Psst... We're working on the next generation of Chowhound! View >
HOME > Chowhound > General Topics >
Dec 8, 2006 08:46 PM

For the chemists/biologists among us: Sugar in Canned Fruit?

If you rinse off fruit that was canned in heavy syrup, does that remove practically all of the syrup's sugar? It seems possible to me that a lot of sugar might be transported into the cells through osmosis, but I don't know if this actually happens or not.

  1. Click to Upload a photo (10 MB limit)
  1. You got it! Osmosis will pull sugar into the cells of the fruit. Rinsing just gets rid of the sugar on the surface. If you wanted to get rid of some of the sugar, you would have to soak the fruit in multiple changes of fresh water for quite some time. (And then you would have flavorless, waterlogged fruit)

    1. A simple rinsing of canned fruit would not remove all of the sugar added to the fruit by the syrup. A significant fraction would still remain in the fruit. Soaking the fruit in a large volume of water for a period of time should allow most of the additional sugar to move from the cells to the water, but you might also lose some of the "fruit flavors" in the process.

      1. Thanks for your (amazingly consistent) replies! It's all coming back to me... osmosis, homeostasis, etc. I was never into science, but my dad was an organic chemistry prof. Guess some of it rubbed off!

        1. To be the big nerd, this isn't a process of osmosis; it's diffusion. The membranes of the fruit cells are permeable to sugar so sugar moves across into the fruit cells. As was previously stated, you would need to provide an environment of lower concentration of sugar for the fruit cells, i.e. a water bath, so that there is a concentration gradient, an area of higher concentration next to an area of lower concentration. The sugar moves down the gradient from areas of higher concentration to areas of lower-- from the fruit cells to the water. However, as was also noted, some of the natural sugars would also move out into the water, leaving you with sugarless membranous fruit parts.