Some bioactive extracts have been proven to be effective antimicrobials and antioxidants; however, their addition to fruit may cause changes in sensorial attributes, as shown in Table 2. For example, green tea extract (GT) has been evaluated as being able to act in the preservative treatment of fresh-cut lettuce. Different quality markers, such as respiration, browning, ascorbic acid, and carotenoid content were evaluated. Several GT concentrations (0.25, 0.5, and 1 g/100 mL) at different temperatures (20 °C and 50 °C) were tested. Optimal GT treatments (0.25 g/100 mL at 20 °C) were compared with chlorine (120 ppm at 20 °C). High GT concentrations (0.5 g/100 mL and 1.0 g/100 m L) to a large extent prevented ascorbic acid and carotenoid losses of 0.25 g/100 mL GT as did chlorine. However, GT enhanced the browning of the samples, probably as a result of the high polyphenol content of the treatment, though heat-shock reduced this negative effect. No significant differences were observed between chlorine and the optimal GT (0.25 g/100 mL at 20 °C) in the browning appearance and sensory properties. GT kept the antioxidant activity of the samples better than chlorine did.