微生物酶法生产高活性膳食纤维的研究

【作者】 李凤敏；

【导师】 刘东波；

【作者基本信息】 东北师范大学 ， 植物学， 2003， 硕士

【摘要】 玉米皮是玉米淀粉加工的副产品，其来源丰富，纤维含量高，植酸含量低，易于通过化学、物理以及生物学的方法进行改性处理，是加工和生产膳食纤维的极好原料。 本实验分别采用微生物酶法、化学法去除玉米皮中的淀粉和蛋白质。微生物酶法具有处理条件温和、选择性强、不破坏天然纤维结构、不损失具重要生理功能的可溶性纤维素和半纤维素等优点；而化学法去除淀粉、蛋白质比较彻底，但化学法处理底物选择性差，玉米皮中的半纤维素又溶于碱溶液，从而，使在玉米膳食纤维中起重要生理功能的可溶性纤维素、半纤维素都有不同程度的损失，导致产品的整体生理活性降低。经测试其总体指标，膳食纤维制取工艺的研究中微生物酶法优于化学法。 已有研究表明：膳食纤维中的不溶性成分主要作用于肠道产生机械蠕动效果，而可溶性成分则更多的发挥代谢功能。因此，膳食纤维中可溶性成分的组成比例是影响膳食纤维生理功能的一个重要因素。 在本实验中，我们采用木聚糖酶和纤维素酶对去除淀粉和蛋白质后所得的玉米皮膳食纤维作进一步处理，以改变天然膳食纤维中部分聚合物的化学结构与相对含量。通过此工艺，我们得到了分子量在31560～136960D之间的可溶性半纤维素和纤维素多糖。这些可溶性成分由于其溶解性好，分子表面活性基团多，新增和强化了原先没有或即使有但很微弱的功能特性，包括有益于人体健康的生理功能和有利于应用在食品中的工艺特性两个方面。 通过以上的研究，我们获得了一种微生物酶法生产高活性膳食纤维的加工工艺，为进一步的大规模工业化生产奠定了坚实的基础。更多还原

【Abstract】 Corn cortex, which is a byproduct in corn starch production, contains a great deal of dietary fiber and a low content of phytic acid. What’s more, It is easy to improve the properties of corn cortex through chemical or biological methods. So corn cortex is a kind of very good raw material to process the dietary fiber (DF).In this study, microbial enzyme method and chemical method were adopted to remove starch and protein existed in corn cortex separately. The microbial enzyme method has many advantages in the moderate conditions, the maintenance of natural structure of fiber and a strong specialty, and the active contents such as soluble fiber and hemi-cellulose can be protected effectively to improve the physiological activity of the DF. On the contrary, the chemical methods lead to a drastic removal of starch and protein but a poor selectivity on substrates, and the hemi-cellulose in corn cortex could dissolve in an alkali solution, which makes soluble fiber and hemi-cellulose having important physiological activities lost. From the results of the test, it can be easily concluded that microbial enzyme method is prior to chemical method in preparation of the DF.Some research results have showed that unsolvable contents of DF mainly act on intestines to arouse mechanical vermiculation and the soluble contents primarily affect the metabolism function. The composite proportion of soluble contents in the DF is an important factor affecting the physiological functions of the DF.So the corn cortex DF obtained from the above is decomposed by xylanase and cellulase in order to change the chemical structure and relative content of the polymer composing the natural DF. By this technique, the soluble hemi-cellulose and cellulose polysaccharides whosemolecular weight lie in 31560-136960 are obtained, and these soluble components have better soluble properties and more active terminals on its surface. These add some new functions or properties to the DF or fortify those intrinsic but weak functions, which include two aspects: the physiological functions contributing to human health and the technological properties applied into food.Through the study above, the process that high activities soluble dietary fiber can be acquired effectively through the microbial enzyme method has been concluded. This processing method would be applied to the industrialized production.更多还原