磷酸氢二钠法制备甘薯果胶工艺及其凝胶特性研究
发布时间：2019-01-10 11:54
【摘要】：甘薯是我国第四大产量的粮食作物,在工业上主要用来生产淀粉及淀粉类产品,在此过程中产生大量薯渣。通常情况下,薯渣被作为饲料简单利用或作为废物丢弃,造成环境污染和资源浪费。薯渣中含有丰富的果胶资源,但目前对甘薯果胶的研究很少。本研究首先采用磷酸氢二钠法提取甘薯果胶并对其工艺进行了优化,然后采用离子交换树脂法对最优提取条件下所得果胶进行了纯化。最后分别采用酸法和磷酸氢二钠法最优工艺提取甘薯果胶,进而采用超滤、酒精沉淀和离子交换树脂法纯化果胶,对不同提取、纯化方法所得甘薯果胶的组成和凝胶特性进行比较分析。结果如下: 1)以薯渣为原料,采用磷酸氢二钠法提取甘薯果胶,在单因素试验基础上,通过二次回归正交旋转组合试验探讨了液料比、提取时间、提取温度和溶液pH对果胶得率的影响,确定最优的提取条件为:液料比20:1,提取时间3.3 h,提取温度66℃和溶液pH 7.9。在此提取条件下,果胶得率为10.24%。最优工艺条件下制备果胶半乳糖醛酸含量为60.02±0.03%,淀粉、灰分含量分别为10.42%和10.58%。 2)采用离子交换树脂法对磷酸氢二钠法最优提取条件下所得果胶粗提液进行纯化,以果胶得率、灰分含量和果胶脱色效果为指标,从001×7、201×7、D001和D201中筛选出D001和D201两种离子交换树脂,组成D001-D201串联式离子交换柱。进一步考察D001-D201离子交换柱在不同上样液流速下的果胶得率、灰分含量和果胶脱色效果,筛选确定最佳上样液流速为1 BV/h。在最佳离子交换树脂纯化条件下,果胶半乳糖醛酸含量从60.02%上升至65.02%,果胶流出液相对颜色从0.384显著下降至0.124,果胶灰分含量从10.58%显著下降至3.2%,特别是果胶中磷含量从19,000 ug/g显著下降至0.11 ug/g。表明采用离子交换树脂法对果胶粗提液有一定脱色效果,可降低果胶灰分含量,提高果胶纯度。 3)采用磷酸氢二钠法制备果胶得率(7.2-9.7%)高于酸法制备果胶(4.6-7.0%),分子量和凝胶强度分别为480.6-1201.0 kDa和61.9-278.1 g/cm~2,均高于酸法制备果胶的250.8-771.1 kDa和149.4-534.0 g/cm~2。磷酸氢二钠法制备果胶的酯化度为9.08-10.4%,低于酸法制备果胶的28.7-31.11%。 4)采用磷酸氢二钠法提取果胶,离子交换树脂法所得果胶半乳糖醛酸含量(65.0%)显著高于超滤和酒精沉淀法(45.0-51.5%),灰分含量(3.2%)显著低于超滤和酒精沉淀法(9.6-10.6%),中性糖含量最低为22.6%,且凝胶强度最高为534.0 g/cm~2。但离子交换树脂法所得果胶分子量(1098.0 kDa)显著低于超滤法纯化果胶(1201.0 kDa)。 5)采用酸法提取果胶,超滤法纯化果胶半乳糖醛酸含量(63.1%)显著高于酒精沉淀和离子交换树脂法(57.1-58.5),中性糖含量(16.3%)显著低于酒精沉淀和离子交换树脂法(20.2-22.6%),分子量和凝胶强度最高,分别为771.1kDa和278.1g/cm~2。
[Abstract]:Sweet potato is the fourth largest grain crop in China. It is mainly used to produce starch and starch products in industry. Generally, potato residue is simply used as feed or discarded as waste, resulting in environmental pollution and waste of resources. There are abundant pectin resources in potato dregs, but there are few researches on sweet potato pectin. In this study, the pectin of sweet potato was extracted by hydrogen disodium phosphate method and optimized, then the pectin was purified by ion exchange resin method. Finally, the optimum technology of acid method and hydrogen phosphate disodium method was used to extract pectin from sweet potato, and then to purify pectin by ultrafiltration, alcohol precipitation and ion exchange resin. The composition and gel properties of sweet potato pectin obtained by purification method were compared and analyzed. The results are as follows: 1) using potato dregs as raw material, using hydrogen phosphate disodium method to extract sweet potato pectin. On the basis of single factor experiment, the ratio of liquid to material and extraction time were studied by quadratic regression orthogonal rotation combination test. The effects of extraction temperature and solution pH on pectin yield were determined. The optimum extraction conditions were as follows: ratio of liquid to material 20: 1, extraction time 3.3 h, extraction temperature 66 鈩，
本文编号：2406275
[Abstract]:Sweet potato is the fourth largest grain crop in China. It is mainly used to produce starch and starch products in industry. Generally, potato residue is simply used as feed or discarded as waste, resulting in environmental pollution and waste of resources. There are abundant pectin resources in potato dregs, but there are few researches on sweet potato pectin. In this study, the pectin of sweet potato was extracted by hydrogen disodium phosphate method and optimized, then the pectin was purified by ion exchange resin method. Finally, the optimum technology of acid method and hydrogen phosphate disodium method was used to extract pectin from sweet potato, and then to purify pectin by ultrafiltration, alcohol precipitation and ion exchange resin. The composition and gel properties of sweet potato pectin obtained by purification method were compared and analyzed. The results are as follows: 1) using potato dregs as raw material, using hydrogen phosphate disodium method to extract sweet potato pectin. On the basis of single factor experiment, the ratio of liquid to material and extraction time were studied by quadratic regression orthogonal rotation combination test. The effects of extraction temperature and solution pH on pectin yield were determined. The optimum extraction conditions were as follows: ratio of liquid to material 20: 1, extraction time 3.3 h, extraction temperature 66 鈩，
本文编号：2406275
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