[bobbyshmurda]

Fruit juice is essentially: water, sugar, vitamins/minerals?

When it is fermented, yeast bacteria eat the sugar and turn it into alcohol.

Is this the only thing that happens to its composition? So would the composition of the new beverage be: water, ethanol, vitamins/minerals (same exact vitamins)?

Does the yeast completely turn all the sugar into alcohol (or 99% of it)?

[kriggy]

Does the yeast completely turn all the sugar into alcohol (or 99% of it)?

No the bacteria which does that dies when the concentration of ethanol is somewhere around 15-20%. Im not sure on this number.

[Arkcon]

Is this the only thing that happens to its composition? So would the composition of the new beverage be: water, ethanol, vitamins/minerals (same exact vitamins)?

No, the yeast needs other nutrients to grow, and it will metabolize some of the vitamins, perhaps all of them.  The yeast will also use the minerals, and those will be gone too, if the yeast are filtered away.

[Borek]

yeast bacteria

No such thing. Yeast are fungi.

So would the composition of the new beverage be: water, ethanol, vitamins/minerals (same exact vitamins)?

Yeast may consume some of the vitamins present but it produces some vitamins of B group on its own, so the re is a definite change in the vitamins composition.

Does the yeast completely turn all the sugar into alcohol (or 99% of it)?

Yeast (depending on the exact variety) can survive ethanol concentrations of up to 18-19%. Depending on the yeast variety and initial amount of sugar fermentation can turn most of the sugar into ethanol, or only part of it, if the ethanol concentration kills the yeast before all sugar is used.

[zsinger]

Borek took the words out my mouth.  Indeed, I learned that 20% EtOH was the cutoff for the yeast surviving their surroundings.  This is much more of a Microbiology question, but interesting no less .  Hope this helps.
          -Z

[bobbyshmurda]

Very helpful. Thank you everybody.

[bobbyshmurda]

What is the process for extracting sugar from fruit/vegetable juice?

My initial thought was to ferment the sugar into alcohol, which could then easily be evaporated out. But this would change the vitamin/mineral content too much.

I came across this: http://www.faqs.org/patents/app/20100068373 which vaguely describes a method that uses "sugar absorbing material."

Is it possible to remove sugar from juice without affecting the vitamin/mineral content too much? If not, what about from fruit pulp?

[bobbyshmurda]

Another question. When the yeast metabolize the vitamins/minerals, would they still be absorbed by the human body (if the yeast aren't filtered out)? Because no vitamins/minerals have disappeared, they have chemically changed. Will the human body still digest/absorb these new chemically changed substances and would they be as useful as the vitamins/minerals?

[Arkcon]

Yes, even if its not in a fermented, people do eat yeast as a nutrient source.  However, excessive consumption of yeast can give you the runs.

[Arkcon]

I have no idea what a "sugar absorbing material" actually is.  I've never heard of one.  And skimming a patent didn't help me.  Which is typical, a patent is meant to defend an invention, not to give one away.  This doesn't strike me as a trivial, D-I-Y, application.

[bobbyshmurda]

This doesn't strike me as a trivial, D-I-Y, application.

This is not necessarily a DIY home project. I'm just trying to figure out any methods that might exist, because I can't find any.

[billnotgatez]

@beefybij
just as a quick side question
What fruit juice do you have in mind?
or arbitrarily pick one you might use

[bobbyshmurda]

What fruit juice do you have in mind?

Experimenting with carrot juice right now. Made some carrot wine, doesn't taste too bad!

[billnotgatez]

I am combining your earlier thread with this one since they are related to your project


I merged
 Composition of Juice vs. Fermented Juice

[billnotgatez]

Made some carrot wine

I love it
But, carrot juice/wine can cause issues if you consume too much

So the closest list of carrot juice content I could easily find was here
http://ndb.nal.usda.gov/ndb/foods/show/3345

Value per 100 g
Water   g   88.87
Energy   kcal   40
Protein   g   0.95
Total lipid (fat)   g   0.15
Carbohydrate, by difference   g   9.28
Fiber, total dietary   g   0.8
Sugars, total   g   3.91
Minerals   
Calcium, Ca   mg   24
Iron, Fe   mg   0.46
Magnesium, Mg   mg   14
Phosphorus, P   mg   42
Potassium, K   mg   292
Sodium, Na   mg   66
Zinc, Zn   mg   0.18
Vitamins   
Vitamin C, total ascorbic acid   mg   8.5
Thiamin   mg   0.092
Riboflavin   mg   0.055
Niacin    mg   0.386
Vitamin B-6   mg   0.217
Folate, DFE   µg   4
Vitamin B-12   µg   0.00
Vitamin A, RAE   µg   956
Vitamin A, IU   IU   19124
Vitamin E (alpha-tocopherol)   mg   1.16
Vitamin D (D2 + D3)   µg   0.0
Vitamin D   IU   0
Vitamin K (phylloquinone)   µg   15.5
Lipids   
Fatty acids, total saturated   g   0.027
Fatty acids, total monounsaturated   g   0.007
Fatty acids, total polyunsaturated   g   0.071
Cholesterol   mg   0
 
Some of what I am saying here has been said before here
In the merged thread you suggested using fermentation to change the sugars to ethanol and potentially removing some of the sugars that way.
It was pointed out that the yeast will use other nutrients as well as the sugar.
Although you might leave the yeast in and get the benefits of the nutrients by ingesting them. Additionally, in many cases the yeast is limited in the amount of conversion because it dies off somewhere below 20 percent ethanol.
Maybe you can do the math to see if all the sugar will be used up by fermentation before the yeast die. Or, find out how much water you have to add to prevent yeast death.
I also am not sure all the different sugars could be metabolized by one type of yeast.
I assume your goal was to drive off the ethanol leaving a sugar free juice.

Since the fermentation process had some draw backs you now are asking for a substance or process to remove the sugar other than fermentation.

An attempt to attack and remove the sugar may also do the same to some of the nutrients and possibly any other carbohydrates in the juice. And, said process may also leave behind substances you do not want to ingest.
I know there is a patient application out there that claims to use a sugar absorbing material with a centrifuge process. Remember that many patients make claims based on theory.

I know there are processes to get pure sugar from sugar cane and sugar beets, but I bet they are destructive to the other things in the juice. There may even be crystallization methods, but again there are probably unwanted side products.

You might GOOGLE or WIKI sugar production from sugar beets to see what is done in industry.


Back to carrot juice -- too much is not good for you.