Seasonal variation of Salmonella enterica prevalence in milk and cottage cheese along the dairy value chain in three regions of Ethiopia.

Seasonal fluctuations influence foodborne illness transmission and affect patterns of microbial contamination of food. Previous investigations on the seasonality of Salmonella enterica prevalence in dairy products in Ethiopia have been minimal. However, such data are needed to inform strategic development of effective interventions to improve food safety, as seasonal differences may affect intervention strategies. This study was conducted to identify differences in the prevalence of Salmonella in milk and cheese samples between wet and dry seasons. A longitudinal study design was utilized with a random sampling occurring during both dry and wet seasons. A total of 448 milk and cottage cheese samples were collected from Oromia, Sidama, and Amhara regions. Samples were tested for Salmonella using the ISO 6579-1: 2008 method, followed by PCR confirmation. A chi-square test was conducted to assess the significance of differences in the prevalence of Salmonella in the samples between the two seasons. Results from this study showed a higher prevalence of Salmonella in all sample types during the dry season (P < 0.05). Moreover, when comparing raw milk, pasteurized milk, and cottage cheese samples, a significant difference was observed in Salmonella prevalence from raw milk samples (27.08%) collected in the Oromia region. Additionally, data showed a significantly higher prevalence of Salmonella in samples collected from raw milk producers (29.17%) during the wet season (P < 0.05). This study indicates that in order to enhance the safety of dairy products in Ethiopia, comprehensive, long-term awareness building on hygienic milk production and handling that consider seasonal influence is warranted. Supplementary Information: The online version contains supplementary material available at 10.1186/s40550-024-00108-4.

Improvement of Raw and Pasteurized Milk Quality through the Use of Lactoperoxidase Systems (LPSs) along the Dairy Value Chain, under Real Conditions in Ethiopia.

Lactoperoxidase systems (LPSs) can enhance the microbiological quality of raw milk when there is lack of cooling facilities. In this study, a total of 250 milk samples were collected from farmers, collectors, and factories. Experimental samples were both LPS-activated morning and overnight milk. The samples were tested with several chemical and microbiological tests, such as total bacterial count (TBC), total coliform count (TCC), and Escherichia coli count (EC). Results indicated that all LPS-activated milk samples had a higher quality than all the control samples. For instance, both the morning and overnight farm milk samples had mean TBCs of 5.79 log and 6.55 log cfu/mL, which is significantly (p < 0.05) lower than the control samples' mean TBC of 6.73 log and 7.31 log cfu/mL, respectively. When this was compared with the Ethiopian Standard, 51.4% of morning and 39.5% of overnight farm milk with LPS activation met the acceptable quality, while only 28% of morning and 15.7% of overnight control milk met the standard. Moreover, LPS activation has also significantly improved the shelf life of collectors' raw milk and pasteurized milk at the factories. Therefore, a better hygienic practice with LPS application can be practiced in conditions that lack cooling infrastructure and electricity.

Level of aflatoxins in dairy feeds, poultry feeds, and feed ingredients produced by feed factories in Addis Ababa, Ethiopia.

Aflatoxins are one of the major factors that affect the quality and safety of feeds. They can be transferred into livestock through contaminated feed and then onto humans via animal sources of food such as milk, meat, and eggs. The objective of this study was to detect and quantify the level of aflatoxins (B1, B2, G1, G2, and total aflatoxin) in dairy feeds, poultry (layer and broiler) feeds, and feed ingredients produced in Addis Ababa. A total of 42 feeds and feed ingredients consisting of dairy feeds (n = 5), poultry broiler feeds (n = 6), layer feeds (n = 6), and feed ingredients (n = 25) were collected from feed factories in the city and analyzed in fresh weigh basis. The aflatoxins were analyzed using high-performance liquid chromatography after clean-up with immunoaffinity columns. Aflatoxin B1 levels in feeds ranged from 51.66 to 370.51 µg/kg in dairy cattle feed, from 1.45 to 139.51 µg/kg in poultry layer feed, and from 16.49 to 148.86 µg/kg in broiler feed. Aflatoxin B1 levels in maize ranged from 2.64 to 46.74 µg/kg and in Niger seed cake from 110.93 to 438.86 µg/kg. Aflatoxin B1 levels in wheat bran, wheat middling, and soybean were below 5 µg/kg. 100% of dairy feeds, 67% of poultry layer, 67% of broiler feeds, and 24% of ingredients contained aflatoxin in levels higher than the maximum tolerable limit set by the US Food and Drug Administration and Ethiopian Standard Agency. This shows the need for strong regulatory monitoring and better feed management practices to prevent consumers of animal-source foods from significant health impacts associated with aflatoxins.

