Feeding dextrose

[PT Wick]

I have an option on fairly large, cost-effective quantities of beyond best-before date dextrose powder. So far, I have only used it as an icing sugar substitute as part of Varroa IPM. Probably be OK for sugar-roll counting mites as well. However, if appropriate for feeding, so much the better. I have been unable to find much assistance on-line. Does anyone have any experience of feeding dextrose as thin or thick syrup and/or in paper on the “wet sugar bag” principle?

 

[Finman]

. I wondered what heck sugar is that, but its another name is glucose.

Glucose makes crystals in the honey, and fructose is as liquid form.

The common sugar sacharose does not form crystals in the beehive.

.

 

[Beersmith]

I am not replying on beekeeping issues but as a brewer, I do know a little about sugars.

Dextrose is another name for Glucose. It is not exactly the same as Fructose. The basic chemical formula for both is C6H12O6, but the atoms are joined in a different configuration.

I suspect the expert beekeepers will suggest it is perfectly acceptable as a feed, but not on its own, due to problems with crystallization. Hopefully you will get some guidance on an acceptable mix and the correct proportions to combine with, say, ordinary sucrose.

 

[Finman]

.I use fructose in pollen patty, because it absorbs moisture from nest air.
I have no idea, how glucose takes water to itself during winter and does it matter.

 

[Walrus]

This research compared different feeds and glucose didn't come out well

http://academic.oup.com/jee/article-abstract/111/5/2003/5048229

 

[Beersmith]

This research compared different feeds and glucose didn't come out well

http://academic.oup.com/jee/article-abstract/111/5/2003/5048229

That is an excellent comment and strong evidence that the use of glucose as a single food source is a bad idea.

 

[PT Wick]

Thank you for the replies. Steve, the abstract of the paper was useful. If anyone has any other references, I’d be pleased to see them. Knowing scientific papers, they may have an entirely opposite result but that’s the way it goes. Beersmith: long time since my chemistry A-Level so things are a bit hazy but let me try. If the disaccharide sucrose is inverted to the two monosaccharides, dextrose (glucose) and fructose, do the latter two occur as a 1:1 ratio? If so, and the dextrose is free, my break-even point for cost is if I can obtain fructose at double the cost of sucrose. This 1:1 ratio is probably not the case e.g. unless the dry matter content of each powder is the same, which may well not be the case but for purposes of the argument, let us assume so. I see an advert for fructose powder on-line at £42/25kg bag plus £?? delivery. Local Poundstretcher sugar is £0.49/kg equivalent to £12.25/25kg. The bees have to invert the sucrose. A mix of dextrose and fructose avoids this requirement. I can get liquid Ambrosia at £1.20/kg equiv. £30/25kg. On the basis of the poor report of feeding dextrose and these figures I can’t see a use for the dextrose powder as feed. At least I can do many, many sugar dusting treatments before I run out!

 

[Curley]

If the disaccharide sucrose is inverted to the two monosaccharides, dextrose (glucose) and fructose, do the latter two occur as a 1:1 ratio?

This 1:1 ratio is probably not the case e.g. unless the dry matter content of each powder is the same, which may well not be the case but for purposes of the argument, let us assume so.

The bees have to invert the sucrose.

Inverting 1 molecule of Sucrose (with one molecule of water) gives one of glucose and one molecule of Fructose so yes the ratio is 1 to 1

Not sure what the relevance of dry matter is but fructose is slightly denser if that's what you mean

Bees inverting sucrose - not a problem at this time of year.