Abstract
Melanoidins are colored products that can be found in food and drinks, formed by Maillard reactions. Sometimes these compounds are considered undesirable in certain food products, because they impart a brownish color and must be removed. An overview of recent patents related to melanoidin removal indicates that it can be performed by chemical/biological degradation or by adsorption processes. Therefore, in the present study, the adsorption mechanism for synthetic melanoidin removal from aqueous solutions was studied using different Raphanus sativus press-cake sorbents, with the precursor material being carbonized in a microwave oven, either with direct heating or after a chemical activation process with phosphoric acid, nitric acid or potassium hydroxide. Physical and chemical modifications were evaluated by FTIR, pHPZC, thermogravimetry and BET. The adsorption kinetics was better described by a pseudo-second order model for all activated carbons (ACs). Evaluation of the diffusion process showed dependence on the initial melanoidin concentration due to the wide range of sizes of the adsorbed molecules. The equilibrium data were best fitted by the Langmuir model for the acid-treated AC and by the Freundlich model for the base-treated and non-chemically treated ACs. Melanoidin adsorption was characterized as a spontaneous, favorable and endothermic process involving hydrogen bonds and π-π interactions between the adsorbents surfaces and the adsorbed molecules.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Recent Patents on Food, Nutrition & Agriculture
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
