THE EFFECTS OF WALNUT OIL AND KEFIRAN ON THE TEXTURE AND RHEOLOGICAL PROPERTIES OF ICE CREAM

Introduction: Starch might be regarded as a polysaccharide consumed considerably. Starches as a food ingredient has important roles in the texture of food. Starch is used in food industry as thickening, stabilizing and gelling agent but some limitations such as low shear stress resistance, thermal decomposition, high tendency towards retrogradation and high syneresis might limit its application. The modification of starch can alter its physical and chemical properties and improves its functional characteristics Materials and Methods: In this work, starch isolated from barley grains, the variety Bahman was cultivated in Lordegan area of Chaharmahal and Bakhtiyari province and acetylated with acetic anhydride (%6 w/w) at two different times of 10 minutes and 5 hours followed by the evaluation of physicochemical properties concerned with syneresis, swelling power, thermal properties, viscosity and morphological characteristics. Results: The results showed that acetylated starches had higher swelling power. There was not a significant difference between the starch acetylated at 10 min and the control but this difference was considerable with the acetylated starch at 5 hours and the control (p˂5%). Decreases in syneresis and gelatinization temperature and increase in viscosity were significant as compared to the native barley starch. These modifications altered the size of the starch granules. Conclusion: According to the results, modification of barley starch can improve some of its functional characteristics.