Evaluation of Protein Quality in Blends Prepared from Commercial Wheat (Triticum aestivum) and Yellow Maize Flours (Zea mays) and African Walnut (Tetracarpidium conophorum) Protein Isolate


  • Oluwayemisi Foluke Jonathan Awofadeju


African walnut seed is an underutilized crop gaining attention by the researchers in developing countries like Nigeria due to poor protein consumption. Based on preliminary study, the blends of Commercial Wheat Flour (CWF) (30-50%), Yellow Maize Flour (YMF) (20-30%) and African Walnut Protein Isolate (AWPI) (10-20%) were prepared using optimal mixture design of response surface methodology to generate twenty composite flours. The 100% commercial wheat flour serves as control. The composite flours were subjected to proximate composition using standard method. Among the twenty composite flours, three flour blend samples 4, 8 and 11 with superior qualities as assessed by highest protein and crude fibre, and lowest fat content were selected and further evaluated for amino acid profiling and in-vitro protein digestibility using standard procedure.  Data obtained were subjected to ANOVA at ?0.05. The result of the flours showed that AWPI had the highest protein (90.80%) content. The flour blends were significantly different in their moisture (8.33-9.17%), protein (17.27-31.27%), fat (0.86-1.20%), ash (1.60-2.22%), crude fibre (0.70-1.16%) and carbohydrate (49.16-70.36%) contents. Among the samples with superior qualities assessed by highest protein (31.27%) and crude fibre (1.16%), and lowest fat (0.86%), sample 11 scored highest values in lysine (4.6150%) and tryptophan (1.1480%) as well as in-vitro protein digestibility (78.31%). However, the best proportion of flours that can improve protein quality in our Nigerian food industry, homes and ready-to-eat snacks was established.

Key words: Composite blends, African walnut seed, Protein quality, Yellow maize flour, Commercial wheat flour

Author Biography

Oluwayemisi Foluke Jonathan Awofadeju