True or false?

[sdj56]

I tried a very simple experiment. I threw some yeast into a gallon of cider and let it bubble for about a week.


Regarding the quality of the product,true or false: The methanol content would be low because the pasteurization of the cider reduced the activity of pectin methylesterase.

Thanks.

 

[armorshell]

This better not end up in your biochem homework, but the pasteurization only affects the enzymes in the juice, as soon as you add the yeast (Which have their own pectin methlyesterase, the one you're worried about) the pasteurization becomes a non-issue.

 

[sdj56]

This better not end up in your biochem homework, but the pasteurization only affects the enzymes in the juice, as soon as you add the yeast (Which have their own pectin methlyesterase, the one you're worried about) the pasteurization becomes a non-issue.

It's not for homework. I'm just concerned about the methanol levels of my creation.

 

[EvilTOJ]

There's methanol in every fermented beverage, there's no avoiding it. However, the only way to get dangerous levels of it is to distill it down or drink prodigious amounts of alcohol in one sitting.

 

[armorshell]

Or you could chug some copy toner.

 

[gratus fermentatio]

First off, I would hope there would be ZERO methanol in your cider, as it is a deadly poison. Methanol is commonly known as "wood alcohol." ETHANOL on the other hand, is the type of alcohol we enjoy in a cider, beer, wine, etc... So I'm thinking that the answer to your original question would be "False," as there should not be any methanol production at all. Regards, GF.

 

[borracho_brewer]

First off, I would hope there would be ZERO methanol in your cider, as it is a deadly poison. Methanol is commonly known as "wood alcohol." ETHANOL on the other hand, is the type of alcohol we enjoy in a cider, beer, wine, etc... So I'm thinking that the answer to your original question would be "False," as there should not be any methanol production at all. Regards, GF.

Actually EvilTOJ is correct, there is usually some level of methanol and other pretty nasty alcohols in fermented beverages, but, as stated, unless distilled it's not toxic, but the OP probably knows that.

I found this kind of interesting, it's about methanol levels in wines, and an experiment with concord grapes specifically.

AJEV -- Sign In Page

They used heat treated must, skins and no skins. The heat did seem to lower methanol levels, and fermentation on skins increased it (though for cider i don't supposed that matters)

The thing I noticed, is that they used 140 degree F heat for 30 minutes and from looking at this apple juice is pasteurized, generally, at higher temps for shorter periods, which makes me wonder:

Does this modern method of heat treatment have an equal/lesser/greater effect on the enzymes in question compared to the above experiment.

 

[Firstnten]

Actually EvilTOJ is correct, there is usually some level of methanol and other pretty nasty alcohols in fermented beverages, but, as stated, unless distilled it's not toxic, but the OP probably knows that.

I found this kind of interesting, it's about methanol levels in wines, and an experiment with concord grapes specifically.

AJEV -- Sign In Page

They used heat treated must, skins and no skins. The heat did seem to lower methanol levels, and fermentation on skins increased it (though for cider i don't supposed that matters)

The thing I noticed, is that they used 140 degree F heat for 30 minutes and from looking at this apple juice is pasteurized, generally, at higher temps for shorter periods, which makes me wonder:

Does this modern method of heat treatment have an equal/lesser/greater effect on the enzymes in question compared to the above experiment.

You have to be a member to get that art. And I did not have the patients to look through the "free sample" I did find some info which has peaked my interest.

Methanol in Wines and Musts: Source and Amounts -- Gnekow and Ough 27 (1): 1 -- American Journal of Enology and Viticulture

I'll look into PPM and the relationship between temp, ectolytic enzyme preparations etc.

although I'm not sure why you are interested in this info.

 

[Firstnten]

Actually EvilTOJ is correct, there is usually some level of methanol and other pretty nasty alcohols in fermented beverages, but, as stated, unless distilled it's not toxic, but the OP probably knows that.

I found this kind of interesting, it's about methanol levels in wines, and an experiment with concord grapes specifically.

AJEV -- Sign In Page



Does this modern method of heat treatment have an equal/lesser/greater effect on the enzymes in question compared to the above experiment.

On first glance it seems the (edit: Maceration not maturation) process is a greater factor not temp aside from adding chemcials, being that there is no real wine like Maceration process for cider that I have seen. As it's my understanding that whole parts of the apple skin stems etc are not in the must. But more specifically your question "Does this modern method of heat treatment have an equal/lesser/greater effect on the enzymes in question compared to the above experiment" from the information I have seen and I say BRIEFLY glanced at and using mescal as the testing material the answer to that would be no. "BUT" and here is a big "but" I do know that applejack has the potential to have a high methanol content what factors affect this I have no idea but when I have more time I will look into it.

 

[Magbwa]

I wouldn't be too concerened with methanol levels as they are bound to be dwarfed by the ethanol levels created by the yeast. The antidote for methanol poisoning is ethanol consuption which if I remember correctly is due to ethanol's increased affinity for alcohol dehydrogenase. Once ethanol is in the liver it binds up all the alcohol dehyrogenase which allows the methanol to pass through the body unmetabolized into toxic products.

 

[0202]

Methanol : 0
Ethanol: 1

 

[borracho_brewer]

Firstnten, I don't know what you mean about having to be a member? For what? What free sample? Patients? Who needs a doctor?

Also, you said no to a question that wasn't a yes or no:

What is the higher temp short time pasteurization's effect on the naturally occurring enzymes that are at least partly responsible for methanol production, compared to the lower temp longer time heating used in the experiment that I linked?

Secondly, I know that cider, especially when made from store bought filtered juice, is not fermented or resting on skins or stems, but the enzyme is still present, yes? (though at lower concentrations)

So, the question hasn't been answered.

