Effects of Dry Heat Treatment on Characteristics of Hydrophobically Modified Rice Starch and its Emulsification in Pickering Emulsion

Abstract

The effects of electric dry heat (EDH) and roast dry heat (RDH) on characteristics of octenyl succinic anhydride modified rice starches are investigated. The oil-in-water Pickering emulsions are prepared using EDH and RDH starch particles as stabilizers, the stability and interfacial structure of emulsions are evaluated. The results from scanning electron microscopy and Fourier transform infrared spectroscopy demonstrate that rice starches remain in granule structure, and no new absorption peaks are detected after heat treatments. The results of differential scanning calorimeter revealed that gelatinization temperatures (T O , T P, T C ), and enthalpy (𝚫H gel ) have significant reductions after heat treatment (p < 0.05). The starches remain an A-type crystallite with increased in vitro digestibility, however the relative crystallinity decreases from 26.73% to 21.74%. The emulsions stabilized by starches of RDH treatments at 180 °C for 40 and 60 min have the maximum cream volumes, while the emulsions stabilized by EDH starches have no obvious effects. Confocal laser scanning microscopy indicates that the multiple-modified starch particles adsorb at the oil-water interface and present a mechanical barrier to prevent droplets from merging, thus increasing the emulsion stability. The dry heat treatments coupling with hydrophobic modification may be a promising technique to produce starch-based Pickering stabilizers.

Effect of Molecular Weight on the Structural and Emulsifying Characteristics of Bovine Bone Protein Hydrolysate

“…As the molecular weight of the polypeptide increased, the oil droplet particle size of the emulsion system gradually diminished, and the degree of dispersion increased. This demonstrated that the emulsion formed by high-molecular-weight peptides had a more compact and detailed microstructure, which increased the interaction force between the peptides and droplets, and prevented oil droplets from aggregating [37]. This enhanced the stability of the emulsion and was consistent with the findings of earlier studies.…”

Pickering emulsion stabilised by double‐modified starch particles and its delivery property for curcumin

“…Figure 2c shows that the viscosity of the emulsions gradually increased when the pH values increased from 3.0 to 9.0. However, the viscosity was the lowest when the pH was 11.0 because DHT caused a decrease in starch gelatinization temperature (Gong et al ., 2022). When preparing the emulsion, the strong alkali made the starch partially gelatinize, causing the reduction of viscosity.…”

“…While during the 20–30 min of digestion, the FFA release of the emulsion stabilised by RDH‐40, and the bulk sunflower oil increased rapidly. The emulsion stabilised by OS‐starch had the lowest FFA release rate because of its high‐resistant starch content (Gong et al ., 2022). After 60 min of digestion, the triacylglycerols were almost hydrolysed, so the rates of FFA release changed more gently.…”

“…DHT is a new physical modification technique, and it has no significant influence on the appearance of starch granules. However, it increases the starch digestibility due to the structural disintegration of starch granules and the disruption of the double helix within the starch/the reorientation of crystallites (Liu et al ., 2019; Gong et al ., 2022).…”

Preparation, Characterization, and Utilization of Crosslinked and Dual‐Modified Banana Starch for Stabilizing Pickering Emulsion

“…The DHT on native and crosslinked starch was performed according to Gong et al. [ 21 ] Starch sample (50 g, dry weight) was placed in hot air oven at 180 °C for 1 h and then cooled at room temperature. The temperature and time were selected based on the findings of Gong et al., [ 21 ] who found better storage stability for o/w emulsion stabilized by roast dry‐OSA starch.…”