A. Diane L. McKay,
PhD, an assistant professor at Tufts’ Friedman School, answers: “According to
the California Walnut Commission , the nutrient profile of walnuts does not
change significantly when they are roasted, toasted or baked for short periods
of time, i.e., 350 degrees for 8-10 minutes. A 2012 study conducted by Vinson
et al. at the University of Scranton also reported no effect of roasting on the
total amount of polyphenols (phytochemicals) in walnuts. Of course, if the nuts
are roasted in oil, and then salted, their fat and sodium content is
increased.”
