Metabolic Availability of Lysine in Milk and a Vegetarian Cereal-Legume Meal Determined by the Indicator Amino Acid Oxidation Method in Indian Men

Sulagna Bandyopadhyay; Rebecca Kuriyan; Nirupama Shivakumar; Santu Ghosh; Rajendran Ananthan; Sarita Devi; Anura V Kurpad

doi:10.1093/jn/nxaa235

Metabolic Availability of Lysine in Milk and a Vegetarian Cereal-Legume Meal Determined by the Indicator Amino Acid Oxidation Method in Indian Men

J Nutr. 2020 Oct 12;150(10):2748-2754. doi: 10.1093/jn/nxaa235.

Authors

Sulagna Bandyopadhyay¹, Rebecca Kuriyan¹, Nirupama Shivakumar¹, Santu Ghosh², Rajendran Ananthan³, Sarita Devi¹, Anura V Kurpad⁴

Affiliations

¹ Division of Nutrition, St. John's Research Institute, Research Center of University of Mysore, St. John's National Academy of Health Sciences, Bengaluru, India.
² Department of Biostatistics, St. John's Medical College, St. John's National Academy of Health Sciences, Bengaluru, India.
³ Food Chemistry Division, ICMR-National Institute of Nutrition, Jamai-Osmania, Hyderabad, India.
⁴ Department of Physiology, St. John's Medical College, St. John's National Academy of Health Sciences, Bengaluru, India.

PMID: 32840572
DOI: 10.1093/jn/nxaa235

Abstract

Background: Lysine rich foods such as milk and legumes serve as important food additions to the lysine deficient cereal-based diets of vegetarian populations in low- and middle-income countries (LMICs) to alleviate the risk of quality corrected dietary protein inadequacy. Dietary protein quality can be determined by estimating the metabolic availability (MA) of lysine.

Objectives: The study aimed to estimate the MA of lysine in spray-dried cow milk powder (SMP), heat-treated spray-dried cow milk powder (HSMP), and a habitually consumed cereal-legume based vegetarian meal (VM), using the indicator amino acid oxidation (IAAO) slope-ratio method.

Methods: The MA of lysine in SMP, HSMP, and VM was estimated in 7 healthy young men aged 19-24 y with BMI of 21.5 ± 0.5 kg/m2 in a repeated measures design. The IAAO response slopes with 2 graded lysine intakes (10.5 and 15.0 mg·kg-1·d-1) from the SMP and VM were compared with the response slope generated with 3 graded crystalline lysine intakes (6.0, 10.5, and 15.0 mg·kg-1·d-1) at the subrequirement level. To produce HSMP, pasteurized cow milk was heat treated and spray dried. The MA of lysine in HSMP was tested at a single level of lysine intake (15 mg·kg-1·d-1). A total of 8 IAAO experiments were conducted on each participant in randomized order. The IAAO slopes were estimated using a linear mixed-effect regression model.

Results: The MA of lysine in SMP, HSMP, and VM was 91.9%, 69.9%, and 86.6% respectively.

Conclusions: Heat treatment reduced the MA of lysine by 22% in HSMP compared with SMP in healthy Indian adults. The lysine MA estimates can be used to optimize lysine limited cereal-based diets, with the addition of appropriately processed legumes and milk powder, to meet the protein requirement. This trial was registered at Clinical Trials Registry of India (http://ctri.nic.in) as CTRI/2019/08/020568.

Keywords: Protein quality; cereal-legume meal; heat-treatment; indicator amino acid oxidation; metabolic availability; milk.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Biological Availability
Diet, Vegetarian*
Dietary Proteins / administration & dosage
Fabaceae*
Humans
Lysine / chemistry
Lysine / metabolism
Lysine / pharmacokinetics*
Male
Meals*
Milk / chemistry*
Young Adult

Substances

Dietary Proteins
Lysine

Associated data

CTRI/CTRI/2019/08/020568