山苍子蛋白碱提工艺优化及其功能性质研究

Optimization of protein alkali extraction technology from Litsea cubeba and its functional properties

以山苍子提油后的粕为原料,采用碱溶酸沉法提取山苍子蛋白,以浸提p H、料液比、浸提温度、浸提时间为考察因素,运用单因素试验和正交试验确定山苍子蛋白的最佳提取工艺条件,并测定了山苍子蛋白的起泡性、乳化能力、持水能力等功能性质。结果表明:在碱液pH 11、料液比1∶15、浸提温度35℃、浸提时间60 min时,山苍子蛋白的提取率达到31. 03%,粗蛋白提取物中蛋白质含量为75%。山苍子蛋白等电点在4. 0左右,酸性pH范围溶解性较低,中性至碱性p H范围溶解性较高,起泡性和泡沫稳定性在偏碱性pH范围较高,山苍子蛋白持水力在温度低于60℃时高于大豆分离蛋白。

Litsea cubeba protein was extracted by alkali extraction and acid precipitation method from meal after oil extraction. The extraction pH,solid-liquid ratio,extraction temperature and extraction time were chosen as the factors,and the single factor experiment and orthogonal experiment were used to determine the optimal conditions. The functional properties including foaming,emulsifying and water holding capacity were evaluated. The results showed that the optimal extraction conditions were abtained as follows: extraction pH 11,solid-liquid ratio 1∶ 15,extraction temperature 35 ℃ and extraction time 60 min. Under these conditions,the extraction rate of Litsea cubeba protein reached 31. 03%. The protein content in crude protein extract was 75%. The isoelectric point of Litsea cubeba protein was around pH4. 0. The solubility,foaming ability and foam stability were lower at acidic pH than alkali pH condition.The water holding capacity was higher compared with commercial soybean protein isolate when the temperature was below 60 ℃.