Mycoflora, Mycotoxin Contamination and Proximate Mineral Composition of Smoke-Dried Frog (Aubria sp.) (Konko) Sold in Ibadan, Oyo State, Nigeria

Abstract

Mycoflora, mycotoxin contamination and proximate mineral composition of smoked-dried frog (Aubria sp.) samples purchased from different markets in Ibadan, Oyo State were investigated. A total of 20 composite samples made up of 120 smoked-dried frog samples were collected. The total fungi count ranged from 1.0 x103 – 8.0 x 103 cfu/g. A total of 70 fungal strains including: Alternaria sp., Aspergillus flavus, Aspergillus niger, Aspergillus tamarii, Cladosporium sphaerospermum, Fusarium compacticum, Fusarium oxysporum, Fusarium sacchari, Fusarium solani, Fusarium verticillioides, Penicillium chrysogenum, Penicillium citrinum, Penicillium oxalicum, Trichoderma viridae and Rhizophus sp. were isolated from the samples. All the samples were contaminated with aflatoxin and 70% were contaminated with deoxynivalenol (DON). The total Aflatoxin and DON in the two sampling ranged from 5.06h – 9.17a ppb, 1.86h – 5.58a ppb and 0.00 – 0.96 ppm and 0.00 – 0.09 ppm. The levels of mycotoxins contamination were within the maximum limit permitted. The Aspergillus flavus and Fusarium spp. were able to produce aflatoxin and DON which ranged from 1.65 – 3.56 ppb and 0.05 – 0.19 ppm. The percentage crude protein, K, Ca and Fe content in the samples ranged from 40.79j – 53.93a, 217.85 – 1235.83 mg/100 g, 4201 – 437.25 mg/100 g and 431.75 – 1065.0 mg/100 g. The moisture content ranged from 11.58h – 16.31a. The Cd, Zn and Cu content ranged from 0.00 – 0.22 mg/100 g, 9.43 – 5.20 mg/100 g and 7.05 – 18.58 mg/100 g. The presence of mycotoxigenic fungi and mycotoxin levels in the dried frog samples is of public health concern and proper attention is needed for the control of quality and adequate preservation before sales and consumption.