ABSTRACT

African breadfruit (Treculia africana) seeds were processed into whole, dehulled, malted and defatted flours. Flours from African breadfruit and maize, and coconut grits were blended with the following combinations: 0:95:5 (control), 20:75:5, 25:70:5, 30:65:5, 35:60:5 and 95:0:5% for African breadfruit, maize and coconut respectively. The flour combinations were mixed with other ingredients to form dough, placed in pans, baked, cut to 5cm length and packaged. Developed snack bars from whole, dehulled, malted and defatted African breadfruit were analysed for proximate composition, anti-nutrient factors, dietary fibre content, digestible, resistant and total starch, in vitro protein and starch digestibilities and in vitro glycemic indices. A two factor factorial experiment in a completely randomized block design was used to study the effects of processing, levels of African breadfruit seed flour and the interaction of the two variables on the responses analysed. Crude protein content of snack bars ranged from 16.16 to 27.15%, crude fibre content of the snack bars ranged from 10.12 to 18.13 %, ash content was from 2.66 to 4.57%, fat content ranged from 6.03 to 8.93% and energy content was from 324.01 to 371.30 kcal/100g. Processing significantly (p<0.05) reduced the anti-nutrient contents of the African breadfruit seed flours and consequently the snack bars. Up to 51.72% reduction of tannin was obtained by dehulling. Defatting, malting and dehulling resulted in 18.75, 34.37 and 65.62% reduction respectively in oxalate content. Highest reduction was obtained by dehulling, and was 70.69% in phytate, 79.95% in saponin, and 48.17% in trypsin inhibitor activity. Dehulling reduced the fibre content, while malting and defatting processes increased the fibre content of the snack bars. High fibre content was recorded in snack bars, which ranged from 10.72 to 30.41%. Snack bar formulated with 20% African breadfruit showed the highest in vitro starch and protein digestibilities irrespective of the processing method involved. In vitro digestibilities decreased with increasing amount of African breadfruit in the blend. Processing African breadfruit significantly increased the in vitro nutrient digestibilties investigated. An increase of 3.00 to 24.10% by defatting, 5.90 to 29.09% by malting and 9.70 to 31 80% by dehulling was recorded in in vitro starch digestibility. Improvement, up to 9.97% by dehulling, 9.86% by malting and 8.64% by defatting, was recorded in in vitro protein digestibility. In vitro glycemic index of the snack bars ranged from 43.62 to 55.83%, which qualifies their classification as low or medium glycemic index (GI) foods. Malted African breadfruit based snacks recorded the highest values of essential amino acids. Sensory evaluation revealed that 20:75:5 formulation was preferred and most accepted above all other African breadfruit supplemented snack bars. Effect of processing on the sensory scores showed snack bars from dehulled African breadfruit was most preferred probably because of its high hedonic score in appearance and aroma. All snack bar formulations had good sensory acceptance.