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薯渣及柚皮果胶提取工艺的研究

Study on Extraction Process of Pectin from Potato Residues and Polemo Peel

【作者】 张允

【导师】 陈劲春;

【作者基本信息】 北京化工大学 , 微生物与生化药学, 2012, 硕士

【摘要】 农业废弃物做为果胶原料的来源,日渐为人们所关注。本文就硫酸-咔唑法测定果胶的条件进行了确定试验;对高淀粉含量的两种薯渣进行了酶解去淀粉的处理;并对预处理后的马铃薯渣,红薯渣和柚皮的回收利用提取果胶的工艺进行了优化得出了最优的提取条件,对三种不同原料提取的果胶性质进行了比较研究。硫酸-咔唑法做为果胶测定的常规方法,确定其反应条件是非常必要的。本试验固定浓硫酸加入量为6mL,研究了咔唑加入量和显色时间对各个浓度的果胶液的测定影响,并最终确定咔唑加入量0.2mL显色2h做为其测定条件。薯渣淀粉的酶解试验最终确定了在pH6.5,温度65℃时,马铃薯渣和红薯渣淀粉去除的酶用量分别为20u/g和16u/g;酶解时间都为60min,淀粉去除率分别为93.27%和96.58%。由单因素和响应面试验得出了:马铃薯渣在pH1.45的盐酸溶液中,固液比1:16,90℃水浴摇床控制转速100转提取87min时,果胶得率5.61%;红薯渣和pH1.33的盐酸以固液比1:20,搅拌速度100转,水浴87℃提取92min时,果胶得率7.13%;柚内皮在30倍pH1.33的盐酸中,调节水浴摇床100转,99℃提取60min得到最大果胶得率38.9%。确定果胶提取的工艺条件后,制备果胶样品,测定了三种果胶的理化性质及凝胶性能。最终比较发现,两种薯渣果胶的成胶性能很差,远远低于柚内皮果胶,这跟果胶结构以及灰分含量高密切相关。

【Abstract】 Agricultural wastes are concerned as the source of pectin. In this paperthe sulfuric acid carbazole method for the determination of pectin wasdetermined to test. The abundant starch must be degradated by the enzyme inthe potato and sweet potato residue. After the pretreatment of potato residue,sweet potato residue and pomelo peel, the extraction of pectin from the threeagricultural wastes were optimized to solve the optimal extraction conditions,and the properties of pectins extracted from three kinds of raw materials werestudied.The sulfuric acid carbazole method was a conventional methods fordetermination of pectin,so the test was very necessary to determinate itsreaction condition.In the condition of6ml of sulphric acid, the effect of thecarbazole adding amount and color of time was studied on the determinationof each pectin concentration and the final determination conditions wereidentified as carbazole adding quantity of0.2mL and2h chromogenic time.When the enzymatic hydrolysis conditions were controlled in pH6.5,temperature65℃, the enzyme dosage of the potato residue and the sweetpotato residue respectively was20u/g and16u/g and the enzymatic hydrolysis time was60min. The starch removal rates was up to93.27%and96.58%.By the single factor and response surface experiment: the extractionconditions of the potato residue pectin,sweet potato residue pectin and pomelopeel pectin was pH1.45,1.33,1.33hydrochloric acid,stirring speed100rpm,90℃,87℃,99℃hot water and extraction time87min,92min,60min and thepectin extraction rate separately was5.61%,7.13%,38.9%and the ratio ofsolid to liquid respectively is1:16,1:20and1:30.The physicochemical properties and gelation properties of the three kindsof pectin were determined. The final comparison showed the other two kindspectin more lower gelation performance was poor, far below the pomelo peelpectin. It was closely related to the pectin structure and high ash content.

【关键词】 马铃薯渣红薯渣柚皮果胶
【Key words】 potato residuesweet potato residuepomelo peelpectin
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