Effect of barley antifreeze protein on thermal properties and water state of dough during freezing and freeze-thaw cycles

Abstract

This study examined the effects of barley antifreeze protein (BaAFP-1) on the thermal properties and water state of dough during freezing and freeze-thaw cycles. The thermal properties of treated and untreated fresh dough, including the apparent specific heat, freezing temperature, melting temperature, freezable water content and glass transition temperature were determined and compared. For frozen dough samples, the change in melting performance, freezable water content, pasting properties, moisture content, water mobility and water distribution during freezing and freeze-thaw cycles were analysed. The results demonstrated that the addition of BaAFP-1 increased the apparent specific heat of dough after freezing, increased the freezing temperature and the temperature range of the melting and glass transition temperatures, and decreased the melting enthalpy and freezable water content of fresh dough. The addition of BaAFP-1 also influenced the melting performance and gelation property of frozen dough after freeze-thaw cycles. It slowed the decrease in moisture content, weakened the influence of the freeze-thaw treatment on water mobility and influenced the water distribution in frozen dough.