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Highlights in BioScience             

ISSN: 2682-4043 

DOI:10.36462/H.BioSci.20222                                                                                                          
 

 

Highlights in BioScience                                                                                                                                                                  September 2020| Volume 3 

http://bioscience.highlightsin.org/ 

Page 1 of 4 

                                          

Research Article 

 

Open Access 

 
 

 

 

 

1Department of Home Economics, College of 

Education Jigawa State, Nigeria 
2Department of Food Science and Technology, 

Faculty of Agriculture, Bayero University, 

Kano 
3College of Biosystems Engineering and Food 

Science, National-Local Joint Engineering 

Laboratory of Intelligent Food Technology 

and Equipment, Zhejiang Key Laboratory for 

Agro-Food Processing, Zhejiang R & D 

Center for Food Technology and Equipment, 

Zhejiang University, Hangzhou 310058, 

China. 
4Department of Microbiology, Kano University 

of Science and Technology Wudil, Kano State 

Nigeria 

 

Contacts of Authors  

 

* To whom correspondence should be 

addressed: Sanusi Shamsudeen 

Nassarawa 

 

Citation: Zaharaddeen Salisu, Sanusi 

Shamsudeen Nassarawa and Sadisu Farouq 

(2020). Microbial quality assessment of roasted 

and fried meat sold in Gumel town. Highlights 

in BioScience Volume 3. Article ID 20222. 

dio:10.36462/ H.BioSci.20222 

 

Received:  June 17, 2020 

 

Accepted:  September 7, 2020 

 

Published: September 20, 2020 
 

Copyright: © 2020 Salisu et al. This is an 

open access article distributed under the terms 

of the Creative Commons Attribution License, 

which permits unrestricted use, distribution, 

and reproduction in any medium, provided the 

original author and source are credited. 

 

Data Availability Statement: All relevant data 

are within the paper and supplementary 

materials 

 

Funding: The authors have no support or 

funding to report. 

 

Competing interests: The authors declare that 

they have no competing interests. 

Microbial quality assessment of roasted and fried meat 

sold in Gumel town 

 
Zaharaddeen Salisu

1
, Sanusi Shamsudeen Nassarawa

2,3
* and Sadisu Farouq

4
  

 

Abstract 

        Roasted and fried meats are the two commonest and preferred meat 

varieties consumed in northern Nigeria. The consumption of these meat 

varieties is, nevertheless, without ascertaining its fitness in terms of 

contamination by pathogens. In line with this occurrence and preference, 

it is a good approach to assess the quality of roasted and fried meat in one 

of the prehistoric towns of northern Nigeria, which is Gumel. A total of 

10 samples of both fried and roasted meat were randomly collected, 

prepared and microbiological analyses for mesophilic bacteria, fungi and 

coliform group conducted in the laboratory. The mean bacterial load was 

observed between 3.0 x 10
4 

and 6.5 x 10
4 

CFU/g for roasted beef meat 

and 4.7 x 10
4
 and 5.3 x 10

4
 CFU/g for fried beef meat. It was 4.5 x 10

4
 

and 6.0 x 10
4 

CFU/g in roasted chicken meat and 4.0 x 10
4
 and 4.7 x 10

4
 

CFU/g in fried chicken meat. For the fungal load, it was observed to be 

between the range of 1.0 x 10
4 
and 3.0 x 10

3 
CFU/g for roasted beef meat 

and 1.0 x 10
4
 and 7.0 x 10

3
 CFU/g for fried beef meat. For the chicken 

meat, it ranges from 1.0 x 10
4
 to 4.0 x 10

3
 CFU/g for the roasted type and 

1.0 x 10
4 

and 7.0 x 10
3
 CFU/g for the fried meat. Investigation of the 

coliform group showed no growth in both samples. On biochemical tests, 

bacterial species confirmed to be present were Staphylococcus aureus, 

Bacillus spp, and Streptococcus spp. while Penicillium spp, Mucor 

hiemalis, Aspergillus species and Rhizopus spp. are the fungal species 

observed in the meats. This research was, therefore, conducted to assess 

the quality of roasted and fried meat sold in Gumel town to relate it to 

some common diseases affecting the community.  

 

Keywords: Roasted meat, fried meats, microbial quality assessment. 

