Miyazaki S, Umemura Y
Natl Inst Anim Health Q (Tokyo). 1981 Winter;21(4):175-81.
Formation of a toxic substance inducing gizzard erosion (GE) was examined by using mainly a casein-histidine mixture as a simple model of fish meal. When a casein-histidine mixture was heated at 135 degrees C for three or five hours or at 160 degrees C for one hour, it induced severe GE. Changes in pH of histidine solution seemed to have little effect on the production of the toxic substance. Addition of a heated mixture of 30 mg of histidine and 150 g of casein (per kg of diet) failed to induce GE. A mixture of 750 mg of histidine and 150 g of casein was enough to produce a maximal toxicity. A heated mixture of histidine and isolated soybean protein, ovalbumin or gluten induced severe GE. A heated mixture of gelatin and histidine had a somewhat milder toxicity. On the other hand, zein and yeast treated in the same way showed only a slight toxicity. Two kinds of pre-treatment of casein before the addition of histidine were proved to be ineffective to inhibit the formation of the toxic substance. The toxicity of heated casein-histamine was rather lower than that of heated casein-histidine. Studies were also made on releasing of the toxic substance from heated casein-histidine into the soluble fraction by acidic hydrolysis and precipitation of this substance at acidic pH.
主要使用酪蛋白 - 组氨酸混合物作为鱼粉的简单模型，研究了诱导肌胃糜烂（GE）的有毒物质的形成。当酪蛋白 - 组氨酸混合物在135℃加热3或5小时或在160℃加热1小时时，会诱发严重的肌胃糜烂。组氨酸溶液pH值的变化似乎对有毒物质的产生影响不大。添加30毫克组氨酸和150克酪蛋白的加热混合物（每千克饲料）未能诱发肌胃糜烂。750毫克组氨酸和150克酪蛋白的混合物足以产生最大毒性。组氨酸与分离大豆蛋白、卵清蛋白或面筋的加热混合物会诱发严重的肌胃糜烂。明胶和组氨酸的加热混合物毒性稍弱。另一方面，以相同方式处理的玉米醇溶蛋白和酵母仅表现出轻微毒性。在添加组氨酸之前对酪蛋白进行的两种预处理被证明对抑制有毒物质的形成无效。加热的酪蛋白 - 组胺的毒性低于加热的酪蛋白 - 组氨酸。还研究了通过酸性水解将加热的酪蛋白 - 组氨酸中的有毒物质释放到可溶部分中，以及该物质在酸性pH下的沉淀情况。
