Developing a bioactive brew is a novel track for revalorization of palm date byproducts. The effect of roasting temperature (160, 180 and 200 °C ) and roasting time (10, 20 and 30 min) on the hardness of the roasted date seeds, moisture content of the defatted roasted date seed powder (DRDSP), bulk density of the DRDSP, color parameters of DRDSP, quality attributes (extraction yield, pH and browning index), the chemical properties (antioxidants and total phenolic content) and the sensory attributes (color, aroma, taste and overall preference) of the brew prepared from DRDSP was studied. The physicochemical, quality, and sensory attributes were found to be significantly influenced by the roasting temperature and time. Additionally, the models proposed could satisfactorily describe the changes in the different properties during the roasting process. The optimum conditions of the roasting process obtained using the superimposed contour plot were 199.9 °C and 21.5 min. In the longer term, the results of this study would be beneficial for the manufacturers of the date seeds powder and brew.

Palm date seeds can be a potential source to prepare a decaffeinated coffee-like brew and to produce oil. Hence, the objectives of this work are to model the changes in colour and hardness of date seeds during roasting process, as well as to study the effects of roasting conditions on the total specific grinding energy and the oil extraction yield of the seeds. General reaction models and general regression equation were applied to simulate the changes in colour, hardness, oil extraction yield, and total specific grinding energy during roasting process. The outcomes showed that the colour parameters (L*-value and b*-value) and the hardness of the roasted date seeds can be satisfactorily described by the first-order equation, while a*-value and ΔE were adequately defined by the zero-order model. A decrease in total specific grinding energy and an increase in oil yield were recorded as the roasting temperature and time were increased. Hence, this study concludes that the roasting of date seeds at 200 ℃ for 30 min generates the lowest grinding energy and a high amount of oil.

No abstract

No abstract

No abstract