Production and Evaluation of Pasta (Noodles) from Rice, Cowpea and Orange-Fleshed Sweet Potato Flour Blends

Abstract

Aims: The aim was to produce and evaluate the properties (proximate and functional) of pasta from blends of local rice (Oryza sativa), white cowpea beans (Vigna unguiculata) and orange-fleshed sweet potato [Ipomoea batatas (L) Lam.] (umusco/3 variety) flours as well as to evaluate the cooking characteristics, microbiological quality and sensory attribute of the formulated pasta. Study Design: The experimental design that was used is Completely Randomized Design. Place and Duration of Study: The study took place at the Department of Food Science and Technology, University of Nigeria, Nsukka between December 2016 and September 2017. Methodology: The study investigated the applicability of local rice, cowpea beans and orange-fleshed sweet potato flour to develop pasta rich in proteins and pro-vitamin A. The local rice and cowpea flours were blended in the ratio of 90:10, 80:20, 70:30, 60:40 and 50:50 to produce pasta which was subjected to sensory evaluation to isolate the best blend (80:20). Following this preliminary study, pastas were formulated from a combination of rice-cowpea flour blend and OFSP flour in the ratio of 90:10, 80:20, 70:30, 60:40 and 50:50 for samples RC/Pa, RC/Pb, RC/Pc, RC/Pd and RC/Pe respectively, while unblended rice (100%) was used as the control. The pasta products were subjected to physical, proximate, pro-vitamin A, cooking, microbiological and sensory analysis using standard methods. Results: The width, height and length of the samples ranged from 0.57 to 0.82 cm, 0.88 to 1.78 cm and 2.24 to 3.48 cm respectively. The protein content, fat, ash, crude fibre and moisture, carbohydrate and caloric contents ranged from 10.91 to 18.80%, 1.95 to 2.24%, 1.74 to 3.43%, 1.52 to 3.29%, 11.09 to 14.63%, 60.95 to 80.47% and 323.85 to 339.91 kcal/g respectively. The protein, fat, ash, fibre and moisture contents of the blends were significantly (p<0.05) higher than the control but their carbohydrate and caloric content were lower than the control. The pro-vitamin A content of the samples varied from 0.93 to 4.07 mg/100 g. There was an increase in the pro-vitamin A content as the ratio of orange-fleshed sweet potato increased in the blend. The cooking analysis showed that sample RC/Pa (90:10) had the highest cooking time and cooking loss while sample RC/Pe (50:50) had the highest cooking yield. The total viable count ranged from 2.0 × 104 to 6.2 × 104cfu/g while mould was not detected except on sample RC/Pd (60:40) which had 4.0 × 101 cfu/g. The microbial content of the samples was not high when assessed using the guideline for microbiological quality of pasta products. The sensory scores showed that all the samples had high ratings.