亚临界水温度对梭子蟹下脚料萃取物性质的影响

目的:为探究亚临界水对梭子蟹下脚料的萃取效果,考察了亚临界水温度对萃取物性质的影响。方法:利用140、170、200、230℃等不同温度的亚临界水提取梭子蟹下脚料萃取物(SCWE),采用凯氏定氮法、苯酚硫酸法和高效液相色谱法等对SCWE的性质进行分析。结果:当亚临界水温度从140℃上升至230℃,SCWE中的总糖和灰分含量分别从1.86%和9.23%下降至0.27%和6.35%,分子量分布为180~1000 u的组分占比从11.09%增加至74.88%,而蛋白含量却出现先上升后下降的趋势。氨基酸分析结果表明,140℃和170℃亚临界水下获得的SCWE氨基酸组成与蟹肉相比没有明显的差别,但进一步提高亚临界水温度,SCWE中的天门冬氨酸、丝氨酸、苏氨酸和精氨酸等氨基酸含量却出现下降趋势。而且,随着亚临界水温度的提高,必需氨基酸和非必需氨基酸的含量均出现先上升后下降的趋势,且在200℃时达到最高值。不管亚临界水的温度是多少,SCWE中的赖氨酸含量都比WHO/FAO模式高。根据蛋白溶解性的结果,发现140℃下提取的SCWE中蛋白存在等电点,而170℃提取的SCWE蛋白溶解度在任一pH下都比其他SCWE高。结论:利用170℃亚临界水萃取梭子蟹加工下脚料获得的SCWE氨基酸不会受到破坏,且蛋白溶解性最高。

Effect of Subcritical Water Temperature on Properties of Extracts from Swimming Crab Waste

Objective:To explore the extraction effect of subcritical water on the swimming crab waste,the effect of subcritical water temperature on the properties of extracts was investigated. Methods:Swimming crab waste extracts(SCWE)were prepared by subcritical water at the temperature of 140,170,200,230℃. The properties of SCWE were determined by Kay-type nitrogen method,phenol sulfuric acid method and high-performance liquid chromatography method. Results:When the subcritical water temperature were increased from 140℃ to 230℃,the contents of total sugar and ash were decreased from 1.86% and 9.23% to 0.27% and 6.35% respectively,and the ratio of weight molecular distribution with 180~1000 u was increased from 11.09% to 74.88%,while the protein content were increased and then declined. Based on the result of amino acid analysis,no significant differences in the amino acid composition were found between the SCWE extracted by subcritical water at 140℃ & 170℃ and swimming crab meat. However,the contents of aspartic acid,serine,threonine and arginine in the SCWE were decreased when the subcritical water temperature was further increased. With the increase of subcritical water temperature,the contents of both essential and non-essential amino acids were decreased after increasing,and the maximum value was found at the subcritical water temperature of 200℃. The lysine content in the SCWE extracted at subcritical water irrespective of temperature was higher than that in the WHO/FAO model. An isoelectric point was observed in the protein of SCWE extracted at 140℃. Irrespective of pH,the protein solubility of SCWE extracted at 170℃ was higher than that of the other SCWE. Conclusion:When swimming crab waste was extracted at 170℃ of subcritical water,the amino acids in the obtained SCWE were not destroyed,and the protein solubility was the highest.