Influence of Fermentation Conditions on Glucosinolates, Ascorbigen, and Ascorbic Acid Content in White Cabbage (Brassica oleracea var. capitata cv. Taler) Cultivated in Different Seasons

The content of glucosinolates (GLS), ascorbigen, and ascorbic acid in white cabbage (Brassica oleracea var. capitata cv. Taler) cultivated in different seasons (summer and winter) was determined, before and after spontaneous and starter-induced fermentation. Different salt concentrations (0.5% NaCl or 1.5% NaCl) were used for sauerkraut production. Glucoiberin, sinigrin, and glucobrassicin were dominating in raw white cabbage cultivated either in winter or summer seasons. Ascorbigen precursor, glucobrassicin, was found higher in cabbage cultivated in winter (2.54 mu mol/g dw) than those grown in summer (1.83 mu mol/g dw). Cabbage fermented for 7 d was found to contain only traces of some GLS irrespective of the fermentation conditions used. Ascorbigen synthesis occurred during white cabbage fermentation. Brining cabbage at low salt concentration (0.5% NaCl) improved ascorbigen content in sauerkraut after 7 d of fermentation at 25 degrees C. The highest ascorbigen concentration was observed in low-sodium (0.5% NaCl) sauerkraut produced from cabbage cultivated in winter submitted to either natural (109.0 mu mol/100 g dw) or starter-induced fermentation (108.3 and 104.6 mu mol/100 g dw in cabbages fermented by L. plantarum and L. mesenteroides, respectively). Ascorbic acid content was found higher in cabbage cultivated in summer and fermentation process led to significant reductions. Therefore, the selection of cabbages with high glucobrassicin content and the production of low-sodium sauerkrauts may provide enhanced health benefits towards prevention of chronic diseases.