Quality changes during storage of spinach and lettuce baby leaf

Spinach and lettuce are important vegetable products in the minimally processed leafy vegetables industry. The quality parameters of these products are represented by leaf pigments that affect the visual appearance and by internal quality components such as ascorbic acid, carotenoids and phenols. Storage experiments were performed on leafy vegetables harvested at commercial stage and stored at 4 or 10°C. The content of ascorbic acid, chlorophyll, carotenoids and phenols were determined at the beginning of the experiment and after 6 days of storage. Ethylene accumulation was also measured. Results obtained showed that chlorophyll, carotenoids and phenols did not change in both species after 6 days of storage at both temperatures. Ascorbic acid declined during storage. The decrease was more pronounced in lettuce than in spinach. In lettuce ascorbic acid content was below 0,5 mg/100 g FW after 6 days of storage, at both storage temperatures. In spinach ascorbic acid decreased in leaves stored at both temperatures, but at higher temperature (10°C) the degradation process was faster. Ethylene levels after 6 days of storage were below 0.1 μl L-1 in bags of spinach. In the case of lettuce, ethylene levels after storage were about 1 μl L-1. Even if some quality parameters are stable during the 6 days of storage, the decline of ascorbic acid suggests, at least for lettuce, a fast commercialisation and a correct cold chain for the best health benefit.