Cornell researchers reveal how to cut onions without crying

Cutting onions can evoke tears and discomfort, a common experience for many cooks. Recent research conducted by a team at Cornell University has revealed insights into why this occurs and how to mitigate the effects. The study, published in the 'Proceedings of the National Academies of Science,' employed high-speed cameras to observe the mechanics of onion cutting. It identified the primary irritant, propanethial S-oxide, and explained the process through which this compound is released into the air when onions are sliced. The investigation indicates that the pressure buildup within the onion cells during cutting leads to the ejection of droplets containing the irritant, contributing to the tearing effect experienced by many. This two-stage process occurs as the knife penetrates the layers of the onion, with pressure forcing out a mist at significant speeds, which can pose food safety concerns as well. The study revealed that a sharper knife minimizes the droplet release, thereby reducing the chances of tears and preventing the potential spread of pathogens if the onion is contaminated. Furthermore, researchers suggest an alternative approach by coating the onion with oil before cutting, which adds another layer of protection against tear-inducing compounds. The findings from this research provide practical tips to enhance the cooking experience while emphasizing food safety in relation to handling onions.