Rheological and textural properties of camel milk ice cream by using resistant starch, Arabic and xanthan gums in a new formulation

  Camel milk and its products have different physicochemical properties from those of cow's milk. The present study was aimed to investigate the feasibility of production of a functional ice cream from camel milk by application of resistant starch (RS), Arabic and xanthan gums. The resultant ice creams were evaluated in terms of their physicochemical, rheological, textural and organoleptic properties. In this research work, maize RS, Arabic and xanthan gums were used as stabilizers in ice cream formulation. Different ingredients including skim milk powder, stabilizer-emulsifier, sugar, and vanilla were mixed to set the dry matter of camel milk ice cream on 30%. To prepare one kilogram of ice cream mix, camel milk was mixed with 160g sugar, 3g stabilizer-emulsifier, 1 g vanilla powder, and RS or gums; then the dry matter was adjusted by using skim milk powder. Ice cream mix was pasteurized at 68 °C for 30 min and then aged at 4 °C for 24 h. The aged mix was then frozen using a laboratory ice cream machine. Ice cream samples were evaluated for their textural and rheological characteristics. The least overrun value (28.02%) belonged to the sample containing the maximum amount of gums and RS, while the control sample had the highest overrun (50.75%). Ice cream mix prepared with the maximum amount of RS showed the highest viscosity, while the control sample had the least viscosity. The least (22.02%) and highest (52.63%) melting rates belonged to the samples containing the maximum amounts of RS or gum and control sample, respectively. xanthan and Arabic gums and RS were significantly affected by the first dripping time in the linear parameter. Both gums had a significant effect on hardness and adhesiveness (p<0.01), while RS had no significant effect on adhesiveness (p>0.01). Results for the fitting of rheological behavior of ice cream mixes showed that the Herschel-Bulkley model could predict the behavior of fluid with a high correlation coefficient. Sensory properties of camel milk ice creams significantly improved by increasing amounts of xanthan and Arabic gums. Results of formulation optimization revealed that the best amounts of RS, Arabic and xanthan gums were in the range of 0.48-0.5, 0.6, and 0.23, respectively. It was concluded that maize RS, Arabic and xanthan gums had the significant impact on physicochemical properties of camel milk ice cream. These ingredients have the potential to be used as stabilizers in ice cream formulations.