Influence of nitrogen fertilizer rate and variety on tef [Eragrostis tef (Zucc.) Trotter] nutritional composition and sensory quality of a staple bread (Injera).

In Ethiopia, tef is one of the major staple crops used as a basic raw material for food development such as stable bread called injera. Studies reported that imbalanced N fertilizer reduces the overall deliciousness of grains. Nowadays nitrogenous fertilizers are considered as the source of variation for the quality of injera, Ethiopian traditional flat bread. Therefore, a field experiment was conducted to assess the effects of N fertilizer rates (0, 30, 60, 90, and 120 kg N ha-1) on grain nutrition and sensory quality of injera of three tef varieties of (Kora, Boset, and Asgori). The experiment was conducted in main cropping season in Randomized Complete Block Design with three replications and Di-ammonium Phosphate was used in the same dose. Crop attribute parameters were determined using standard methods. Sensory quality and color of injera were determined by panelists and injera eye software respectively. Results showed that only protein content increased with nitrogen rates, while carbohydrate decreased significantly at (P < 0.05). Kora at the control plot (K0) had better color, flavor, texture, and taste values of injera, but they decreased with nitrogen rates. Injera from white tef varieties had a better acceptance as compared with Asgori red tef variety. Injera eye software indicated that the color of injera was significantly affected by varieties. Kora had a higher (55.74) lightness value followed by Boset (54.71), and Asgori (51.26). Injera from the Asgori variety had a maximum red color. Kora and Boset had higher yellow color on the control plot, but for Asgori it increased with the nitrogen rate.

Seasonal Comparison of Microbial Hygiene Indicators in Raw and Pasteurized Milk and Cottage Cheese Collected across Dairy Value Chain in Three Regions of Ethiopia.

A longitudinal design with a simple random sampling method was used to collect and compare microbial hygiene levels between the dry season (January to April) and wet season (June to August). A total of 456 milk and cottage cheese samples were collected from each site along the dairy value chain from three regions. Enumeration of total aerobic mesophilic bacteria (APC), total coliforms (TCC), and Escherichia coli (EC) was performed according to standard methods. Independent t-tests were employed to assess the significant variation at (p < 0.05) between the two seasons. The cumulative result of APC of 7.61 log cfu/mL and g and TCC of 3.50 log cfu/mL in the dry season were significantly higher than the wet season of 7.15 log cfu/mL and 2.49 log cfu/mL, respectively, whereas generic E. coli count (EC) was significantly higher in the wet season (0.70 log cfu/mL and g) than that in the dry season (0.40 log cfu/mL and g). The results of hygienic indicator microbial load significantly varied with season. Hence, hygienic milk production and handling practices that comprehend seasonal influence should be implemented to improve the safety of milk.

Effect of enset (Ensete ventricosum) varieties and fermentation time on nutritional compositions, antinutritional factors, functional properties, and sensory acceptance of Bulla.

The effect of enset varieties and fermentation time on the nutritional composition, antinutritional content, functional properties, and sensory acceptance of bulla was assessed. Bulla samples were prepared from newly improved enset varieties yanbule, gewada, zereta, and messina and were fermented for 0, 15, and 30 days. The result revealed that bulla prepared from gewada had relatively better values of fat (0.3 g/100 g), fiber (1.04 g/100 g), carbohydrate (97.7 g/100 g), energy (394.2 Kcal), and Fe (2.54 mg/100 g). Yanbule had relatively higher ash content (1.05 g/100 g) and considerably higher Ca (317.9 mg/100 g) than bulla prepared from the other varieties. Mg (56.8 mg/100 g) and Zn (2.3 mg/100 g) were relatively higher in bulla prepared from Messina. A very low level of tannin was detected only for gewada, but high contents of phytate up to 112.5 mg/100 g were obtained. With respect to the functional properties of bulla fermented for 30 days, no significant differences were observed among the varieties except for water absorption capacity. In terms of sensory quality, bulla porridge prepared from yanbule had comparatively higher overall acceptability score (7.6).

