Effects of Metal Concentration, pH, and Temperature on the Chlorophyll Derivative Content, Green Colour, and Antioxidant Activity of Amaranth (Amaranthus viridis) Purees

The thermal process of green amaranth leads to the partial or complete degradation chlorophyll pigments and loss colour due formation derivatives. This study aimed evaluate a stabilisation utilising metal ions obtain stable metal-chlorophyll derivative complexes. In this study, effects CuSO4 (0–240 ppm), ZnCl2 (0–1800 ppm) ions, pH (4–9), temperature (60–100 °C) on purees with constant time 15 min were investigated. tapered leaf amaranths, sample depicted higher contents (0.33 mg/g), b (0.34 total (0.68 mg/g) than round amaranths (chlorophyll = 0.28 mg/g, 0.29 0.58 mg/g). A content (0.62 DPPH scavenging activity (93 mM TE/g), FRAP value (54 TE/g) Cu-amaranth successfully achieved using 210 ppm after heating at 6 80 °C. Zn-amaranth produced 1500 8 90 °C for 0.39 79 TE/g, 57 TE/g. HPLC chromatograms, two major peaks identified as chlorophylls in fresh amaranths. Nevertheless, these disappeared Cu- purees, presumably metallo-chlorophyll