Abstract: A high protein food that is easy to swallow for people with dysphagia was prepared by blending milk with Hericium erinaceus (HE) powder, soy protein isolate (SPI) or whey protein (WP) (which was added to obtain a final protein content more than 10% of the total mass), and one of three thickeners including xanthan gum (XG), kappa carrageenan (KC) and carboxymethylcellulose (CMC), and its rheology, viscoelastic properties and in vitro digestion characteristics were determined. The results showed that all samples exhibited a weak gel behavior. According to the steady-state rheological test, the values of high resistance to deformation (high G* value) and good elasticity (low tan δ value) were ranked as follows: HE-SPI-CMC > HE-SPI-XG > HE-WP-XG > HE-WP-KC, and higher G* values were more favorable for people with dysphagia and the elderly. In the in vitro simulated digestion test, the viscosity (η) and consistency coefficient (K) values were in the following order: HE-WP-KC > HE-WP-XG > HE-SPI-XG. The soluble protein contents were ranked as follows: HE-WP-CMC > HE-WP-KC > HE-SPI-KC. The contents of free amino acids after digestion were in the following order: HE-WP-CMC > HE-WP-KC > HE-SPI-KC > HE-WP-XG. Therefore, HE-WP-KC was more suitable for consumption by the elderly. This study has explained how protein-hydrocolloid interactions and food matrix determine the rheological properties and digestibility properties of the samples, which may provide theoretical support for meeting the dietary needs of people with dysphagia.

Key words: Hericium erinaceus; rheology; in vitro digestion; proteolysis