Barley β-glucan cryogels as encapsulation carriers of proteins: Impact of molecular size on thermo-mechanical and release properties

Publication date: Available online 30 September 2015 Source:Bioactive Carbohydrates and Dietary Fibre Author(s): A. Lazaridou, K. Kritikopoulou, C.G. Biliaderis The potential use of barley β-glucan cryogels as encapsulation carriers for delivery-controlled release of proteins was explored. For cryogel preparation, mixed β-glucan (4.2% w/w) / protein (0.8%) aqueous dispersions were subjected to 10 freezing (−23°C/24h) and thawing (25°C/24h) cycles, using three purified barley β-glucan isolates differing in molecular weight, Mp (55, 140 and 320kDa) and four proteins, selected as model core constituents; i.e. β-lactoglobulin (18kDa), ovalbumin (43kDa), bovine serum albumin (67kDa), invertase (270kDa). Dynamic rheometry revealed that the mechanical properties of the composite cryostructurates, were significantly affected (p<0.05) by the molecular size of β-glucan and protein. With increasing polysaccharide molecular size the elastic modulus (G′) and the melting enthalpy (ΔΗ) values of the cryogels decreased, while the melting temperature (Tm) of the gels (calorimetry) increased. Incorporation of the highest Mw protein in the β-glucan cryogels also increased (p<0.05) the G′. Large deformation mechanical tests have shown an increase of compression modulus (E) and true stress (σTR) with increasing Mp of the polysaccharide, whereas the cryogel’s swelling capacity, followed the reverse trend. Release kinetics of entrapped proteins was monitor...
Source: Bioactive Carbohydrates and Dietary Fibre - Category: Food Science Source Type: research