Effect of the Stage of Ripening on the Nutrients, Anti-nutrients and Functional Properties of Flours Made from Whole Plantain Fruit
U. E. Inyang *
Department of Food Science and Technology, Faculty of Agriculture, University of Uyo, Uyo, Akwa Ibom State, Nigeria
S. E. Nkop
Department of Food Science and Technology, Faculty of Agriculture, University of Uyo, Uyo, Akwa Ibom State, Nigeria
E. B. Umoh
Department of Biochemistry, University of Uyo, Uyo, Akwa Ibom State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Background and Aim: Plantain processing generates large quantities of peel that is discarded despite its nutritional and bioactive constituents. The aim of the study was to produce whole plantain flour at unripe, semi-ripe and fully ripe stages and compare the nutrients, anti-nutrients and functional properties of the flours.
Study Design: Analysis of variance (ANOVA) was carried out.
Place and Duration: Department of Food Science and Technology, University of Uyo, Akwa Ibom State, Nigeria, from September 2016 to March 2017.
Methodology: Freshly harvested unripe plantains were shared into three portions. Portion 1 was processed into whole plantain flour immediately. Portions 2 and 3 were ripened naturally and processed into flours at semi-ripe and fully ripe stages, respectively. For flour production, unpeeled plantains were washed, steam blanched (100°C for 10 min), cooled, sliced, oven dried (60°C), milled and sieved to obtain the flour used for analysis.
Results: The results revealed that all the parameters analyzed varied with ripening stages. Protein, carbohydrate, Na, and Fe in the flours decreased from 6.39%, 86.73%, 28.14mg/100g, and 2.45 mg/100 g at unripe stage to 5.98%, 85.69%, 27.96 mg/100 g and 2.38 mg/100 g at fully ripe stage. Conversely, fat, ash, crude fibre, K, Ca, Mg and Zn increased from 0.70%, 2.57%, 3.61%, 476.09 mg/100 g, 148.52 mg/100 g, 121.32 mg/100 g and 3.60 mg/100 g in unripe plantain flour to 1.16%, 3.43%, 3.74%, 481.21 mg/100 g, 149.58 mg/100 g, 124.11 mg/100 g and 3.66 mg/100 g, respectively in fully ripe flour. All the anti-nutrients decreased significantly (P = .05) with ripening. Bulk density, water and oil absorption capacities as well as swelling index decreased while foaming capacity increased with stages of ripening.
Conclusion: Production of flours of high nutrients and low anti-nutrients from unpeeled plantain at various stages of ripening would ensure efficient utilization of plantain fruit with no waste generation and should be exploited.
Keywords: Whole plantain flour, ripening stages, nutrients, anti-nutrients, functional properties.