复凝聚法回收淀粉加工废水中蛋白质的研究

发布时间：2018-07-18 08:53

【摘要】：淀粉工业是以马铃薯、小麦、大米、玉米等农作物为原料生产淀粉或者淀粉深加工产品的行业。我国是世界上马铃薯和小麦产量最大的国家,随着马铃薯和小麦深加工的发展,生产淀粉过程中产生的淀粉废水也不断增多,工业上一般未经处理直接排放,或采用热絮凝法沉淀淀粉废水中的可溶性蛋白质,所得蛋白发生不可逆的变性导致营养功能性质大幅度降低。复凝聚法是一种条件温和的方法,原理是使带相反电荷的蛋白质和多糖发生静电相互作用形成电中性、不溶性的复合物,进而形成相分离。复凝聚法回收蛋白质能够最大程度地保留蛋白质的相关性质,避免工业上的酸热条件,提高副产物资源的附加值。通过浊度滴定研究马铃薯蛋白-壳聚糖复凝聚过程中的相行为,以及不同p H、蛋白/壳聚糖比例对蛋白质回收效果的影响。结果表明:随着壳聚糖添加量的增大,蛋白/壳聚糖比例的降低,马铃薯淀粉废水/壳聚糖混合体系的浊度曲线向高p H方向偏移。最佳的蛋白回收条件为:p H 6.0,蛋白/壳聚糖比例1:2,蛋白回收率为51.9%。壳聚糖能选择性地回收酸性蛋白糖蛋白,通过电泳光密度分析,糖蛋白纯度达到88.6%。进一步对蛋白-壳聚糖复合物进行分离,回收产物蛋白含量由25%提高到78.9%。通过浊度滴定研究马铃薯蛋白-卡拉胶复凝聚过程中的相行为,以及不同p H、蛋白/卡拉胶比例对蛋白质回收效果的影响。结果表明:随着卡拉胶添加量的增大,蛋白/卡拉胶比例的下降,马铃薯淀粉废水/卡拉胶混合体系浊度曲线向低p H值方向偏移。最佳的蛋白回收条件为:p H 3.5,蛋白/卡拉胶比例2.5:1,蛋白回收率达100%,回收产物蛋白含量为67.2%。卡拉胶对马铃薯蛋白的回收没有选择性,不同p H和比例下得到的蛋白组分无明显差异。系统研究不同阴离子多糖对蛋白质回收效果的影响,并对不同阴离子多糖分子量与蛋白质回收率之间的关系进行深入探讨。结果表明:卡拉胶、黄原胶、海藻酸钠、CMC、阿拉伯胶的最佳蛋白回收率分别为100%、99.2%、94.7%、85%和74%。多糖分子量与蛋白质回收率之间存在正相关关系,相关方程为y=10.895ln(x)+22.869,相关系数R2为0.8584。对照组酸沉法在p H 2.5,蛋白回收率为74.3%。酸热法在100℃下加热2 min,蛋白回收率为93.5%。通过对p H 3.5,蛋白/卡拉胶2.5:1下离心得到的上清液进行液相色谱分析和氨基酸测定,得出上清液中存在大量的游离氨基酸,因此选用001×8型苯乙烯强阳离子交换树脂对游离氨基酸作进一步回收。结果表明:Thomas模型能较好地拟合氨基酸的穿透曲线,拟合方程为y=-0.1054x+5.0035,相关系数R2为0.992。穿透体积下上样游离氨基酸回收率达88.4%,洗脱液中氨基酸干基含量达89.5%。为进一步验证复凝聚法回收淀粉废水中蛋白质的适用性,研究不同p H、蛋白/卡拉胶比例对小麦淀粉废水中蛋白质的回收。结果表明:随着卡拉胶添加量的增大,蛋白/卡拉胶比例的降低,浊度曲线向低p H值方向偏移。最佳的蛋白回收条件为:p H 4.5,蛋白/卡拉胶为2.5:1,蛋白回收率达95.7%。
[Abstract]:Starch industry is the industry of producing starch or starch processing products with potato, wheat, rice, corn and other crops as raw materials. China is the country with the largest production of potato and wheat in the world. With the development of deep processing of potato and wheat, starch wastewater from the process of producing starch is also increasing. Treatment of direct discharge or the use of thermal flocculation to precipitate soluble protein in starch wastewater. The irreversible degeneration of the protein leads to a large reduction in the properties of the nutritional function. The complex condensation method is a mild method. The principle is that the interaction of proteins and polysaccharides with opposite charges can form electrical neutrality and insolubility. The complex coacervation can form the phase separation. The recovery of protein by the complex condensation method can preserve the relative properties of the protein to the maximum extent, avoid the industrial acid heat conditions and increase the added value of the by-product resources. By turbidimetric titration, the phase behavior in the process of potato protein chitosan complex condensation, as well as the different P H, protein / chitosan ratio, are studied. The results showed that with the increase of the amount of chitosan, the ratio of protein / chitosan decreased and the turbidity curve of potato starch wastewater / chitosan mixed system shifted to high P H direction. The best protein recovery conditions were p H 6, protein / chitosan ratio 1:2, protein recovery rate of 51.9%. chitosan The acid protein glycoprotein was selectively recovered. Through the electrophoresis light density analysis, the purity of glycoprotein was 88.6%. and the protein chitosan complex was further separated. The recovery product protein content was increased from 25% to 78.9%. to study the phase behavior of potato protein carrageenan recovery through turbidimetric titration, as well as different P H, protein / carrageenan. The results showed that as the amount of carrageenan increased, the ratio of protein / carrageenan decreased and the turbidimetric curve of potato starch wastewater / carrageenan mixed system shifted to low P H value. The best protein recovery conditions were p H 3.5, protein / carrageenan ratio 2.5:1, protein recovery rate of 100%, recovery production. The protein content of 67.2%. carrageenan was not selective for the recovery of potato protein, and there was no significant difference in the protein components of different P H and proportion. The effect of different anionic polysaccharides on the recovery of protein was systematically studied, and the relationship between the molecular weight of different anionic polysaccharides and the recovery rate of protein was discussed. The best protein recovery of carrageenan, xanthan gum, sodium alginate, CMC and Arabia gum was 100%, 99.2%, 94.7%, 85% and 74%. were positively correlated with protein recovery, the correlation equation was y=10.895ln (x) +22.869, the correlation coefficient R2 was p H 2.5 in 0.8584. control group, and the recovery rate of protein was 74.3%. acid heat. The method was heated at 100 C for 2 min, and the recovery rate of protein was 93.5%. through liquid chromatography analysis and amino acid determination by P H 3.5, protein / carrageenan 2.5:1 centrifuge. A large number of free amino acids were found in the supernatant. Therefore, the free amino acids were further recovered by using 001 x 8 styrene strong Yang dissociation resin. The results show that the Thomas model can better fit the penetration curve of amino acids, the fitting equation is y=-0.1054x+5.0035, the correlation coefficient R2 is 88.4% of the free amino acid of the upper sample under the 0.992. penetration volume, and the content of the amino acid dry base in the eluent is 89.5%. to further verify the applicability of the recovery of the protein in the starch wastewater by the complex condensation method. The recovery of protein in wheat starch wastewater with different P H and protein / carrageenan ratio showed that with the increase of the amount of carrageenan, the ratio of protein / carrageenan decreased and the turbidimetric curve shifted to the low P H value. The best protein recovery conditions were p H 4.5, protein / Cara glue as 2.5:1, and the protein recovery rate of 95.7%.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X792;TQ936

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