Ultrasound combined mechanical wall-breaking extraction of new Ganoderma leucocontextum polysaccharides and their application as a structural and functional improver in set fat-free goat yogurt production.

Herein, we investigate the yield, micro-structures, rheological properties and bioactivities of new Ganoderma leucocontextum polysaccharide (GLP) obtained from Kangding via ultrasound combined mechanical wall-breaking extraction (UBE), and examine the effect of GLP as a structural and functional improver on the physicochemical, sensory, aromatic, water-holding capacity (WHC), textural, rheological, micro-structural and protein structural properties, and bioactivities of set fat-free goat yogurt (set-FGY). Through response surface optimisation, the extracted GLP achieved a maximum yield of 2.18 %, showing good apparent viscosity and elastic behaviour in 3 % aqueous solution as well as good micro-structure and significant anti-oxidant and anti-diabetic activities.