Polysaccharide-stabilized aqueous foams to fabricate highly oil-absorbing cryogels: Application and formation process for preparation of edible oleogels

The application of biopolymers in soft edible materials has been gaining particular concerns, especially the replacement of saturated fats. This work presented a lightweight and highly oil-absorbing cryogel fabricated by two polysaccharides (hydroxypropyl methylcellulose (HPMC) and xanthan gum (XG)) via the foam-templated method to prepare oleogels with low-saturated oils. The cryogel was freeze-dried from HPMC and XG co-stabilized aqueous foams, in which the polysaccharide-based network was established. The thickening effect of XG dramatically improved the bubble stability, which avoided the bubble collapse during cryogelation and greatly heightened the oil absorption capacity of cryogels. Cryogels had a porosity >97% and could absorb 72 times their weight of oils at the HPMC concentration of 0.8 wt%. Increased HPMC diminished pores of cryogels, hardening the cryogel and generating a greater capillary force for preparing viscoelasticity-enhanced oleogels. The temperature-stable oleogel was endowed with a better structural recovery ability from adding XG. Absorption kinetic models showed that irregular pores in cryogels had similar sizes. Polysaccharides are promising materials to create porous bio-functional cryogels and construct low saturated oleogels, facilitating oleogels to substitute saturated fats.