Hathcock J N
Center for Food Safety and Applied Nutrition, Food and Drug Administration, Washington, DC 20204.
Adv Exp Med Biol. 1991;289:273-9. doi: 10.1007/978-1-4899-2626-5_20.
Trypsin inhibitor (TI) occurs naturally in many foods from plants, notably soybean protein products. Heat treatment inactivates TI and improves nutritional quality, but residual TI activity of 5 to 20% remains after typical commercial treatments. Chronic feeding of TI or products that contain TI can inhibit trypsin and chymotrypsin, stimulate their secretion, cause hypertrophy and hyperplasia of the pancreas, and lead to adenomas and carcinomas of the exocrine pancreas. In the rat, TI promotes pancreatic carcinogenesis initiated by azaserine. Data needed for possible risk assessment on TI would include 2-year bioassays from animals treated with TI and fed diets carefully controlled for type and amount of fat (which also promotes pancreatic carcinogenesis). The effects of TI on protein nutrition would have to be considered when identifying the maximum tolerated dose. Major reductions in human dietary TI exposure may not be feasible because of the multiple sources of TI, the substantial promotion by other factors such as fat, and the adverse effects of excessive heat on food products. For risk assessment of TI in a particular food, other promotors and the feasibility of decreasing TI intake must be considered.
胰蛋白酶抑制剂（TI）天然存在于许多植物性食物中，尤其是大豆蛋白产品。热处理可使TI失活并提高营养质量，但在典型的商业处理后，仍会残留5%至20%的TI活性。长期喂食TI或含有TI的产品会抑制胰蛋白酶和糜蛋白酶，刺激它们的分泌，导致胰腺肥大和增生，并引发外分泌性胰腺癌。在大鼠中，TI会促进由氮杂丝氨酸引发的胰腺癌发生。对TI进行可能的风险评估所需的数据将包括对用TI处理并喂食脂肪类型和量严格控制（脂肪也会促进胰腺癌发生）的饮食的动物进行的两年生物测定。在确定最大耐受剂量时，必须考虑TI对蛋白质营养的影响。由于TI的来源众多、脂肪等其他因素的显著促进作用以及过度加热对食品的不利影响，大幅降低人类饮食中TI的摄入量可能不可行。对于特定食物中TI的风险评估，必须考虑其他促进因素以及降低TI摄入量的可行性。
