How much more resistant starch is in cold rice as opposed to hot?!
Answers:
One study (Muir & O'Dea, "Measurement of resistant starch: factors affecting the amount of starch escaping digestion in vitro", American Journal of Clinical Nutrition, 1992) specifically measured the amount of resistant starch in cooked and cooled potatoes. It's not rice, but it's comparable. They found a 2.8 fold increase in resistant starch content after cooling. As you suspected, however, the quantities are still small. The quantity started at 0.028 grams of RS/gram of dry weight of freshly boiled potato and increased to 0.079 grams of RS/gram of dry weight of cooked and cooled potatoes. To translate this into everyday terms, the 2002 USDA database identifies a 2-1/3 inch by 4-3/4 inch baked potato flesh only is 156 grams. It also says it's 75% water. My arithmetic says that this size potato would contain 39 grams of dry weight. If freshly boiled, it would contain 1 gram of resistant starch. If eaten cooked and cooled, it would contain 3 grams of resistant starch.
I haven't seen this exacting information on rice. USDA lists 1 cup of cooked white long grain rice as 158 grams and 68% water. If the percentages for rice were the same as the percentages for potatoes, my arithmetic says that one cup of cooked rice would contain 50 grams of dry weight. Hot would contain 1.4 grams of resistant starch and cooked and cool would contain 4 grams.
If you're trying to get resistant starch in your diet, have you considered using Hi-maize resistant starch? A tablespoon of this ingredient contains 5-6 grams of resistant starch and you can cook with it instead of eating it raw or cold. You can find info on this ingredient at www.hi-maize.com
www.resistantstarch.com and www.hi-maize.com
what do you mean by "resistant starch"?
starch is starch... but hot starches are generally more loose, which is why things like rice are softer when hot, and firm back up when they get colder.
