Ice recrystallization inhibition effect of cellulose nanocrystals: Influence of sucrose concentration

Abstract

Stabilizers are commonly used to inhibit the ice recrystallization process that leads to the formation of large ice crystals, decreasing consumer acceptance of ice cream. However, the ice recrystallization inhibition (IRI) effect of stabilizers is very dependent on measurement conditions. The cause of this dependence is not clear, which imposes problems in comparing the IRI activity and understanding the IRI mechanism of stabilizers. This study investigated the influence of sucrose concentration on the IRI effect of cellulose nanocrystals (CNCs), which are newly identified IRI active materials. A splat assay and a sandwich assay were used to determine IRI activities of CNCs at sucrose concentrations from 2.0% to 49.0% w/w and incubation temperature of −8 °C for 30 min. The IRI activities of CNCs were higher at low sucrose concentrations, almost disappeared at medium sucrose concentrations, and restored slightly at high sucrose concentrations. The IRI effect of CNCs is correlated with the ratio between CNCs concentration in the unfrozen phase and total surface area of ice crystals. This surface area-related IRI effect was also observed with guar gum, locust bean gum, and poly(vinyl alcohol). It is a strong evidence of an ice-binding mechanism for the IRI effect of stabilizers. These research findings offer a new perspective in comparing and understanding the measurement condition-dependent IRI effect of stabilizers, which could potentially benefit the ice cream industry in developing new materials and recipes to control ice recrystallization.