Nutritional quality and adulterants of cow raw milk, pasteurized and cottage cheese collected along value chain from three regions of Ethiopia.

Milk is a nutritionally rich food for humans. However, fulfilling the quality of milk is a major concern for milk factories, nutrient requirements, and public health. The objective of this research was to assess the composition of raw and pasteurized milk and cheese, evaluate change in milk and cheese composition along the value chain, and identify adulteration of milk. A total of 160 composite samples were determined using lactoscan and conventional approved methods along value chain. Results indicate that there were significant (p < 0.05) changes of in milk composition along the value chain in the study regions. The range values were; total solid (8.41-11.7%), protein (2.25-3.06%), fat (2.16-3.17%), lactose (3.33-4.76%), ash (0.52-0.73%), P (62.7-84.2 mg/100 g) and Ca (78.2-109 mg/100 g) of liquid milk were obtained in all regions. Liquid milk was found to be adulterated by water along the value chains in all regions (ranged from 0 to 24.8%). Formalin (4 samples) and starch (1 sample) were detected at farmer's and collectors' respectively. In all regions, there was no significant (p > 0.05) difference in cheese nutritional quality between farmers and retailers. The grand mean for moisture, protein, fat, total ash, Ca, P and pH values were 77.1%, 17.1%, 1.42%, 1.18%, 37.8 mg/100 g, 88.2 mg/100 g and 3.7 respectively. Comparison of liquid products with the Compulsory Ethiopian Standard (CES) indicates that 80.2% for fat, protein, and SNF in raw and pasteurized milk were below the CES. In conclusion, liquid milk had poor nutritional composition and varied along the value chain in the study regions. Moreover, there is milk fraud where all dairy value chain add water into milk and milk consumers are consuming lower nutrients and paying for substandard liquid milk. Therefore, training should be provided to all value chain to improve the quality of milk products and quantification of formalin and other adulterants need to be further studied.

Exposure and Health Risk Assessment of Aflatoxin M1 in Raw Milk and Cottage Cheese in Adults in Ethiopia.

Aflatoxin M1 (milk toxin) found in milk is formed from the hepatic biotransformation of AFB1 (aflatoxin B1) and poses a risk to human health when consumed. The risk assessment of AFM1 exposure due to milk consumption is a valuable way to assess health risk. The objective of the present work was to determine an exposure and risk assessment of AFM1 in raw milk and cheese, and it is the first of its kind in Ethiopia. Determination of AFM1 was conducted using an enzyme-linked immunosorbent assay (ELISA). The results indicated that AFM1 was positive in all samples of milk products. The risk assessment was determined using margin of exposure (MOE), estimated daily intake (EDI), hazard index (HI), and cancer risk. The mean EDIs for raw milk and cheese consumers were 0.70 and 0.16 ng/kg bw/day, respectively. Our results showed that almost all mean MOE values were <10,000, which suggests a potential health issue. The mean HI values obtained were 3.50 and 0.79 for raw milk and cheese consumers, respectively, which indicates adverse health effects for large consumers of raw milk. For milk and cheese consumers, the mean cancer risk was 1.29 × 10-6 and 2.9 × 10-6 cases/100,000 person/year, respectively, which indicates a low risk for cancer. Therefore, a risk assessment of AFM1 in children should be investigated further as they consume more milk than adults.

Aflatoxin M1 in Raw Milk, Pasteurized Milk and Cottage Cheese Collected along Value Chain Actors from Three Regions of Ethiopia.