 

Introduction 

Meat is mainly composed of water and protein and is usually eaten together 

with other foods. It has been reported that meat is rich in protein (15-20%), 

minerals, vitamins, and all the essential amino acids. Meat is animal flesh that is 

eaten as food [1]. Humans are omnivorous and have hunted and killed animals for 

meat since prehistoric times [2,3]. The advent of civilization allowed for the 

domestication of animals such as chickens, sheep, fish, seafood, pigs, and cattle 

and eventually their use in meat production on an industrial scale. It is edible raw 

but is normally eaten after it has been cooked and seasoned or processed in a 

variety of ways. Meat consumption varies worldwide, depending on cultural and 

religious differences, as well as the socio-economic status of the people. 

Nigerians depend mainly on domestic animals and aquatic organisms and to some 

extent on game animals and birds. This is true of the urban as well as rural 

communities [4]. Unprocessed meat will spoil within hours or days. 

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Salisu et al., 2020                                                                                                     Microbial quality assessment of roasted and fried meat sold in Gumel town 

 

 

Highlights in BioScience                                                                                                                                                                  September 2020| Volume 3 

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Spoilage is caused by the practically unavoidable 

infection and subsequent decomposition of meat by bacteria 

and fungi, which are born by the animal itself, people 

handling the meat and their implements [5]. Because of this, 

meat nowadays serves as a source of various foodborne 

diseases due to improper processing, handling and storage. 

This usually results in the reduction of valuable proteins 

and leads to various foodborne infections. However, 

considering the random addiction of eating meat anyhow in 

mostly states of Northern Nigeria without ascertaining its 

fitness in terms of contamination by either bacteria or fungi, 

which is mostly attributed to the lack of good knowledge on 

the possible spoilage, it is pertinent to set up a mechanism 

that will be geared towards investigating the possible 

contamination sources and assess the quality of roasted and 

fried meat sold in Gumel town, one of the prehistoric towns 

of northern Nigeria. 

Materials and Methods  

This research was conducted at Gumel town, one of 

the Local Governments of Jigawa State, Nigeria. It is 

located at latitude 12.63°N
 
and

 
longitude 9.30

°
E and 36 

meters elevation above the sea level with an estimated 

population of about 42,742. A total of 10 samples 

comprising three fried and roasted beef meat each, and two 

fried and roasted chicken meat were randomly collected 

from the study area. The samples were placed into cleaned 

polythene bags and transported immediately to the 

laboratory for preparation and subsequent analysis. All the 

media used in this study were prepared and handled 

according to the manufacturer's instructions. For the 

enumeration of aerobic mesophilic bacteria and fungi, the 

social dilution method, as described by the American Public 

Health Association [6], was employed.  

Plates containing between 30 and 300 colonies were 

selected and counted for bacteria, and the number obtained 

was multiplied by the dilution factor. This gave the number 

of bacterial colony-forming units per gram of meat samples 

(CFU/g of the meat sample). For fungi, the plate that 

contained less than 50 colonies were selected and counted 

after 3-5-day incubation period. The count was reported as 

fungi/mold colony forming a gram of meat sample (CFU/g). 

Sets of control for each sample containing agar and diluents 

were also incubated to ascertain the sterility of the media. 

The following formula was used to calculate the number of 

bacteria/fungi colony forming units per gram of the meat.  

N=   ; Where:  N= the number of bacterial/fungal 

colonies per gram of sample; n= number of colonies 

counted; v= volume of sample used; d= dilution factor.  

 

For the enumeration of mesophilic coliform bacteria, 

the three tube method described by [6] was employed. The 

color, size, shape and microscopy (for Gram staining), 

surface elevation and margin of different colonies 

developed on the plates were observed. A representative 

colony of the various morphological types was picked and 

transferred to a freshly prepared, sterilized and solidified 

nutrient agar incubated at 35°C for 24hours to obtain a pure 

culture of the organisms [6]. The isolated organisms were 

then subjected to grams staining techniques, and 

microscopy then followed. 

The fungal isolates were identified as described in the 

illustrated genera of imperfect fungi [7] and microbiological 

methods [8]. Catalase tests coagulate test, methyl red-Voges 

Proskauer, citrate test, urease test, motility test and indole 

test were all carried out according to the method described 

by Cheesbrough [9]. 

