State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, China.
International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China.
Appl Microbiol Biotechnol. 2018 Apr;102(7):3007-3015. doi: 10.1007/s00253-018-8834-7. Epub 2018 Feb 23.
Difructose dianhydride III (DFA III) is a cyclic difructose containing two reciprocal glycosidic linkages. It is easily generated with a small amount by sucrose caramelization and thus occurs in a wide range of food-stuffs during food processing. DFA III has half sweetness but only 1/15 energy of sucrose, showing potential industrial application as low-calorie sucrose substitute. In addition, it displays many benefits including prebiotic effect, low cariogenicity property, and hypocholesterolemic effect, and improves absorption of minerals, flavonoids, and immunoglobulin G. DFA III is biologically produced from inulin by inulin fructotransferase (IFTase, EC 4.2.2.18). Plenty of DFA III-producing enzymes have been identified. The crystal structure of inulin fructotransferase has been determined, and its molecular modification has been performed to improve the catalytic activity and structural stability. Large-scale production of DFA III has been studied by various IFTases, especially using an ultrafiltration membrane bioreactor. In this article, the recent findings on physiological effects of DFA III are briefly summarized; the research progresses on identification, expression, and molecular modification of IFTase and large-scale biological production of DFA III by IFTase are reviewed in detail.
三异麦芽酮糖醇（DFA III）是一种含有两个相互糖苷键的环状异麦芽酮糖。它可由蔗糖焦糖化少量生成，因此在食品加工过程中广泛存在于各种食品中。DFA III 的甜度为蔗糖的一半，但能量仅为蔗糖的 1/15，具有作为低热量蔗糖替代品的潜在工业应用价值。此外，它具有许多益处，包括益生元作用、低致龋性和降胆固醇作用，并能提高矿物质、类黄酮和免疫球蛋白 G 的吸收率。DFA III 是由菊粉经菊粉果糖转移酶（IFTase，EC 4.2.2.18）生物合成的。已经鉴定出大量的 DFA III 产生酶。菊粉果糖转移酶的晶体结构已经确定，并对其进行了分子修饰以提高催化活性和结构稳定性。已通过各种 IFTase 研究了 DFA III 的大规模生产，特别是使用超滤膜生物反应器。本文简要总结了 DFA III 的生理作用的最新研究发现；详细综述了 IFTase 的鉴定、表达和分子修饰以及 IFTase 大规模生物合成 DFA III 的研究进展。