Milk is a highly nutritious and perfect natural food for humans. However, when lactating animals feed on Aflatoxin B1 (AFB1)-containing feed, the hydroxyl metabolite aflatoxin M1 (AFM1) contaminates the milk and dairy products. The objective of the current study was to assess the level of AFM1 in raw milk, normally pasteurized milk and Ethiopian cottage cheese collected from value chain actors (producers, collectors, processors and retailers). Cross-sectional study and simple random techniques were used to collect primary samples. A total of 160 composite samples was collected; raw milk (n = 64), pasteurized milk (n = 64) and cheese (n = 32) was analyzed. Quantitative analysis of AFM1 was conducted using enzyme-linked immunosorbent assay (ELISA). The results indicate that AFM1 was detected in all milk products. Results along value chains show that the concentration of AFM1 in raw milk from collectors was significantly higher than from producers, and in pasteurized milk from processors and retailers (p < 0.05). However, no significant (p > 0.05) difference was observed in cottage cheese value-chain actors in all regions. Comparison of AFM1 mean values among all dairy products shows that raw milk had a significantly higher concentration of AFM1 followed by pasteurized milk and cottage cheese. However, there was no significant difference between raw and pasteurized milk (p > 0.05). The mean AFM1 contamination in milk products ranged from 0.137 to 0.319 µg/L (mean value 0.285 µg/L). The contamination percentages of AFM1 in raw milk (62.50%), pasteurized milk (67.20%) and cottage cheese (25%) were above the regulatory limit set by the European Union (EU) (0.05 µg/L). According to USA/Ethiopian Standard (US/ES) (0.50 µg/L), 21.87%, 25% and 1% exceeded the regulatory limit for the above products, respectively. The overall prevalence (56.88%) was above the EU regulatory limit and 19.38% over US/ES regulations. Therefore, to provide accurate information about the health risk to consumers, there is a need to conduct risk assessment studies in consumers of milk and dairy products at different age groups.

Nutritional and alcoholic contents of cheka: A traditional fermented beverage in Southwestern Ethiopia.

Cheka is a cereal and vegetable-based beverage which is consumed in Southwestern parts of Ethiopia particularly in Dirashe and Konso. In this study, nine cheka samples were collected from vending houses in Konso and Dirashe districts for the laboratory analysis of the nutritional profile and chemical properties of cheka. The pH and titratable acidity of the samples ranged from 3.53-3.99 and 0.80%-1.11%, respectively. The total solids, crude protein, crude fat, crude fiber, total ash, carbohydrate, and gross energy contents of the samples ranged from 21.05%-26.87%, 3.12-4.44 g/100 g, 1.17-1.81 g/100 g, 0.94-1.27, 0.65-0.93 g/100 g, 14.16-19.03 g/100 g, and 82.04-107.17 Kcal, respectively. The dietary Ca, Fe, and Zn content of the samples were ranged from 8.31-19.60 mg/100 g, 13.94-27.59 mg/100 g and 0.82-1.07 mg/100 g, respectively. The methanol and ethanol contents of the cheka samples ranged from 163.1-2,380 ppm and 3.04%-8.96% v/v, respectively. The findings of this study indicated that cheka has low nutrient content and thus, suggests that people in Konso and Dirashe should not rely on it without eating solid foods as it is almost always diluted with a significant amount of water. In conclusion, the longer fermentation time of cheka resulted in high methanol levels that can present adverse health effects to consumers.

Total aflatoxins in complementary foods produced at community levels using locally available ingredients in Ethiopia.

This study was conducted to determine the occurrence and levels of total aflatoxins in complementary foods (CFs) and their ingredients. A total of 126 samples collected from 20 Districts from Amhara, Tigray, Oromia, and Southern Nations Nationalities and Peoples (SNNP) regions were analysed for levels of total aflatoxins using enzyme linked immunosorbent assay (ELISA). Aflatoxins were detected in 62 out of 66 pre-milling samples with mean range of 0.3-9.9 µg/kg. Aflatoxins were also detected in 19 out of 20 post-production CFs and in all of the one-month stored CFs at households and grain banks, with a mean range of 0.5-8.0, 3.6-11.3, and 0.2-12.4 µg/kg, respectively. Overall, 3 out of 126 samples exceeded the maximum limit (10 µg/kg). Although most aflatoxin levels were below the maximum limit and thus considered to be safe for consumption, more effort should be implemented to reduce contamination, as these CFs are intended for consumption by young children.

Vitamin A and zinc deficiencies among tuberculosis patients in Ethiopia.

