Mineral, vitamin C and crude protein contents in kale (<i>Brassica oleraceae var. acephala</i>) at different harvesting stages

Abstract

This study compares mineral, vitamin C and crude protein contents at different harvesting stages in kale (Brassica oleraceae var. acephala). Three different harvest periods as first harvest stage (at the rosette stage), second harvest stage (at the budding stage) and third harvest stage (at the flowering/blooming stage) were utilized in the study. The results of the study presented the highest values as follows: Third harvesting stage for vitamin C with 109.43 mg 100 g^–1; first stage for crude protein value of 35.00%; first harvesting stage for nitrogen (N) and iron (Fe) with 5.60% and 15.31 mg 100 g^–1, respectively; and second harvesting stage for phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn), cupper (Cu), and zinc (Zn) as 0.57, 4.62, 2.67, 0.38%, and 15.63, 0.20, 2.12 mg 100 g^–1 respectively. In conclusion, kale is a relatively good source of abundant antioxidants with its vitamin C, crude protein and mineral contents. The study propounds that kale can be consumed as a choice of fundamental nutrients selections and it would be worth considering the harvesting stage of maturity.

Key words: Kale (Brassica oleracea var. acephala), harvesting stage, vitamin C, crude protein, mineral content.