HW 7 micro

(T/F) When food supplies, such as beef and pork, are gamma irradiated to kill pathogenic organisms, the food becomes temporarily radioactive. There is no harm to humans because the effects have worn off by the time the meat reaches grocery store shelves

F

your friend tells you that she is lactose intolerant, but can eat yogurt without developing the cramps and bloating the other dairy products trigger. Why is this the case?

The bacteria in yogurt ferment almost all of the lactose to lactate

Johnny buys a package of fresh sliced ham from the deli and places it in his refrigerator. Unbeknownst to him, there are 10,000 E. coli cells on his ham. After three days under refrigeration, predict the number of E. coli cells that would be on his ham, using what you know about the effects of refrigeration on most microbes.

slightly more than 10,000

various chemicals are used to preserve food and prevent microbial spoilage. if you wanted to prevent Clostridium botulinum spore germination in your sausage meat, it would be best to use

sodium nitrate

at freezing temperatures, most bacteria

stop growing, but are not dead

Foods can be spoiled by both intrinsic and extrinsic factors. Extrinsic factors can include things such as ________.

storage temperature

above 100C (212F) most bacteria

are destroyed

With ideal environmental factors, the reproduction rate of many bacterial species is

extremely rapid

The major environmental factors that affect microorganism growth include chemical inhibitors, oxygen, pH, nutrients, moisture, and

temperature