Physicochemical and in vitro digestive characteristics of water-soluble chickpea polysaccharides extracted using ultrasound and freeze-thaw methods

A combination of ultrasound and freeze-thaw treatments was used to extract water-soluble polysaccharides (CWP) from chickpea (Cicer arietinum L.), a nutrient-dense legume rich in dietary fiber and bioactive compounds. The result was an enhanced extraction yield of up to 13.76 % and improved antioxidant properties, as indicated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical-scavenging rates of 59.66 % and 70.49 %, respectively. Assessment of the physicochemical and digestive characteristics of CWP using in vitro simulated digestion and fermentation models confirmed that CWP underwent partial degradation during simulated saliva-gastrointestinal digestion and was further utilized by gut microbiota during fecal fermentation. CWP promoted 1.6-fold and 1.1-fold increases in short-chain fatty acid production compared to blank and positive (inulin) controls, respectively. CWP also supported the growth of probiotic bacteria, including Bifidobacterium spp. and butyrate-producing species (i.e., Blautia spp.). These findings highlight the potential of CWP as a functional food ingredient with gut health benefits.