AUTHOR=Jiang Suwei , Xiao Wei , Zhu Xingxing , Yang Peizhou , Zheng Zhi , Lu Shuhua , Jiang Shaotong , Zhang Guochang , Liu Jingjing 

TITLE=Review on D-Allulose: In vivo Metabolism, Catalytic Mechanism, Engineering Strain Construction, Bio-Production Technology

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2020.00026

DOI=10.3389/fbioe.2020.00026

ISSN=2296-4185

ABSTRACT=<p>Rare sugar <italic><sc>D</sc></italic>-allulose as a substitute sweetener is produced through the isomerization of <italic><sc>D</sc></italic>-fructose by <italic><sc>D</sc></italic>-tagatose 3-epimerases (DTEases) or <italic><sc>D</sc></italic>-allulose 3-epimerases (DAEases). <italic><sc>D</sc></italic>-Allulose is a kind of low energy monosaccharide sugar naturally existing in some fruits in very small quantities. <italic><sc>D</sc></italic>-Allulose not only possesses high value as a food ingredient and dietary supplement, but also exhibits a variety of physiological functions serving as improving insulin resistance, antioxidant enhancement, and hypoglycemic controls, and so forth. Thus, <italic><sc>D</sc></italic>-allulose has an important development value as an alternative to high-energy sugars. This review provided a systematic analysis of <italic><sc>D</sc></italic>-allulose characters, application, enzymatic characteristics and molecular modification, engineered strain construction, and processing technologies. The existing problems and its proposed solutions for <italic><sc>D</sc></italic>-allulose production are also discussed. More importantly, a green and recycling process technology for <italic><sc>D</sc></italic>-allulose production is proposed for low waste formation, low energy consumption, and high sugar yield.</p>