PESTO SAUCE TYPE PRODUCTS: INFLUENCE OF BEESWAX AND STORAGE CONDITIONS ON RHEOLOGY AND COLLOIDAL STABILITY.

One of the major problems for pesto sauce type products is the tendency of oil to cream, causing their alteration and decreasing consumer's acceptability. In this study, colloidal and oxidative stability of pesto samples with (0.5-1.2%) of beeswax was evaluated during storage at 4, 20 and 40°C. The rheological behavior and color analysis was evaluated at the same temperatures. Sensory evaluation by using a hedonic test was also perfomed. Increasing the samples beeswax content increased the pesto colloidal stability. The samples with 0.8-1.2% have the highest stability and overall performed well on sensory analysis. The peroxide values of samples increased significantly (p<0.05) with storage time and temperature, as well as the p-anisidine values. During the storage at 40°C, peroxide values of samples without wax and with 1,2% wax increased from 11.75 to 33.81 and 32.72 meq O2/kg, respectively. In the same condition, p-Anisidine values increased from 4.51 to 10.71 and 9.94, respectively. For these same samples stored 793 h, peroxide values increased from 13.33 to 33.81 and to 32.72 meq O2/kg, when the temperature increased from 4 to 40°C. The same observation was made for p-anisidine values, which increased from 8.40 to 10.71 and 9.94. As expected, the pesto samples showed the best oxidative stability at low temperature. It was shown that beeswax content, temperature and time of storage are important parameters for controlling pesto rheology, colloidal and oxidative stability. In fact, the pseudo plasticity of samples increases with increasing beeswax added and with decreasing the temperature. The colloidal and oxidative stability of samples decreased as the storage time and temperature increased. [ABSTRACT FROM AUTHOR]