Publications
An observational study on the true indispensable amino acid digestibility of legume protein in infants.
Hegde, Shalini G.; Kashyap, Sindhu; Shivakumar, Nirupama; Devi, Sarita; Sachdev, Harshpal Singh; Kurpad, Anura V. BACKGROUND: In low- and middle-income countries, legumes are commonly used as a high-quality protein source in complementary foods. However, the digestibility of legume protein in infants might be low because of the immaturity of the digestive system at that age. OBJECTIVES: The aim of this study was to measure the true indispensable amino acid (IAA) digestibility of mung bean protein in infants aged 10-12 mo. METHODS: This was a cross-sectional study in which the IAA digestibility of intrinsically (2)H-labeled mung bean protein was measured against U-[(13)C]-spirulina protein as a reference in 6 apparently healthy infants using the dual stable isotope technique. The IAA digestibility of the reference protein, U-[(13)C]-spirulina, was also measured in an additional 3 infants against a (2)H-free amino acid mixture. RESULTS: The mean true IAA digestibility of mung bean protein and that of spirulina protein was 83.6% ± 23.0% and 103.5% ± 33.0%, respectively. These values in infants were higher than those determined earlier in adults (83.6% compared with 63.2% and 103.5% compared with 85.2% for mung bean and spirulina protein, respectively). In mung bean, digestibility ranged from 59.4% ± 11.6% (valine) to 126.5% ± 20.8% (isoleucine) and in spirulina from 46.9% ± 3.3% (valine) to 148.0% ± 17.7% (isoleucine). The digestible indispensable amino acid score (DIAAS) for mung bean protein at this age was 50%. CONCLUSIONS: Infants have a high mean IAA digestibility for mung bean protein, although the generalizability of this finding needs to be confirmed. The estimated DIAAS remains low at 50%. In plant-based complementary foods, a ratio of 1:2 of a legume-cereal mix is required to meet protein requirement in infants at this age. This trial was registered at the Clinical Trials Registry of India as CTRI/2020/09/027639.
