FDS和FDP具有较高的利用价值,可开发为人类重要的蛋白来源。

Nutritional evaluation of enzymatic hydrolysates by Papain from Antarctic Krill

The nutrient content and composition of amino acids and fatty acids of enzymatic hydrolysates(including supernatant and precipitate) from fresh Antarctic Krill mince after treatment with papain enzyme(1.5%) for 3 h at 55 ℃ were detected and analyzed.The results showed that the degree of hydrolysis was 44.24% under this condition.While the crude protein and total sugar content of freeze-dried supernatant(FDS) were 67.13% and 13.91%,respectively.In addition,the total content of essential amino acids(ΣEAA) and flavor amino acids(ΣDAA),the content of taurine and F ratio(the ratio of total branched chain amino acid gross to total aromatic amino acid gross) increased by 8.96%,6.06%,39.10% and 16.67% than those in fresh krill,respectively.The results indicated that the protein nutrient value and functional properties of FDS were apparently improved compared to those in fresh krill.In the freeze-dried precipitate(FDP),the content of crude protein and total sugar were 44.49% and 10.40%,respectively.The total content of amino acids(ΣAA),ΣEAA,ΣDAA,taurine and F ratio were lower than those in fresh krill.However,8 essential amino acids of FDP were better than the need quantity pattern according to FAO/WHO.The content of crude fat in precipitate was very high(33.28%),and there were 21 kinds of fatty acids found in FDP,including 8 kinds of saturated fatty acid(SFA,44.81%),6 kinds of monounsaturated fatty acid(MUFA,27.55%) and 7 kinds of polyunsaturated fatty acid(PUFA,27.64%).Particularly,precipitate had higher content of EPA(13.56%) and DHA(8.87%).All above results suggested that FDS and FDP obtained by papain enzymolysis could be an excellent protein resource for human.