Quality Changes during Storage of Spinach and Lettuce Baby Leaf A. Spinardi, G. Cocetta, V. Baldassarre, A. Ferrante and I. Mignani Dipartimento di Produzione Vegetale, University of Milano Milano Italy Keywords: anthocyanins, ascorbic acid, carotenoids, chlorophyll, vegetables, phenols, ethylene Abstract 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. INTRODUCTION Minimally processed leafy vegetables consumption has been increasing in all developed countries. The production and commercialization of these vegetables are very close for their limited shelf life. Usually processing industries for consumer safety limits the commercialization of minimally processed fruits and vegetables to 6-7 days (Role and Chasm, 1987). In the recent years, the nutraceutical properties of products have been gaining interest among consumers especially for their effect on human health (Drewnowski and Gomez-Carneros, 2000). These compounds include ascorbic acid, carotenoids, anthocyanins, phenols and vitamins. The most part of these compounds are also called phytonutrients because of their beneficial effect (Goldman, 2003). Many nutraceutical compounds are also antioxidants and contribute to establish the antioxidant potential of produces. Carotenoids are lipid-soluble pigments and their health benefits include prevention of certain cancers, cardiovascular and eye diseases as well as enhanced immune system (Kospell and Kospell, 2006). Anthocyanins as carotenoids are able to prevent degenerative diseases, vascular diseases and certain cancers. The anthocyanins are able to scavenge free radicals in the human body and their effect is due to the antioxidant properties and inhibition of lipid peroxidation of cells (Zafra-Stone et al., 2007). Moreover, plant phenols have been found to prevent DNA damage induced from oxidative stress and inhibit cancer development in certain stages (Hollman, 2001). Ascorbic acid (AA) plays a key role in cell metabolism, owing not only to its antioxidant action, but also to many AA dependent metabolic reactions that influence essential physiological processes, including cell division and the activation of biological defence mechanisms (De Tullio and Arrigoni, 2004). Because of its lability, AA is routinely used as an index to measure handling and processing effects on nutrient retention and tissue senescence (Vanderslice et al., 1990). 571 Proc. 6 th International Postharvest Symposium Eds.: M. Erkan and U. Aksoy Acta Hort. 877, ISHS 2010