Influence of Sucrose on the Mutarotation Velocity of Lactose

Abstract

The kinetics of mutarotation of lactose in the presence of sucrose was determined at 25, 30 and 35 C. The rate of mutarotation of lactose decreased slightly by sucrose added to 40% and thereafter greatly decreased. Increasing sucrose from 30 to 60 g per 100 ml solution, decreased the velocity constant 1.8 to 1.9 times, independent of the concentration of lactose. In a whey-salt solution, mutarotation was increased 1.8 to 1.9 times. With sucrose the whey-salt solution did not increase the rate constant and mutarotation rates were then essentially the same as in distilled water. Increasing sucrose decreased mutarotation constants in the whey-salt solution as in distilled water. Effect of sucrose was apparent at 25 g per 100 ml solution. Potassium dihydrogen phosphate, Na3-citrate, and K3-citrate catalyzed the mutarotation velocity of lactose, did not increase the rate constant with 30 g sucrose per 100 ml solution. © 1970, American Dairy Science Association. All rights reserved.