Antioxidant properties and lipidic profile as quality indexes of cauliflower (Brassica oleracea L. var. botrytis) in relation to harvest time

The cauliflower is considered as a food of high nutritional value and some authors indicate that its quality is related to stability of its fatty acids. Samples of ‘Verde di Macerata’ variety were analysed for their main quality parameters, fatty acid composition and stability, and for their antioxidant properties by using a test based on linoleic acid enzymatic degradation. Cauliflower buds were harvested early and late over three different years (2001, 2002 and 2003). The samples were evaluated both raw and after a defatting treatment with CHCl3/MeOH 1:1 solution, in order to check the role of liposoluble substances. The main results were a very different composition profile for cauliflowers harvested in 2002 (increase of dry and fatty matter, polyphenols and antioxidant activity, decrease in ascorbic acid content), and a difference in fatty acid composition related to a relative increase in unsaturated fatty acids with respect to saturated ones in all late harvested samples. The difference shown in 2002 was probably due to environmental stress suffered by plants, like water loss and low temperature.