Optimized Roasting Parameters of Full-fat Date Palm Seed (Phoenix Dactylifera L.) Using a Central Composite Design and Chemometric Approach to Prepare Antioxidant-rich Beverage

Date palm seeds Phoenix Dactylifera L. can be used as a food substitute through roasting. The method is a pretreatment process of date seed powder at a temperature range of 160°-200°C. The main objective of this study was to investigate the effects of roasting parameters on the phytochemical compounds present in date palm seeds Phoenix Dactilifera L. and their activities by DPPH assay using a Central Composite Design (CCD) approach. The CCD was applied to optimize the roasting parameters such as temperature (X1: 160–200°C) and roasting time (X2: 15–45 min). Our results show that antioxidant activity increases with increasing roasting parameters (temperature, time) of roasted date seeds. At the same time, the extraction yield and pH value are less affected by the process. On the other hand, there was a significant increase in the Browning Index (BI) associated with changes in powder tone. Furthermore, the Principal Component Analysis (PCA) reveals a substantial positive connection between the antioxidant activity and the phenolic compounds. Consequently, the roasted seeds had important value-added in terms of antioxidant activities. The results of this study will be useful to food manufacturers of date palm seeds, especially as a substitute for decaffeinated coffee with higher bioactive compounds.