Well, I've been working on my Sanitization and Safety course (#5 of 6) and I'm really enjoying it so far. The following post may or may not appeal to some of you, but I need to talk it out, so you might as well come along for the ride :) I've come across a bit of a... how can I say...lack of understanding on a subject. Before I get to that, I'll review a few things I've learned (or re-learned from forgetting) that I'd like to share.
PHF (Potentially Hazardous Foods) are any foods that are capable of supporting the rapid growth of (infectious and toxic) bacteria. PHF's are foods high in protein or carbohydrates, have a pH above 4.6 and a water activity above 0.85. The requirements for said bacteria growth is from 6 conditions - FATTOM*.
Food (high in protein or carbohydrates)
Acidity (pH 4.6 to 7.0)
Time (4 hours)
Oxygen (though some can even survive without)
Moisture (water activity higher than 0.85)
What I'm having a problem understanding is bacteria and spores. It says all bacteria exist in a vegetative state, but the text defines vegetative state as, "the active state of a bacterium in which the cells take in nourishment, grows and produces waste". That, to me, defies "vegetative". If something is vegetative, it doesn't do anything, especially to which being active and producing waste. Mental block #1. Next fact; some bacteria have the ability to produce spores (which help bacteria survive in stressful environments), but spores are *not* active. They are though, resistant to stress and can be harmful if eaten (and can live for months on a subject). So I'm trying to wrap my head around inactive bacteria that's actually active and spores that are inactive but promote...activity. AARGH!!
*To help with understanding, in case it all seems Greek, examples of each are as follows...
Protein and carbs are self-explanatory, but if you need me to expand, tell me.
Acidity - pH ranges from 0-14, 7 being neutral (distilled water). Under 7 is acidic (i.e chicken, milk, soupls, pickles, mayo), over is alkaline (soda crackers, egg whites).
Temperature - foods should be held outside of above stated temps.
Time - 4 hours is a danger zone; food shouldn't be held in unstable temps longer than this, though some texts state even 2 hrs). We observe 1-1.5 hrs at the hospital.
Moisture - water activity (symbol: Aw) is rated from 0-1.0. 0.85-1.0: dairy, poultry, meats, shellfish, melons, steamed rice. 0-0.85: dry pasta, flour, uncut fruits and veggies, jams & jellies, frozen food.