液压压榨澳洲坚果粕酶解制备多肽工艺优化

Optimizing the Preparation of Crude Peptides from Hydraulic Macadamia Nut Meal by Enzymatic Hydrolysis

以液压压榨澳洲坚果粕为原料,分析了其常规营养成分含量与氨基酸组成。采用碱性蛋白酶与中性蛋白酶催化酶解澳洲坚果粕蛋白制备多肽。以水解度为指标,利用单因素试验与正交试验考察了各因素对澳洲坚果粕蛋白水解度的影响。结果表明:液压压榨澳洲坚果粕中含有32.25%的蛋白质,17种氨基酸,含量为25.05%。碱性蛋白酶各因素对澳洲坚果粕蛋白水解度影响的主次顺序为:酶解时间>酶解温度>加酶量>酶解pH值>底物质量浓度,最佳工艺条件为:酶解温度60℃、酶解时间3.5 h、底物质量浓度110 g/L、酶解pH 8.0、加酶量2 400 U/g,在此条件下水解度达到了22.83%。中性蛋白酶各因素影响水解度的主次顺序为:加酶量>酶解时间>底物质量浓度>酶解温度>酶解pH值,最佳工艺条件为酶解温度55℃、酶解时间3.5 h、底物质量浓度100 g/L、酶解pH 7.0、加酶量3 200 U/g,水解度达到了22.78%。碱性蛋白酶与中性蛋白酶各因素对澳洲坚果粕蛋白水解度的影响均达到了极显著水平(P<0.01)。在最佳工艺条件下,碱性蛋白酶酶解液压压榨澳洲坚果粕制备多肽的效果优于中性蛋白酶。

Proximate nutritional components and amino acid composition were analyzed in hydraulic macadamia nut meal. Further, crude peptides were prepared by enzymatic hydrolysis of macadamia nut meal with either alkaline or neutral protease. The effects of five processing conditions on the degree of hydrolysis were explored by single factor and orthogonal array design methods in order to optimize these conditions. Results showed that hydraulic macadamia nut meal contained 32.25% protein consisting of 17 amino acids with a total content of 25.05%. The effect of five processing conditions on the degree of hydrolysis of macadamia nut meal protein with alkaline protease was in the descending order of hydrolysis time, reaction temperature, enzyme dosage, p H, and substrate concentration. The optimal hydrolysis conditions were found to be reaction at 60 ℃ and pH 8.0 for 3.5 h with a substrate concentration of 110 g/L and an enzyme dosage of 2 400 U/g, giving a degree of hydrolysis as high as 22.83%. In the case of hydrolysis with neutral protease, the decreasing order of five processing conditions was enzyme dosage, hydrolysis time, substrate concentration, temperature, and pH, and their optimal levels that provided maximum degree of hydrolysis as high as 22.78% were determined as 3 200 U/g, 3.5 h, 100 g/L, 55 ℃, and 7.0, respectively. In both cases, the effect of five processing conditions on the degree of hydrolysis reached up to a significant level（P〈0.01）. Under the optimized hydrolysis conditions, alkaline protease was superior to neutral protease in preparing crude peptides from macadamia nut meal protein.