色氨酸在植物蛋白和动物蛋白中的真消化率。

True Digestibility of Tryptophan in Plant and Animal Protein.

机构信息

Centre for Doctoral Studies, Manipal Academy of Higher Education, Manipal, India; Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences (A Unit of CBCI Society for Medical Education), Bengaluru, India.

Division of Nutrition, St. John's Research Institute, St. John's National Academy of Health Sciences (A Unit of CBCI Society for Medical Education), Bengaluru, India.

出版信息

J Nutr. 2024 Nov;154(11):3203-3209. doi: 10.1016/j.tjnut.2024.09.014. Epub 2024 Sep 20.

DOI:10.1016/j.tjnut.2024.09.014

PMID:39307282

Abstract

BACKGROUND

Protein quality, evaluated using Digestible Indispensable Amino Acid Score (DIAAS), requires ileal digestibility values of individual indispensable amino acids (IAAs) in each protein. However, true tryptophan (Trp) digestibility has rarely been quantified in humans.

OBJECTIVE

To measure the true Trp digestibility and DIAAS of H-intrinsically labeled plant and animal protein sources in humans, using the dual isotope tracer technique.

METHODS

The true Trp digestibility of H intrinsically labeled plant proteins such as whole mung bean (n = 6) and dehulled mung bean (n = 6), chickpea (n = 5), and yellow pea (n = 5), and protein from animal source foods such as egg white (n = 6), whole egg (n = 6), chicken meat (n = 6), and goat milk (n = 7) was determined against the known digestibility of U-C spirulina whole cell protein as reference, except for goat milk protein that was measured against free crystalline C-Trp as reference. Banked samples from earlier studies conducted to determine true IAA digestibility of different protein sources were used for the analysis. DIAAS was calculated for each test protein using digestibility corrected IAA scores (mg IAA/g of protein) in comparison with the IAA requirement score for adults.

RESULTS

The true Trp digestibility of whole mung bean, dehulled mung bean, chickpea, yellow pea, egg white, whole egg, chicken meat, and goat milk were 67.6 ± 3.7%, 74.5 ± 4.4%, 72.6 ± 2.3%, 72.5 ± 2.2%, 89.7 ± 2.5%, 91.4 ± 2.6%, 95.9 ± 2.2%, and 92.8 ± 2.9%, respectively. The true Trp digestibility of plant protein sources was significantly lower than that of animal protein sources (P < 0.05). Trp was not a limiting IAA in all the tested proteins.

CONCLUSION

The true Trp digestibility determined in this study ranged from 67.6 ± 3.7% to 95.9 ± 2.2% for whole mung bean and chicken meat, respectively, and adds to the database of individual true IAA digestibility of different protein sources.

TRIAL REGISTRATION NUMBER

This study was registered in Clinical Trials Registry of India (CTRI) with registration numbers CTRI/2017/11/010468, CTRI/2020/04/024512, and CTRI/2018/03/012265.

摘要

背景

蛋白质质量可通过可消化必需氨基酸评分（DIAAS）进行评估，这需要每种蛋白质中单个必需氨基酸（IAA）的回肠可消化率值。然而，人体中真正色氨酸（Trp）的消化率很少被量化。

目的

使用双同位素示踪技术测量人体中 H 标记的植物和动物蛋白来源的真实 Trp 消化率和 DIAAS。

方法

采用双同位素示踪技术，对 H 标记的植物蛋白（全绿豆、去壳绿豆、鹰嘴豆和黄豌豆）和动物蛋白（蛋清、全蛋、鸡肉和山羊奶）中的真实 Trp 消化率进行了测定，以螺旋藻全细胞蛋白的已知消化率为参考标准，除山羊奶蛋白外，其他蛋白均以游离结晶 C-Trp 为参考标准进行测定。利用早期研究中测定不同蛋白质源真实 IAA 消化率时保存的样本进行分析。使用校正消化率后的 IAA 评分（mg IAA/g 蛋白）计算每种测试蛋白的 DIAAS，并与成人 IAA 需求评分进行比较。

结果

全绿豆、去壳绿豆、鹰嘴豆、黄豌豆、蛋清、全蛋、鸡肉和山羊奶的真实 Trp 消化率分别为 67.6 ± 3.7%、74.5 ± 4.4%、72.6 ± 2.3%、72.5 ± 2.2%、89.7 ± 2.5%、91.4 ± 2.6%、95.9 ± 2.2%和 92.8 ± 2.9%。植物蛋白源的真实 Trp 消化率明显低于动物蛋白源（P < 0.05）。所有测试蛋白中的 Trp 均不是限制 IAA。