【作者】 曲娜；

【导师】 顾正彪；

【作者基本信息】 江南大学 ， 食品科学， 2012， 硕士

【摘要】 马铃薯渣是马铃薯淀粉生产过程中的副产物,含水量高,不易储藏,如果不加以回收利用,不仅造成资源浪费,而且会产生严重的环境污染。马铃薯渣的开发利用率较低,其加工利用问题一直没有得到较好的解决。将马铃薯渣酶解后整体添加到饲料中,是其深加工中具有发展潜力的方向。本文以马铃薯渣为原料,采用耐高温α-淀粉酶酶解薯渣中的残余淀粉,使得薯渣中与淀粉紧密啮合的纤维素更好释放出来发挥作用,酶解前后薯渣表现出不同的理化性质,同时淀粉酶解成小分子糖提高了体系的适口性和消化性,通过纤维素和淀粉酶解物协同作用促进动物的增重,并在消化道后段被肠道菌群选择性发酵利用,从而实现其作为饲料添加组分的应用。最后将酶解处理后的马铃薯渣代替麸皮添加至大鼠饲料中进行动物应用实验,考察其对大鼠生长性能和肠道菌群的影响。首先,分析了马铃薯渣的主要成分及酶解工艺。通过对马铃薯渣的成分测定可知,薯渣的含水量很高,成分主要有淀粉、纤维素、果胶、蛋白质、灰分等。采用耐高温α-淀粉酶将马铃薯渣进行一定程度的酶解,通过酶解掉一部分淀粉使薯渣纤维更好的释放出来,然后调节pH值至4进行灭酶,得到不同酶解程度的样品,通过测定还原糖含量确定其DE值。结果表明:薯渣含水量高达73.6 %,干基的主要成分为淀粉35.4 %、纤维素15 %、半纤维素30 %、果胶12.1 %、蛋白质1.6 %、灰分0.4 %。通过调节酶添加量,制备出DE值分别为6、11、14、18、22的样品。其次,研究了不同DE值马铃薯渣酶解产物的结构和理化性能。扫描电镜分析发现薯渣经过酶解后,淀粉和纤维素紧密啮合的状态被破坏,结构松散,有利于纤维素发挥作用。利用傅里叶变换红外光谱仪(FTIR)和X射线衍射仪(XRD)研究了不同DE值马铃薯渣的化学组成和结晶性。结果表明:酶解后薯渣的纤维素本质没有变化,但其结构松散,纤维素可以更好的发挥作用。酶解后马铃薯渣阳离子交换能力、纤维素转化率、消化性、膨胀率、持水率和持油率均有所提高,乳化性和乳化稳定性也较高。可见,纤维素与淀粉分开后表面微结构的变化对薯渣物化性质的影响不容忽视。一些不利于生长消化的指标,例如淀粉酶抑制力和葡萄糖束缚能力,随着薯渣酶解程度的加深,其抑制束缚的作用效果也越强。所以综合考虑酶解马铃薯渣的作为饲料组分的理化性能,选择酶解程度适中的样品(DE=14)制备饲料较为合适。最后,将DE值为14的马铃薯渣添加到大鼠饲料中取代部分麸皮,以马铃薯渣原浆和未添加薯渣的饲料作对照,进行相同条件的饲喂,考察马铃薯渣对大鼠生长性能和肠道菌群的影响,并核算饲料成本。结果表明:添加酶解马铃薯渣饲料喂养的大鼠(酶解组)增重效果1-7 d显著高于未添加薯渣的饲料(对照组)和添加马铃薯渣原浆喂养的大鼠(原浆组)。酶解组回肠、盲肠、结肠内容物及相应粘膜上乳酸杆菌数量显著高于对照组和原浆组。酶解组回肠、盲肠、结肠内容物及相应粘膜上大肠杆菌数量显著低于对照组和原浆组。酶解组饲料的润肠效果较好,大鼠粪便含水量较高,并且酶解组饲料有较低的成本优势。更多还原

【Abstract】 Potato pulp is one of the main by-products during potato starch processing. The potato pulp with high water holding capacity is not easy for storage. If not recycled, the pulp will not be only a waste of resources, but also cause serious environmental pollution. Potato residue utilization rate is low, and its processing has not effectively settled. And the potato residue after processing as a feed component added is a promising direction for potato pulp. This paper adopted potato pulp as raw material, and the residual starch was dealed withα-amylase. Different functional properties were shown in these samples after hydrolysis which releases cellulose better from the pulp to play a role, and to solve the problem of palatability and digestibility by enzymatic. The synergy of cellulose and starch hydrolysates promotes animal growth, and ferments selectively of the intestinal flora in the digestive tract after paragraph. Then it was been added into feed by replacing some wheat bran, and the effects of feed with hydrolyzed potato pulps on growth performance and intestinal flora of rats were investigated. Firstly, the ingredients and hydrolysis process of potato pulp were determined.Determination of composition of the potato pulp showed that it had high water content, the main ingredients were starch, cellulose, pectin, protein, ash and so on. The potato pulp was dealed withα-amylase, and cellulose could release better by the starch hydrolysis, and adjusted the pH to 4 for enzyme inactivation. Then kinds of degree of hydrolysis of samples were got, DE value was determined by measuring the reducing sugar content. The results showed that: Potato residue moisture content was about 73.6 %, and dry basis of the main components was starch 35.4 %、cellulose 15 %、hemicellulose 30 %、pectin 12.1 %、protein 1.6 %、ash 0.4 %. By adjusting the amount of enzyme added, kinds of hydrolysates with different DE values 6、11、14、18、22 were prepared.Secondly, the characterization and properties of different DE values of potato potato were analysised. Scanning electron microscope showed that enzymolysis made the struture looser, and the close engagement state of starch and cellulose was destroyed which was favorable for cellulose to play a beneficial role. The chemical composition and crystalline structure of potato pulps of different DE value were studied by FTIR and XRD. The results showed that the hydrolyzed potato pulps did not change compared with that of untreated, but the effect of the change of the separated cellulose and starch on the surface for the properties of micro-structural changes of potato residue should not be overlooked. Higher values of ion exchange capacity, cellulose conversion ratio, digestibility, expansibility, water-and oil- holding rate were found in potato pulp after treatment by enzyme treatment. And that higher emulsifying activity with high emulsion stability was shown in hydrolyzed potato pulps. Some indicators that not conducive to growth and digestion, such as amylase inhibition and glucose binding ability, increase with the deepening of the enzymatic hydrolysis extent. Therefore, from the point of view as the feed, considering the properties of potato pulp, choosing some moderate degree of hydrolysis of the sample (DE = 14) for feed was more appropriate.At last, the DE value of 14 of potato pulp by enzyme was added into feed instead of 5 % wheat bran with the residue and that not added as control. At the same conditions of feeding, the effects of feed with hydrolyzed potato pulps on growth performance and intestinal flora of rats were investigated and the feed cost was accounted. The results showed that: Rats fed with feed which contained hydrolyzed potato pulps (hydrolysis group) gained higher increase in weight than control and those fed with feed containing untreated potato pulps (untreated group) and significant difference could be found during the first 7 days. The number of lactoacillus in enzymatic group ileum, cecum, colon contents and on the corresponding mucous membranes was significantly higher than control untreated group. The number of E. coli in enzymatic group ileum, cecum, colon contents and on the corresponding mucous membranes was significantly smaller than control dprotoplasmic group. Enzymatic group intestines better, and get higher water content in rat feces. Besides, the enzyme group has lower feed cost advantage.更多还原