French fries, hash browns, mashed potatoes with gravy, potato latkes, there are so many things to make with the humble potato. The potato is a tuber from the perennial plant Solanum Tuberosum of the Solanaceae family. There are actually about 5,000 varieties of potatoes, but most of them can be traced back to the original potato from southern Peru. This single ancestor originated more than 10,000 years ago. In addition to being high in vitamins and minerals, potatoes have a varying amount of starch. Starch is the source of stored energy that a plant uses to feed itself. In this cooking and food science fair project, investigate the starch content of different varieties of potatoes. An easy way to determine the starch amount in a potato is to cut the potato into two pieces, rub them together, pull them apart, and then put the two pieces back together again. Is there a difference in how the different potatoes stick together? Do you notice foam, and if so, do different varieties make different foam? Is there a difference in the stickiness of the foam? Once you have determined starch content, look into how starch content affects boiling the potatoes. Are all of the potatoes fluffy after boiling, or are they waxy? What is the texture of the different potatoes after boiling?
Figure 1. Potatoes are a humble, but tasty, vegetable.
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Science Buddies Staff. (2014, October 22). You Say Po-tay-to and I Say Po-tah-to, but No Matter What, There's Starch in Those Taters!. Retrieved December 28, 2016 from http://www.sciencebuddies.org/science-fair-projects/project_ideas/FoodSci_p032.shtml
Potatoes make a great side dish, but they also make great subjects for hands-on science! Food chemistry, plant biology, and even basic electronics are all on the menu when you experiment with potatoes.
South American cultures had been eating potatoes for thousands of years before Spanish explorers brought them to Europe in the late 1500s. Despite their high nutritional value, it took about 200 years for potatoes to begin appearing regularly on European dinner tables. Until then, they were mostly used to feed animals. Now, however, potatoes are a staple in cultures all over the world, baked, boiled, steamed, mashed, and especially fried.
What Can You Learn from a Potato?
Some people say that fish is brain food. Try one of these Science Buddies Project Ideas, and you may decide that potatoes are brain food too!
Potato Batteries: How to Turn Produce into Veggie Power!: Our bodies use food for energy, but is it possible to power a light bulb with a potato? Yes! This fun Project Idea leads young scientists through the basics of batteries and circuits.
Do Potatoes Regulate the Formation of New Sprouts?: Why does a potato have eyes? All the better to grow with! When placed in a dark location, potatoes can grow new stems from their eyes and eventually produce new potatoes. Do all of the eyes grow new stems? Investigate whether there's a limit to the number of sprouts that can grow from a single potato.
How Greasy is Your Potato Chip?: Traditional potato chips are fried in oil to give them a nice crunch. Newer recipes call for different cooking methods to make them more healthful. With a rolling pin and graph paper, see for yourself how much fat different varieties of potato chips contain.
Smashing for the Mash: The Science of Making Memorable Mashed Potatoes: Be the mashed potato hero in your home! In this hands-on experiment, you'll try a variety of cooking and mashing methods to discover how to create the most delicious potatoes for your dinner table.
Hey, Do You C My Potatoes?*: "Eat your veggies!" Grown-ups know that fruits and vegetables provide us with essential vitamins, but do cooking methods change the amount of vitamins that end up on our plates? Discover the best way to get the most vitamin C from your potatoes.
Boston, MA April 25, 2013 - Research recently presented at the Federation of American Societies for Experimental Biology conference in Boston, MA shows that resistant starch content of potatoes is similar across potato varieties; but can be altered significantly by the cooking and serving methods. Resistant starch is starch that is resistant to enzymatic digestion and, thus, is not absorbed in the small intestine.
