Seeds of Sinapis alba is commonly known as white or yellow mustard and it is a most common species used in food. Moreover; it is used in produce medicine, pickles, source of edible oil since ancient times, seasoning of meats and chicken. The present study was undertaken to determine chemical components of mustard powder, and used in grilled beef as a seasoning to improve sensory and physical properties, as well as inhibiting Escherichia coli, Staphylococcus aureus and increase shelf life of meat. Mustard powder contained higher amounts of both protein 36.69%, and oil 40.64%.Oil of mustard seed contained high amount of erucic acid 51.3%, and the major dominant unsaturated fatty acids were, oleic acid followed by linoleic and linolenic acids. Sensory evaluation of the grilled meat slices showed high significant effect, especially in odor, in the acceptability of meat treated with 2.0% mustard powder. The addition of 1.5 or 2.0% of mustard powder to fresh meat reduced the natural flora to undetectable levels at 4 or 30 °C till 2days from storage. At 1.5, 2.0% of mustard powder was able to reduce E.coli number to uncountable levels at zero time and till 3 days at 4°C .The same effect was scored by mustard powder 2.0% against Staph. aureus, and it improved the physical properties of meat at 4°C  during  6 days of storage time. The study recommended that mustard powder at 2% is considered, antibacterial, anti- microflora, natural preservative spices in food. Also it improves taste, odor and physical properties of meat and increase shelf life of meat. Further study in this area may be helpful for finding of new principle compound.