Research Advances of d-allulose: An Overview of Physiological Functions, Enzymatic Biotransformation Technologies, and Production Processes

Abstract

d-allulose has a significant application value as a sugar substitute, not only as a food ingredient and dietary supplement, but also with various physiological functions, such as improving insulin resistance, anti-obesity, and regulating glucolipid metabolism. Over the decades, the physiological functions of d-allulose and the corresponding mechanisms have been studied deeply, and this product has been applied to various foods to enhance food quality and prolong shelf life. In recent years, biotransformation technologies for the production of d-allulose using enzymatic approaches have gained more attention. However, there are few comprehensive reviews on this topic. This review focuses on the recent research advances of d-allulose, including (1) the physiological functions of d-allulose; (2) the major enzyme families used for the biotransformation of d-allulose and their microbial origins; (3) phylogenetic and structural characterization of d-allulose 3-epimerases, and the directed evolution methods for the enzymes; (4) heterologous expression of d-allulose ketose 3-epimerases and biotransformation techniques for d-allulose; and (5) production processes for biotransformation of d-allulose based on the characterized enzymes. Furthermore, the future trends on biosynthesis and applications of d-allulose in food and health industries are discussed and evaluated in this review.

Recent Advances Regarding the Physiological Functions and Biosynthesis of D-Allulose

“…More than 30 kinds of rare sugars have been reported ( Granström et al, 2004 ). They have unique biological functions and have been used as food additives, cancer cell suppressors, and building blocks for anticancer and antiviral drugs ( Zhang et al, 2016b ; Li et al, 2017 ; Guerrero-Wyss et al, 2018 ; Hoshikawa et al, 2018 ; Xia et al, 2021 ). D-Allulose (also called D-psicose) is well known as the most remarkable of rare sugars.…”

Water Dynamics in Starch Based Confectionery Products including Different Types of Sugar

“…It has been shown that d -allulose exhibits different water-binding properties compared to other monosaccharides [ 13 ], and physical properties of the confectionery products can be affected by the water binding ability of sugars used in formulations. d -allulose has a wide array of biomedical applications, such as improving insulin resistance, its anti-obesity effects, its anti-inflammatory nature, and in regulating glucolipid metabolism [ 14 , 15 ]. It is also worth mentioning that d -allulose intake improves cholesterol metabolism, leading thus to a reduced risk of atherosclerotic plaque formation, which is considered a major cause of ischemic heart disease [ 16 ].…”

Produce D-allulose from non-food biomass by integrating corn stalk hydrolysis with whole-cell catalysis

“…The excessive intake of high energy sugars has caused many health problems, such as diabetes, hypertension, hyperlipidemia, and other diseases (Xia et al, 2021). D-allulose (D-psicose or D-ribo-2-hexulose) is a good sugar substitute, because it is an low calorie sweeter (70% sweetness of sucrose), and inert in energy metabolism (Iida et al, 2010).…”