Nonionic surfactant and interfacial structure impact crystallinity and stability of β-carotene loaded lipid nanodispersions.

The stability, crystallization, and melting behavior of canola stearin (CaSt) solid lipid nanoparticle dispersions (SLN) and canola oil-in-water emulsions (COE) with 10 wt % Poloxamer 188 (P188) or Tween 20 (T20) with and without 0.1 wt % β-carotene (BC) were investigated. Particles or droplets with diameters in the range of 115 nm were formed and stable for up to 90 days at 4 or 20 °C.

Digestibility and β-carotene release from lipid nanodispersions depend on dispersed phase crystallinity and interfacial properties.

The influence of interfacial structure and lipid physical state on colloidal stability and digestibility of solid lipid nanoparticle dispersions (SLN) and canola oil-in-water emulsions (COE) stabilized with the non-ionic surfactants Poloxamer 188 (P188) and Tween 20 (T20) were examined and the release of encapsulated β-carotene (BC) under simulated gastrointestinal conditions determined. While the SLN and COE were all stable during exposure to gastric conditions (mean diameter ∼115 nm), more destabilization was observed for the COE than SLN during the duodenal phase. ζ-Potential measurements indicated rapid adsorption of bile salts (BS) and phospholipids (PL) to both solid and liquid interfaces, with greater surfactant displacement observed for the COE.

Interfacial design of protein-stabilized emulsions for optimal delivery of nutrients.

Proteins are often used as ingredients in food emulsions, as their amphiphilic structures provide electrostatic and steric stabilization. Significant attention has recently been directed at understanding how the composition and structure of oil-water interfaces change during digestion and how these can be manipulated to enhance the delivery of nutrients contained within the oil droplets. These efforts have necessitated the development of more sophisticated in vitro digestion models of greater physiological relevance and increased efforts in research to identify the role of the various digestive parameters on interfacial dynamics.

Release of lipophilic molecules during in vitro digestion of soy protein-stabilized emulsions.

Scope: Solubilization of lipophilic bioactives in gastrointestinal fluids contributes to their bioavailability, but a better understanding of the transfer processes involved and the impact of molecular structure is required.

Methods And Results: The transfer of β-carotene (BC), coenzyme Q10 (CoQ10), vitamin D3 (VitD3), and phytosterols (PSs) from soy protein isolate-stabilized oil-in-water emulsions to the aqueous phase during in vitro digestion was investigated. In the absence of lipolysis, transfer was mainly governed by molecular structure and partitioning within the oil droplets.

Impact of interfacial composition on emulsion digestion and rate of lipid hydrolysis using different in vitro digestion models.

A sequential in vitro model of digestion was used to investigate the changes in the physicochemical properties of emulsions during gastrointestinal transit. Oil-in-water emulsions were prepared with whey protein isolate (WPI) or soy protein isolate (SPI) at the same protein concentration (1.5%).

Surface adsorption alters the susceptibility of whey proteins to pepsin-digestion.

An in vitro digestion model mimicking the gastric phase of the human gastrointestinal tract coupled with SDS-PAGE and MALDI-TOF mass spectroscopy was employed to study the hydrolysis profiles of whey proteins in solution and adsorbed at the oil-water interface. The objective of this work was to understand the differences in hydrolysis behaviour of whey protein isolates once adsorbed at the interface, and comparisons were carried out with pure beta-lactoglobulin and alpha-lactalbumin fractions. In solution, while beta-lactoglobulin appeared to be resistant to enzymatic treatment, alpha-lactalbumin was fully degraded.

Protein recovery in soymilk and various soluble fractions as a function of genotype differences, changes during heating, and homogenization.

Harovinton, a variety of tofu type soybean, and 11 derived null soybean genotypes lacking specific glycinin (11S) and beta-conglycinin (7S) protein subunits were investigated to determine whether changes in protein composition affected the protein recovery in soymilk and its soluble fractions after various centrifugation steps. As both heating and homogenization have a marked effect on the increase in protein solubility, the changes occurring during these processing steps were studied for each soybean genotype. Harovinton and 11S-null genotypes showed significantly higher protein yields than the other genotypes evaluated.