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The physiological and chemical traits of three red ( MS151, Copacabana and Excellent) and three green ( Ortis 398, Summerbell and Babybell) baby leaf lettuce cultivars were evaluated during postharvest cold storage. In addition, their potential use as a source of antioxidants, after the expiration date, was also investigated. Red cultivars showed the best performance in terms of nutritional and physiological parameters. In particular, the antioxidant activity was 11-fold higher in red than in green baby leaf lettuces. Moreover, Ortis 398, MS151 and Copacabana, showing the lowest values for respiration rate, ammonium accumulation and electrolyte leakage, were selected as suitable for ready-to-eat processing and preservation. Finally, the cultivars Ortis 398, MS151 and Excellent were found to be of interest for the extraction of antioxidants due to their high phenol content. Practical Applications The selection of the most appropriate cultivars for ready-to-eat ( RTE) salads is of primary importance in order to have good quality, to reduce storage losses and to have, after the expiration date, a produce still exploitable for the extraction of phytochemicals. Ortis 398, MS151 and Copacabana were selected, among the studied new baby leaves cultivars, for their particular aptitude for RTE processing. In addition, because RTE lettuce remains often unsold due to the loss of its fresh appearance, our results suggest the possibility to re-utilize the waste (after the expiration date) as a source of antioxidants. This could represent a practical application opportunity for the food industry. With this aim, the cultivars Ortis 398, MS151 and Excellent were selected for their high content in total polyphenols even after the expiration date. [ABSTRACT FROM AUTHOR]

Fresh-cut iceberg lettuce was treated with two different concentrations of L-cysteine, in order to select the proper treatment able to improve the storage in air. L-cysteine at 0.1% was selected because it significantly slowed down browning, respiration activity and soluble o-quinones formation and preserved the antioxidant activity. Thus, a second experiment in which this concentration was applied to fresh-cut lettuce processing was carried out. The effectiveness of the treatment with L-cysteine was confirmed and enhanced by the storage in modified atmosphere, increasing the shelf life of 40% respect to control samples. Sensory analysis confirmed the effectiveness of the treatment, showing that fresh-cut lettuce dipped with L-cysteine obtained better scores for appearance, texture, and absence of browning and of unpleasant odor than control. Finally, treatment with L-cysteine resulted with a suitable anti-browning agent, which could be used in fresh-cut lettuce processing. [ABSTRACT FROM AUTHOR]