Probiotic Ice Cream Made with Tiger-nut ( Cyperus esculentus ) Extract

摘要

Objective: This study has been done to investigate/evaluate the effect of incorporation different ratios of tiger-nut extract, together with two probiotic bacterial strains in ice cream. Methodology: Substitution of aqueous phase by 25, 50, 75 and 100% tiger-nut extract (TNE) in the manufacture of probiotic ice cream, using two probiotic bacterial strains namely Lactobacillus acidophilus La-5 and Bifidobacterium bifidum Bb-12 was evaluated. Results: The results indicated that all treatments had no significant effect (p>0.05) on the pH, surface tension and whipping ability of ice cream mix, while the mix viscosity increased as the percentage of TNE was increased. Moreover, no significant effect (p>0.05) on the overrun, meltdown and sensory properties of resultant substituted ice cream were observed. Over storage period of 90 days at -20°C, the viability/survival of the two probiotic bacterial strains was higher in all ice cream treatments, made with TNE than in control. The same was true for the total bacterial counts. Conclusion: The results indicated that substitution of aqueous phase by 50% TNE was the most superior for production of ice cream with no adverse effect on the physical and sensory properties . In the same time, it also enhanced the survival of the incorporated probiotic bacterial strains.