Microbial safety and quality of edible oil examined at Ethiopian public health institute, Addis Ababa, Ethiopia: a retrospective study

Abstract

Background: Nowadays food safety is considered to be one of the most global public health concerns. Edible oil is one of the most popular types of food to be consumed in every Ethiopian house. Though, its safety is not emphasized. It is produced in Ethiopia from small scale production to large industry level and / or imported from other countries.Objective: To evaluate microbial and hygienic quality of edible oil. Methods:A six year retrospective study design was conducted from January 2010 to January 2015 on 125 edible oil samples which were examined at Ethiopian public health institute, food safety and public health microbiology research laboratory, Addis Ababa, Ethiopia. The data was extracted using developed format from a laboratory registration book. Edible oil samples were examined for the presence of yeast, mould, aerobic plate count, total coliforms, fecal coliforms and Escherichia coli (E.coli). Additionally, examination for the presence of pathogenic organisms like salmonella species, shigella species, and staphylococcus aureus (S. aureus) were also performed. Data was cleaned and entered to Microsoft XL and then exported to SPSS for statistical analysis and values of different parameters were expressed as the mean±standard error (±S.E).Results: One hundred twenty five edible oil samples were examined among which 62(48%) samples were containing a varying number of bacteria and/or Moulds. Results given in Table1 shows that the aerobic plate count was detected in 46(35.6%), moulds 32(24.8%), Yeasts 4(3.1%), total coliforms 6(4.5%) samples. Fecal coliforms, E.coli and S.aureus were found only in one sample. None of the examined edible oil samples contain salmonella and shigella organisms. Conclusion:Some isolated microorganism indicates unhygienic condition of the edible oil somewhere in its way from processing to packaging and market display. The average microbial load is not higher than 105cfu/ml for Aerobic mesophillic bacteria and 104cfu/ml for moulds. These concentrations may be able to cause health problems in individuals who consume without enough heat processing and also some of the food spoilage organisms, specially the moulds, can hasten the deterioration the edible oil.

Oxidative Stability, Microbial Safety, and Sensory Properties of Flaxseed (Linum usitatissimum L.) Oil Infused with Spices and Herbs

“…It was also evident from the results that there was no reduction in the number of microorganisms during storage, from which we can conclude that the oregano was already contaminated with an increased number of microorganisms before its addition to flaxseed oil, despite the results in Figure 3 (69.12% DPPH) indicating an increased antioxidant activity of oregano. These results correspond in part to the literature, since there are no data on the number of colonies of bacteria from the Enterobacteriaceae family but on coliform bacteria [ 74 ], but the presence of molds and aerobic mesophilic bacteria was in accordance with literature. Microbiological testing of bacteria from the Enterobacteriaceae family is included in the Guideline on microbiological food criteria [ 66 ] as an indicator of hygiene.…”

“…The increase in the number of the microorganisms was observed at the fourth and sixth months of storage ( Table 2 ), which could also be related to the results of the peroxide value (0.88 mmol O 2 /kg on the 180th day of storage, Figure 2 ) due to the availability of available water. The results of the analyses in the literature on commercial edible oils and infused oils, as well as our results, showed that certain spices or herbs and their concentration in oil strongly affected the survival of microorganisms, regardless of the type and amount of initial contamination [ 74 , 75 ].…”

Optimization of cold press and enzymatic‐assisted aqueous oil extraction from tomato seed by response surface methodology: Effect on quality characteristics

“…Plate count agar (PCA Oxoid, pH 6.8-7.2) and conventional dilution procedures were performed to determine aerobic mesophilic bacteria count according to the pour plate method (Gobena et al, 2018).…”

Chemical Properties of Unbranded Vegetable Oils Sourced From Five Different Markets in Benin City, Edo-State, Nigeria

“…2.1.1. Acid Value (AV) AV was determined by directly titrating the oil/fat in an alcoholic medium against standard potassium hydroxide/sodium hydroxide solution (Gashaw and Getachew, 2014).…”

“…More worrisome is the quality of edible oils in circulation in the markets especially in the third world countries. The quality of edible oil is a function of the method of obtaining the oils from their plant sources (Gobena et al, 2018).…”