【作者】 叶勇；

【导师】 王坤余；

【作者基本信息】 四川大学 ， 皮革化学与工程， 2004， 硕士

【摘要】 制革工业是以原材料的高投入、高消耗、低产出为特征的传统工业,用于制革的原料中有近30%被制成二、三层革,这类产品档次低,成本高,污染重,导致整体效益降低。研究如何更有效利用二层皮和制革副废弃物,提高其使用价值,减少环境污染,具有非常重要的现实意义。开发人造胶原肠衣正是实现这一目标的有效途径之一,人造胶原肠衣制造成本低(只及天然肠衣成本的一半),制备工艺简单,生产过程无污染,产品绿色化,具有广阔的市场前景。采用红外、高效液相色谱、SDS-PAGE凝胶电泳、DSC等分析、测试手段,研究了大分子胶原蛋白制备和性能。结果表明胃蛋白酶是较好的胶原蛋白降解酶,降解后的胶原蛋白具有较为完整的α螺旋结构。皮胶原的降解程度和酶解产物的分子质量分布,可以通过作用时间来控制。胃蛋白酶作用的最佳条件为pH2.5-3;温度4℃;时间48h。HPLC分析结果表明在此条件下提取的胶原蛋白中单条α肽链组分达60%以上,20%为含有两条α链的β肽链。同时制备工艺简便可行,为皮胶原蛋白的进一步开发利用提供了技术基础。研究发现单纯的胶原蛋白膜的物性远不能达到肠衣所需要求,因此要得到符合肠衣要求的胶原膜必须对其改性。考虑到肠衣产品的可食性,本论文选用与其它可食性物质共混改性方式来实现。实验证明:胶原、壳聚糖、PVA共混复合膜透光率比壳聚糖膜有较好改善,三组分相容性较好。共混复合膜随胶原用量的增加,断裂伸长率增加,抗张强度却降低。复合膜材料面积增长率、吸水率和保水率都随胶原蛋白和聚乙烯醇含量的增加而升高,同时随反应温度的升高,复合膜溶胀性能也得到极大提高,在40℃时达到最好。虽然通过改性使胶原复合膜性能有所改善,但降解胶原所制膜仍不能满足肠衣的机械性能。将制革二层皮制成主要成分为胶原纤维的胶原泥作为主要的肠衣制造原料,与羧甲基纤维素钠、改性玉米淀粉、聚乙二醇等可食性物质共混改性,能显著提高胶原肠衣质量。工业化试验结果表明,使用戊二醛作为交<WP=7>联剂,使用量为0.2%时能明显提高肠衣质量。随交联剂用量增加,肠衣断裂伸长率和吸水性降低,交联剂用量对断裂抗张强度影响不大。增塑剂用量为25%时,人造肠衣机械性能较好,所以增塑剂用量最好不要超过25%。肠衣制备过程中适当中和处理对保障最终产品的性能很重要。经过熟化处理是必不可少的,此过程有利于各物质相互均匀渗透,改善成品肠衣质量。通过优化配方和工艺后,所制的胶原肠衣基本能满足灌肠生产的需要。更多还原

【Abstract】 As we known, leather industry is a high devotion/ consume and low output traditional one, and about 30% raw material become into split leather with low quality, high cost, serious environmental pollution, which results in low benefit in whole trade. How to use the split leather and leather waste effectively/ enhance their value/ reduce the environmental pollution is very important in the reality. Exploring the artificial sausage casing is one of the ways to realize. It has a vast market foreground for its lower cost/ simple preparation technics/ no pollution during produce/ products for green. Large molecules of collagen are studied with FT-IR/ HPLC/ SDS-PAGE gel electrophoresis/ DSC etc analysis and testing instrumentality. The results show that pepsin is a better collagen enzyme, and the hydrolyzed collagen can keep integrityαhelix structure. The hydrolyzed extent of collagen and the range of molecule weight can be controlled through the reaction time of enzyme and collagen. The best process condition of pepsin is at pH 2.5-3 and 4℃ for 48 hours. Moreover, the results of HPLC indicate that above 60% of collagen are α peptide and about 20% are β peptide. At the same time, the simple and feasible technics supply a foundational technique for more exploitation and utilization. From the forward chapter, we have known that the physical characteristics of the film made of pure collagen cannot reach the demand by sausage casing, so modification must be required. Blending with other edible things was chosen as the way of modification for the edibility. The results prove that collagen/ chitin and PVA are miscible for the better optical transmittance capacity than chitin film. On the other hand, the breaking extension increase and the tensile strength decrease with the collagen added. Exception this, the increasing ratio of area and water absorption and <WP=9>water keeping of blending films increase with the content of collagen and PVA. At the same time, preparation temperature is important, and the dissolve and expanding capability of the films are best when it at 40℃.Through the mechanism capability of film has been improved a lot after modified, the film component of hydrolyzed collagen can not meet the requirement by the sausage casing, so the collagen fibrils from the split leather are used as the material of casing and blended with CMC/ modified corn starch/ polyethylene glycol etc edible substance. The results of industrialization experiments show that we can gain the needed effect when the content of glutaraldehyde as the cross-linking reagent is 0.2%. The tensile strength and water absorption capacity will increase suddenly if the content of it is below 0.2%. But the tensile strength and water absorption capacity do little change when above 0.2%. The plasticizer is important for the mechanism capability of artificial collagen casing, but the content of it cannot be above 25%, and the neutralization treatment is necessary for the products. The collagen sausage casings have met the demand by the produce after optimized the prescription and technics.更多还原