QUESTION: I have heard that adding ginger to the water used to cook beans will reduce the amount of intestinal gas from eating the beans. Is this true? Where does the gas come from? How much ginger for 1 pound of beans? Should fresh ginger or ground ginger be used?
K.S., San Diego
ANSWER: Beans contain particular carbohydrates called oligosaccharides. The body does a poor job at digesting these because we don't produce sufficient amounts of the particular enzyme to do the job. As a result, these carbs travel through the small intestine undigested, then move into the large intestine, where they are devoured by the natural flora that live there. The flora give off methane and other gases as a metabolic byproduct of their meal.
Some of this gas can be absorbed through the intestinal wall, but the excess tends to be passed out of the body. How much goes where will vary from individual to individual.
I am familiar with ginger's reputation of being able to reduce the gas from beans. There is, however, little available in the scientific literature and elsewhere that describes how this herbal root might accomplish the task.
Some of the information says that ginger works its wonders when you add it to the soaking water, as you mention. I could not, however, find any guide that specified amounts or types of ginger.
What is confusing is that there were other articles saying that the anti-gas effect comes when you use ginger as a seasoning with the cooked beans. One article even made reference to "research in India," but again, there was little to be found in the scientific literature.
On top of all this, we have ginger's reputation as a digestive aid unrelated to beans, as well as its recommended use to help with various forms of nausea, including morning sickness and post-surgical nausea.
Aside from giving ginger at try, there are other techniques that can help limit the impact of gas production. One is to eat more slowly and enjoy the beans as a part of a meal that contains protein and fat. This slows the rate at which the food travels through the digestive tract. The gas accumulates as a slower rate, and more can be absorbed.
Another option is to take one of the over-the-counter products that contain some of the missing enzyme.
For an excellent article about beans and cooking techniques, consult www.cdc.gov/nccdphp/dnpa/5ADay/month/beans.htm
Most fresh potatoes are not right out of the field, but are stored, sometimes over many months. Do they lose their nutritional value in storage?
Fresh tends to be best, but if stored under proper conditions, potatoes do quite well, with little nutrient loss. Keeping them in a place that is cool (45 to 50 degrees), dry and dark is the key. Don't refrigerate, as the cold will cause some of the starch to turn to sugar.
If exposed to heat or light, the potato will come out of dormancy, begin to sprout and take on a greenish tinge. Potato sprouts or green parts of potatoes are not to be eaten because they contain a toxin called solanine.)
If stored correctly, mature potatoes will keep well for up to 2 months. Aside from their carbohydrate content, an average size potato with skin is a good source of vitamin C and potassium, and it also provides a couple of grams of fiber, several B vitamins, magnesium iron, phosphorous and zinc.
Ed Blonz, Ph.D., is a nutritional scientist based in Northern California. General-interest questions about nutrition can be mailed to: Ed Blonz, Focus on Nutrition, P.O. Box 120191, San Diego, CA 92112-0191, or sent via e-mail to UTFood@blonz.com