A grand total of 1400 g fresh minced beef meat samples were divided into 7 equal groups (200 g of
each) and then irradiated. Aspergillus niger was inoculated into each group with infective dose 105
cfu/g. The used chemical preservatives natamycin (100, 200 and 300 ppm) and potassium sorbate (0.1%,
0.2% and 0.3%) were added. The inoculated samples were stored at 4oC in refrigerator till be used. The
inoculated groups were examined every 24 hrs for A. niger count and sensory examination (overall
acceptability). The experiment was performed in triplicate. Natamycin (100, 200 and 300 ppm)
decreased count of A. niger (log cfu/g) from 5.00 (initial load) to 2.83, 2.79 and 2.76 with reduction
percentages 43.40%, 44.20% and 44.80% on 8th, 8th and 10th days of storage, respectively. Potassium
sorbate (0.1%, 0.2% and 0.3%) decreased count of A. niger (log cfu/g) from 5.00 (initial load) to 3.02,
2.97 and 2.85 with reduction percentages 39.60%, 40.60% and 43.00% on 8th, 8th and 10th day of
storage, respectively. While, in control group A.niger count increased From 5.00 (initial load) to 5.56
on 6th day Furthermore, natamycin (300 ppm) treated minced meat samples artificially inoculated with
A. niger showed overall acceptability till 8th day of storage. In comparison, potassium sorbate (0.3%)
showed overall acceptability till 7th day. While, control group showed overall acceptability till 4th day.
Generally, natamycin (300 ppm) proved to be more efficient than potassium sorbate (0.3%) in
suppression of A. niger growth in minced meat. So, the use of natamycin (300 ppm), as it is safe
antifungal agent, is therefore recommended to improve safety of the meat products.