Comparative analysis of vitamin C, crude protein, elemental nitrogen and mineral content of canola greens (Brassica napus L.) and kale (Brassica oleracea var. acephala)

Abstract

This study aims at promoting the consumption of canola greens (Brassica napus L.) as alternative, affordable and available dietary sources of vitamin C, minerals and protein. As one of the oldest-known forms in cabbages family, kale (Brassica oleracea var. acephala L.) greens are among the most consumed vegetable cabbages in Turkey. In this study, kale and canola greens were compared with regards to vitamin C, crude protein and mineral materials. At the end of the study, vitamin C content was found to be 68.3 mg 100 g^-1 for canola and 80.12 mg 100 g^–1 for kale; crude protein content was determined to be 31.1% for canola and 29.8% for kale; nitrogen (N) content was found to be 4.90% in canola and 4.70% in kale; phosphorus (P) content was 0.40 mg 100 g^–1 in canola and 0.46 mg 100 g^–1 in kale; potassium (K) content was 3.06 mg 100 g^–1 in canola and 3.60 mg 100 g^–1 in kale; calcium (Ca) content was found to be 2.65 mg 100 g^–1 in canola and 2.51 mg 100 g^–1 in kale; magnesium (Mg) content was 0.29 mg 100 g^–1 in canola and 0.33 mg 100 g^–1 in kale; manganese (Mn) content was was 16.50 mg 100 g^–1 in canola and 5.55 mg 100 g^–1 in kale; copper (Cu) content was found to be 0.35 mg 100 g^–1 in canola and 0.16 mg 100 g^–1 in kale; ıron (Fe) content was 23.96 mg 100 g^–1 in canola and 14.01 mg 100 g^–1 in kale; zinc (Zn) content was reported to be 2.95 mg 100 g^–1 in canola and 2.06 mg 100 g^–1 in kale. Finally, the study states that canola greens might be consumed like kale and that these greens might replace each other.

Key words: Canola greens, kale, vitamin C, crude protein, elemental nitrogen, mineral content.