Abstract
The aim of this research was to study the use of different concentrations (2, 4 and 6% w/w) of methanolic extract of mulberry leaves (Morus spp.) to increase the shelf life of minced beef. Treated samples were compared with the control and gamma irradiated sample at dose level of 5 kGy during cold storage at (4 +/- 1 degrees C) for 24 days. Microbiological, chemical and sensory characteristics of treated minced beef were determined every 2 days during the cold storage. Obtained results showed that minced beef treated with different concentrations of mulberry leaves methanolic extract reduced the initial total bacterial count, psychrophilic bacteria, enterobacteriaceae and total mold & yeast as well as prolonged the shelf-life of minced beef compared to the control. Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis and Escherichia coli counts were reduced. The mulberry leaves methanolic extract caused slight increase in the thiobarbituric acid reactive substances and total volatile nitrogen contents of minced beef during the cold storage. Sensory results showed that the shelf life of minced beef was 6 days for the control, and 8, 10, and 14 days for minced samples treated with mulberry leaves methanolic extract (2, 4 and 6%) respectively compared to gamma irradiated (22 days).