沙田柚籽中蛋白质的提取及其性质研究

为了提取和利用沙田柚籽中的蛋白质,通过碱溶酸沉法研究其提取条件,并探讨其功能性质。以沙田柚籽为原料,通过单因素试验研究了提取温度、提取液pH值、料液比、提取时间等4个因素对蛋白质提取率的影响,并结合正交试验确定蛋白质的最佳提取条件。结果表明,不同提取条件对柚籽蛋白提取率的影响顺序为料液比>提取液pH值>温度>提取时间,在料液比1:50 g/mL、提取液pH11、提取温度50 ℃、提取时间50 min的条件下,柚籽蛋白的提取率达12.5%。柚籽蛋白的持水性为2 mL/g,持油性为4.4 mL/g,乳化性为53.12%,乳化稳定性为78.43%,等电点为5。可见沙田柚籽蛋白功能性质良好,可利用其改变食品的某些性质,如增强食品的嫩度、出汁率、乳状液稳定等,是一种优质的植物来源蛋白质。

Extraction and Properties of Protein from Pomelo Seed

In order to extract and utilize the protein in the pomelo seed,this article uses the alkaline solution and acid precipitation method to study its extraction conditions and discuss its functional properties.Using pomelo seed as the raw material,the influence of four factors,including extraction temperature,extract pH,material-to-liquid ratio,and extraction time,on the protein extraction rate was studied through single factor experiment,and the optimal extraction conditions of protein were determined by combining with orthogonal experiment.The results showed that the order of influence of different extraction conditions on the extraction rate of pomelo seed protein was:material-to-liquid ratio>extracting fluid pH>temperature>extraction time,at a material-to-liquid ratio of 1:50 g/mL,extraction fluid pH 11,extraction temperature 50 ℃,extraction time 50 min,the extraction rate of pomelo seed protein reached 12.5%.The water holding capacity of pomelo seed protein is 2 mL/g,the oil holding capacity is 4.4 mL/g,the emulsification is 53.12%,the emulsification stability is 78.43%,and the isoelectric point is 5.Pomelo seed protein has good functional properties and can be used to change certain properties of food,such as enhancing food tenderness,juice yield,and emulsion stability.It is a high-quality plant-derived protein.