LAUSR

&NA; Plants and natural molecules are generally consumed not in raw state but after different processing conditions (heating, mechanical agitation or cooking). The understanding of the chemistry and biological outcome of thermal treatment is still scarce. In the current study, Eriodictyol, a natural flavanone, has undergone heat treatment, generating hence three different products ((3‐(3,4‐dihydroxyphenyl)‐3‐hydroxypropanoic acid, (3‐(3,4‐dihydroxyphenyl) propanal) and an unidentified component). The consequences of aforementioned treatment on the immunomodulatory behavior of resulted molecules were evaluated. The amount of nitric oxide production and the lysosomal enzyme activity were determined in vitro on mouse peritoneal macrophages. The kinetic of cellular antioxidant activity in splenocytes and macrophages was measured. The present investigation demonstrates that heat‐processed eriodictyol significantly enhanced the proliferation of lymphocytes B and T compared to native eriodictyol. Indeed, this compound showed an important improvement on cytotoxic T lymphocyte (CTL) and natural killer (NK) activities. In addition, the production of nitric oxide (NO) and suppression of phagocytic activity of activated macrophages have been increasingly important after thermal processing. Furthermore, it was also revealed that heat‐treated Erio in comparison with the native (non heat‐treated) molecule has a highest cellular anti‐oxidant activity in splenocytes and macrophages cells. These findings highlight the importance of heat‐process as feasible and effective strategy to improve the immunomodulatory and the antioxidant efficiency of an known flavanone Eriodictyol. Graphical abstract: Figure. No caption available. HighlightsHeated and native eriodictyol showed non cytotoxic effect against splenocytes and macrophages.Heat‐treated eriodictyol increased the proliferation of both lymphocytes B and T and improved CTLs and NK activities.Heated eriodictyol revealed an efficient anti‐inflammatory effect.Heated eriodictyol improved the cellular anti‐oxidant activity in splenocytes and macrophages cells compared to native one.