Sensory and microbiological qualities of tidbits produced with flour from cassava and bambara nut

Abstract

Sensory properties of a food product depict its consumer acceptability, while the microbiological quality critically determines the safety, as this relates directly to public health. This study evaluated the sensory and microbiological qualities of tidbits produced with blends of flour from cassava and Bambara nuts. Cassava roots were processed into high-quality cassava flour via unit operations such as harvesting, peeling, washing, grating, pressing, pulverizing, and drying using a flash dryer at 120 °C for 8 min. The flour was milled using a cyclone hammer mill with a 250 µm screen, then cooled and stored in high-density polyethylene bags. Wholesome bambara nut seeds were processed into flour (BNF) through unit operations such as sorting, soaking, dehulling, sprouting, malting, draining, drying, milling, sieving, and packaging. A total of eight (8) samples/runs were generated as depicted by a simplex lattice mixture design, using Design Expert software. Each flour blend and proportionate ingredients were mixed thoroughly in 200 ml of water. Each sample was extruded into groundnut hot oil, to which sliced onion was added for additional flavor. It was then fried in deep, hot vegetable oil until golden brown at 190 °C for 12 minutes using a deep fryer. The cooled tidbits produced were evaluated for sensory and microbiological qualities. Results showed that the range of values for sensory score for appearance, colour, aroma, texture, taste, texture crunchiness and overall acceptability of the tidbits samples were 4.48-7.52%, 4.92-7.56%, 4.92-7.16%, 3.64-7.08%, 3.04-6.96%, 2.40-7.80%, 3.88-7.40%, respectively. According to the Standards Organization of Nigeria (SON), aerobic plate counts ranging
from 10⁴ to 10⁶ CFU/ml in foods are acceptable. The sensory and microbiological qualities were significantly affected by fortifying high-quality cassava flour with bambara nut flour; the microbial counts in this study remained within safe limits for consumption.