Predication of Shelf Stability of Beef Muscles Slaughtered in Addis Ababa Slaughter Houses
No Thumbnail Available
Date
2014-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
The 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 evaluation
Description
Keywords
Shelf life, predictive model Beef muscle, spoilage bacteria, Sensory evaluation