It would seem to me that yes, heat treatment reduces the enzyme's activity. But, by how much, and what is the effect of different methods of heat treating?

Below is the FDA's recommendations on apple juice pasteurization, so, how is one to know how any given brand/batch of juice is treated?

If it is very high temp treated very quickly does that effect the enzyme as much as a lower, longer treatment?

"For apple juice at pH values of 4.0 or less, FDA recommends the following thermal processes to achieve a 5-log reduction for oocysts of Cryptosporidium parvum. Because this parasite is believed to be more heat resistant than E. coli O157:H7, these parameters will also control bacterial pathogens.

160 degrees F for at least 6 seconds
165 degrees F for at least 2.8 seconds,
170 degrees F for at least 1.3 seconds,
175 degrees F for at least 0.6 seconds, or
180 degrees F for at least 0.3 seconds

71.7 degrees C (161 degrees F) for 15 seconds (milk pasteurization) is also considered adequate."


Also, Apple Jack is going to have a higher methanol content because it has a lower water content, thus higher concentration for all alcohols. I don't think the fermenting/yeast action has anything to do with that.

From doing a little lurking on distillation forums it seems methanol is not really as dangerous at people often think. Though it does seem to make for a worse hangover.

 

[Firstnten]

Firstnten, I don't know what you mean about having to be a member? For what? What free sample? Patients? Who needs a doctor?

Also, you said no to a question that wasn't a yes or no:

What is the higher temp short time pasteurization's effect on the naturally occurring enzymes that are at least partly responsible for methanol production, compared to the lower temp longer time heating used in the experiment that I linked?

Secondly, I know that cider, especially when made from store bought filtered juice, is not fermented or resting on skins or stems, but the enzyme is still present, yes? (though at lower concentrations)

So, the question hasn't been answered.

It would seem to me that yes, heat treatment reduces the enzyme's activity. But, by how much, and what is the effect of different methods of heat treating?

Below is the FDA's recommendations on apple juice pasteurization, so, how is one to know how any given brand/batch of juice is treated?

If it is very high temp treated very quickly does that effect the enzyme as much as a lower, longer treatment?

"For apple juice at pH values of 4.0 or less, FDA recommends the following thermal processes to achieve a 5-log reduction for oocysts of Cryptosporidium parvum. Because this parasite is believed to be more heat resistant than E. coli O157:H7, these parameters will also control bacterial pathogens.

160 degrees F for at least 6 seconds
165 degrees F for at least 2.8 seconds,
170 degrees F for at least 1.3 seconds,
175 degrees F for at least 0.6 seconds, or
180 degrees F for at least 0.3 seconds

71.7 degrees C (161 degrees F) for 15 seconds (milk pasteurization) is also considered adequate."


Also, Apple Jack is going to have a higher methanol content because it has a lower water content, thus higher concentration for all alcohols. I don't think the fermenting/yeast action has anything to do with that.

From doing a little lurking on distillation forums it seems methanol is not really as dangerous at people often think. Though it does seem to make for a worse hangover.

I thought I gave you a link to the conclusion of an abstract that was a study done on a ratio of methanol from different temps of pasteurization in making mescal which I will see if I can find again. Which showed there was little to no difference.

The point with the applejack if apple jack which is essentially cider distilled down has the possibility of having lethal or at the very lest an amount of Methanol that can make you sick could mean that even without Maceration cider could contain more methanol.

 

[SegmentedMonkey]

When distilleries run their gear to make any spirits, methanol has a lower boiling point than ethanol, so will boil off before the desired product. Most will discard a certain amount of the initial product that comes out, to ensure lower methanol contents in the final spirit.

But as has been said, the amount that's in brewed beverages like wine, beer and cider is minute, and indeed, not dangerous. Ethanol is used as a treatment for methanol poisoning. In pop culture, this was done on an episode of House MD, when a prisoner attempted suicide by drinking copier fluid (mostly methanol), House helped him by sharing an entire bottle of scotch with the patient.

 

[Firstnten]

When distilleries run their gear to make any spirits, methanol has a lower boiling point than ethanol, so will boil off before the desired product. Most will discard a certain amount of the initial product that comes out, to ensure lower methanol contents in the final spirit.

But as has been said, the amount that's in brewed beverages like wine, beer and cider is minute, and indeed, not dangerous. Ethanol is used as a treatment for methanol poisoning. In pop culture, this was done on an episode of House MD, when a prisoner attempted suicide by drinking copier fluid (mostly methanol), House helped him by sharing an entire bottle of scotch with the patient.

was the initial question "was it dangerous in cider"? Because if it was it went right over my head. I thought the question was superfluous/curiosity. Basically is there a ratio between pasteurization temps and methanol.

I didn't know that ethanol was a remedy for methanol consumption.

 

[SegmentedMonkey]

was the initial question "was it dangerous in cider"? Because if it was it went right over my head. I thought the question was superfluous/curiosity. Basically is there a ratio between pasteurization temps and methanol.

I didn't know that ethanol was a remedy for methanol consumption.

I just went for a ramble, thats all. I do it a lot. I never know where the journey starts, just where it is.

Don't mind me.

To quote a doctor on the subject of treatment of methanol poisoning with ethanol:

I have included an answer provided by a madsci colleague regarding the
lethality of methanol after my own answer. The reason you can treat methanol
poisoning with ethanol is that ethanol acts as a competitive inhibitor.
Ethanol is a competing substrate and so it blocks the conversion of methanol
to its toxic products. Competitive inhibitors act by occupying the same site
in the enzyme that the substrate occupies thus preventing the substrate from
being acted upon by the enzyme. For a good discussion of enzymes and
inhibitors you can read:

Stryer:Biochemistry, read the chapter on Introduction to Enzymes.

hope this helps
gabriel vargas md/phd