Determination of Optimum Processing Conditions for the Proximate Composition and Pasting Characteristics of Flour Made from Parboiled Cassava Chips: A Response Surface Analysis

Abstract

The effects of processing conditions on the proximate composition and pasting properties were investigated using A Rotatable Central Composite Design (RCCD) for three variables. Processing conditions included parboiling time (10, 12, 13, 14 and 15 min), soaking time (24, 36, 48, 60 and 72h) and drying temperature (40, 45, 50, 55, and 60 ℃). Response data on the pasting properties were analysed in a regression model while the three-dimensional graphs were plotted. Crude protein, fat and fibre contents significantly decreased with increase in soaking time from 24 to 72h. There was also a significant decrease of peak viscosity (from 260.60 – 380.33 to 260.60 RVU) and peak time (from 4.82 to 3.54 min) with an increase in the time of soaking the parboiled cassava chips samples from 24 to 72 h. Increasing the soaking time beyond 48h resulted to increase in breakdown viscosity (175.30 – 221 RVU) of the parboiled cassava flour samples. The breakdown viscosity of the flour samples also decreased significantly with increase in drying temperature from 40℃ to 60℃. There was a decrease in the final viscosity (228.00 to 184.83 RVU) with an increase in the cooking time of cassava parenchyma from 10 to 15min. The optimum processing conditions were found to be parboiling time of 12 min (x1), a soaking time of 24 h (x2), and drying temperature of 60℃ (x3).