Sweetening agent and preparation method thereof

The invention discloses a sweetening agent and a preparation method thereof. The method adopts natural trehalose which is glucose disaccharide with a structure of alpha, alpha, 1, 1-butt joint; 2-hydroxyl group of two glucose residues of the natural trehalose is substituted by chlorine atoms, and a configuration is turned into an S-configuration at the same time; the 6-hydroxy group on one of thetwo glucose residues is substituted by chlorine atoms. In the invention, a sweetness test shows that the sweetening agent is superior to granulated sugar and trehalose. The sweetening agent has the advantaged of improving sweetness, reducing food sugar addition and avoiding no obesity promotion, can be widely applied to sweetness additives of foods, beverages, and is healthy to eat and safe to eat. The invention provides a feasible preparation process, and by introducing a triphenylmethyl protecting group which is easy to crystallize, the product purification can be completed through a recrystallization technology in