Amino acid composition and protein quality of commonly consumed cooked foods in Nigeria

This study determined the amino acid (AA) composition and protein quality of selected Nigerian meals. The AA profile of nineteen meals was determined by ion-exchange chromatography and quantified by high performance liquid chromatography-mass spectrometry. Protein quality was evaluated using AA scores, interactions, essential amino acid index, predicted protein efficiency ratio and biological value. Eighteen AAs were identified. Afang soup ranked highest in all the AAs except in tryptophan and proline while ofada rice and stew, and boiled yam and garden egg sauce, ranked the least. The indispensable AA content ranged from 2,404.07 (boiled yam and garden egg sauce) to 14,149.20 mg/100 g (afang soup) and is below 43%. The leucine/isoleucine and leucine/valine values were greater than one while basic/acidic AAs was below 1.0, but greater than 0.5 in all the meals. The protein quality indices showed that most Nigerian meals met the recommended score for all indispensable AAs except for leucine and phenylalanine, but had low biological protein quality. Strong positive correlations existed among most AAs, and afang soup clustered exclusively in indispensable, conditionally indispensable AAs and AA groups. These findings are essential for updating the Nigerian food database. It can also serve as baseline for food-based dietary guideline. •Amino acid profile of some Nigerian meals were analyzed for the first time.•Leucine and phenylalanine scores were below recommendations for most meals.•Most meals have low predicted biological protein quality, but high efficiency.•Frequent amino acid correlations exist in most Nigerian meals.•Afang soup clustered exclusively in indispensable amino acid.