Post Packaging Concerns
You can tell if the vacuum packaged meat has been contaminated by noticing it’s color which should be dark purple. If there is a color difference, then don’t take any chances and use the product but not before discerning if it’s safe for cooking.
Bacterial action can still take place in an oxygen depleted atmosphere. So, it’s natural for certain vacuum sealed meat to give out a strong odor after being opened. However, this should subside within 20-30 minutes of the meat being exposed to outside air, but if this is not the case, then don’t take any chances and throw it right away.