Quality characteristics of coffee-like beverage from roasted date seeds (Phoenix dactylifera, L.) were determined and compared with those of traditional Arabic coffee. The date seed beverage was found to have lower amount of total phenolic compounds and to be a less powerful antioxidant than Arabic coffee. Phytochemical screening showed that date seed extracts contained steroids, tannins, and coumarins, while caffeine, terponoids, saponins, alkaloids, anthraquinones, and anthocyanins were not detected. The levels of trace elements in the date seed extracts were within the ranges reported for Arabic coffee with the exception of cadmium (0.16-0.42 compared to <0.1 in Arabic coffee). The sensory evaluation revealed that the date seed extracts were acceptable but were slightly lower in quality compared to Arabic coffee. The date seed extracts were lighter in color, less cloudy, less bitter, and have less coffee flavor compared to the reference Arabic coffee. Before roasted date seed extracts will be approved for human consumption, their possible estrogenic effects need to be evaluated.

Kinetics of thermal texture softening, color change and loss of ascorbic acid in potato (Solanum tuberosum) were investigated at selected temperature range (70–100°C) and heating time range (0–50 min). Cut samples of potatoes were heated in a constant temperature water bath at various temperatures. Heat-treated samples were evaluated for texture, color and ascorbic acid by use of a texture-testing machine, a color meter and spectrophotometer, respectively. The biphasic first-order model, the fractional conversion model and the simple first-order model were used for fitting experimental data of time dependence kinetics, while the simple first-order model and Arrhenius model were used for temperature dependence kinetics. The results indicated that the biphasic first-order model can match well to the texture softening of potato samples, the fractional conversion model can well describe the kinetics of color, and the simple first-order model can be used for the kinetics of ascorbic acid. The kinetic parameters including decimal deduction time (D), reaction rate (k), temperature dependence (z) and activation energy (Ea) were determined by the nonlinear regression method. The correlation matrix between quality attributes including texture properties, color and ascorbic acid loss was developed based on the kinetic models. The results obtained from this study were compared with those previously reported.