M.A. Thesis:

Study of persimmon puree on the physico-chemical, Microbial and sensory properties of Functional ice cream

In this research, the persimmons (Japanese variety, quite ripe) were coverted in to puree. Persimmon purees were added at 0, 10, 20, 30, 40 and 50% levels to ice cream formulations containing 12% fat, 16% sugar, 11% solid non fat, 0.2% stabilizer, 0.2% emulsifier and 39.4% total solids. Then the physicochemical, microbial and sensory characteristics of the samples were compared. Analysis of variance showed that increasing the persimmon puree to the ice cream samples caused in decrease pH, viscosity, overrun and melting resistance, but density increased significantly (P <0.05). Meanwhile, the increase of persimmon puree in the samples increased the total phenols significantly. In the microbial tests section, the increase of persimmon purée in the specimens caused Enterobacteriaceae and total count of microorganisms to be positive. There was a significant difference between the samples. But Escherichia coli was not observed in the samples. Of course, the number of microorganisms was no more than standard. In the sensory tests, increasing the persimmon puree to the samples caused in to desirable color and appearance, more odor and better taste. But increasing persimmon puree caused in to increased roughness of the samples. Finally, the panelists in terms of overall acceptance, chose sample contain 30% persimmon puree as the best, and the sample has 40% persimmon puree as the most appropriate, but reported level of 50% similar with 20%, 10% and control.

Keywords: Keywords: ice cream, Persimmon puree , total phenols , physicochemical and sensory characteristics, microbial activity