Researchers from the USDA Agricultural Research Service (ARS) Grand Forks Human Nutrition Research Center in North Dakota and the University of Minnesota developed a standardized protocol to examine the amount of resistant starch in three different potato varieties (Yukon Gold, Red Norland and Russet Burbank) subjected to two methods of preparation (baking or boiling) and served at three service temperatures (hot, chilled for 6 days and chilled followed by reheating). Results show that the resistant starch content of potatoes varied significantly by method of preparation and service temperature but not variety (p > 0.05). More specifically, regardless of potato variety, the baked potatoes had significantly higher resistant starch at 3.6 grams of starch per 100 grams of food (3.6/100g on average) than boiled potatoes (2.4/100g). Also on average, chilled potatoes (whether originally baked or boiled) contained the most resistant starch (4.3/100g ) followed by chilled-and-reheated potatoes (3.5/100g) and potatoes served hot (3.1/100g).
Thirty years of research in human models suggests that the consumption of resistant starch may help regulate blood glucose levels and favorably alter bacteria in the colon. Emerging research in animals has linked resistant starch fermentation to satiety.
"This research adds important information to the growing database of resistant starch contents of foods," explained Susan Raatz, lead investigator on the study. "Resistant starch is garnering more interest among the scientific community and consumers. Identifying foods that are high in resistant starch, and preparation methods that can increase the content of resistant starch in a particular food, has valuable practical applications."
This study was funded by the United States Potato Board and the USDA-ARS. For Quick & Healthy potato recipes, videos and nutrition information please visit: http://www.potatogoodness.com.
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About the United States Potato Board
The United States Potato Board (USPB) is the nation's potato marketing and research organization. Based in Denver, Colorado, the USPB represents more than 2,500 potato growers and handlers across the country. The USPB was established in 1971 by a group of potato growers to promote the benefits of eating potatoes. Today, as the largest vegetable commodity board, the USPB is proud to be recognized as an innovator in the produce industry and dedicated to positioning potatoes as a nutrition powerhouse-truly, goodness unearthed.
French fry lovers, beware! You may be exposed to a chemical more commonly associated with heavy industry than crispy fried potatoes. Fortunately, researchers are finding ways to reduce that exposure.
French fries contain acrylamide. The chemical poses a risk for several types of cancer in rodents. However, the evidence from human studies is still incomplete. The International Agency for Research on Cancer considers the chemical a "probable human carcinogen."
Scientists first began paying attention to the unwanted chemical's presence in food more than a decade ago. Trace amounts of acrylamide are present in many foods cooked at temperatures higher than 248 degrees Fahrenheit. Relatively high levels are found in fried potatoes, including French fries and potato chips.
With that in mind, a group of scientists set out in 2011 to identify potato varieties that form less acrylamide.
Led by University of Idaho researcher Yi Wang, the group assessed more than 140 potato varieties. The researchers' goal was to identify potatoes that make great French fries and form less acrylamide. The amount of the chemical found in fried potatoes is thought to be directly linked to the chemistry of the raw potatoes.
Raw potatoes contain an amino acid called asparagine. The amino acid is found in many animal and plant food sources, and it's a known precursor of acrylamide. When cooked at high temperatures, sugars react with amino acids, including asparagine, in a chemical process known as the Maillard reaction. The reaction is what gives fried potatoes their prized flavor and color, but it is also what produces acrylamide.
Researchers planted 149 potato breeds in five potato-growing regions across the United States. Upon harvesting, they sent some of the raw potatoes to labs. There, the potatoes were stored in conditions similar to commercial potatoes. After storage, the labs tested the potatoes for their levels of reducing sugars and asparagine. Researchers then fried some of the potatoes and observed how much acrylamide the potatoes formed.
The researchers found that it is fairly achievable to identify potato breeds that produce less acrylamide, especially when compared with the industry standard potato breeds, Ranger Russet and Russet Burbank.
"The real challenge is to find the varieties that not only have those characteristics, but also yield finished products with desirable processing quality that meet the stringent standards of the food industry," Wang said.
Two of the most promising varieties -- Payette Russet and Easton -- have already been released for commercial use.
Wang said the group hopes to identify genes that are related to lower acrylamide in certain fried potatoes. The study shows a strong relationship between the genetics of a raw potato and its potential to form acrylamide. If researchers are able to identify the specific genes, they may be able to eliminate them in the future.
The team's research is published in Crop Science.
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