Impact of Different Adulterants on Honey Quality Properties and Evaluating Different Analytical Approaches for Adulteration Detection.

The study was carried out keeping in view the recently emerging concern of adulteration of natural honey on the honey markets. This study intended to investigate honey adulteration detection using physical and chemical composition to achieve a foreign component (a marker) that is present in the honey that confirms either the adulteration or authenticity of the honey. The technique was evaluated on honey samples that were 5-50% adulterated with various common adulterants in Ethiopia. Preliminary quick tests and characterization of physicochemical and antioxidant properties were tested as alternative analytical approaches for honey adulteration detection. Preliminary quick test methods were used to detect adulterated honey, but these methods were found specific to adulterant materials. The proline and pH levels decreased as molasses, sugar, and banana adulterants increased, while increased as melted candy and shebeb adulterants increased. Moisture content decreased as sugar, melted candy, and shebeb adulterants were increased, while decreased as molasses and banana adulterants increased. HMF content increased as molasses, melted candy, and shebeb adulterants were increased. The sugar compositions are key differential criteria to detect the adulteration of honey with sugar. Based on their physical characteristics, PCA demonstrated a considerable difference between samples of pure and contaminated honey. In conclusion, it was observed that honey adulteration was detected based on significant deviations of physicochemical and biochemical components from expected values in the concentration of naturally occurring components. This study successfully demonstrated a method to rapidly and accurately classify and authenticate honey. Accordingly, it is recommended that frequent training for stakeholders on adulteration detection methods should be carried out to avoid adulteration of honey from the markets.

Genomic characterization of Listeria monocytogenes and Listeria innocua isolated from milk and dairy samples in Ethiopia.

Listeriosis caused by Listeria monocytogenes often poses a significant threat to vulnerable populations. Dairy products have been implicated in outbreaks of listeriosis worldwide. In Ethiopia, studies have identified Listeria spp. and L. monocytogenes in various dairy products, but the genetic diversity and phylogenetic relationships of these bacteria remain largely unknown in the low- and middle-income countries. Therefore, we conducted whole-genome sequencing on 15 L. monocytogenes and 55 L. innocua isolates obtained from different levels of the dairy supply chains across three regions in Ethiopia. Genomes were assembled and used for MLST genotyping and single nucleotide polymorphism (SNP) analysis to infer phylogenetic relationships. We identified a total of 3 L. monocytogenes (i.e., 2, 145, and 18) and 12 L. innocua (i.e., 1489, 1619, 603, 537, 1010, 3186, 492, 3007, 1087, 474, 1008, and 637) MLST sequence types among the studied isolates. Some of these sequence types showed region-specific occurrence, while others were broadly distributed across regions. Through high-quality SNP analysis, we found that among 13 L. monocytogenes identified as ST 2, 11 of them were highly similar with low genetic variation, differing by only 1 to 10 SNPs, suggesting potential selection in the dairy food supply chain. The L. innocua isolates also exhibited low intra-ST genetic variation with only 0-10 SNP differences, except for the ST 1619, which displayed a greater diversity.

Physicochemical and antioxidant characterization of commercially available honey sample from Addis Ababa market, Ethiopia.

High-quality and genuine honey is crucial to provide consumers with natural honey and prevent any potential health issues. This study aimed to examine the quality of commercial honey available in the Addis Ababa market. A total of 30 honey samples were randomly collected from eight sub-cities of Addis Ababa city. Both High-Performance Liquid Chromatography (HPLC) and UV-Vis spectroscopic methods were used to determine 12 physicochemical and three antioxidant activity parameters in the honey samples according to internationally recognized standards. The findings of this study showed that the hydroxymethylfurfural (HMF), free acidity, and ash content of all commercial honey samples conformed to honey standards. However, except for honey samples collected from processors (19.48 ± 0.4 %) and retail outlets (20.49 ± 0.13 %), all other commercial honey samples failed to meet the moisture content criteria (≤21 %). Proline levels in honey samples taken from the street (67.1 ± 0.52 mg/kg) were also found to be below the required standard. The commercial honey samples contained fructose, glucose, sucrose, and maltose within a range of 33.85 ± 0.65 to 48.61 ± 0.51 %, 33.07 ± 1.58 to 44.3 ± 0.82 %, 0.91 ± 0.05 to 6.23 ± 2.49 %, and 0.51 ± 0.14 to 2.4 ± 0.44 %, respectively. Furthermore, honey samples from market areas showed good Total Phenolic Content (TPC), Total Flavonoid Content (TFC), and antioxidant activity. Overall, the results revealed that all physicochemical parameters, except for proline, moisture, and sucrose content, complied with approved standards (Codex Alimentarius, European Union (EU), and Ethiopia Standard Agency (ESA). Accordingly, it is recommended that stakeholders receive regular training on how to manage honey quality issues and detect adulteration techniques to prevent contaminated honey from reaching the markets.

Application of Fourier transform infrared (FT-IR) spectroscopy and multivariate analysis for detection of adulteration in honey markets in Ethiopia.

