Alyssa Paoletti1, Abrar Fakiha1, Zujaja Tul-Noor1, Paul B Pencharz1,2,3,4, Crystal L Levesque5, Ronald O Ball2,4, Dehan Kong6, Rajavel Elango7,8, Glenda Courtney-Martin1,4,9. 1. Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada. 2. Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada. 3. Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada. 4. Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada. 5. Department of Animal Science, South Dakota State University, Brookings, South Dakota, USA. 6. Department of Statistical Sciences, University of Toronto, Toronto, Ontario, Canada. 7. Department of Pediatrics, School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada. 8. BC Children's Hospital Research Institute, BC Children's Hospital, Vancouver, BC, Canada. 9. Faculty of Kinesiology & Physical Education, University of Toronto, Toronto, Ontario, Canada.
Abstract
BACKGROUND: Sorghum is the fifth most consumed cereal grain but limiting in the indispensable amino acid lysine. Complementing sorghum with lentils can improve the quality of sorghum-based diets. However, knowledge of lysine bioavailability in sorghum is lacking. OBJECTIVES: The study objectives were to determine the bioavailability of lysine in sorghum and to assess the effect of complementation of sorghum and lentils in a mixed-meal format. METHODS: We studied 5 healthy young men (≤30 years; BMI <25 kg/m2) in a repeated-measure design using the indicator amino acid oxidation (IAAO) method, with L-[1-13C] phenylalanine as the indicator. Each subject participated in 8 determinations in random order. On the reference diet, subjects received 4 amounts of L-lysine (5, 8, 12, and 15 mg. kg-1 . d-1) from a crystalline amino acid mixture patterned after egg protein. On the test diet, they received 3 levels of lysine (8.2, 12.5, and 15.7 mg. kg-1 . d-1) from sorghum, and on the complementation diet they received 1 level of lysine from a mixed meal of sorghum and lentils. The bioavailability of lysine in sorghum was estimated by comparing the IAAO response to the test diet with the IAAO response to the reference diet using the slope-ratio method. Effectiveness of complementation was assessed by comparing the IAAO response to the mixed meal to the IAAO response to the test protein. RESULTS: The bioavailability of lysine from sorghum was 94%. Upon complementation with lentils, there was a decline in the oxidation of L-[1-13C] phenylalanine by 19% (P < 0.0495), reflecting an improvement in available lysine in the mixed meal due to increased lysine intake. CONCLUSIONS: Although the bioavailability of lysine in sorghum is high, its lysine content is limiting. Complementation with lentils in a 1:1 ratio is recommended to achieve the lysine requirement for adult men consuming a sorghum-based diet. This trial was registered at clinicaltrials.gov as NCT03411005.
BACKGROUND: Sorghum is the fifth most consumed cereal grain but limiting in the indispensable amino acid lysine. Complementing sorghum with lentils can improve the quality of sorghum-based diets. However, knowledge of lysine bioavailability in sorghum is lacking. OBJECTIVES: The study objectives were to determine the bioavailability of lysine in sorghum and to assess the effect of complementation of sorghum and lentils in a mixed-meal format. METHODS: We studied 5 healthy young men (≤30 years; BMI <25 kg/m2) in a repeated-measure design using the indicator amino acid oxidation (IAAO) method, with L-[1-13C] phenylalanine as the indicator. Each subject participated in 8 determinations in random order. On the reference diet, subjects received 4 amounts of L-lysine (5, 8, 12, and 15 mg. kg-1 . d-1) from a crystalline amino acid mixture patterned after egg protein. On the test diet, they received 3 levels of lysine (8.2, 12.5, and 15.7 mg. kg-1 . d-1) from sorghum, and on the complementation diet they received 1 level of lysine from a mixed meal of sorghum and lentils. The bioavailability of lysine in sorghum was estimated by comparing the IAAO response to the test diet with the IAAO response to the reference diet using the slope-ratio method. Effectiveness of complementation was assessed by comparing the IAAO response to the mixed meal to the IAAO response to the test protein. RESULTS: The bioavailability of lysine from sorghum was 94%. Upon complementation with lentils, there was a decline in the oxidation of L-[1-13C] phenylalanine by 19% (P < 0.0495), reflecting an improvement in available lysine in the mixed meal due to increased lysine intake. CONCLUSIONS: Although the bioavailability of lysine in sorghum is high, its lysine content is limiting. Complementation with lentils in a 1:1 ratio is recommended to achieve the lysine requirement for adult men consuming a sorghum-based diet. This trial was registered at clinicaltrials.gov as NCT03411005.
Authors: Mahroukh Rafii; Paul B Pencharz; Ronald O Ball; Christopher Tomlinson; Rajavel Elango; Glenda Courtney-Martin Journal: J Nutr Date: 2020-07-01 Impact factor: 4.798