采用缓冲液法对马尾松毛虫幼虫中的蛋白质进行提取研究。结果表明:原料粗细度、提取温度、提取时间和沉淀pH对幼虫蛋白质的提取率有显著影响(P〈0.05),而料液比、蛋白质的沉淀温度和沉淀时间对提取率无显著影响。试验确定的最佳条件为:缓冲液为Na2HPO4-NaOH(pH为9.5);料液比为1∶15(m/v);原料粗细度为40目虫粉;抽提时间为5 h,抽提温度为40℃;沉淀pH为5.0,沉淀温度为5℃,沉淀时间为1 h。在此条件下,所得蛋白产品的粗蛋白含量为(71.12±0.16)%,总氮提取率为(60.36±1.25)%。蛋白产品中氨基酸总量为69.58%,必须氨基酸占氨酸总量的45.16%。安全评价结果表明:该蛋白产品的LD50在12 050 mg.kg-1以上,属实际无毒范围。
Proteins extraction from the larva of Dendrolimus punctatus with a buffer solution method was studied. The results revealed that granularity of materials, extraction temperature, extraction time and precipitation pH showed significant effects on the extraction rate of the proteins ( P 〈 0.05 ), while relative amount of materials and extraction solvent, precipitation temperature, and precipitation time had no significant effects. The optimal conditions were as follows. The buffer solution was Na2HPO4-NaOH(pH 9.5), materials need to be fine powder (40 mesh), thc ratio of materials to extraction solvent was 1 : 15 (m/v), extraction time was 5 h, extraction temperature was 40 ℃, precipitation pH was 5.0, precipitation temperature was 5 ℃, precipitation time was 1 h. The protein content of the product obtained at the optimal condition was (71.12 ± 0.16) %, and the extraction rate was (60.36±1.25) % total mitrogen. The total amino acids content was 69.58 % in the extract, of which the essential amino acids content was 45.16% . LD50 of the protein product is was more than 12 050 mg· kg^- 1, suggesting the product was actually no poisonous.