Food & Nutrition

Arab Journal of Food & Nutrition
84. Studying of the Evaluation of Shelf Life of Packaged Roast Beef and Some
Treatments for its Extension (2006)
Tamador S. Maayah\ University of Jordan
Supervisor: Dr. Basem Al – Abdullah
This study was carried out to investigate the effect of nitrite concentration, and
abused chilling temperature against proper chilling temperature on the chemical,
microbiological, sensory properties, and shelf life of roast beef stored at 4C and 12 C.
Four roast beef treatments were formulated. The first treatment was prepared by
adding 60ppm nitrite and stored at 12 C; the second treatment contained 120ppm
nitrite and stored at 12 C; the third treatment contained 180ppm nitrite and stored at
4 C and was used as a control.
Results showed that roast beef containing 260ppm nitrite and stored at 4 C had
the lowest thiobarbituric acid (TBA) value which was significantly different when
compared with the other treatments. Thiobarbituric acid (TBA) values of the roast beef
gradually increased during 25 days of storage with the highest TBA values in the
treatment containing in the 60ppm added nitrite, stored at 12 C.
It was shown that the lowest percentage of nitrite losses during storage were in
the samples having 260 ppm added nitrite to roast beef.
The aerobic plate count, Enterobacteriaceae, lactic acid bacteria (LAB), and
spore former count were increased throughout the storage period. The APC counts
remained within the acceptable limit throughout the storage period in the treatments
containing 260 and 180 ppm added nitrite were 3.05ˣ10 3 CFU/g and 2.3ˣ10 5 CFU/g
respectively, whereas the count exceeded the limits in the two other treatments.
With respect to sensory scores, no significant differences were detected between
the roast beef treatments.
All product sensory characteristics had negative correlation coefficients with all
studied factors (nitrite concentration, time, temperature of storage, TBA, and bacterial
counts).
The results emphasized the risk of abused temperatures and the importance of
keeping this product under efficient and consistent refrigeration during storage and the
use of high nitrite concentration to protect it and elongate its shelf life.
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Volume 11, No. 25, 2011
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