Improved Energy and Sensory Properties of Instant Porridge Made from a Roasted Mixture of Grated Orange-Fleshed Sweet Potatoes and Flour Made from Shredded Sun Dried Cassava

Abstract

Mozambican diets are often lacking in vitamin A. Orange-fleshed sweet potatoes (OFSP) are rich in beta-carotene, a precursor of vitamin A, but are not easily introduced into the diet as the consistency of the porridge made from OFSP is unappetising. Flour made from roasted cassava (garri) produces a palatable porridge with a high energy density. We propose a simple procedure for producing an instant porridge by roasting grated OFSP with flour from shredded sun-dried cassava (G-OFSP). This is an easily adopted variant of the traditional garri-making process. The consistency of this porridge made from milled G-OFSP (G-OFSPf) was compared to the consistency of porridges made from maize flour (Mf), cassava flour (Cf), OFSP flour (OFSPf) and garri flour (Gf) at 43 ° C, and then correlated to the perceived characteristics assessed by a sensory panel. The dry matter concentration of the porridges was adjusted to give similar consistency, measured by the maximum force of back extrusion, using traditional maize porridge as a reference. The porridges were additionally characterized by back extrusion force relaxation time. Short relaxation times were obtained for G-OFSPf, Mf and Gf porridges and longer times for Cf and OFSPf porridges, corresponding roughly to the sensory preference. In the sensory test of consistency, G-OFSPf porridge was ranked first, followed by Mf, Gf, OFSPf and Cf. In overall sensory tests comparing G-OFSPf porridge to Gf porridge, G-OFSPf porridge was significantly preferred with regard to all sensory attributes evaluated (p < 0.01). The energy density of the G-OFSPf porridge was 5.6 kJ/ml; the highest of the three most preferred porridges with regard to texture. The preparation of flour from a mixture of grated OFSP and shredded sun-dried cassava improved the perceived porridge consistency, increased its energy density, and its high acceptability would increase the intake of betacarotene.