Method for mass-producing sweetener having taste quality similar to that of sugar and having d-allulose functionality

A method for mass-producing a sweetener containing three saccharides D-glucose, D-fructose, and D-allulose, having functionality of D-allulose, and having a taste quality close to that of sugar, comprising:

• using, as a raw material, an inexpensive composition containing D-glucose and D-fructose,
• acting D-allulose 3-epimerase on the raw material to allow isomerization of D-fructose therein to proceed by an isomerization reaction between D-fructose and rare sugar D-allulose, terminating the reaction at a stage when a rare sugar D-allulose content reaches an intended content of an intended product, and
• obtaining the intended product having, in a composition of rare sugar D-allulose, D-glucose, and D-fructose, a D-fructose content in a range that compensates for a weak point of D-allulose in a sweetness degree and gives the intended product a taste quality close to that of sugar in cooperation with D-allulose and D-glucose, wherein:
• world scale mass production with sufficient price competitiveness is achieved by using, as the D-allulose 3-epimerase, D-allulose 3-epimerase having high heat resistance and high productivity and derived from Arthrobacter histidinolovorans to realize total productivity depending on the high heat resistance and high durability (long life span) of the enzyme as a result thereof and performing production without using simulated moving bed chromatography.