热处理对小米蛋白体外消化率的影响

Effects of Heat Treatments on the in vitro Digestibility of Millet Protein

为探究不同热处理方式的小米蛋白质的消化情况,采用胃蛋白酶-胰蛋白酶体外模拟消化法测定蒸制、煮制、挤压处理并经淀粉酶解的小米蛋白消化率。对从小米生粉中提取的醇溶蛋白蒸制、煮制的蛋白消化率进行测定,结果表明,经120 min的胃蛋白酶和胰蛋白酶处理,蒸制、煮制和挤压处理的小米的体外蛋白消化率分别较未处理小米降低了31.00%,17.15%和11.02%。蒸煮的醇溶蛋白消化率也分别降低了35.57%和28.63%。蒸煮对小麦蛋白的消化率有不利影响,挤压处理优于蒸煮处理。蒸煮处理降低小麦蛋白体外消化率可能与醇溶蛋白消化率的降低有关。

Pepsin-trypsin digestion method was used to study the in vitro protein digestibilities of steamed, boiled and extruded millet which was hydrolyzed by amylase. The digestibility of prolamine extracted from millet has also been determined after steaming and boiling. The results showed that after digesting for 120 min by pepsin and trypsin respectively, the in vitro protein digestibilities of steamed, boiled and extrude millet were reduced by 31.00%, 17.15% and11.02% respectively compared with untreated millet. The digestibilities of steamed and boiled prolamine were also reduced by 35.57% and 28.63% respectively compared with untreated millet prolamine. These indicated that steaming and boiling would make adverse effects for the in vitro protein digestibility of millet, extrusion would be better than steaming and boiling in improving the protein digestibility of millet. The decrease of protein digestibility of steamed and boiled millet may be related to the reduction of prolamine digestibility in millet.