BACKGROUND: The link between tuberculosis (TB) and malnutrition has long been recognized. Vitamin A and zinc deficiencies may reduce the host defenses and increase the risk for diseases. OBJECTIVE: The aim of the present study was to estimate the difference in vitamin A and zinc deficiencies together with dietary intakes among pulmonary TB patients and controls. MATERIALS AND METHODS: A case-control study design was employed to undertake this study in North Shewa, Ethiopia. Sputum smear examination, high-performance liquid chromatography (HPLC), flame atomic absorption spectrometry (FAAS), and enzyme-linked immunosorbent assay (ELISA) were used to analyse acid fast bacilli (AFB), vitamin A, zinc, and C-reactive protein (CRP), respectively. Dietary intake was assessed using a 24-h recall questionnaire. Mann-Whitney U test, Kruskal-Wallis test, Chi-square, odds ratio (OR), Spearman correlation, and multinomial logistic regression model were computed for data analyses. RESULTS: In this study, 62 TB cases and 59 controls were included. The proportions of vitamin A deficiency among TB cases and controls were 56.4% and 39.0%, respectively. All TB cases and 92.5% controls were zinc deficient. The odds of TB cases with deficiencies of vitamin A and zinc was 2.3 (95% CI: 1.1 to 4.8)times more likely as compared to the controls. More than 80% of all participants had below average fulfilment of energy and vitamin A intakes. CONCLUSION: Vitamin A and zinc deficiencies are severe problems among TB patients. Moreover, undernutrition determines the development of TB. Therefore, the management programs of TB need to address the problems of vitamin A and zinc deficiencies together with protein-energy malnutrition.

Assessment of aflatoxin exposure among young children in Ethiopia using urinary biomarkers.

The direct measurement of biomarkers of exposure in biological fluids such as urine has become important for assessing aflatoxin exposure in humans as it is the only tool that integrates exposures from various routes. For this reason, a study was conducted to assess aflatoxin exposure among young children in Ethiopia using urinary biomarkers. A cross-sectional study was conducted in ten Woredas (Districts) from Amhara and Tigray regional states of Ethiopia including 200 children (aged 1-4 years). A total of 200 urine samples were collected from 200 children and assessed for the levels of aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2) and aflatoxin M1 (AFM1) using a validated LC-MS/MS method. Aflatoxins were detected in 34/200 (17%) of the urine samples whereby four out of five analysed aflatoxins were detected. AFM1 was detected in 14/200 (7%) of the urine samples in a range of 0.06-0.07 ng/mL. AFB2, AFG2 and AFG1 were detected in respectively 9/200 (4.5%), 6/200 (3%) and 5/200 (2.5%) of the urine samples whereas AFB1 was not detected in any of the samples. In this study, there was no association between the different malnutrition categories (stunted, wasting and underweight) and aflatoxin exposure. However, the biomarker analysis showed a clear exposure of young children to aflatoxins. Therefore, awareness to the public is important to prevent potential health consequences of aflatoxins.

Effect of conventional milling on the nutritional value and antioxidant capacity of wheat types common in Ethiopia and a recovery attempt with bran supplementation in bread.

The effect of wheat flour refined milling on nutritional and antioxidant quality of hard and soft grown in Ethiopia was evaluated. Bread was prepared with the supplementation of the white wheat flour with different levels (0%, 10%, 20%, and 25%) of wheat bran. Whole (100% extraction) and white wheat (68% extraction) flours were analyzed for proximates, minerals, and antioxidants. Results indicated that at a low extraction rate (68%), the protein, fat, fiber, ash, iron, zinc, phosphorous, and antioxidant contents of the samples significantly (P < 0.05) decreased by milling. The TPC (total phenolic content) of the white wheat flours, which ranged from 3.34 to 3.49 mg GAE (gallic acid equivalent)/g, was significantly (P < 0.005) lower than those of the whole wheat flours, whose TPC ranged from 7.66 to 8.20 GAE/g). At 50 mg/mL, the DPPH (2-diphenyl-1-picrylhydrazyl) scavenging effect of the wheat extracts decreased in the order of soft whole, hard whole, soft white, and hard white wheat flour, which was 90.39, 89.89, 75.80, and 57.57%, respectively. Moreover, the proximate and mineral contents of the bran-supplemented breads increased significantly (P < 0.05) with the bran level of the bread, and the highest values (protein, 12.0 g/100 g; fat, 2.6 g/100 g; fiber, 2.5 g/100 g; ash, 3.3 g/100 g; iron, 4.8 mg/100 g and zinc, 2.33 mg/100 g) were found in 25% bran supplemented bread. The sensory evaluation of bread showed that all the supplementation levels had a mean score above 4 for all preferences on a 7- point hedonic scale. The results indicated that refined milling at 68% extraction significantly reduces the nutritional and antioxidant activity of the wheat flours. Bread of good nutritional and sensory qualities can be produced from 10% and 20% bran supplementations.