Effects of Processing Methods on the Yield, Functional and Pasting Properties of “Garri Analogue” Produced from Different Varieties of Orange Flesh Sweet Potato

Abstract

Garri is a fermented, dry granular meal produced from cassava roots which is of high carbohydrate content with little of other nutrients. Orange Fleshed Sweet Potato (OFSP) is a root crop with high nutritional properties and so its use for “garri analogue” has been found to be of better nutritional qualities than cassava. However, considerations are yet to be given to the effect of varieties and processing variables of OFSP on the qualities of “garri analogue”. Therefore, this study evaluated the effect of different varieties and processing variables of OFSP on the qualities of “garri analogue”. Three varieties of OFSP (Mother’s Delight, King J and Solo Gold) were procured from local farmers in Osun State. Two different processing parameters: fermentation time (24, 48 and 72h) and particle size (1.4, 1.8 and 2.36mm) were considered. The yield, functional properties (bulk density, water absorption capacity, oil absorption capacity, gelatinization temperature, least gelation concentration and swelling capacity) and pasting properties of the “garri analogue” were evaluated. Data obtained were subjected to Analysis of Variance and means were separated using Duncan Multiple Range Test at 5% level of significance. The yields for the three varieties of OFSP are 0.50, 0.60 and 0.80kg for Mother’s Delight, King J and Solo Gold respectively. Oil absorption capacity (1.40 -3.27 , 1.77 - 2.67 and 1.50 -2.77 g/100g), water absorption capacity (1.70 -4.57 , 2.17 -3.87 and 2.17 -3.87 g/100g), gelling (20.00 – 50.00 , 20.00 – 50.00 and 20.00– 50.00 g/dm3), gelatinization temperature (95.00-100.00, 94.00-100.00 and 94.00-100.00oC), swelling capacity (20.00– 50.00, 20.00– 50.00 and 20.00– 50.00 g/dm3) and bulk density (0.42 -0.53, 0.42 -0.53 and 0.42 -0.53g/ml). Peak viscosity (1.52 x102-4.59 x 102, 3.70 x102 -5.58 x 102 and 2.68 x 102-5.83 x 102 RVU), trough viscosity (1.32-3.22 x 102, 2.65x102 -3.73 x 102 and 1.82. x 102-5.62 x 102 RVU), breakdown viscosity (13.6-1.37 x 102, 1.03 x 102 -93.14 x 102 and 21.64 x 102 -1.14 x 102 RVU), final viscosity (2.09-5.16 x 102, 4.30 x 102 -5.28 x 102 and 2.82 x 102 -6.00 x 102 RVU), setback viscosity (76.72-2.07 x 102, 1.27 x 102 -1.89 x 102 and 1.10 x 102 – 2.36 x 102 RVU), peak time (5.01-6.11, 5.05-5.49 and 5.00-7.00 mins) and pasting temperature (85.13-89.90, 87.58-91.50 and 87.47-92.57oC). The variety that had an effect on the functional and pasting properties of the “garri analogue” was Mother’s Delight, while in term of processing variables on the functional and pasting properties of “garri analogue: from the different varieties are Mother’s Delight and King J. The optimum results in term of the processing variables on the yield, functional and pasting properties from the different varieties are Mother’s Delight and Solo Gold. The optimum results were obtained at 48.00 and 72.00hrs with particle sizes of 1.88 and 2.36mm respectively.