Physicochemical Properties and Molecular Characterization of Microbial Flora of Imported WheatFlour in Port Harcourt Metropolis

Abstract

Abstract The Physicochemical properties and molecular characterization of microbial flora of imported wheat flour in Port Harcourt metropolis was investigated. Imported wheat flour was purchased from five locations in Port Harcourt. Flour samples were collected over a six weeks period on a weekly basis. The samples were subjected to physicochemical analysis, microbial counts and molecular identification of fungal species and compared with crushed wheat sample. The result of the physicochemical analysis over a six weeks period revealed a moisture range of 12–14%, protein content range of 10.95–13.21%, falling number of 260-387sec, particle size of 0.12–0.30µm and water absorption capacity range of 60.00-62.10%. Ash content of the flours collected ranged from 0.60–0.75% while that of the flour milled crushed sample ranged from 1.20–1.65% higher than the NIS standard. Throughout the collection period, moisture, ash, and protein contents of the wheat flour samples collected did not exceed standards set for wheat flour. Microbial counts of the samples also revealed total bacteria count range of NG (no growth) to 4.90×10− 4cfu/g, total mould count range of 1.50×10− 4-4.87×10− 4cfu/gand total yeast count range of NG to 4.49×10− 3cfu/g with low counts observed for the flour mill crushed wheat sample. Microbial counts of the samples throughout the period of collection were also within the acceptable statutory limits for wheat flour. Results of the molecular identification of the isolates shoed the presence of A.nigerand Aspergillus sydowii, Aspergillus niger, Fusarium lichenicola, Penicilliumgriseofulvum, Cladosporium tenuissimum and Hypopichiaburtonii. Of all the species isolates, Fusarium lichenicolawas the most frequently identified in the studied samples which encourages future studies on the research of toxins in these samples.It is therefore recommended that wheat flour for sales in open market by retailers should be stored in a cool and dry condition to prevent rapid spoilage and less performance.