Evaluation of rain tree (Samanea saman) pod flour characteristics and bread made from composite flours

Abstract

Rain tree pods (RTP) are underutilized in Ghana, but they have high nutritive content that could be explored for better utilization in the food industry. In this study, the physicochemical, functional, mineral, phytochemical and pasting properties of the RTP flour were analyzed. Its suitability as composite flour in bread and the impact on the bread’s nutritional, physicochemical and sensory properties were evaluated. The results showed that the RTP flour contained 9.8% moisture, 2.37% fat, 18.56% protein, 6.87% crude fiber, 3.17% ash and 59.24% carbohydrate. The minerals include sodium (185.20 ± 0.58 mg/100 g), potassium (1828.00 ± 0.07 mg/100 g), Magnesium (72.00 ± 0.05 mg/100 g), Calcium (587.00 ± 0.11 mg/100 g) and Phosphorus (279 ± 0.12 mg/100 g). The phytochemical screening showed low (+) presence of tannins, saponins, sterols, triterpenoids, moderate (++) presence of alkaloids but no/(-) presence of flavonoids. The RTP flour had bulk density as 0.64–0.80 g/mL with Hausner ratio 1.25, water absorption capacity (209.62 ± 8.15%), oil absorption capacity (127.18 ± 4.94%), solubility (16.74 ± 0.58%), swelling power (8.38 ± 0.52%) and foaming capacity (8.17 ± 0.5%). Substituting wheat with 15% RTP flour resulted in appreciable increase in the bread’s fiber and protein content. Statistically, there was no significant difference (p > 0.05) between the whole wheat bread and the composite bread from the RTP flour in terms of the overall acceptability. The findings suggest that RTP flour could serve as a fortification to wheat bread on the basis of its nutritional profiles.