Development of a Process for Color Improvement of Low-Grade Dark Maple Syrup by Adsorption on Activated Carbon

Abstract

Low-grade dark maple syrup was successfully discolored on activated carbon. Several experimental parameters were tested, namely, the mixing time (20, 40, and 60 min), concentration of the activated carbon (0.1, 0.3, and 0.5 g/100 mL), type of activated carbon (I, II, and III), activated carbon particle size (25, 50, and 75 μm), stirring speed (200, 400, and 600 rpm), and temperature (40, 60, and 80 °C). The obtained results showed that the discoloration is optimal by applying the following parameters: a mixing time of 40 min with a type III activated carbon at a concentration of 0.3 g/100 mL. These parameters yielded a light transmittance at 560 nm of 83.70 ± 0.21%, which ranks the syrup in the extra clear class according to the Canadian classification. The results showed that among the tested carbons, the adsorption on the type III carbon followed the Langmuir, Freundlich, and Langmuir–Freundlich adsorption isotherms. Regarding the effect of the particle size, the obtained results showed that a mean size of 25 μm combined with a stirring speed of 200 rpm and working temperature of 80 °C was the most effective one. The optimized conditions showed a good adequacy with the Langmuir and Freundlich models. The discoloration process by using the type III activated carbon followed the pseudo-second-order kinetics.

A Review on Sweet Potato Syrup Production Process: Effective Parameters and Syrup Properties

“…One possible approach to achieve this goal is to use activated carbon, which has been demonstrated to be effective in reducing color precursors and off-flavors. This method has been explored in the work of Aït-Aissa et al [111] and has been shown to be effective in improving the quality of glucose syrup by removing unwanted compounds [111].…”