MICROBIOLOGICAL QUALITY AND SAFETY ASSESSMENT OF KULI-KULI PRODUCED IN SELECTED LOCATIONS IN OGUN-STATE SOUTHWEST, NIGERIA.

Abstract

ABSTRACT Kuli-kuli, a popular snack derived from groundnut (Arachis hypogea) is particularly prone to contamination by a wide variety of microorganisms. This research aimedto assess the microbiological quality of commercially availablekuli-kuliand also survey its traditional processing practicesso as to identify the possible cause of contamination (physical, chemical and biological) at different processing stages. Samples at processing stages were collected from four local producers and sixteen street vendorsin four selected towns in Ogun State. Samples prepared in the laboratory served as the control. Microbiological, chemical and physical assessments of samples were carried out using standard procedures. Total Bacterial Counts, Staphylococci, coliform, yeast and mold counts were enumerated on Nutrient, Mannitol Salt, MacConkey, yeast extract and Sabourad Dextrose agar, respectively.Microbial isolates were identified using morphological, biochemical and molecular methods. Chemical analysis was carried out using Kirk and Sawyer method. Mycotoxins of health concern: aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), ochratoxin A (OTA), deoxynivalenol (DON), fumonisin B1 (FB1), HT-2 toxin, T-2 toxin and zearalenone (ZEN) were also analyzed using Ultra High Performance Liquid Chromatography/Time-Of-Flight Mass Spectrometry method. Baseline assessment score sheet were used to obtain information about vending and processingarea, handling practices and process control.All data obtained were analyzed using Statistical Package for Social Sciences Version 17.0.Means were separated using Duncan multiple range test. The total bacterial counts in the raw groundnut samples ranged from 1.56±0.00 to 3.66±0.00Log10 CFU/g, moulded kuli-kuli ranged from 2.00±0.06 to 2.75±0.06 Log10 CFU/gand the final product ranged from 1.10±0.08 to 2.30±0.08Log10 CFU/g. The fungal count in the raw groundnut ranged from 1.43±0.10 to 10.01±1.99Log10 CFU/g, moulded kuli-kuli ranged from 1.02± 0.05 to 3.05± 0.60Log10 CFU/g and the final product ranged from 0.50± 0.01 to 3.00± 0.07 Log10 CFU/g.Bacterial species isolated from street vended samples includedPseudomonas spp, Proteus vulgaris, Staphylococcus aureusand Escherichia coli, while mould isolated were Aspergillus fumigatus, Aspergillusniger, Mucorhiemalis,Rhizopusspp. and Sacharomyces cerevisiae. Some physical contaminants were observed during the processing stages of kuli-kuli. In the street vended kuli-kuli, cadmium concentrations ranged from (0.01 to 1.03)mg/kg, arsenic (0.10 to 12.05)mg/kg. Lead (0.03)mg/kg was detected only in the sample collected from one out of the sixteen vendors. Cadmium concentrations ranged from 0.24±0.03 to 6.10± 0.10 mg/kg in the raw groundnuts and 0.14±0.06 to 7.45± 1.50 mg/kg in the finished products both obtained from local producers.Lead was not detected in any of the stages during processing. High levels of AFB1 (162 µg/ kg), FB1 (154 µg/kg), AFB2 (59 µg/kg), and FB2 (57 µg/kg) were recorded in the samples. The level of the microbial, chemical and physical contamination at different processing stages of kuli-kuli in this study showed that there are safety concerns in the kuli-kuli products from the different local producers and street vendors.