Results and Discussion 

The results of bacterial colony counts (colony-forming 

units per gram, CFU/g) as presented in Table 1 for the beef 

meat were observed to be within the range of 3.0 x 10
4 

to 

6.5 x 10
4 

and 4.7 x 10
4
 to 5.3 x 10

4
 CFU/g for roasted and 

fried beef meat, respectively.  

 

Table 1. Total bacterial count of roasted and fried meats in 

beef and chickens.  

S/N Sample 
 Bacterial colony count per 

gram of sample (CFU/g) 
Log No. 

1 BR-1 3.5X10
4
 4.5 

2 BR-2 6.5X10
4
 4.8 

3 BR-3 3.0X10
4
 4.5 

4 BF-1 4.7X10
4
 4.7 

5 BF-2 3.8X10
4
 4.6 

6 BF-3 5.3X10
4
 4.7 

7 CR-1 4.5X10
4
 4.7 

8 CR-2 6.0X10
4
 4.8 

9 CF-1 4.7X10
4
 4.7 

10 CF-2 4.0X10
4
 4.6 

KEY: BR=Roasted beef meat,   BF=Fried beef meat,   CR= 

Roasted Chicken meat   CF=Fried chicken meat 

 

In comparison, it was observed to be within the range 

of 4.5 x 10
4 

to 6.0 x 10
4 

and 4.0 x 10
4
 to 4.7 x 10

4
 CFU/g 

for roasted and fried chicken meat, respectively. These 

values obtained for the mean bacterial and fungal loads 

were within the acceptable range of 1 x 10
3
 to 1 x 10

7 

CFU/g  as provided by Ledward [10]  and 1.0 x10
3
 for the 

acceptable limits for the ready to eat foods and is an 

indication that the meat was processed thoroughly because 

Heetun et al. [11] reported that meat and meat products are 

highly perishable commodities and if not properly stored, 

processed, packed and distributed microbial growth will be 

highly accelerated. The level of microorganisms present in 

meat products as reported by Jay et al. [12] can be reduced 



 

 

Salisu et al., 2020                                                                                                     Microbial quality assessment of roasted and fried meat sold in Gumel town 

 

 

Highlights in BioScience                                                                                                                                                                  September 2020| Volume 3 

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Page 3 of 4 

only when they are further processed. Another report 

Davies and Board [13] has revealed that if spoilage 

microorganisms such as Brochothrix thermosphacta and 

Pseudomonas spp. are present and grow to a high number, 

the meat will spoil and will be unfit for human 

consumption. The total fungal count (Table 2) was 

observed to range between 1.0 x 10
4 

to 3.0 10
3
 and 1.0 x 

10
4
 to 7.0 x 10

3 
CFU/g for roasted and fried beef meat, 

respectively. It was, however, observed that in chicken 

meat, it ranged between 1.0x 10
4
 to 4.0 x 10

3
 and 1.0 x 10

4
  

 

to 7.0 x 10
3
 CFU/g for roasted and fried meat variety. 

 

Table 2. Fungal count of roasted and fried meat (beef and 

chickens).  

S/N Sample 
Fungal  colony count  per 

gram of sample (CFU/g) 
Log No. 

1 BR-1 1.0X10
4
 4.0 

2 BR-2 3.0X10
3
 3.5 

3 BR-3 1.0X10
4
 4.0 

4 BF-1 1.0X10
4
 3.8 

5 BF-2 4.0X10
3
 3.6 

6 BF-3 7.0X10
3
 3.8 

7 CR-1 4.0 X10
3
 3.6 

8 CR-2 1.0X10
4
 4.0 

9 CF-1 1.0X10
4
 4.0 

10 CF-2 7.0 x10
3
 3.8 

KEY: BR=Roasted beef meat;   BF=Fried beef meat;   CR= 

Roasted Chicken meat; CF=Fried chicken meat. 

 

In the same vain, Ismail et al. [14] studied the 

microbial quality of some meat products obtained from 

local markets in Egypt, and reported many types of fungi 

belonging to several genera such as Aspergillus, Candida, 

Cladosporium, Eupenicillium, Eurotium, Geotrichum, 

Mucor, Penicillium, Rhototorula besides aflatoxin B1. 

