In the present study, persimmon puree was incorporated into the ice cream mix at different concentrations (8, 16, 24, 32, and 40%) and some physicochemical (dry matter, ash, protein, pH, sugar, fat, mineral, color, and viscosity), textural (hardness, stickiness, and work of penetration), bioactive (antiradical activity and total phenolic content), and sensory properties of samples were investigated. The technique for order preference by similarity to ideal solution approach was used for the determination of optimum persimmon puree concentration based on the sensory and bioactive characteristics of final products. Increase in persimmon puree resulted in a decrease in the dry matter, ash, fat, protein contents, and viscosity of ice cream mix. Glucose, fructose, sucrose, and lactose were determined to be major sugars in the ice cream samples including persimmon and increase in persimmon puree concentration increased the fructose and glucose content. Better melting properties and textural characteristics were observed for the samples with the addition of persimmon. Magnesium, K, and Ca were determined to be major minerals in the samples and only K concentration increased with the increase in persimmon content. Bioactive properties of ice cream samples improved and, in general, acetone-water extracts showed higher bioactivity compared with ones obtained using methanol-water extracts. The technique for order preference by similarity to ideal solution approach showed that the most preferred sample was the ice cream containing 24% persimmon puree.

In the current study, Gleditsia triacanthos gum and tapioca starch were combined and rheological characterization of the binary mixture was performed. Gleditsia triacanthos gum at four different concentrations (0.1, 0.4, 0.7, and 1.0%, w/v) was mixed with tapioca starch at a constant level (2.5%, w/v). Steady shear and dynamic shear rheological properties of samples were determined using a stress/strain controlled rheometer at a constant temperature (25ºC). Oswald de Waele model was used to describe the shear rate effect on apparent viscosity values of the samples. Increase in the Gleditsia triacanthos level increased the apparent viscosity and consistency coefficient of the samples. Similarly, dynamic shear rheological parameters of the samples increased with the increase of Gleditsia triacanthos gum. The concentration of 0.7% for Gleditsia triacanthos gum was determined to be cross point for the liquid–solid phase. From this level, the elastic behavior became more dominant compared to viscous behavior because tangent delta was equal to one in this concentration. To describe the effect of Gleditsia triacanthos level on the studied rheological parameters, the Power law and exponential type models were used.

In the current study, the effect of air exposure to the gelatin solution on improvement of gel structure was investigated in terms of the steady and dynamic shear rheological properties. Prepared gelation solution (5% w/v) was covered to prevent air incorporation and it was subjected to 5 h gelatin and rheological analyses were carried out for the comparison of non-covered ones. It was observed that the preventing of air into the gelatin solution affected the rheological parameters. Apparent viscosity and complex viscosity values of samples increased during gelation and these values were measured to be tremendously high (1.894 and 8.346 Pa s, respectively) in non-covered gelatin solution while they were 0.474 and 1.611 Pa s in covered samples after 5 h gelation, respectively. Similarly, storage modulus (G′) of samples increased with the increase in gelation time and it was recorded to be 52.203 Pa in gelatin solution exposed to air while it was 9.848 Pa in gelatin solution covered to prevent air incorporation. These results showed importance of air in gelatin solution to the food industry using gelatin in food formulation for the structure of processed foods.