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| dc.contributor.author | Abebe Melese | |
| dc.date.accessioned | 2025-03-28T08:05:19Z | |
| dc.date.available | 2025-03-28T08:05:19Z | |
| dc.date.issued | 2024-03 | |
| dc.identifier.uri | http://ir.bdu.edu.et/handle/123456789/16684 | |
| dc.description.abstract | Milk preservatives can originate from a natural or synthetic source. Incorporation of synthetic source leads to undesirable effect to consumers. In addition, the tendency of consumers to use natural preservatives has greatly influenced the food industry. Among natural preservatives, honey bee propolis was effective in preservation of food. Therefore, the aim of this research was to evaluate the effectiveness of extracted honey bee propolis as a natural preservative for raw cow’s milk. The propolis was harvested from three agro ecologies of Awi zone namely Banja, Dangla and Chagni and extracted using 70 % ethanol. One hundred millilitres of raw cow’s milk samples collected from injibara university dairy farm were placed into five pre-sterilized sample bottles in each study districts and ethanol extracted honey bee propolis from three sources (Banja,Dangla and Chagni) prepared with a volume of T1 (control), T2 (5ml), T3 (10ml), T4 (15ml) and T5 (20ml) was added in to 100 ml of raw cow’s milk samples. All samples were analyzed for the physicochemical (protein, fat, ash, solid nonfat, pH, TA clot on boiling, alcohol, and methylene blue reduction test, microbiological (aerobic plate count (ABC), coliforms count (CC) and Yeast and mold counts (YMC), and organoleptic properties. The data was encoded and analyzed by using SAS version 9.4 software. The study shows the Fat, SNF, Ash, pH, TA and Protein content were significantly (p˂0.05) influenced by propolis concentration and agro-ecologies of propolis harvested. The interaction has shown a significant (p˂0.05) effect on protein and fat contents of raw cow’s milk. However, a nonsignificant (p>0.05) interaction effect on SNF,pH and TA contents of raw cow’s milk. In organoleptic test, both propolis concentration and agro-ecologies were a significantly (p˂0.05) affected all the sensory values of raw cows milk. However, interaction effects of propolis concentration and agro-ecologies of propolis collected significant (p˂0.05) only on color and flavor values of raw cow’s milk. Result revealed that significantly (p˂0.05) higher preference on sensory parameters of milk was recorded in milks treated with propolis concentration harvested from Banja than Dangla and Guangua woredas and lower preference in T4 and T5 concentration treated raw cow’s milk. Agro ecologies and propolis concentration had highly significant (P < 0.001) effect on the main and significance (P < 0.05) interaction effect on clot on boiling, alcohol and methylene blue reduction tests of raw cow’s milk. The shortest coagulation time (2 hour) was recorded in control group. However, the highest coagulation time was recorded in BT5 9 hour in clot on boiling, 9:50 hour/minutes in alcohol test, DT5 10 hour both in clot on boiling and alcohol test and in GT5 12 hour both in clot on boiling and alcohol test and in MBRTs in GT5 (12 hour), DT5 (10.50 hour/mitutes) and BT5 (9 hour). In microbial test, agro ecologies of propolis harvested and propolis concentration had a highly significant (P < 0.001) effect on ABC, CF and YM counts of sample raw cow’s milk. In the main effects of agro-ecologies propolis harvested, a significant lower ABCs,TCFs and YMCs values were registered in Guangu woredas and the highest was recorded in Banja and Dangla woreds in decreasing order. Regarding, propolis concentration, the microbial counts significantly (P<0.05) decreased with the addition of higher concentrations of ethanol extracted propolis. Finally, it can be concluded that the use of 5ml and 10ml extracted honey bee propolis concentration harvested from Guangua Woredas (lowland) extends the shelf life of raw milk for 8–9 hours under ambient temperatures without affecting organoleptic/sensory characteristics. | en_US |
| dc.language.iso | en | en_US |
| dc.subject | Animal Production | en_US |
| dc.title | Evaluation of Extracted Honey Bee Propolis as a Natural Preservative of Raw Cow’s Milk in Awi Zone, Ethiopia | en_US |
| dc.type | Thesis | en_US |
