彝、藏族青年男子膳食蛋白质吸收利用研究

目的　探讨、比较彝、藏族青年男子膳食蛋白质来源与人体吸收利用情况 ,为完善我国膳食蛋白质推荐摄入量提供基础数据。方法　以凉山彝族自治州和阿坝藏族羌族自治州两个学校的 18～ 2 2岁男子为受试对象 ,采用人体氮平衡试验 ,对其进行为期 14天的代谢试验 ,收集制备 9天的膳食、粪便和尿等样品 ,以半微量凯氏定氮法测定样品氮含量 ,计算分析蛋白质吸收利用指标。结果　彝族青年男子蛋白质摄入量为71 5 5g d ,蛋白质表观消化率为 73. 19% ,真消化率、生物价、净利用率的估算值分别为 79. 79%、4 7. 5 8%、38. 17% ,氮平衡为 0 . 71g d。藏族相应以上指标的数据为 94 . 33g d、86 . 6 9%、91 .4 3%、4 8. 0 7%、4 4. 0 0 %和3 .16g d。结论　藏族青年男子膳食蛋白质的供给与吸收利用状况优于彝族 ,但两者均能保持机体正氮平衡。

Study on the dietary protein bioavailability by young men of Yi and Tibetan

Objective To compare the dietary protein intakes and bioavailability of young male adults of Yi and Tibetan. Methods Two groups of subjects aged fr om 18 to 22y were respectively recruited from schools of Liangshan Yi autonomous region and Tibetan-Qiang autonomous region. Samples of diet, fecal and urine i n the nitrogen balance study for each group of subjects were collected, and the n itrogen content was analyzed by semi-micro-Kjeldahl. Results Tota l protein inta ke, apparent absorption, true absorption, biological value, net protein utilizat ion and nitrogen balance for the young man of Yi people were 71.55g/d, 73.19%, 7 9.79%, 47.58%, 38.17% and 0.71g/d. The corresponding figures for young Tibet an m an were 94.33g/d, 86.69%, 91.43%, 48.07%, 44.00% and 3.16g/d.Concl usion The dietary protein intake and bioavailability of young Tibetan m an were better than those of Yi, but both Yi and Tibetan young men were able to keep positive N balance with their respective dietary pattern.