酶解血粉的单因素和响应面条件的优化

Optimization of condition of the single factor and the response surface of the hydrolytic enzyme

动物血液是资源丰富、非常具有开发价值的蛋白类饲料原料,因此开发和利用血液资源可解决饲料资源短缺的问题,且减轻血液排放对环境造成的有机污染。但是血粉的消化率差、血腥味和颜色深导致无法大量使用以及氨基酸含量不平衡等问题,且其含有的血腥味导致了其适口性差。目前,普遍使用的加工处理方法仍然无法解决血粉使用过程中存在的问题。加强对畜禽血液资源的精深加工和综合利用,继而研发出安全、营养、价廉的优质血粉产品对我国畜牧行业的可持续发展具有深远影响和重大意义。基于生物技术的发展和酶制剂生产的进步,酶解处理是一种很有潜力的处理血粉的方法,有可能更有效地解决血粉使用过程中遇到的消化率低、适口性差等问题。酶解处理可以改善血粉的营养特性,提高血粉的营养价值。酶解处理可以增加血粉中的游离氨基酸的含量。酶解处理可以改变血粉蛋白结构特性(分子质量变化和二级结构变化),提高血粉的可消化物质的含量。由于酶受到底物种类、底物浓度、酶添加量、p H值、温度、酶解时间的影响,因此每个蛋白酶都必须探讨其对某种特定的蛋白底物的作用条件。本实验首先筛选出最好的碱性蛋白酶,通过单因素实验找到最优的工艺条件,再通过响应面实验筛选出最佳的条件。结果表明,酶解血粉的最优条件为:底物浓度为41.44 mg/ml,温度为45℃,酶/底物比(E/S,酶添加量)为0.803 4,酶解时间为14 h,此时水解度达到了16.39%。

Animal blood resources is rich in resources, has the development value of protein resource, so the development and use of blood resources can solve the problem of shortage of feed resources, and reduce the discharge of organic pollution of the environment by blood. But poor digestibility and blood meal deep cause can not use scent and color and the content of amino acid imbalance and other issues, and it contains blood lead to its palatability. Currently, the commonly used processing methods still fail to solve the problems in the use of blood powder. To strengthen the deep processing of live- stock and poultry blood resources and comprehensive utilization, and then developed blood meal safe- ty, nutrition, cheap, high quality products for the sustainable development of animal husbandry indus- try in China has a far-reaching influence and significance. Based on the development of bioteehnology and the progress of the production of enzyme preparation, digestion process is a potential method of procesSing blood meal, may be more effective to solve encountered in the process of blood meal use of low digestion rate and poor palatability. The enzymatic solution can improve the nutrition- al properties of the blood meal and improve the nutritional value of the blood meal. The enzyme solution can increase the amount of free amino acids in the blood meal. The enzyme solution can change the structural characteristics of the haemoglobin protein （molecular mass change and sec- ondary structure change）, and increase the amount of soluble substances in the blood meal. Because the enzyme is bottom species, substrate concentration, enzyme content, the influence of pH, tempera- ture, digestion time, therefore each protease must discuss the condition of the role of a particular pro- tein substrates. This experiment first selected the best alkaline protea_se, through the single factor exper- iment to find the optimal process conditions, to filter out the best conditions by response surface experi- ments. The optimal conditions for the enzymolysis blood meal： the best condition of enzyme solution for the substrate concentration is 41.44 mg/ml, temperature 45 ℃, the ratio of the bottom to the enzyme complex concentration is 0.803 4, enzymolysis time for 14 h, the degree of hydrolysis reaches 16.39%.