Abstract:
ABSTRACT
Introduction: Edible oils are imported and produced in Ethiopia, notably in Gondar, its
production has expanded considerably in recent years. The expansion of locally
produced edible vegetable oils, along with a lack of severe quality control, has resulted
in a high level of susceptibility to their health-related quality. Substandard edible oil
production and quality deterioration may contribute to the formation of reactive and
hazardous oxidation products which may cause public health problems.
Objective: To determine microbiological quality and levels of certain heavy metals of
edible vegetable oils being produced and marketed in Gondar city, northwest Ethiopia.
Methods: A laboratory-based cross-sectional study design was conducted from May to
July 2021 in Gondar City. Simple random sampling techniques was used to collect 51
edible oil samples. Aseptically collected samples were analyzed in biology/chemistry lab
room using selected oil quality parameters. Digestion of the samples was carried out
using microwave. Analysis of heavy metals was carried out using atomic absorption
spectrophotometer. Microbiological quality of vegetable oil was assessed by using
standard microbiological procedures and techniques to enumerate, isolate, identify and
characterize the different microorganisms associated with the oils assessed. To make
the frequency distribution more symmetrical, microbial data was first converted to Log
10 values to determine fungal and bacterial load of oil samples. The collected data were
entered to Microsoft Excel and Stata Version 17 and Non- parametric Kruskal Wallis
test was used to assess significant variations.
Result; Fifty-one vegetable edible oil samples were examined which contain varying
number of bacteria, yeast and Molds. Staphylococcus. aureus, Klebsiella Pneumonie,
Pseudomonas. Aeruginosa were the identified bacteria whereas Saccharomyces
cerevisiae, Aspergillus Niger, Aspergillus flavus, Aspergillus fumigatus were the
identified fungi. Total coliform and fecal coliform isolates were identified. The total
aerobic bacterial plate count ranged from 7.5×104 to 2.01× 105 cfu/mL with locally
produced mixed oil having the highest bacterial load and sample of Niger seed oil from
market site had less count. The yeast and mold count of oil samples ranged from 0 to
9×104 cfu/mL. The concentration of heavy metals were observed in the range of 0.01-
