most recent 30 from http://paleohacks.com 2013-05-21T23:47:46Z http://paleohacks.com/feeds/question/151785 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://paleohacks.com/questions/151785/geeky-science-frozen-probiotics-in-the-microwave Jake 2012-09-25T10:26:22Z 2012-10-06T05:32:18Z

<p>I'd brought along a bit of kefir today to mix into a salad dressing but it ended up frozen in the fridge. I nuked it in the microwave to get it back into liquid form. Still cold, but I know probiotics don't stand up to heating. If, however, they are brought from solid to liquid form and still cold, would the probiotics survive?</p> <p>And as a follow up - are frozen probiotics (fro yo, kefir, etc.) as potent as room temp or the fridge? </p>

http://paleohacks.com/questions/151785/geeky-science-frozen-probiotics-in-the-microwave/151835#151835 CD 2012-09-25T16:48:13Z 2012-09-25T16:48:13Z

<p>Yes, microwaving can kill bacteria. But it is the heat of the microwave, not the microwave's themselves that kill the bacteria. </p> <p>So most likely, the vast majority of probiotics were not harmed, although some likely were sacrificed, especially any occupying the surface.</p> <p>However, this sounds like a really cool science experiment. It would be easy to grow harmless bacteria, and then with a control (left on the counter), one in the freezer then microwave, one on the counter and microwave, compare the results. Try it out and post back your results.</p> <p>As for freezing probiotics. It is very likely that freezing greatly reduces the bacteria, but does not kill off all of it. This study (done by a student who needs to learn how to label his graphs and table better (but I digress...)) suggests that the traditional method of producing kefir is more resilient than commercial products to freezing. <a href="http://etd.lsu.edu/docs/available/etd-04252012-155457/unrestricted/obrien-thesis.pdf" rel="nofollow">http://etd.lsu.edu/docs/available/etd-04252012-155457/unrestricted/obrien-thesis.pdf</a></p>

http://paleohacks.com/questions/151785/geeky-science-frozen-probiotics-in-the-microwave/151840#151840 Timar 2012-09-25T17:41:04Z 2012-09-25T17:59:26Z

<p>I use to make my own yoghurt with probiotic cultures (a mixture of Lactobacillus acidophilus LA1 and Bifidobacterium animalis ssp. lactis BB12). From my experience, it doesn't make any difference whether I microwave the milk to ca. 40°C inoculation temperature before or after adding the freeze dried starter culture, so I conclude that the radiation from an ordinary microwave oven doesn't hurt probiotic bacteria unless due to the heat it generates.</p>

http://paleohacks.com/questions/151785/geeky-science-frozen-probiotics-in-the-microwave/151890#151890 Janknitz 2012-09-25T23:43:16Z 2012-09-25T23:43:16Z

<p>Freezing won't harm the probiotics but it will slow them down--kind of like a movie in slow motion. Heat can kill them, but whether or not the heat from the microwave was enough or not, I don't know. Microwaves "excite" the molecules, that's what generates the heat, so I would expect that some of the probiotics did get harmed, but probably not all. </p>