School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

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The valorization of galactose derived from acid whey to low-calorie tagatose has gained increasing attention. Enzymatic isomerization is of great interest but faces several challenges, such as poor thermal stability of enzymes and a long processing time. In this work, non-enzymatic (supercritical fluids, triethylamine, arginine, boronate affinity, hydrotalcite, Sn-β zeolite, and calcium hydroxide) pathways for galactose to tagatose isomerization were critically discussed. Unfortunately, most of these chemicals showed poor tagatose yields (70%). The latter is able to form a tagatose–calcium hydroxide–water complex, which stimulates the equilibrium toward tagatose and prevents sugar degradation. Nevertheless, the excessive use of calcium hydroxide may pose challenges in terms of economic and environmental feasibility. Moreover, the proposed mechanisms for the base (enediol intermediate) and Lewis acid (hydride shift between C-2 and C-1) catalysis of galactose were elucidated. Overall, it is crucial to explore novel and effective catalysts as well as integrated systems for isomerizing of galactose to tagatose.


This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Agricultural and Food Chemistry, copyright © 2023 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see RIGHTS & PERMISSIONS.

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Journal of Agricultural and Food Chemistry


Available for download on Sunday, March 03, 2024