Potential of β-d- glucan to enhance physicochemical quality of frozen soy yogurt at different aging conditions

β-d- glucan as a soluble dietary fiber, has many desirable physical and physiological characteristic. In this research the effect of β-d- glucan and aging conditions (Time and Temperature) on some physicochemical and textural properties of frozen soy yogurt was investigated. Three variables including concentration of oat β-d- glucan (0, 1 and 2%), aging time (2, 13 and 24 h) and aging temperature (2, 4 and 6°C) were studied. The results showed that the addition of β-d- glucan to frozen yogurt increased viscosity, overrun, hardness and fat destabilization but the melting resistance and L*value were decreased.  In terms of aging conditions, it was revealed that increasing aging time could improve the quality of product whereas higher temperature had an undesirable effect on the quality of frozen soy yogurt. Longer aging time caused an increase in viscosity, hardness, fat destabilization and melting resistance. By increasing aging temperature, fat destabilization, overrun and viscosity were decreased and melting rate was increased. It was concluded that addition of β-d- glucan as a dietary fiber and prolonged aging time at low temperature could adjust textural properties of frozen soy yogurt and improve quality of this frozen dessert.