The Effect of Mg2+, Cu2+ and Zn2+ pre-treatment on the color of yerba maté (Ilex paraguariensis) leaves

ABSTRACT

The aim of this work was to study the effect of alkaline blanching followed by an immersion in salt solutions of Mg2+, Cu2+ and Zn2+ on color preservation of Yerba Maté leaves. The concentration of NaOH in the alkaline solution influenced all of the color parameters. Ion concentration and dipped time influenced only some color parameters. The color parameters of the product obtained with different treatments were different from the control sample (blanched with boiling water instead of alkaline blanching) and from the product obtained via industrial processing. The green color in the pre-treated and control samples was more intense (greater values of -a) and darker (low values of L and b). Ionic and ash content in the leaves increased with the treatments.