Are blue corn chips any healthier for you than chips made from regular corn?
It's often said that the more (naturally) colorful your plate is, the healthier the meal is for you. This saying still holds true in the corn arena: blue corn is a healthier option. Its healthy status comes from the fact that it contains more of the amino acid lysine and the antioxidant anthocyanin than "regular" yellow corn. That being said, it can lose much of these nutrients when it's processed into a chip. And because there are multiple methods of creating a corn chip, it might be helpful to break down how each method can affect the nutritional content.
One way is through nixtamalization, or lime cooking, a process in which corn is soaked and cooked in an alkaline (non-acidic) solution, typically limewater, and the outer covering of the corn is removed. To make a tortilla chip, the corn is then fried, often with calcium hydroxide (the compound in limewater), further resulting in an alkaline flavor. While this process does decrease the nutritional value of the corn, there are ways of preserving some of the nutrients in white, yellow, and blue corn during lime cooking. For example, using calcium salts in the process can result in higher total dietary fiber, lower glycemic index (GI) value, and higher antioxidant levels in corn tortillas.
Another way that corn is prepared is through extrusion. Extrusion, simply put, is a method used for pastas, cereals, and other processed foods in which food materials are pushed through a device and using a screw or piston, and then (with the help of a die cut or shears) given a certain shape. If you’ve ever played with Play-Doh™ or made cookies with a home cookie maker, chances are you’ve used an extruder. During the extrusion process for corn chips, the maize is ground and turned into flours. It’s then put into an extruder that mixes and heats the food materials through a combination of adding moisture and pressure. Then as the product exits the extruder, steam is used to puff and shape the chip, and then it is fried.
So what’s the difference between these two methods? Well, blue corn chips made through the extrusion process had higher levels of anthocyanin (healthy flavonoids that make blue corn, well, blue!) and phenolics (chemical compounds that have been associated with higher antioxidant activity). The extruded corn also had a lower oil content, which is healthier, but may disappoint those searching for the perfect dipping chip — oil is known to prevent chip breakage! Frying chips with calcium lactate, after both extrusion and lime cooking, is also an alternative process that can produce naturally colored flours and tortilla chips with higher antioxidant content.
On another note, when it comes to fresh, not fried, blue corn tortillas, they do contain more protein than their yellow or white corn counterparts. The protein content in blue corn, as well its lower glycemic index, may prove to be helpful to people on low GI diets, such as diabetics, because food with less starch and a low GI breaks down more slowly into sugars absorbed by the blood stream and can help people avoid spikes in blood sugar levels.
Reader, when it comes to picking out a healthier chip, generally most research suggests that blue corn chips may be slightly more nutritious in this sense. Keep in mind, though, that chips of any color are often fried and can be high in fat and calories, so it's probably best not to make them a regular snack. While not all labels will tell you how the chips are cooked, when opting for a healthier chip you might try looking for baked chips.
With all of this in mind, if you're trying to increase the amounts of lysine or antioxidants in your diet, fresh and whole fruits, vegetables, and lean proteins are much better sources. For more information on antioxidants, check out Antioxidants in the Go Ask Alice! archives and the Related Q&As.Alice!