People who have eaten potato chips should have noticed that when the chips are packaged in plastic bags, they appear to have a large quantity. However, upon opening the bag, they might find that there are only a few chips inside, while the rest seems to be gas, resembling an inflated pillow. So, why do potato chip packages contain so much gas?
According to a report by IFLScience, it is commonly said that the presence of a large amount of gas in potato chip packaging helps prevent them from breaking prematurely during transport, acting somewhat like a safety airbag. Additionally, this gas can aid the chips in adapting to changes in atmospheric pressure, which is crucial if the chips are being transported by air.
In fact, the gas contained in potato chip packaging is not regular air from the factory but rather nitrogen. Exposing the chips to oxygen in the air would cause them to quickly become soft and less tasty, similar to leaving a bag of chips open overnight.
However, nitrogen can prevent the fats and starch in the chips from oxidizing, thereby extending their freshness and crispiness. Previous studies have shown that nitrogen is stable, odorless, and safe for use in food packaging as it does not easily undergo chemical reactions.
Some critics argue that certain potato chip manufacturers overfill their bags with gas in order to profit more. When opening a bag of chips, one may find that 90% of its content is gas, leaving only 10% for the actual chips.
Previously, the BBC reported that Henry Hargreaves, a food photographer, had long been disappointed in the perceived value of potato chips. In a somewhat informal experiment, he wanted to see if it was necessary to fill chip packages with so much gas.
Initially, he believed that gas could prevent the chips from breaking, but he found that the chips in the packages with the most gas were actually more broken. He suggested that vacuum sealing is the most effective method to transport and handle chips without damaging them.
Hargreaves assumed that the potato chips from the American brand Pringles would hold the most value due to their packaging in tubes. However, upon opening them, he discovered a significant amount of gas inside, not filling the container entirely.
Regarding the issue of whether buying potato chips is equivalent to purchasing gas, Taiwan’s Food and Drug Administration (referred to as FDA) previously explained on “Good Food and Drug Articles” why these chips require so much gas in their packaging.
The FDA pointed out that the key to delicious potato chips lies in high-temperature frying, but once fried chips come in contact with air, they are prone to oxidation, resulting in them becoming soft, broken, and even developing rancid flavors, making them undesirable. Therefore, to preserve the chips, two crucial elements are needed: sealed packaging and filling them with nitrogen.
Sealed packaging prevents potato chips from coming into contact with air, reducing the degree of oxidation and extending their shelf life. Currently, manufacturers utilize plastic bags with inner layers made of composite materials like tin foil or aluminum foil, which not only block out air, fats, moisture, and microbes, but also assist in light-blocking, further reducing oxidation.
Furthermore, in order to prevent chips from being damaged or breaking due to collisions and pressures during transport, ensuring their quality, safety, intact appearance, good taste, and protection from microbial contamination, manufacturers fill the packaging with sufficient nitrogen.
Nitrogen is chemically stable, colorless, tasteless, odorless, almost insoluble in water, and does not readily react with other substances. It is the most abundant gas in Earth’s atmosphere, comprising 78.09% of the total volume, making it easily accessible and cost-effective.