Hydroxypropylmethylcellulose Having High Thermal Gel Strength, Method For Producing The Same And Food Comprising The Hydroxypropylmethylcellulose

Abstract

Provided is hydroxypropylmethylcellulose having a high thermal gelation temperature and a high thermal gel strength and a method for producing the same and a food comprising the hydroxypropylmethylcellulose. More specifically, provided is hydroxypropylmethylcellulose having an average substitution degree of a methoxy group of 1.0 to 2.0 per glucose unit, an average substitution degree of a hydroxypropoxy group of 0.05 to 0.4 per glucose unit, and a A/B value of 0.305 or greater wherein A represents a substitution degree of a methoxy group directly substituted for a hydroxy group on carbon at position 6 in a glucose unit free from a hydroxypropoxy group-substituted hydroxy group, B represents a substitution degree of a methoxy group per glucose unit, and the A/B represents a value of A divided by B.

1 . Hydroxypropylmethylcellulose having an average substitution degree of a methoxy group of 1.0 to 2.0 per glucose unit, an average substitution degree of a hydroxypropoxy group of 0.05 to 0.4 per glucose unit, and an A/B value of 0.305 or greater wherein A represents a substitution degree of a methoxy group directly substituted for a hydroxy group on carbon at position 6 in a glucose unit free from a hydroxypropoxy group-substituted hydroxy group, B represents a substitution degree of a methoxy group per glucose unit, and the A/B value represents a value of A divided by B. 
     
     
         2 . The hydroxypropylmethylcellulose according to  claim 1 , having a thermal gelation temperature of 64° C. or higher. 
     
     
         3 . A food comprising hydroxypropylmethylcellulose according to  claim 1 . 
     
     
         4 . A method for producing hydroxypropylmethylcellulose having an average substitution degree of a methoxy group of 1.0 to 2.0 per glucose unit, an average substitution degree of a hydroxypropoxy group (C) of 0.05 to 0.4 per glucose unit, and an A/B value of 0.305 or greater wherein A represents a substitution degree of a methoxy group directly substituted for a hydroxy group on carbon at position 6 in a glucose unit free from a hydroxypropoxy group-substituted hydroxy group, B represents a substitution degree of a methoxy group per glucose unit, and the A/B value represents a value of A divided by B, the method comprising at least the steps of:
 reacting a pulp with an alkali to obtain alkali cellulose; and   adding a methyl etherification agent and a hydroxypropyl etherification agent to react with the alkali cellulose to obtain hydroxypropylmethylcellulose, wherein addition rates of the methyl etherification agent and the hydroxypropyl etherification agent are adjusted such that a reacted portion of the hydroxypropyl etherification agent becomes less than 50% at the time when a reacted portion of the methyl etherification agent is 50% or more, or such that a reacted portion of the hydroxypropyl etherification agent becomes less than 30% at the time when a reacted portion of the methyl etherification agent is 30% or more, so as to obtain a C/D value of 0.28 or less wherein C represents the average substitution degree of a hydroxypropoxy group per glucose unit of the hydroxypropylmethylcellulose, D represents the number of moles of the hydroxypropyl etherification agent per glucose unit of the hydroxypropylmethylcellulose, and the C/D value represents a value of C divided by D.