Yogurt cultures...

[Externet]

Yogurt is supposed to be beneficial to digestive tract, contributing with live cultures.

 

Does frozen yogurt contain live, dead or ´suspended animation´ cultures that become alive/active when warmed by ingestion ?

[fiveworlds]

Hey, what a good question. What happens to the bacteria depends on the rate at which you freeze the yoghurt. Slow freezing causes large ice crystals to form which will break the bacteria cell walls and make the whole product not taste very nice. Most foods are destroyed by slow freezing which is why you shouldn't refreeze food in a normal freezer. In order to preserve the bacteria cell walls factories cool their products using liquid nitrogen which causes small ice crystals to form. This idea can be easily shown with shop bought ice cream if left to defrost and refrozen it tastes horrible..

[Manticore]

Yogurt is supposed to be beneficial to digestive tract, contributing with live cultures.

 

Does frozen yogurt contain live, dead or ´suspended animation´ cultures that become alive/active when warmed by ingestion ?

Fresh yoghurt only.

[John Cuthber]

Freezing doesn't reliably kill bacteria so there might still be some.

Itt's not, in principle, a difficult experiment to do if you can get sterilised milk.

[StringJunky]

Yogurt is supposed to be beneficial to digestive tract, contributing with live cultures.

 

Does frozen yogurt contain live, dead or ´suspended animation´ cultures that become alive/active when warmed by ingestion ?

Probably all three states are there but the figure I've seen is 90-99% killed. Danone, who make probiotics don't guarantee their product if frozen,

[CharonY]

Note that in many cases the cell count in yoghurt is far lower than used in studies showing benefits or probiotics. I.e. it is not clear whether the number of bacteria surviving the passage have a net benefit. However, freezing will further reduce the number (as well as storing it at room temperature, for that matter).

[StringJunky]

Note that in many cases the cell count in yoghurt is far lower than used in studies showing benefits or probiotics. I.e. it is not clear whether the number of bacteria surviving the passage have a net benefit. However, freezing will further reduce the number (as well as storing it at room temperature, for that matter).

After reading about the low commensal-type bacteria survival through the gut via the stomach, I figured it makes more sense to provide the nutrients to the existing population unless there is an actual serious deficit of bacteria, say, from using antibiotics. I use galacto-oligosaccharides in the form of arabic gum. This nutrient is more slowly metabolised, producing gas at a slower rate. My initiative for this exercise was having an adenomatous polyp which may have been caused by my lousy diet.

 

I read that using glycerol in the media helps labs store bacterial samples down to -80^oC.

Edited May 2, 2017 by StringJunky

[geordief]

After reading about the low commensal-type bacteria survival through the gut via the stomach, I figured it makes more sense to provide the nutrients to the existing population unless there is an actual serious deficit of bacteria, say, from using antibiotics. I use galacto-oligosaccharides in the form of arabic gum. This nutrient is more slowly metabolised, producing gas at a slower rate. My initiative for this exercise was having an adenomatous polyp which may have been caused by my lousy diet.

 

 

Is that a kind of prebiotic?

 

I heard there were a few foods that were prebiotics.Artichokes,from memory for example.

[CharonY]

 

I read that using glycerol in the media helps labs store bacterial samples down to -80^oC.

 

Yes, that is standard procedure to create freezer cultures.

[StringJunky]

Is that a kind of prebiotic?

 

I heard there were a few foods that were prebiotics.Artichokes,from memory for example.

Yes, it is a prebiotic. Resistant starch is another form.. Artichokes, some cereals and some veg have fructo-oligosaccharides (FOS) which are famous for gas production; it is more rapidly metabolised by gut bacteria. Live yoghurt is both prebiotic and probiotic. i chose arabic gum because it typically has 85% of the GOS in it and produces less gas to the point, after a few weeks, that I don't notice. It also seems to have specificity for increasing Lactobacillus and Bifidobacteria without also significantly increasing the pathogen population.

Edited May 2, 2017 by StringJunky

[John Cuthber]

Probably all three states are there but the figure I've seen is 90-99% killed. Danone, who make probiotics don't guarantee their product if frozen,

What do they "guarantee" about it anyway?

[StringJunky]

What do they "guarantee" about it anyway?

Probably that it contains a minimum number of live bacteria per unit.