Proximate composition and functional properties of extruded snacks from breadfruit-sweet potato flour
Objective: The objective of the study was to determine the proximate composition and functional properties of extruded snacks from breadfruit-sweet potato flour blends.
Materials and methods: African bread fruit and sweet potato tubers were processed into flour and formulated into different proportions (100: 0; 90: 10; 80:20; 70:30; 60:40and 50: 50% of breadfruit and sweet potato, respectively). The proximate composition, functional properties and sensory acceptability of the composite flour and extruded snacks were evaluated using standard methods. Extruded snacks were made from varying combinations of breadfruit and sweet potato flour using a single screw cooking extruder. The proximate composition, functional properties and sensory acceptability of the composite flour and extruded snacks were determined using standard laboratory procedures. Data obtained were subjected to analysis of variance using SPSS version 20.
Results: Moisture, ash, fat, protein, crude fibre and carbohydrate contents of the composite flour ranged from 5.70 to 15.00%, 1.34 to 2.67%, 0.40 to 0.80%, 2.11 to 3.12%, 2.55 to 5.29% and 81.77 to 73.47%, respectively while that of the snacks ranged from 5.70 to 7.32%, 7.11 to 9.46%, 2.18 to 9.28%, 8.56 to 12.68%, 8.16 to 10.95% and 54.61 to 64.54%, respectively. Breaking force, lateral expansion and bulk density of the snacks ranged from 12.60 to 34.20 N, 6.80 to 7.76 and 0.03 to 0.05 g/cm3, respectively; while water solubility and water absorption indices ranged from2.81 to 3.25 and 1.48-2.15, respectively. The proportions of the composite flour did not (p≥ 0.05)influence the sensory acceptability of the snack samples.
Conclusions: The study showed that extruded snacks with higher protein and crude fibre proximate composition, functional properties and sensory acceptability can be prepared from breadfruit-sweet potato flour blends.
Keywords: Snacks, sweet potato, breadfruit, texture, sensory acceptability