Valorizing Fresh-Cut Lettuce Quality Following Sustainable Soil Disinfestation Practices

Fresh lettuce is a key ingredient in ready-to-eat salads that are considered a valued dietary choice. Lettuce quality is strongly influenced by soil management practices, particularly in sustainable farming systems. This study evaluated the effects of three different soil disinfestation methods (flame weeding, microwave irradiation, and biological control (Trichoderma spp. inoculation) on the quality traits of Lactuca sativa L. var. Margò grown in a protected environment in southern Italy in a winter growth cycle. Minerals, nitrate content, colorimetric parameters, carotenoids, polyphenols, and antioxidant activity were assessed. The treatment with Trichoderma spp. significantly reduced nitrate accumulation (−21.3%) and increased some phenolic compounds and P (22%), while microwave irradiation treatment boosted total phenolic content by 44%. Flame weeding, although partially effective, was associated with a slight increase in carotenoids. Overall, microwave irradiation and Trichoderma spp. treatments emerged as the most promising options for balancing food safety and nutritional value. These findings offer valuable insights about the effect of soil disinfestation strategies on leafy vegetable quality.