Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

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Author: search.filters.author.van der Wielen NSubject: search.filters.subject.protein quality

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    True Ileal Amino Acid Digestibility of Human Foods Classified According to Food Type as Determined in the Growing Pig
    (Elsevier Inc on behalf of the American Society for Nutrition, 2025-10-18) Hodgkinson SM; Stroebinger N; Stein HH; Fanelli NS; de Vries S; van der Wielen N; Hendriks WH; Moughan PJ
    Background: A Food and Agriculture Organization Expert Consultation recommended the use of digestible indispensable amino acid score (DIAAS) to evaluate protein quality of foods for humans. Calculation of DIAAS requires true ileal digestibility (TID) of amino acid (AA) values but currently insufficient data are available. Objectives: This study aims to generate in pigs TID of AA for a wide range of foods commonly consumed by humans and determine the range of differences in TID of AA among food types. Methods: A standardized protocol was followed to determine TID of AA in 97 foods across 3 laboratories. Female pigs (25–100 kg during study, n ≥ 6) received foods for 7 d following a Youden Square design with ileal digesta collected via T-cannula on days 6–7. Endogenous AA losses were determined by feeding a protein-free diet. Foods, diets, and digesta were analyzed for nitrogen, AA, reactive lysine, titanium and dry matter. Foods were categorized into food types with the degree of variation within each food type evaluated using descriptive statistics. Results: The TID (mean of AA) ranged from 0.247 (apples) to 0.988 (beef tenderloin). The median TID of AA was high (mean of AA > 0.90) for foods categorized as dairy products, eggs, fish and seafood, isolates and concentrates, meat, nuts, plant-based burgers, soy products and wheat products. Food categories with median TID < 0.80 were baked products, fruit, pulses and seeds, and wheat bran cereal, yeast, and zein. Food categories with low variations between foods were fish and seafood (1% units), dairy products (3% units), and eggs (5% units), whereas categories with the greatest variation were grains (18% units), vegetables (16% units), seeds (14% units), and fruit (12% units). There was considerable variation in TID for individual AA both within and among foods. Conclusions: The database with TID of AA of 97 foods generated by 3 laboratories using a standardized methodology can be utilized for protein quality evaluation.
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    Editorial: Dietary protein for human health.
    (Frontiers Media S.A., 2025-01-15) Moughan PJ; Hendriks WH; Hodgkinson SM; Chungchunlam SMS; Lim WXJ; Mensink M; Stroebinger N; van der Wielen N; Pivovarova-Ramich O
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    Presence of Unabsorbed Free Amino Acids at the End of the Small Intestine Indicates the Potential for an Increase in Amino Acid Uptake in Humans and Pigs
    (Elsevier Inc on behalf of American Society for Nutrition, 2023-03) van der Wielen N; de Vries S; Gerrits WJ; Lammers-Jannink K; Moughan PJ; Mensink M; Hendriks W
    BACKGROUND: Unabsorbed free amino acids (AAs) at the end of the small intestine result in a potential preventable nutritional loss. OBJECTIVES: This study aimed to quantify free AAs in terminal ileal digesta of both humans and pigs to investigate its relevance for the nutritional value of food proteins. METHODS: Two studies with three diets were performed: a human study-ileal digesta from eight adult ileostomates were collected over 9 h after ingestion of a single meal unsupplemented or supplemented with 30 g zein or whey; pig study-12 cannulated pigs were fed for 7 d with a diet containing whey or zein or no-protein diet, and ileal digesta were collected on the last 2 d. Digesta were analyzed for total and 13 free AAs. True ileal digestibility (TID) of AAs was compared with and without free AAs. RESULTS: All terminal ileal digesta samples contained free AAs. The TID of AAs in whey was 97% ± 2.4% (mean ± SD) in human ileostomates and 97% ± 1.9% in growing pigs. If the analyzed free AAs would have been absorbed, TID of whey would increase by 0.4%-units in humans and 0.1%-units in pigs. The TID of AAs in zein was 70% ± 16.4% in humans and 77% ± 20.6% in pigs and would increase by 2.3%-units and 3.5%-units, respectively, if the analyzed free AAs would have been fully absorbed. The largest difference was observed for threonine from zein: if free threonine was absorbed, the TID would increase by 6.6%-units in both species (P < 0.05). CONCLUSIONS: Free AAs are present at the end of the small intestine and can potentially have a nutritionally relevant effect for poorly digestible protein sources, whereas the effect is negligible for highly digestible protein sources. This result provides insight into the room for improvement of a protein's nutritional value if all free AAs are to be absorbed. J Nutr 2023;xx:xx-xx. This trial was registered at clinicaltrials.gov as NCT04207372.