Mechanical properties of weak locust bean gum (LBG) gels under controlled rapid freeze-thawing

Locust bean gum (LBG) solutions and gels were studied in compression, and stress-relaxation was monitored by an Instron universal testing machine (UTM). The strength of the formed gels under freeze-thaw treatment was dependent upon the freezing and thawing rates and the temperature of freezing. LBG solution which froze at a rate of 50C/min was stiffer than those samples which froze at a rate of 1C/min. LBG solution thawed at a rate of 1C/min was stiffer than those samples which were thawed at 10C/min. Very high freezing rates may reduce the size of the formed ice crystals (less disturbance to network formation), while slow thawing may induce the favored gelation. LBG solutions frozen to -60C were stiffer than those frozen to -20C. A short holding time (up to 90 min) at the freezing temperature did not influence the strength of the cryogels. These parameters are important in building products which require a priori knowledge of their texture.