Eduardo Artuto Soto-Bustamante

This study compared the physicochemical properties of inulin caffeate, where caffeic acid (CA) was covalently bound to inulin (CA-Inu, degree of substitution: 0.07), with CA spray-dried inulin microparticles (Mp(CA/Inu)), as well as release profiles of CA from CA-Inu and Mp(CA/Inu) under in vitro simulated gastrointestinal digestion. Encapsulation by spray drying was optimized using a Central Composite Design, achieving an encapsulation efficiency of 98%. CA was rapidly released from Mp(CA/Inu) during the oral and gastric phases, followed by a slight decrease in the intestinal phase due to interaction with digestive enzymes. In contrast, no release of CA was detected from CA-Inu during the oral and gastric phases. Approximately 30% was released in the intestinal phase, with a further increase in the colonic phase, especially in the presence of inulinase. This strategy, based on the covalent binding of phenolic compounds to biopolymers, can promote targeted delivery in the later stages of gastrointestinal digestion.

The development of phenolic-based functional food ingredients is of growing interest due to their beneficial effects on human health. This study investigated the combined influence of microparticle physical state, phenolic compound type (gallic acid, GA; and ellagic acid, EA), and model food matrix on the release profile, bioaccessibility, and antioxidant activity of GA and EA during in vitro gastrointestinal digestion. GA and EA were encapsulated with inulin (In) by spray-drying. By varying formulation and operational conditions, both semicrystalline (GA-InSc, EA-InSc) and amorphous (GA-InA, EA-InA) microparticles were obtained. Microparticles were characterized for crystallinity, encapsulation efficiency, particle size, morphology, and release profile during in vitro simulated gastrointestinal digestion following the INFOGEST method. The physical state of microparticles and type of phenolic compound critically influenced release profile, bioaccessibility, and antioxidant activity during digestion. GA, being more water-soluble, was rapidly released, reaching nearly 100% in the gastric phase, whereas EA exhibited limited gastric release and higher intestinal release, particularly in EA-InSc. Incorporation into different food matrices further modulated these effects; carbohydrate- and blend-based matrices improved phenolic release and antioxidant activity for both compounds. These findings highlight the importance of microparticle formulation, phenolic characteristics, and matrix interactions in designing functional food ingredients with optimized health benefits.

Purified walnut oil (PWO) microparticles with Capsul^® (C, encapsulating agent), sodium alginate (SA) as outer layer and ascorbic acid (AA) as oxygen scavenger were obtained by spray drying using a three-fluid nozzle. AA was incorporated in the inner infeed (PWO-C(AA)/SA), in the outer infeed (PWO-C/SA(AA)) and in both infeed (PWO-C(AA)/SA(AA)). PWO-C(AA)/SA (4.56 h) and POW-C(AA)/SA(AA) (2.60 h) microparticles showed higher induction period than POW-C/SA(AA) (1.17 h), and lower formation of triacylglycerol dimers and polymers during storage (40 °C). Therefore, AA located in the inner infeed improved the oxidative stability of encapsulated PWO by removing the residual oxygen. AA in the SA outer layer did not improve the oxidative stability of encapsulated PWO since oxygen diffusion through the microparticles was limited and/or AA weakened the SA layer structure. The specific-location of AA (inner infeed) is a strategy to obtain stable spray-dried polyunsaturated oil-based microparticles for the design of foods enriched with omega-3 fatty acids.

Beeswax-based organogels were formulated with linseed oil and curcumin according to a statistical design to increase the oxidative stability of spreadable meat products (pâté) where these organogels (OGCur) were incorporated as fat substitutes. The organogels obtained under optimal conditions (9.12% beeswax, 0.54% curcumin) showed a mechanical strength similar to pork backfat determined by back extrusion and high oil binding capacity (OBC; over 90%). The incorporation of curcumin at this concentration did not lead to any change in the arrangement of the crystal network, OBC, and mechanical, thermal, or rheological properties of the organogels. Beeswax organogels with and without curcumin, with a β’ orthorhombic subcell structure, showed a predominant elastic behavior and a melting event wider and shifted to lower temperatures than pure beeswax, suggesting a plasticizer effect of the oil in the wax crystals. The oxidative stability of the organogels under accelerated oxidation conditions increased due to the incorporation of curcumin. A decrease in the curcumin content was found from day 4 at 60 °C, together with a significantly lower formation of both peroxides and malonaldehyde. When pork backfat was partially or totally replaced by OGCur in pâtés, a noticeable protective effect of curcumin against lipid oxidation was found during chilled storage

The synthesis and phase characterisation of a homologous series of monomers of acrylic phenyl benzoates has been carried out. The characterisation comprises polarised optical microscopy, differential scanning calorimetry and powder x-ray diffractometry. All monomers are mesogenic, exhibiting either nematic and/or smectic phase. Shorter monomers are nematogenic while longer monomers show a more smectogenic character. Most of the monomers show monotropic phases.

The effect of the physical state of flavonoid-inulin microparticles (semi-crystalline/amorphous) on the oxidative stability of lipid matrices was studied. Epicatechin (E) and quercetin (Q) microparticles with inulin were formulated at two infeed temperatures (15 °C and 90 °C) by spray drying. X-ray diffraction analyses showed that flavonoid-inulin microparticles obtained at feed temperature of 15 °C were semi-crystalline (E-In-15, 61.2% and Q-In-15, 60%), whereas those at 90 °C were amorphous (Q-In-90, 1.73 and Q-In-90 2.30%). Semi-crystalline state of flavonoid-inulin microparticles enhanced the EE (68.8 and 67.8% for E and Q, respectively) compared to amorphous state (41.6 and 51.1% for E and Q, respectively). However, amorphous Q-microparticles showed the highest antioxidant activity both in methyl linoleate and sunflower oil, increasing the induction period and decreasing the polar compounds and polymer triglyceride formation during long-term oxidation study. Therefore, the physical state of spray-dried flavonoid-inulin microparticles may determine their antioxidant activity in lipid matrices.

We observe the changes in the interactions of the liquid crystal (E)-6-(3-hydroxy-4-(((4-octyloxy)phenyl)imino)methyl) phenoxy)hexyl methacrylate (M6R8) with nanoparticles of TiO₂ as the concentration of the nanoparticle increases from 0 wt% to 30 wt%, both as a monomer as well as when they are electropolymerised with the nanoparticles included. The system is studied using transmission X-ray scattering, grazing incidence small angle X-ray scattering (GISAXS) and in-plane direction X-ray scattering. We have found that in addition to the monomer peak, we observe two peaks: a shoulder peak that appears close to the liquid crystal peak and a smaller peak that develops with particle concentration. These two peaks can be considered a result of nanoparticle – liquid crystal interaction. We find that as a function of the concentration the smC can be disordered or ordered, while the smA phases converge to the same order of magnitude, as shown by the convergence of the correlation length ξ. The order observed in the smA phase appears to be the same no matter the concentration used. Once electropolymerised we find no convergence in the region of the smA mesophase of the monomer.