Mushrooms and mannitol

[sk1dar00]

I always thought mushrooms were a good option as they don't taste sweet, but now I read that they are very high in mannitol and am thus apprehensive of them... The NUTTAB tables and some research papers I got from Monash University both give the precise mannitol content per 100g and it seems relatively high at just under 3%..

• But is mannitol as bad as sorbitol?
  Does it breakdown into fructose like sorbitol and if not what does it break down into? Does anyone know?
  
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[glow=red,2,300]
Personal Backstory:[/glow]
I should add that I have only been tested for fructose malabsorption not HFI. However I joined this forum because I related to the way that people on here talk so much about hating the taste of sweet foods and have no desire to eat sugar - which is supposed to be ok for people with FM.

I have some lower GI problems too, but for me the main ones are that I get heartburn to varying degrees after eating and if I eat sweet tasting foods I feel like I've been poisoned. Its the weirdest and most horrible feeling like food poisoning except that I don't normally throw up, I just want to. ( Actually sometimes I do gag a bit)

This only started 10 years ago though. Before that I liked fruit and the sweet veg I now feel so repulsed by.

The only things I seem to be okish with are white pudding rice and meat, but I don't feel full enough after these and I think too much white rice would be bad for me too.

I'm just getting very frustrated trying to figure this all out.
Thanks for any help you can offer. I am also a member of boards for FM so will cross post this question there.

[charlie]

Have posted this on the FM board but folk may be interested to read here too.

I know Meg cannot tolerate mannitol. And she isn't a huge fan of mushrooms but that may just be a kid thing. I suppose unless you ate masses of mushrooms in a sitting you wouldn't be having a high dose of mannitol but it is a sugar alcohol which is on the no list for FM.

Anyway, this is off the wikipedia page about mannitol: (but bear in mind as Colormist has found it isn't always accurate):

Obtaining mannitol[edit] Industrial synthesisMannitol is commonly formed via the hydrogenation of fructose, which is formed from either starch or sugar. Although starch is cheaper than sucrose, the transformation of starch is much more complicated. Eventually, it yields a syrup containing about 42% fructose, 52% dextrose, and 6% maltose. Sucrose is simply hydrolyzed into an invert sugar syrup, which contains about 50% fructose. In both cases, the syrups are chromatographically purified to contain 90–95% fructose. The fructose is then hydrogenated over a nickel catalyst into mixture of isomers sorbitol and mannitol. Yield is typically 50%:50%, although slightly alkaline reaction conditions can slightly increase mannitol yields.[5]

[edit] Biological synthesesMannitol is one of the most abundant energy and carbon storage molecules in nature, produced by a plethora of organisms, including bacteria, yeasts, fungi, algae, lichens, and many plants.[6] Fermentation by microorganisms is a possible alternative to traditional industrial synthesis, producing much higher yields of mannitol, with minimal to no side products. A fructose to mannitol metabolic pathway, known as the mannitol cycle in fungi, has been discovered in a type of red algae (Caloglossa leprieurii), and it is highly possible that other microorganisms employ similar such pathways.[7] A class of lactic acid bacteria, labeled heterofermentive because of their multiple fermentation pathways, convert either three fructose molecules or two fructose and one glucose molecule into two mannitol molecules, and one molecule each of lactic acid, acetic acid, and carbon dioxide. Feedstock syrups containing medium to large concentrations of fructose (for example, cashew apple juice, containing 55% fructose: 45% glucose) can produce yields 200g mannitol/ liter feedstock. Further research is being conducted, studying ways to engineer even more efficient mannitol pathways in lactic acid bacteria, and also studying the use of other microorganism, such as yeast[6] and E. coli bacteria in mannitol productions. When food grade strains of any of the aforementioned microorganisms are used, the mannitol and the organism itself are directly applicable to food products, avoiding the need for careful separation of microorganism and mannitol crystals. Although this is a promising method, steps are needed to scale it up to industrially needed quantities.[7]

[ukbill]

sk1dar00 Welcome to the site and I hope you find useful information here

I would expect the 3% Mannitol would be on dry matter content.. been as mushrooms are about 90% water you would really have to go overboard on eating them to get any sort of a reaction.

3KG (7+ Lbs) = 3g Manitol.. if I got my maths right.??

No Idea if it is broken down in the gut like Sorbitol or not worth investigating though. good science both of you