Effect of temperature on the physicochemical composition and bioactive compounds of taro flour obtained in a spouted bed

Summary The production of flours from fruits, vegetables and not conventionally processed tubers, has been studied as alternative food production. Taro is one of these tubers, which can be consumed in various ways; cooked, pureed, as ingredients for soups and stews, and in the form of flours. Thus, the aim of this work was to study the drying process of taro by atomization in a spouted bed at different temperatures, and assess the influence of the operating conditions on the yield and quality of the product after drying. The following physicochemical analyzes were carried out on the fresh product and the meal: water content, pH, titratable acidity, total ascorbic acid, water activity (25 °C) and colour, as well as the phenolic compound and flavonoid contents. The flours obtained showed amounts of vitamin C ranging from 0.05 to 0.17 mg/100 g, phenolic compounds varying from 4.42 to 5.60 mg/100 g, and flavonoids from 1.05 to 4.30 µg/100 g making them sources of bioactive compounds, which could be added in the preparation of other products or inserted into the human diet. It was concluded that the flour obtained at 90 °C showed the highest vitamin C content, but the flours obtained at temperatures of 70 °C and 80 °C showed pH values near neutrality, besides a reduced water content favouring a longer storage life of the product.