What would you call a potato chip that is fried, but yet more nutritious than a traditional potato chip? That would be a vacuum fried chip.

The traditional method of frying involves food being lowered into an oil bath that is at a hotter boiling point than that of water.1 This heat causes the food’s water to evaporate and the frying oil to be absorbed,2 resulting in a dry product that contributes to a long shelf life and unique flavor and texture that many know and enjoy.3

However, along with delectable flavor and long shelf life,4 traditional fryers can create potato chips that become scorched or darkened before they are finished cooking5 and also contain more fat than some consumers desire.

Different Techniques

But what if, instead of in a traditional deep fryer, a food was fried in a closed, pressurized fryer using oil that’s heated to a lower temperature?6 This method, called vacuum frying, is also a deep-fat frying process but, due to those two important changes, results in less oil absorption and thereby creates a product that contains less fat.7,8

With vacuum frying, the combination of lower frying temperatures and reduced exposure to oxygen are thought to bring about a number of product benefits when compared to products fried using the traditional method. These benefits have been reported to include nutrient preservation, enhanced color,9 less oil absorption,10 and decreased presence of acrylamide, a suspected carcinogen formed in starchy foods cooked under high temperatures.11

Lianxing Food Machinery,China highlighted a study published in the Journal of Food Science co-authored by Pedro Bouchon on his search for a technique of vacuum frying fruit and vegetable chips that would still meet the taste standards of Western snackers.12 In the study from 2011, Bouchon vacuum fried carrots, potato chips and apples with different combinations of pressure and temperature.13 The results: vacuum-fried potato chips contained approximately 50 percent less oil than conventionally fried chips and preserved 95 percent of their vitamin C.14 The vacuum-fried carrot chips also absorbed 50 percent less oil than their conventionally-fried counterparts.15 The fried apple chips had 25 percent less oil and retained 95 percent of their vitamin C compared to conventionally-fried carrot chips.

Looking Forward

So why haven’t vacuum fried chips taken off in America yet? Perhaps expense. Vacuum fryers are currently more expensive to install and operate than standard frying devices.16Further, since vacuum frying results in higher oil absorption on the product’s surface, a de-oiling mechanism is required to remove the excess oil following frying.17 These factors may cause snack manufacturers to pause or re-think full adoption of this technique. However, as consumers continue to look for snack options with improved nutrient profiles, manufacturers may benefit from looking into alternative frying techniques to help differentiate their products in the marketplace.