Honey is a highly susceptible food item to adulteration in national and international trade. Spectrum screening by FTIR coupled with multivariate analysis was investigated as an alternate analytical technique for honey adulterations and authentication. This technique was evaluated using pure honey samples that were blended at a ratio of 0-50% with commonly known adulterant materials and honey samples that were readily available for purchase in the Addis Ababa markets channel. Holeta Bee Research's bee farm pure honey, which is authentic honey, is employed as the control in this experiment. In the region, 4000-400 cm-1, spectral data of honey samples and five adulterant materials were recorded. The combination of spectra measurement with multivariate analyses resulted in the visualization of honey grouping and classification based on their functional group. The bands at 1800-650 cm-1 spectral region were selected for successful discrimination of clusters. Based on spectral differences, cluster analysis (CA) is also capable of grouping and separating pure from contaminated honey. Principle component analysis was able to visualize the differentiation of deliberately adulterated honey and commercially available from authentic ones. According to the results of our investigation, using FTIR analysis methods along with multivariate statistical analysis of the data could be considered useful fingerprinting procedures for identifying samples of pure and adulterated honey.

Prevalence and associated risk factors for Salmonella enterica contamination of cow milk and cottage cheese in Ethiopia.

Animal sourced foods, such as dairy products, are common sources of Salmonella enterica, a foodborne pathogen of increasing global concern, particularly in developing countries. In Ethiopia, most data on the prevalence of Salmonella in dairy products is highly varied and limited to a specific region or district. Furthermore, there is no data available on the risk factors for Salmonella contamination of cow milk and cottage cheese in Ethiopia. This study was therefore conducted to determine the presence of Salmonella throughout the Ethiopian dairy value chain and to identify risk factors for contamination with Salmonella. The study was carried out in three regions of Ethiopia, including Oromia, Southern Nations, Nationalities and Peoples, and Amhara during a dry season. A total 912 samples were collected from milk producers, collectors, processors, and retailers. Samples were tested for Salmonella using the ISO 6579-1: 2008 method, followed by PCR confirmation. Concurrent with sample collection, a survey was administered to study participants to identify risk factors associated with Salmonella contamination. Salmonella contamination was highest in raw milk samples at the production (19.7%) and at milk collection (21.3%) levels. No significant difference in the prevalence of Salmonella contamination among regions was detected (p > 0.05). Regional differences were apparent for cottage cheese, with the highest prevalence being in Oromia (6.3%). Identified risk factors included the temperature of water used for cow udder washing, the practice of mixing milk lots, the type of milk container, use of refrigeration, and milk filtration. These identified factors can be leveraged to develop targeted intervention strategies aimed at reducing the prevalence of Salmonella in milk and cottage cheese in Ethiopia.

Prevalence of Campylobacter species and associated risk factors for contamination of dairy products collected in a dry season from major milk sheds in Ethiopia.

A cross-sectional study was conducted to investigate the prevalence and risk factors for contamination of Ethiopian dairy products with Campylobacter. A total of 912 dairy food samples were collected from establishments of 682 study participants that were interviewed. Samples were tested for Campylobacter by following the ISO 10272-1:2017 standard and PCR confirmation. Campylobacter was detected in 11% of tested food samples and all detected Campylobacter were C. jejuni. The highest prevalence of C. jejuni was found in raw milk (16%), followed by pasteurized milk (9%) and cottage cheese (2%) (P < 0.001). Using warm water and soap for cleaning cow udders and teats on farms reduced the likelihood of detecting Campylobacter in milk (AOR = 0.3, P = 0.023). Filtering milk with a cloth, using a plastic filter (AOR = 0.065, P = 0.005), and storing milk in an aluminum container (AOR = 0.23, P = 0.027) reduced the likelihood of detecting Campylobacter in milk at the collection facilities. In contrast, Campylobacter detection was significantly more likely in milk collected at collection centers with concrete floors (AOR = 5.2, P = 0.004). The odds of detecting Campylobacter in milk were 17 times greater (AOR = 17, P = 0.007) in milk processing facilities that did not calibrate a pasteurizer on an annual basis. Finally, having a separate refrigerator for milk storage reduced the odds of detecting Campylobacter in retail (AOR = 0.29, P = 0.021).

Review of the prevalence of foodborne pathogens in milk and dairy products in Ethiopia.

Food safety is a significant barrier to social and economic development throughout the world, particularly in developing countries. Here, we reviewed the prevalence of major bacterial foodborne pathogens (Salmonella spp., Listeria monocytogenes, Escherichia coli O157:H7 and Campylobacter spp.) in the rapidly growing Ethiopian dairy supply-chain. We identified 15, 9, 5 and 0 studies that had reported the prevalence of Salmonella spp., L. monocytogenes, E. coli O157:H7, and Campylobacter spp. in dairy foods, respectively. The studies reviewed reported a median prevalence of Salmonella, L. monocytogenes, and E. coli O157:H7 of 6, 9 and 10%, respectively, in raw cow milk in Ethiopia, indicating a concerning occurrence of bacterial foodborne pathogens in raw milk. Implementation of good hygiene and production practices and assessment of interventions targeting the reduction of contamination in the dairy supply chain is needed to inform coordinated efforts focused on improvement of dairy food safety in Ethiopia.