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High pressure processing (HPP) is an emerging non-thermal processing technology and a preparation method to induce protein-polysaccharide mixed gels, which can encapsulate and delivery thermosensitive bioactive compounds. This study investigated the properties of β-lactoglobulin (β-Lg)/κ-carrageenan (κ-car) mixed gels induced by HPP (0.1–600 MPa for 30 min, 25 °C) with different ratios of β-Lg to κ-car at pH 3.0, 5.0 and 7.0. The results showed that the pressure required to form β-Lg/κ-car mixed gels was at least 400 MPa when the β-Lg/κ-car mass ratio increased to 14:1 at all tested pH values. The water holding capacity and textural properties increased with the increase of pressure levels. The hydrophobic interaction was dominant in the mixed gels induced by HPP at all pH values, and the network structure was more compact and smoother with higher pressure. • It can form mixed gels by HPP directly at β-Lg: κ-car≥8: 1 (P = 600 MPa for 30 min). • HPP can improve gel strength, WHC and textural properties of β-Lg/κ-car mixed gels. • The hydrophobic interaction was dominant in the mixed gels. • The network structure was more compact and smoother with higher pressure. [ABSTRACT FROM AUTHOR]

The effects of different heat-treated temperatures (75, 85 and 95 °C) and times (15, 30 and 45 min) on physical, structural, thermal and morphological characteristics of zein in ethanol-water solution were investigated. The result of particle size distribution suggested that the volume percentage of small zein colloidal nanoparticles (d < 200 nm) was increased from 87.9% to 98.2% after heat treatment at 75 °C for 15 min. Both of the fluorescence intensity and ultraviolet absorption of zein approached to the maximum value when zein solution was heated at 95 °C for 30 min. Differential scanning calorimetry thermograms implied that heat treatment enhanced the thermal stability of zein with the rise of denaturation temperature. The secondary structure changes of zein induced by heat treatment might be explained by a potential mechanism of three-step process, including partial protein folding, a larger extent unfolding and the formation of partial protein aggregates. In addition, heat treatment significantly modified the morphology of zein from the typical sphericity to distinct oval at 75 and 85 °C, as well as obvious dumbbell-like shape at 95 °C for 30 min. [ABSTRACT FROM AUTHOR]