These researchers also isolated Clostridium perfringens and 

Staphylococcus aureus. In this scenery, Yousuf et al. [15] 

have elaborated that the presence of coliforms such as 

Escherichia coli in food is suggestive of faecal 

contamination from animals. The results of the most 

probable number index per gram of coliform of the roasted 

and fried meats of beef and chickens (Table 3) showed no 

growth in all samples. 

 

Table 3. Results of the most probable number index per 

gram of coliform of the roasted and fried meat (beef and 

chickens) 

S/N Sample MPN per gram Log Number 

1 BR-1 No growth - 

2 BR-2 No growth - 

3 BR-3 No growth - 

4 Bf-1 No growth - 

5 Bf-2 No growth - 

6 BF-3 No growth - 

7 CR-1 No growth - 

8 CR-2 No growth - 

9 CR-1 No growth - 

10 CR-2 No growth - 

KEY: BR=Roasted beef meat;   BF=Fried beef meat;   CR= 

roasted Chicken meat;   CF=Fried chicken meat. 

 

The results of morphological characterization of the 

bacterial and fungal isolates (Tables 4 and 5) showed some 

colonies of bacteria appearing yellow and some whitish. 

Most of the fungal colonies, when stained with lactophenol 

stain appeared blackish, brown and greenish with 

characteristic section. 

 

Table 4. Morphology of the bacterial isolates in meat samples (beef and Chicken). 

S/N Isolate  Br-1 Br-2 Br-3 Bf-1 Bf-2 Bf-3 Cr-1 Cr-2 Cf-1 Cf-2  

1        A1  + + + + + + + + + + 

2         B1  + + - - + - + + - - 

3         C1  + - + + + + - - + + 

Key: + = growth observed; –  = growth was not observed. 

 

Table 5.  Morphology of the bacterial isolates in meat samples (beef and Chicken).  

S/N Isolate  Br-1 Br-2 Br-3 Bf-1 Bf-2 Bf-3 Cr-1 Cr-2 Cf-1 Cf-2  

1        A2 - + + - + + + + + + 

2        B2  
- - - + + + + + + 

3        C2 + + + + + + - - - + 

4        D2 + - - + - + - - - + 

Key: + = growth observed; – = growth was not observed. 

 

 



 

 

Salisu et al., 2020                                                                                                     Microbial quality assessment of roasted and fried meat sold in Gumel town 

 

 

Highlights in BioScience                                                                                                                                                                  September 2020| Volume 3 

http://bioscience.highlightsin.org/ 

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Table 6. Biochemical tests of bacterial isolates from roasted and fried meats (beef and chickens).  

Isolate Microscopy 
Gram 

reaction 
Coagulase 

Carbohydrate 

fermentation 
Indole 

Methyl 

red 

Voges 

proskaver 
Citrate Motility 

Expected 

organism 

A1  
Cocci in 

Closter  
- + - - + - - + 

Staphylococcus 

aureus 

B1  Short rod  + + + - + - - - Baccilus spp 

C1 
Cocci in 

chain 
+ - - - + - + - 

Streptococcus 

spp 

Key: + = presence; - = Absence 

 

The fungal species isolated as presented in Tables (6 

and 7) were Penicillium spp, Mucor hiemalis, Aspergillus 

species and Rhizopus spp. On biochemical tests, the 

bacterial species confirmed to be present are 

Staphylococcus aureus, Baccilus spp, and Streptococcus 

spp Table 6. 

 

Table 7. Fungal isolation and identification of roasted and 

fried meats (beef and chickens). 

S/N Isolate Expected organism 

1 A2 Penicillium spp 

2 B2 Mucor hiemalis 

3 C2 Aspergillus spp 

4 D2 Rhizopus nigricans 

Conclusion 

It can be concluded that the total bacterial and fungal 

counts of both roasted and fried meats prepared and sold by 

commercial meat sellers in Gumel town in Nigeria was 

found to fall within the standard range endorsed by WHO 

and other international organizations. Hence, contained 

fewer contaminants, and this can be attributed to the 

hygienic conditions of utensils, water and the ingredients 

used in processing the meat. 

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