Abdisa, Melese (PhD)Bekele, Tilahun (PhD)Seid, Faeza2022-03-312023-11-092022-03-312023-11-092014-05http://10.90.10.223:4000/handle/123456789/31048The objective of the present study was the development of predictive shelf life model for beef muscle based on the growth of specific spoilage organism (SSG) as affected by temperature and pH. Beef muscle was sto,red at four isothermal temperatures (2, 5, 8 and 11 oC) and th e samples were investigated within two days interval for total of fourte en days to quantify the influence of temperature and pH on shelf life. The Micrabial analysis made for the spoilage microorganisms (total viable count, E..coli and Pseudomonas) which are dominantly found on muscle meat parallel to sensory evaluation and pH determination. The collected growth data were converted into log base and have been used as a basis for the development of shelflife model. The result of the present study showed that the growth of the spoilage bacteria were in creased with time and the most rapidly growing bacteria was found to be Pseudomonas with the highest growth rate (O.OlB23 to O.lE33 10g{CFUjml) h·j ) followed by total viable count (O.0097 to O.1 79 10g{CFUjml) h") while E.coli ((W093 toO.169 10g{CFUjml) h") grow slowly. Pseudomonas bacteria also significantly correlated with sensory attributes (p<O.05) indicated that it was the specific spoilage organism (SSG) of beef muscle during aerobic storage. Predictive silelf life model was established based on its growth." Th e shelf life was estimated at the time at which the sensory score reached the value of 3 point which is considered to be the rejection point. The number of bacterial count at the end of shelf life was estimated using the primary growth model and setting time equal to shelf liJe. With this method the samples stored at 2, 5 and 8 °C were found to retain their sensory qualities until the experimental time (192, 165.5, 144 hours respectively) while the sample stored at l1 0C retained these qualities for only 7'!,75hours). The Gompartez equation predict the growth of Pseudomonas bacteria and the R2 value was greater than 0.95 and MSE. was between (0.026-0.23). Key words ShelfJ'ife, predictive model Beef muscle, spoi lage bacteria, Sensory evaluationenShelf lifepredictive model Beef musclespoilage bacteriaSensory evaluationThesis