Nutraceutical and bioactive potential of high-quality date fruit varieties (Phoenix dactylifera L.) as a function of in-vitro simulated gastrointestinal digestion.

The present study aims to investigate the digestive process (gastric and intestinal phases) effects on the survivability of total and individual phenolic compounds, and the in vitro health-related bioactive properties of four high-quality and commonly consumed dates (Phoenix dactylifera) varieties (Safawi, Khalas, Khudri, and Booman). Phenolic compounds were analyzed by HPLC-UV (at 275 nm) and a higher amount of phenolics were identified in Khalas and Booman intestinal digested extracts, compared to the other date varieties-based extracts, which corroborates with the total phenolic contents in those samples, with respective values of 186.5 and 358.14 mg GAE/100 g. Considering their bioactive potentialities, the highest DPPH radical scavenging activities, of around 320 TEAC µg/mL, were observed with Khalas and Khudri gastric extracts. In contrast, Khalas intestinal extract displayed the highest ABTS radical scavenging potential of 969 TEAC µg/mL. Moreover, the Safawi intestinal extract, along with Khalas and Booman gastric extracts, showed the highest increase in the α-glucosidase inhibition activity, compared to the other date varieties-based extracts. Safawi and Khalas intestinal extracts displayed the highest DPP-IV inhibition activities (IC of 2.85 µg/mL). Additionally, regarding the pancreatic lipase and cholesterol esterase inhibition, Khudri and Khalas varieties after intestinal digestion demonstrated the highest activities. These results suggested that the Khalas variety showed more potent bioactive properties than other date varieties, mainly related to the variations in the phenolic content between date varieties. Overall, this study provides additional insight into investigating these dates varieties upon their simulated gastro-intestinal digestion and exhibition of multifunctional bioactive properties.