D-塔格糖的生理活性及生物合成研究进展

D-塔格糖是一种重要的稀有己酮糖，其甜度是蔗糖的92%,热量只有蔗糖的三分之一；D-塔格糖分别于2001年和2014年被美国食品药品监督管理局和我国卫生和计划生育委员会批准为食品新原料。D-塔格糖具有降低血糖、减少肥胖、改善肠道菌群、抗龋齿、抗氧化等功能。D-塔格糖作为一种理想功能性甜味剂，具有广泛的应用价值，然而塔格糖的生产成本以及产量一直是限制塔格糖发展和应用的重要原因。D-塔格糖的合成方法主要有化学合成法和生物转化法。化学合成法生产D-塔格糖虽然是一种经济有效的方法，但是在生产过程中需要高温高压的条件，并且容易生成山梨糖、甘露糖等杂糖，不利于分离纯化。为了克服这些缺点，生物转化法生产D-塔格糖得到了广泛的关注和研究，因此，系统阐述了以不同底物，如己糖(半乳糖醇、D-半乳糖和D-果糖)、乳糖、多糖(麦芽糊精和淀粉)转化成D-塔格糖的研究进展和优缺点，并对其未来研究趋势进行了展望，以期为D-塔格糖的研发与生产提供借鉴。

Research Progress on Physiological Activity and Biosynthesis of D-Tagatose

D-Tagatose is an important rare ketohexose. Its sweetness is 92% of sucrose, and its calories are only one third of sucrose. D-Tagatose was approved as a new raw material for safe food by the America''s Food and Drug Administration and China''s Health and Family Planning Commission in 2001 and 2014, respectively. D-Tagatose has the functions of lowering blood sugar, reducing obesity, improving gut microbiota, anti-caries, anti-oxidation and so on. D-tagatose, as an ideal functional sweetener, has extensive application value. However, the production cost and yield of D-tagatose have always been an important reason limiting the development and application of D-tagatose. The methods for D-tagatose synthesis mainly include chemical route and biological conversion. Although it is cost-effective to produce D-tagatose by chemical approach, it requires high temperature and pressure in the production process, and is easy to generate miscellaneous sugars such as sorbose and mannose, which is not conducive to separation and purification. In order to overcome these shortcomings, the biological conversion of D-tagatose has received extensive attention. Therefore, the research progress, advantages and disadvantages of D-tagatose biosynthesis from different substrates such as hexoses (galactitol, D-galactose and D-fructose), lactose, polysaccharide (maltodextrin and starch) were systematically reviewed, and the research trends in the future were also prospected, which provided reference for the research and production of D-tagatose.