Contents lists available at ScienceDirect Journal of Functional Foods journal homepage: www.elsevier.com/locate/jff Isomaltulose: Recent evidence for health benefits Sangeetha Shyam a , Amutha Ramadas b , Sui Kiat Chang a, ⁎ a Department of Nutrition and Dietetics, School of Health Sciences, International Medical University, Bukit Jalil, 57000 Kuala Lumpur, Malaysia b Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia ARTICLE INFO Keywords: Isomaltulose Sweetener Gut microbiota Prebiotic Postprandial glycaemia Glycaemic control ABSTRACT Isomaltulose (IM) is a naturally occurring disaccharide composed of alpha-1,6-linked glucose and fructose monomers. IM is gaining interest as an alternative sweetener to sucrose primarily because of its low glycaemic index (GI) properties. Low GI has been implicated in the prevention and management of chronic diseases such as cardio-metabolic diseases and cancers. The low glycaemic potential of IM has fuelled the many recent in-vitro, animal and human studies including randomised-controlled trials and cohorts. This review discusses the che- mical and physiological properties of IM in relation to its potential health effects, with a focus on its prebiotic properties. Research health findings from existing literature published within the last 10 years were compiled and summarised. The novel applications of products formulated with IM in improving health, cognition and nutrition are highlighted in this review. This review also evaluates the prebiotic potential of IM, an emerging alternative sweetener. 1. Introduction Isomaltulose (IM), well known by its trade name Palatinose™, is regarded as ‘a slow, yet fully digestible carbohydrate with low gly- caemic index (GI)’ (Maresch, Petry, Theis, Bosy-Westphal, & Linn, 2017). Hence, isomaltulose is gaining interests among food manu- facturers and healthcare professionals. This review discusses the che- mical and physiological properties, and provides updates on its poten- tial health effects, with a novel focus on its prebiotic properties. This review systematically collates evidence on health benefits of IM pub- lished in English during the recent 10 years. The novel applications of products formulated with IM in improving health, cognition and nu- trition are highlighted in this review. 1.1. Structure IM has a molecular formula of C 12 H 22 O 11 with a molecular weight of 360.32. Chemically, IM is known as 6-O-α-D-glucopyranosyl-D-fruc- tofuranose and contains an α-1,6 glycosidic bond instead of α-1,2 in its isomer sucrose (Fig. 1). The α-1,2-glycosidic bond between the glucose and fructose of sucrose molecule is converted into an α-1,6-glycosidic bond during the enzymatic step. This stable bond and its reduced sus- ceptibility to hydrolysis by the human small intestinal mucosa, defines the key physiological characteristics of IM (Maresch et al., 2017; Sentko, 2012). 1.2. Food source, production and applications Naturally, IM occurs in small quantities in honey and sugar cane juice (Schiweck, Munir, Rapp, Schneider, & Vogel, 1990). After the discovery of the isomerase involved in IM production in the 1950s, large scale synthesis of IM is made possible by the enzymatic iso- merization from sucrose (beet sugar) (Sawale, Shendurse, Mohan, & Patil, 2017). Industrial bioconversion of sucrose to isomaltulose hap- pens through the enzymatic activity of sucrose isomerases from nu- merous microorganisms (Goulter, Hashimi & Birch, 2012). The micro- organisms used for the synthesis of isomaltulose are such as, Protaminobacter rubrum (Bai et al., 2016), Erwinia rhapontici (Li et al., 2011), Serratia plymuthica (Oliva-Neto and Menão, 2009), Serratia ply- muthica (Orsi and Sato, 2016), Enterobacter sp. FMB-1 (Park et al., 2010). The most widely used bacterial strain for industrial production of isomaltulose is Serratia plymuthica (Goulter et al., 2012). IM has long been used as a sugar alternative by the food industry in Japan (Schiweck et al., 1990). IM is “generally recognized as safe” (GRAS) by the United States Food and Drug Administration (FDA). After preliminary safety assessments, IM has been approved as a food ingredient in the European Union (Holub et al., 2010), Australia and New Zealand (Maresch et al., 2017). Currently, IM is used as a re- placement to other sugars and maltodextrins in foods and beverages, including sports beverages, energy drinks, malt beverages, special and clinical nutrition feeds, breakfast cereals, cereal bars, dairy products, https://doi.org/10.1016/j.jff.2018.07.002 Received 7 May 2018; Received in revised form 18 June 2018; Accepted 1 July 2018 ⁎ Corresponding author. E-mail address: ChangSuiKiat@imu.edu.my (S.K. Chang). Journal of Functional Foods 48 (2018) 173–178 1756-4646/ © 2018 Elsevier Ltd. All rights reserved. T