CHICAGO – Everyone’s talking about freshness these days, and more convenience stores are adding fresh produce to their shelves to great success. The latest to capitalize on the fresh food movement are fast-food restaurants, which have been procuring fresh fruit for salads and smoothies, the Chicago Tribune reports.

But putting fresh fruit on the menu hasn’t been easy, given that fast food restaurants haven’t usually purchased fresh fruit in large quantities like supermarkets do. For instance, it took Wendy’s more than 24 months to figure out how to add blackberries to a new salad. McDonald’s had similar problems finding enough mangoes for its new fruit smoothie.

While Wendy’s salad and McDonald’s fruit smoothies have been winners, both burger chains had flops, such as when McDonald’s tried baby carrots in its Happy Meals and Wendy’s attempted to offer a fresh fruit bowl—neither were popular with consumers.

“It’s all about speed and convenience, but menu innovation drives people in, so they need to balance the huge demand for fresh food within their traditional framework,” said Dean Small, founder and CEO of Synergy Restaurant Consultants.

The fast-food giants are responding in part to the fast-casual market, which has made fresh an integral part of its menu (think Chipotle and Panera). “It’s important to experiment, but that doesn't necessarily mean that you're rolling out six new menu items and it's all tofu and kale,” pointed out Mark Kalinowski, an analyst with Nomura. “It's more of an evolution, not a revolution.”

For more information on how convenience stores are offering fresh produce, read “Convenience Store Distribution Options for Fresh Produce.”