背景:建议向更多植物性饮食过渡,特别是含有豆类,需要更广泛的植物蛋白生物利用度知识。蚕豆在不同的纬度种植,并越来越多地用于人类营养。
目的:我们旨在评估配备肠管以实施回肠15N平衡法的健康志愿者中蚕豆蛋白的营养质量。
方法:9名志愿者完成了研究(7名男性,两个女人,年龄33±10岁,BMI24.7±2.6kg/m2)。他们配备了鼻回肠管。禁食过夜后,他们摄取了由煮熟的去壳蚕豆种子的糊状物组成的测试餐(约20克蛋白质。250g部分)固有地用15N标记。回肠内容物样本,等离子体,并在餐后8小时内收集尿液。使用同位素质谱法测定未消化的氮(N)和氨基酸(AAs),随后,计算回肠消化率和可消化必需氨基酸评分(DIAAS)。餐后脱氨基的测量允许计算净餐后蛋白质利用率(NPPU)。
结果:回肠氮消化率为84.1±7.7%。餐后脱氨占摄入N的19.2±3.6%,NPPU为64.7±9.7%。单个AA的回肠消化率从组氨酸的85.1±13.7%到谷氨酰胺谷氨酸的94.2±3.6%不等。AA的平均消化率比N的消化率高约6个百分点,达到89.8±5.9%,而不可或缺的AA消化率为88.0±7.3%。组氨酸和色氨酸是第一个限制性AA[DIAAS=0.77(通过豆类特异性N-蛋白转换因子5.4计算):0.67(默认因子6.25)]。硫AA限制在较小程度[DIAA比率=0.94(N*5.4);0.81(N*6.25)]。
结论:煮熟的蛋白质回肠消化率,人类脱壳蚕豆中等(<85%),但AA接近90%。总的蛋白质质量受到有限的组氨酸和色氨酸含量的限制。该试验在clinicaltrials.gov注册为NCT05047757。
The recommended transition toward more plant-based diets, particularly containing legumes, requires a wider knowledge of plant protein bioavailability. Faba beans are cultivated at different latitudes and are used increasingly in human nutrition.
We aimed to assess the nutritional quality of faba bean protein in healthy volunteers equipped with an intestinal tube to implement the ileal 15N balance method.
Nine volunteers completed the study (7 males, 2 females, aged 33 ± 10 y, BMI: 24.7 ± 2.6 kg/m2). They were equipped with a nasoileal tube. After fasting overnight, they ingested a test meal consisting of cooked mash of dehulled faba bean seeds (20 g protein per serving of approximately 250 g) intrinsically labeled with 15N. Samples of ileal contents, plasma, and urine were collected over an 8-h postprandial period. Undigested nitrogen (N) and amino acids (AAs) were determined using isotopic MS, and subsequently, ileal digestibility and digestible indispensable amino acid score (DIAAS) were calculated. The measurement of postprandial deamination allowed calculation of the net postprandial protein utilization (NPPU).
The ileal N digestibility was 84.1% ± 7.7%. Postprandial deamination represented 19.2% ± 3.6% of ingested N, and the NPPU was 64.7% ± 9.7%. The ileal digestibility of individual AAs varied from 85.1% ± 13.7% for histidine to 94.2% ± 3.6% for glutamine + glutamate. The mean AA digestibility was ∼6 percentage points higher than the digestibility of N, reaching 89.8% ± 5.9%, whereas indispensable AA digestibility was 88.0% ± 7.3%. Histidine and tryptophan were the first limiting AAs [DIAAS = 0.77 (calculated by legume-specific N-to-protein conversion factor 5.4); 0.67 (by default factor 6.25)]. Sulfur AAs were limiting to a lesser extent [DIAA ratio = 0.94 (N × 5.4); 0.81 (N × 6.25)].
Protein ileal digestibility of cooked, dehulled faba beans in humans was moderate (<85%), but that of AAs was close to 90%. Overall protein quality was restricted by the limited histidine and tryptophan content. This trial was registered at clinicaltrials.gov as NCT05047757.