Study on the influences of cocoa powder concentrations and substitution of milk fat by vegetable fats in the production of chocolate ice cream

Abstract

This research was carried out to study on the effect of partial and full replacement of MF (milk fat) by different vegetable fats including coconut (Cn), palm and cocoa butter (Cb) on the physical and sensorial properties of chocolate ice-cream. MF from whipping cream was partially and fully replaced by three types of vegetable fats including palm, coconut fat and cocoa butter. In which 4%, 6% and 8% of milk fat were replaced by palm fat, while 10%, 15% and 20% of milk fat were substituted by Cn fat as well as Cb. After that, five physical properties including viscosity, overrun, hardness, melting rate and total solid content of ice-cream in each experiment were measured, in which samples with 100% MF were considered as control sample. Finally, a formula among formulas from previous experiments with desired physical properties was chosen for performing rating for reference sensory test against a commercial product. As the results, viscosity of ice-cream with partial and full MF replaced by Cn fat and Cb similarly increased when concentration were increased. While palm fat has expressed the opposite trend in viscosity comparing to Cn fat and Cb. About overrun, ice-cream with partial MF replaced by palm fat, Cn fat and Cb tended to increase when concentrations were increased. However, when the Cn and Cb used for fully replacing MF, overrun appeared to decrease in value. In addition, increasing concentration of Cb resulted in increasing hardness of ice-cream .Nevertheless, samples with palm fat as well as Cn fat in both partial and whole replacement showed the downward trend in hardness with increasing in concentration used. Besides, measured melting rate of ice-cream from three vegetable fats showed the trend opposite to its hardness. Additionally, about total solid content, samples from all experiments showed very close data with each other. But in common, there was a similar trend of slightly increasing total solid content with increasing in concentration of vegetable fats applied. Finally, when ice-cream with chosen formula of 10% Cb was tested sensory against a commercial chocolate ice-cream product, there was an optimistic result as all sensorial attributed were rated significant higher comparing to the commercial product. Key words: cocoa powder, vegetable fats, chocolate ice cream.