Potential use of red hibiscus flower extract for the production of spray-chilled microparticles: Characterization, stability, and bioaccessibility in vitro of anthocyanins.

Microparticles (MLP) containing red hibiscus flower (Hibiscus rosa-sinensis) anthocyanins were produced by spray chilling, and characterized for physicochemical parameters, accelerated stability, and gastrointestinal release profile. Fully hydrogenated palm oil and cocoa butter were used as wall materials, at a lipid blend to hibiscus extract ratio of 70:30 (w/w). The lipid blends containing fully hydrogenated palm oil (FHPO) and cocoa butter (CB) were produced by ultrasound-assisted technique in the following FHPO to CB ratios: 100:0 (Control), 75:25, 50:50, 60:40, and 40:60. Increasing the cocoa butter content reduced the melting temperature and increased the unstable polymorphic behavior of the microparticles, resulting in amorphous characteristics. The microparticles exhibited higher viscosity, more agglomerates, and holes on the surface, and greater diameters. Characteristic peaks corresponding to the hibiscus extract were observed in the infrared spectra of the spray-chilled microparticles, indicating that the microencapsulation did not affect the anthocyanins. The antioxidant capacity of the red hibiscus anthocyanins ranged from 75 % to 79 %, with the best result observed for the treatment MLP_75:25. Higher antioxidant activities were observed for the lipid blends containing lower cocoa butter concentrations. Concerning the release profile of anthocyanins, the simulated GI digestion in vitro showed reduced release in the gastric tract and more intense release in the intestinal tract for an effective absorption of the antioxidant compounds in the small intestine. Furthermore, the treatment MLP_75:25 showed the highest encapsulation retention and lower total color difference in the accelerated stability study. Overall, the microparticles from all treatments were light-sensitive and thermosensitive at 35 °C. Thus, it is recommended to store the particles in a dark environment at temperatures below 35 °C for an effective use of the microparticles as natural food colorants.

Microstructured lipid microparticles containing anthocyanins: Production, characterization, storage, and resistance to the gastrointestinal tract.

Anthocyanins from grape peel extract have several biological properties and can act as a natural colorant and antioxidant agent. However, these compounds are susceptible to degradation by light, oxygen, temperature, and the gastrointestinal tract. Thus, this study produced microstructured lipid microparticles (MLMs) containing anthocyanins by the spray chilling technique and evaluated the particle stability. trans-free fully hydrogenated palm oil (FHPO) and palm oil (PO) were used as encapsulating materials in the ratios 90:10, 80:20, 70:30, 60:40, and 50:50, respectively. The concentration of grape peel extract was 40 % (w/w) in relation to the encapsulating materials. The microparticles were evaluated for thermal behavior by DSC, polymorphism, FTIR, size distribution and particle diameter, bulk density, tapped density, flow properties, morphology, phenolic compounds content, antioxidant capacity, and retention of anthocyanins. Furthermore, the storage stability of the microparticles was investigated at different temperatures (-18, 4, and 25 °C), and the anthocyanins retention capacity, kinetic parameters (half-life time and degradation constant rate), total color difference, and visual aspects were evaluated during 90 days of storage. The resistance of MLMs to the gastrointestinal tract was also evaluated. In general, higher FHPO concentrations increased the thermal resistance of the MLMs and both showed defined peaks of ß' and ß forms. The FTIR analysis showed that the MLMs preserved the original forms of their constituent materials even after atomization, with interactions between them. The increase in the PO concentration directly affected the increased mean particle diameter, agglomeration, and cohesiveness, as well as lower bulk density, tapped density, and flowability. The retention of anthocyanins in MLMs ranged from 81.5 to 61.3 % and was influenced by the particle size, with a better result observed for the treatment MLM_90:10. The same behavior was observed for the phenolic compounds content (1443.1-1247.2 mg GAE/100 g) and antioxidant capacity (1739.8-1660.6 mg TEAC/100 g). During the storage, MLMs made with FHPO to PO ratios of 80:20, 70:30, and 60:40 showed the highest stability for anthocyanin retention and color changes at the three temperatures (- 18 °C, 4 °C, and 25 °C). The gastrointestinal simulation in vitro revealed that all treatments were resistant to gastric phase and maintained a maximum and controlled release in the intestinal phase, demonstrating that FHPO together with PO are effective to protect anthocyanins during gastric digestion, and can improve the bioavailability of this compound in the human organism. Thus, the spray chilling technique may be a promising alternative for the production of anthocyanins-loaded microstructured lipid microparticles with functional properties for various technological applications.

Development of alginate/pectin microcapsules by a dual process combining emulsification and ultrasonic gelation for encapsulation and controlled release of anthocyanins from grapes (Vitis labrusca L.).

The aim of this study was to investigate the physicochemical, morphological, and gastrointestinal release properties of an anthocyanin-rich extract of grapes in alginate and pectin beads as carriers; the effects of ultrasonic gelation combined with emulsification were also investigated. In general, the alginate beads showed smaller size and more regular shape compared to pectin. The effect of emulsification combined with ionic gelation was more pronounced in the alginate beads and resulted in higher retention of anthocyanins, higher antioxidant capacity, and also allowed the best release profile during intestinal digestion. Thus, the simultaneous strategy could be an interesting delivery system and enhance the release of anthocyanins, providing an opportunity for the development of ingredients with different bioactive properties.

Stability of lime essential oil microparticles produced with protein-carbohydrate blends.

The objective of this work was to analyze the influence of maltodextrin equivalent dextrose on the lime essential oil reconstitution, storage, release and protection properties. Four treatments were evaluated: whey protein concentrate (WPC), and blends of maltodextrin with dextrose equivalents of 5 (WM5), 10 (WM10) and 20 (WM20). The reconstitution and storage properties of the microparticles (solubility, wettability and density), water kinetics adsorption, sorption isotherms, thermogravimetric properties, controlled release and degradation kinetics of encapsulated lime essential oil were studied to measure the quality of the encapsulated materials. The results of the study indicated that the DE degree influences the characteristics of reconstitution, storage, controlled release and degradation characteristics of encapsulated bioactive compounds. The increase in dextrose equivalent improves microparticle solubility, wettability and density, mainly due to the size of the maltodextrin molecules. The adsorption kinetics and sorption isotherm curves confirmed the increase in the hygroscopicity of maltodextrins with higher degrees of polymerization. The size of the maltodextrin chains influenced the release and protection of the encapsulated lime essential oil. Finally, the maltodextrin polymerization degree can be considered a parameter that will influence the physicochemical properties of microencapsulated food.

Stability of spray-dried beetroot extract using oligosaccharides and whey proteins.

The properties and stability of spray-dried beetroot extract using maltodextrin (MD), inulin (IN), and whey protein isolate (WPI) as carrier agents were evaluated. The values of moisture, betalains content, and retention were 3.33-4.24%, 348.79-385.47 mg/100 g (dry-basis), and 88.45-95.69%, respectively. Higher values of antioxidant activity were observed for the treatments using WPI. The treatment with inulin alone presented higher hygroscopicity in the moisture adsorption isotherms at 25 °C and lower thermal stability when evaluating the thermogravimetric curves. When stored at 60 °C, the use of WPI alone conferred lower stability to the beetroot extract powder. In general, the simultaneous use of IN and WPI as carrier agents resulted in good stability of the beetroot extract powder, representing an opportunity for innovation in food products.