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.

Effect of polyvinyl alcohol and carboxymethylcellulose on the technological properties of fish gelatin films.

The objective of this work was to develop biodegradable films by mixing gelatin/carboxymethylcellulose (FG/CMC) and gelatin/polyvinyl alcohol (FG/PVOH) and to evaluate the effect of adding these polymers on the properties of fish gelatin films. The films FG/CMC and FG/PVOH were produced in the proportions 90/10, 80/20 and 70/30 and characterized their physical, chemical and functional properties. The addition of CMC and PVOH improved the mechanical strength, barrier property and water solubility of gelatin films. FG/CMC films showed greater tensile strength and greater solubility than FG/PVOH. The maximum concentration of CMC promoted the highest mechanical resistance, while the highest PVOH content produced the film with the lowest solubility. The proposed mixing systems proved to be adequate to improve the properties of fish gelatin films, with potential for application in the packaging sector.

Encapsulation of camu-camu extracts using prebiotic biopolymers: Controlled release of bioactive compounds and effect on their physicochemical and thermal properties.

Camu-camu (Myrciaria dubia [H.B.K] McVaugh) is a Amazonian fruit rich in ascorbic acid and phenolic compounds, and has been attracting great interest from the food, pharmaceutical and nutraceutical industries due to its potential health benefits. The bioactive compounds from camu-camu are considered sensitive and unstable, resulting in nutritional losses and impairment of its commercialization and export. For this reason, the camu-camu extract (pulp and peel) was subjected to microencapsulation by spray drying process using maltodextrin (MD), inulin (IN), and oligofructose (OL) as carrier agents. Lyophilized in natura camu-camu extract (CEL) was also evaluated. Thus, physicochemical and thermal properties and controlled release at different temperatures (25 °C and 35 °C) were investigated. In contrast with the IN and OL microparticles, the MD microparticles showed lower density and hygroscopicity, besides greater thermal stability, antioxidant activity, and retention of ascorbic acid and anthocyanins. FTIR spectra allowed the qualitative evidence of encapsulation of the bioactive compounds from the camu-camu extract. The highest percentage of volatile compounds was observed in IN microparticles, followed by OL and MD microparticles. The major group of compounds identified in CEL were terpenes (88%). The Korsmeyer-Peppas mathematical model allowed to describe the controlled release behavior of ascorbic acid and anthocyanins in the powder extracts. The controlled release followed a Fickian diffusion mechanism (n ≤ 0.43). The increase of temperature from 25 °C to 35 °C influenced on the release of bioactive compounds in all treatments, showing greater release for MD microparticles. The encapsulating materials were considered effective for the production of camu-camu extract powder, contributing to the better use of this Amazonian fruit. In addition, the encapsulation process increased the stability of its bioactive compounds, representing a tool to facilitate their incorporation in several matrices to act as antioxidant and coloring agents, as well as nutraceutical.