iridoids and maltodextrin

Olive leaves extract (OLE) was spray-dried with maltodextrin (MD) or inulin (IN) to study the evolution of oleuropein (OE) during in vitro gastrointestinal digestion, its bioaccessibility and potential bioavailability. In the case of OLE-MD, OE was partially degraded in gastric and intestinal conditions; whereas in OLE-IN, OE was released under gastric conditions and partially degraded under intestinal conditions. In both cases, the encapsulation of OLE led to higher OE contents at the end of digestion, compared with non-encapsulated OLE, suggesting a protective role of the polysaccharides by the formation of non-covalent polysaccharides-OE complexes. OE bioaccessibility was ten times higher (p ≤ 0.05) in OLE-MD and OLE-IN than in non-encapsulated OLE. However, OE potential bioavailability, evaluated by tangential filtration, was not detected. Encapsulation technology and the encapsulant agent used may determine the release of the encapsulated compounds at a specific-site and their effect on health.

Topics: Biological Availability; Biological Products; Digestion; Inulin; Iridoid Glucosides; Iridoids; Plant Leaves; Polysaccharides

Cross-linked gelatin microgels were formed in gelatin-in-maltodextrin water-in-water (W/W) emulsions and evaluated as carriers of the enzyme β-galactosidase (β-Gal). The phase behavior of aqueous gelatin/maltodextrin mixtures was studied in detail, focusing on the multiphase region of the phase diagram that is constituted by three equilibrium phases: two immiscible aqueous phases plus one solid phase. The solid phase was analyzed by Raman spectroscopy, and water-in-water emulsions were formed within the multiphase region. Gelation of the dispersed gelatin droplets was induced by cooling and cross-linking with genipin, which is a natural cross-linking reagent of low toxicity, leading to the formation of gelatin microgel particles. These microgels were studied as delivery vehicles for the enzyme lactase, used as a model active component. Various incorporation methods of the enzyme were tested, to achieve highest encapsulation yield and activity recovery. Microgel particles, loaded with the enzyme, can be freeze-dried, and the enzyme remained active after a complete cycle of freeze-drying and rehydration. The stability of the enzyme at 37 °C under gastric and neutral pH conditions was tested and led to the conclusion that the cross-linked microgels could be suitable for use in food-industry, where β-Gal carriers are of interest for hydrolyzing lactose in milk products.

Topics: beta-Galactosidase; Emulsions; Freeze Drying; Gelatin; Gels; Hydrogen-Ion Concentration; Iridoids; Particle Size; Phase Transition; Polysaccharides; Water

To improve survival during exposure to adverse conditions, probiotic Bifidobacterium adolescentis 15703T cells were encapsulated in novel mono-core and multi-core phase-separated gelatine-maltodextrin (GMD) microspheres where the gelatine (G) phase was cross-linked with genipin (GP). Microscopy showed that encapsulated cells were exclusively associated with maltodextrin (MD) core(s). Small (average diameter 37 microm) and large (70 microm) GMD and G microspheres were produced by modulating factors (e.g. mixing speed, surfactant, GP and G concentrations) affecting the size, structural stability and phase-separation. In vitro sequential gastro-intestinal (GI) juice challenge experiments revealed increased survival of cells encapsulated in GMD ( approximately 10(6-7) cfu mL(-1)) and G (approximately 10(5) cfu mL(-1)) microspheres as compared to free cells (approximately 10(4) cfu mL(-1)). In GMD microspheres, the bacteria derive energy from MD to survive during exposure to acid and bile salts. In conclusion, the novel food grade GMD microencapsulation formulation was shown to protect probiotic bifidobacteria from adverse conditions.

Topics: Bifidobacterium; Cells, Immobilized; Cross-Linking Reagents; Drug Compounding; Gastric Juice; Gastrointestinal Tract; Gelatin; Iridoid Glycosides; Iridoids; Phase Transition; Polysaccharides; Probiotics

The physical properties and microstructure of gelatin-maltodextrin hydrogels fixed with genipin (GP) were investigated as a function of pH (3-7), maltodextrin (MD) (0-9%, w/w) and GP (0-10 mM levels), at a constant gelatin (G) concentration (10%, w/w). Network strength (elastic modulus, E) and swelling behavior were characterized by large deformation testing and by swelling index (SI). In general, network strength increased and swelling decreased at higher pH, MD and GP levels, except at pH 3, where E was independent of the GP concentration until approximately 7.5 mM, above which it declined. Confocal scanning laser microscopy (CLSM) images showed phase separation to be suppressed at pH 3, whereas at pH 7, separation into a self-similar dispersed phase was apparent. Overall, the judicious use of GP to crosslink G was an appropriate means of kinetically trapping MD within the gelatin network.

Topics: Animals; Chemical Phenomena; Chemistry, Physical; Gelatin; Hydrogels; In Vitro Techniques; Iridoid Glycosides; Iridoids; Microscopy, Confocal; Molecular Structure; Polysaccharides; Pyrans; Swine