Study of the characteristics of quality and shelf life of dry ice cream stored at different temperatures

  Dry ice cream is a traditional Iranian product which can be reproduced as a new dairy product by using new processing methods and offered as a standard product to the global marketing. In the case of these traditional product has not been investigated and these research is the first scientific study on this product. From similar products of dry ice cream can be noted to khoa, danedar khoa, barfi, pedha, lal peda, brown peda and dulce de leche. The aim of current study was study of the characteristics of quality and shelf life of dry ice cream stored at different temperatures. In this process, dry ice cream was prepared by adding milk, sugar, glucose syrup and shortening then it was packed in conventional cardboard boxes. Then all the samples were kept in three different temperatures (-18, +8 and +28 °C) for 60 days. Next qualitative features of them were investigated by physico-chemical (determine the amount of moisture content, protein, fat, ash, pH, acidity, free fatty acid content, peroxide value), textural (determine the firmness), microbiological (total count and mold and yeast count) and sensory analysis (In terms of color, surface, stiffness, mouth feeling, milky taste, rancidity taste and overall acceptability). The results showed that the amount of moisture, protein, fat and ash of dry ice cream was 14.16 percent, 4.76 percent, 2.48 percent and 1.00 percent, respectively. By passing time and increasing storage temperature, moisture content and pH decreased, but acidity, free fatty acid content, peroxide value, firmness, total count and mold and yeast count increased. In the case of sensory features, by increasing storage temperature and passing time, the related scores of color, surface, stiffness, mouth feeling, milky taste, rancidity taste and overall acceptability were decreased. The dry ice creams that stored at +28 °C were withdrawn from the research from the 13th day because of excessive firmness. The results showed that -18 °C and +28 °C was the most suitable and unsuitable kind of storing temperature regarding to the maintaining of quality and shelf life of dry ice cream, respectively. In addition, -18 °C up to 60 days, +8 °C up to 20 days and +28 °C up to 5 days, showed the best sensory features. According to the results of the research, dry ice cream is viable to be produced in industrial scales and by providing new formulations for this product can be increased the per capita consumption of milk in the country.