Biochemical Characterization of Leaves and Bracts of Poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) Valenciana

The aim of this study was to evaluate some chemical components of leaves and bracts of the sun Euphorbia pulcherrima  variety Valenciana for edible purposes.We obtained well developed leaves and bracts from 4 plants in the experimental station of the Autonomous Univesrity of Chapingo.. The samples selected were free of pesticides. First a bromatological analysis was made, considering moisture (M), ash (A), crude protein (TP) ethereal extract (EE) and crude fiber (CF). The other variables considered were: anthocyanins, chlorophylls ,carotenoids, ascorbic acid, total soluble sugars, soluble protein, total phenolic compounds, antioxidant capacity, using different colorimetric assays. We also evaluated color (Lch) and weight loss. Methods were carried out according to the variable. For data analysis confidence intervals were evaluated as well as a correlation analysis, considering three replicates. Results obtained within the intervals were: total anthocyanins in bracts were between7.31-10.38 mg•g, chlorophyll “a” was of 0.03-14 mg• g, chlorophyll “b” 0.27-0.38 mg• g, total chlorophyll content in an interval of 0.08-1.67 mg• g, carotenoids from 3.49 to 3.88 mg• g, ascorbic acid in leaves was between 12.63-26.24 and in bracts 37.68-46.88 μg• g, total soluble sugars 7.30-14.31 in leaves and in bracts 0.91-7.96 mg•g, soluble protein in leaves from 0.1-0.83 and in bracts from 0-0.058 mg•g; total phenolic compounds 1.36-1.58 in leaves, and in bracts from 2.93-3.37 mg• g , antioxidant capacity in leaves 7.56-8.82 and in bracts from 7.12-8.45 μg• g. Dry matter content in leaves was of 24.75%, and 18.54% in bracts.Significant positive correlations were found between chlophyll “a” and total chlorophyll; , chlorophyll “a” with antioxidant capacity, and antioxidant capacity with total phenolic content. The results of the bromatological analysis ara similar to those reported for Round zucchini (Cucurbita pepo), flowers.