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> Ice cream, as a food that is very close to neutral in pH and without much in the way of preservatives, is a common source of listeria bacteria. How come the
by seanwilson 6y ago
> Ice cream, as a food that is very close to neutral in pH and without much in the way of preservatives, is a common source of listeria bacteria.
How come the the high amount of sugar in ice cream doesn't help?
Would it be any different if it was a non-dairy milk like soy?
- rlonstein 6y agoSugar itself is food. It's the fact that sugar draws water out of the medium that it retards some kinds of bacterial growth (not botulinum for example).
- theobeers 6y agoThat effect kicks in at higher sugar concentrations, e.g. a 2:1 sugar:water simple syrup, which can have some shelf stability. I don’t think soft-serve mix would be even close. You need for there to be little enough water in the solution that cells with permeable membranes will be desiccated through osmosis. This can be seen in a common household science experiment, where you remove the outer shell of an egg by leaving it in vinegar for a while, then submerge it in corn syrup to watch its further transformation.
- skykooler 6y agoSugar is pH-neutral, and is not itself a preservative (it's pretty much the opposite).