碎米制糖湿渣蛋白分离提取工艺研究

Extracting protein in wet residue from broken rice

以碎米制糖企业脱糖后湿渣副产物为研究对象,检测其感官、理化、微生物学指标;采用碱法分离提取渣中蛋白,探索蛋白功能特性,旨为糖渣副产物深度开发、提高附加值、延长产业链提供前期研究数据与技术支撑。检测表明:湿渣含水量高(66.58%),易被微生物污染酵解腐败(常温存放3h细菌菌落总数达1.3×107cfu/g),贮藏期短;但其蛋白丰富(约占干物质的50%～65%),氨基酸组成较平衡,谷氨酸(6.15g/100g)、脯氨酸(4.01g/100g)含量较高,有深度开发渣中蛋白的价值。采用碱法正交优化湿渣蛋白分离提取工艺,结果为NaOH0.12mol/L,提取时间t=3h、提取温度T=50℃、固液比1:18,提取率可达80.75%,纯度为62.99%,达到浓缩蛋白的要求。所提蛋白溶解度达12.38%、起泡性35.49%、起泡稳定性72.62%、乳化性46.31%、乳化稳定性77.35%。

The item aim for the wet sugar residue which was from broken rice made sugar of industry as raw materials, is to check its sensory, chemical and microbiological indicators; intending to extract protein use the alkali extraction process in the sugar residue, exploring the properties of processing adaptive of the protein. The purpose are depth development of the sugar residue by-product, increasing the added value, provided the theoretical data and technology support for extending the industrial chain of early stage. The results shows that the moisture of the wet sugar residue is high （66.58%）, the wet sugar residue by-products is susceptible to ferment and corruption （the number of microbe colonies are 1.3x107 cfu/g under the normal temperature 3 h）, Storage period is short. But its protein content is rich （about 50%-65% of dry matter）, the amino acid composition is balance, the content of glutamic acid （6.15 g/100 g）and praline （4.01 g/100 g） is high, it is value to depth development protein of sugar residue. The optimum conditions of alkali extraction of the sugar residue protein are： NaOH 0.12 mol/L, extract time t=3 h, extract temperature T=50 %. The solid-liquid ratio is 1：18, extract rate is 80.75%, the purification degree can reach 62.99%, so it can get the aim of concentrating protein. Mentioned protein degree of hydrolysis is 12.38%, the foaming properties is 35.49%, the foam stability is 72.62%, the emulsifying is 46.31%, the emulsion stability is 77.35%.