بررسی ویژگیهاي فیزیکیشیمیایی عصاره استویا خشک شده به روش پاششی و کاربرد آن بهعنوان جایگزین شکر در تولید ژله آلوئهورا

The purpose of this study was to evaluate the influence of Arabic gum concentration on production yield, physicochemical and morphological properties of spray dried stevia extract. Also, the effect of stevia powders replacement with sucrose on physicochemical, textural and sensory properties of Aloe Vera jelly was investigated. The spray drying process using Arabic gum was carried out at concentrations of 10, 20 and 30% (w/v). Then, 25, 50 and 75% of sucrose in the formulation of Aloe Vera jelly was replaced with 0.25, 0.50 and 0.75% of stevia powders. The results revealed that the maximum yield of powder (47.73%) has been obtained at 10:90 Arabic gum to extract ratio. The amount of moisture, water activity and hygroscopicity of powders decreased with increasing the carrier ratio. Other properties such as bulk density, particle density and true density, solubility and wettability of powders also decreased with increasing the carrier ratio. These properties were varied in the range of 0.39-0.46 g / ml, 0.42-0.57 g / ml, 1.42- 1.55g / ml, 89.10-92.30%, and 15.39- 27.52 s. Also, flow ability behavior of samples improved by increasing the carrier ratios. According to the results of scanning electron microscopy, the increasing of carrier concentration also led to the production of larger particles with wrinkled surface and irregular shapes. Evaluation of the physicochemical properties of the jelly samples revealed that by increasing the stevia concentration, the moisture content, syneresis and acidity of samples increased, while the brix, gel strength and pH decreased. Treatments containing 0.25% and 0.50% of 10% Stevia powder and treatment containing 0.25% of 20% Stevia Powder, showed higher acceptability regarding sensory characteristics and did not show significant differences with the control sample. [ABSTRACT FROM AUTHOR]