McDonald’s announced today that its Chicken McNuggets are now free of artificial preservatives, a change that the fast food giant has been working on for about a year. The pork sausage patties, omelet-style eggs served on items like breakfast sandwiches, and scrambled eggs are also now free of artificial preservatives.
McDonald’s also said that the chicken used in its food, including its McNuggets, is no longer raised with antibiotics important to human health. In March 2015, the company committed to stop using that form of antimicrobials in its U.S. poultry operation by March 2017, but it has completed the transition ahead of schedule.
The McNugget move means the company’s most popular menu item is now free from phosphates, an ingredient that has been used as a preservative. The company did not need to find an alternative, executives told Fortune, because its McNuggets don’t need need a long shelf life; McDonald’s size and scale mean its inventory turns very quickly.
“In the early days we didn’t have as many distributors so we wanted a long shelf life so could go across the country,” McDonald’s U.S. chief supply chain officer Marion Gross tells Fortune. “Times and infrastructure have changed.”
McDonald’s U.S. president Mike Andres says the company also needed to find a new shortening for cooking the McNuggets that was free of artificial preservatives. “That was probably the biggest challenge,” he says.
The announcement from McDonald’s is just the latest from the company linked to its food sourcing, including a decision to serve eggs that come from only cage-free hens within the next decade. The “cleaner” ingredients and push for new animal welfare initiatives comes as the company attempts a turn around after a major sales slump. CEO Steve Easterbrook, who took on the top job in 2015, has signaled that aligning the company with consumers’ changing food preferences is key to getting the company back on track.
McDonald’s started testing the new McNuggets in March in 140 locations in Washington and Oregon. That same month it filed a trademark for the phrase the “the simpler the better.”
As part of today’s announcement, the company also said it will begin rolling out new buns this month that no longer contain high fructose corn syrup. Taken together, all of the announcements impact nearly half the food on the McDonald’s menu.
This article originally appeared on Fortune.com.