Comparability of the amino acid composition of aril and seed of blighia sapida fruit

Abstract

Akee apple fruit (Blighia sapida Konig), is one of the popular small-scale tropical fruits and it is an important crop. B. sapida may be eaten raw (without the pink raphe attaching the aril to the seed) or after cooking when it resembles scrambled eggs. Fruits like the akee apple are novelties for many people except in the savannah belt; in the localities where they grow they are eaten and relished. In view of this, an investigation into the concentrations of amino acids of the aril and seed parts of Blighia sapida fruit was carried out using standard methods to determine amino acid profiles; quality of dietary protein was determined using various methods like: amino acid scores determination [(in three different ways); (i) amino acid score based on the whole hen’s egg, (ii) essential amino acid score based on the provisional amino acid scoring pattern, (iii) essential amino acid score based on suggested school child requirement] essential amino acid index and predicted protein efficiency ratio. For quick precipitation of protein, the isoelectric point was also determined. Glutamic acid was the most abundant amino acid (11.4-12.7 g/100 g) and while Arg was the most abundant (7.25 g/100 g) essential amino acid in the aril, it was Leu (6.58 g/100 g) in the seed. The total essential amino acid in aril was 33.7 g/100 g (50.2 %). It was 33.8 g/100 g (45.8 %) in the seed. The limiting essential amino acid (based on provisional scoring pattern) was Met + Cys (0.60) in aril and Thr (0.59) in seed. The essential amino acid index ranged from 1.08 (seed) to 1.62 (aril); the predicted protein efficiency ratio was 1.83 in aril and 2.20 in the seed whereas the isoelectric point
ranged between 3.89 in aril and 4.0 in the seed. At á 0.05, significant differences existed in the samples in amino acid profiles and calculated isoelectric point (pI). The results of this study indicated that the amino acid profiles of akee apple aril and seed are similar in composition, being good sources of many of the essential amino acids. Whilst the aril is eaten fresh, the seed can be exploited for human food.

Key words: Blighia sapida, amino acid profiles, quality