Metabolic Availability of Tryptophan From White Maize

Study Overview
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Brief Summary
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Our objective is to determine the metabolic availability of Tryptophan in white maize using the indicator amino acid oxidation (IAAO) technique in adult men.

Detailed Description
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Our objective is to determine the metabolic availability of Tryptophan in white maize. Seven young, healthy, male adults will receive graded levels (13.2, 26.4, 39.7, 52.9) of tryptophan requirement of 3.78 mg/kg/d as a crystalline amino acid (AA) mixture and a porridge of white cornmeal protein respectively.

Official Title
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Application of the Indicator Amino Acid Oxidation Technique for the Determination of Metabolic Availability of Tryptophan From White Maize Protein, in Young Adult Men

Conditions
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Healthy

Intervention / Treatment
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* Other: Tryptophan


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy Adult males (20-49years old). Stable body weight Not on any medications that could affect protein and amino acid metabolism e.g. steroids. Exclusion Criteria: Recent weight loss within the last 3 months or on weight reducing diet. Unwillingness to participate or unable to tolerate the diet.

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 49 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Tryptophan Amino Acid<br>13.2, 26.4, 39.7, 52.9% of the mean tryptophan requirement of 3.78 mg/kg/d will be given to subjects. | Other: Tryptophan<br>* Tryptophan will be supplied at 13.2, 26.4, 39.7, or 52.9% of requirement; sourced from crystalline amino acid and white cornmeal maize.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Metabolic Availability of Tryptophan in Corn | The quality of corn protein will be assessed by measuring the amount of its tryptophan available for protein synthesis (metabolic availability) using the slope ration method. The oxidation of the indicator amino acid phenylalanine will be measured in response to feeding graded intakes of tryptophan in a reference protein patterned after egg protein, and provided as a crystalline amino acid mixture. The pattern of oxidation of phylalanine in response to tryptophan provided in corn will be compared to the pattern of oxidation obtained from feeding the reference protein. On each study day, subjects will be fed 8 hourly meals and breath samples will be taken to measure the oxidation of phenylalanine. Samples will be collected at baseline after the fourth meal, and half hourly, beginning 2.5 hrs after the 5th meal. Breath samples will be analyzed for 13CO2 enrichment. | 9 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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protein quality