Insoluble or Soluble? That is the question.January 17, 2011
I love carrots. Okay, I take that back. I like carrots, especially when they are dunked into a Laughing Cow Cheese wedge or swept through a bowl of spinach dip. Some people I know look at me and my carrots and poke fun. They are probably just jealous of my ability to eat these nutritional powerhouses on a regular basis, right? Or maybe I have turned orange and they are making the connection. Or maybe they are sad that the candy they are chowing down on has no fiber. Bummer.
Okay, so let’s talk fiber. Soluble? Insoluble? What? Obviously, soluble fiber dissolves in water and insoluble does not. Because of this, soluble and insoluble fibers both play certain roles in your digestive system and are important for your health. Okay? Lesson over. Nah, let’s get a little deeper….
Labeling a food for dietary fiber is required, so scientists came up with a number of ways to quantitatively determine the amount of fiber in a food. In order to determine the fiber in a food, all other components must be removed. Lipids (fats) easily dissolve in an organic solvent. Protein and minerals are removed through various techniques. Furthermore, the components may be dissolved in a chemical or undergo hydrolysis and enable one to filter the mixture, leaving the undigestible (fiber) portion to be dried and weighed. This insoluble dried portion would be considered the insoluble dietary fiber. Soluble polysaccharides (soluble dietary fiber) may be extracted from the soluble fraction of the food stuff through the addition of ethanol, which causes the polysaccharides to precipitate out. We now know how much total dietary fiber is in our food stuff (soluble + insoluble) and, provided that we have already determined the proximate analysis of the remaining constituents of the food, we are ready to make the nutrition label.
A LOT of work goes into those nutrition labels. They are like a work of art. Kashi makes some of my favorite art pieces:
They also make some of my favorite food items:
If you aren’t a fan of veggies, take comfort in the fact that those tasty carbohydrates (everyone likes carbs, right?) can supply you with plenty of fiber. That is, if you reach for the whole grain varieties. If not, well you will have to resort to that powder fiber that you stir into a class of water and I will resort to laughing at you as I chomp on my carrots. No, I wouldn’t laugh. I would ask if you wanted a carrot.
Fiber comes from fruits, vegetables or grain products. If you are having high fiber cheese or dairy or something along those lines, that would be the brain-child of some crafty food scientist who sees my carrot and raises me a piece of cheese…with the addition of hydrocolloids, gums, resistance starch or something along those lines. Okay, you win. Drop your fiber drink, I’ll drop my carrots…let’s have some CHEESE!
*I am NOT a nutritionist. Obviously, this is talking about fiber. If you completely neglect carrots and all other vegetables/fruits, fiber will be the last of your problems. Eat up…you need those vitamins, antioxidants, etc. I got my knowledge from my love of food & science and this book: Nielsen SS. 2010. Food Analysis. 4th ed. New York: Springer Science + Business Media. 602 p.*