Characterizing date seed polysaccharides: A comprehensive study on extraction, biological activities, prebiotic potential, gut microbiota modulation, and rheology using microwave-assisted deep eutectic solvent

•Date seed polysaccharides: Antioxidant prowess, potent antimicrobial agent.•Microwave-assisted extraction unveils diverse bioactivities in MPS.•MPS inhibits α-glucosidase, α-amylase, ACE, and cancer cells.•Fostering beneficial fecal microbiota with major SCFAs production.•Versatile MPS: Rheological properties and growth of gut-friendly microbes. This study investigated the biological activities, prebiotic potentials, modulating gut microbiota, and rheological properties of polysaccharides derived from date seeds via microwave-assisted deep eutectic solvent systems. Averaged molecular weight (246.5 kDa) and a monosaccharide profile (galacturonic acid: glucose: mannose: fructose: galactose), classifying MPS as a heteropolysaccharide. MPS, at concentrations of 125–1000 µg/mL, demonstrates increasing free radical scavenging activities (DPPH, ABTS, MC, SOD, SORS, and LO), potent antioxidant potential (FRAP: 51.2–538.3 µg/mL; TAC: 28.3–683.4 µg/mL; RP: 18.5–171.2 µg/mL), and dose-dependent antimicrobial activity against common foodborne pathogens. Partially-purified MPS exhibits inhibition against α-glucosidase (79.6 %), α-amylase (85.1 %), and ACE (68.4 %), along with 80 % and 46 % inhibition against Caco-2 and MCF-7 cancer cells, respectively. Results indicate that MPS fosters the growth of beneficial fecal microbiota, including Proteobacteria, Firmicutes, and Actinobacteria, supporting microbes responsible for major SCFAs (acetic, propionic, and butyric acids) production, such as Ruminococcus and Blautia.