Soraia Vilela Borges

Gum arabic/starch/maltodextrin/inulin as wall materials on the microencapsulation of rosemary essential oil.

The effects of the partial or total replacement of gum arabic by modified starch, maltodextrin and inulin on the characteristics of rosemary essential oil microencapsulated by spray drying were evaluated in this study. The lowest level of water absorption under conditions of high relative humidity was observed in treatments containing inulin. The wettability property of the powders was improved by the addition of inulin. The total replacement of gum arabic by modified starch or a mixture of modified starch and maltodextrin (1:1, m/m) did not significantly affect the efficiency of encapsulation, although higher Tg values were exhibited by microcapsules prepared using pure gum arabic or gum arabic and inulin. 1,8-cineol, camphor and α-pinene were the main components identified by gas chromatography in the oils extracted from the microcapsules. The particles had smoother surfaces and more folds when gum arabic or inulin was present. Larger particles were observed in the powders prepared with pure gum arabic or modified starch.

Aproveitamento alternativo da casca do maracujá-amarelo (Passiflora edulis F. Flavicarpa) para produção de doce em calda

Passion fruit peel is a by-product of the juice industry and its processing into preserve is proposed as alternative use. The aims of the work were to select the best syrup concentration for the preserve and test its acceptability among consumers of different ages. The physical characteristics of the fruits were evaluated and the peel composition was determined, The sensory evaluation method of paired comparisons was used to select the best sucrose concentration and the consumer (children, teenagers and adults) acceptance was evaluated using a 5 points hedonic scale. No significant differences were found among the test concentrations but with a 55°Brix syrup showed more than 80% acceptance at all age groups and the preference was significantly higher among children.

Microencapsulation of Rosemary Essential Oil: Characterization of Particles

This study evaluated the influence of wall material concentration (10–30%), inlet temperature (135–195°C), and feed rate (0.5–1.0 L · h−1) on the properties of rosemary oil microencapsulated by spray-drying, with gum arabic as carrier. Powder recovery, surface oil, oil retention, and hygroscopicity varied from 17.25%–33.96%, 0.03%–0.15%, 7.15%–47.57%, and 15.87%–18.90%, respectively. The optimized conditions were determined to be a wall material concentration of 19.3%, an inlet air temperature of 171°C, and a feed flow rate of 0.92 L · h−1. At this condition, particles presented no fissures and the compositions of pure and microencapsulated oil were similar. The sorption isotherms could be described by the GAB model.

Influence of spray drying operating conditions on microencapsulated rosemary essential oil properties

A secagem por atomizacao e um importante metodo utilizado pela industria de alimentos na producao de flavors microencapsulados, melhorando suas propriedades de manuseio e dispersao. O objetivo deste estudo foi avaliar a influencia das condicoes de processo nas propriedades de oleo essencial de alecrim microencapsulado por secagem por atomizacao, utilizando-se goma Arabica como agente encapsulante. Os efeitos da concentracao de material de parede (10% a 30%), temperatura de entrada do ar (135-195 oC) e vazao de alimentacao (0.5-1.0 L.h-1) na umidade, higroscopicidade, molhabilidade, solubilidade, densidades de leito e compactada, densidade de particula, e fluidez e coesividade foram avaliados atraves de um delineamento experimental composto central rotacional 23. A umidade, higroscopicidade e molhabilidade foram afetadas significativamente pelos tres fatores analisados. A densidade de leito foi influenciada positivamente pela concentracao de material de parede e negativamente pela temperatura do ar de entrada. Ja a densidade de particula foi influenciada pelas variaveis concentracao de material de parede e temperatura do ar de entrada, ambas de forma negativa. Para a solubilidade, densidade compactada, fluidez e coesividade, os modelos nao apresentaram bons ajustes para a variacao dos dados. Os resultados indicaram que uma moderada concentracao de material de parede (24%), baixa temperatura de entrada do ar (135 oC) e moderada vazao de alimentacao (0,7 L.h-1) foram as melhores condicoes para o processo de secagem por atomizacao.

Use of allyl isothiocyanate and carbon nanotubes in an antimicrobial film to package shredded, cooked chicken meat

We developed antimicrobial packaging incorporated with allyl isothiocyanate (AIT) and carbon nanotube (CNT), and this packaging was used for shredded cooked chicken meat inoculated with Salmonella Choleraesuis. The following parameters were analysed during the 40 days of storage: microbial counts, colour characteristics and changes in the oxidation of the meat as well as changes in the mechanical properties of the film, the structure of the antimicrobial film and the diffusion of the antimicrobial agent into the food. The incorporation of AIT into the films increased the elongation at the break (E) value of the films and decreased the tensile strength (TS) value of the films. The CNT was important to retain the AIT which is a volatile substance in the film. The diffusion of the AIT from the film into the chicken reduced the microbial contamination, controlled oxidation and reduced the colour changes. Thus, these packages were effective for the 40 days of storage.

Spray-dried tomato powder: reconstitution properties and colour

Tomate em po foi produzido por secagem por atomizacao da polpa de tomate. Um planejamento 23fatorial completo com ponto central foi conduzido variando a taxa de alimentacao (127276 g/min), temperatura de entrada do ar (200-220oC) e a velocidade de atomizacao (25000-35000 rpm). As respostas analisadas foram: conteudo de umidade, solubilidade, molhabilidade, consistencia e cor, ma os fatores somente afetaram significativamente a cor. Todas as amostras tornaram significantemente mais escuras e menos vermelhas com o aumento das variaveis sob estudo. Baixa velocidade de atomizacao (25000 rpm) e menor temperatura do ar de secagem (220oC) produziram pos de maior indice de cor (a/b) e menor escurecimento.

Optimization of fish oil spray drying using a protein: inulin system

The aim of this work was to investigate the use of an unconven-tional polymeric material, inulin, in fish oil spray drying. The influence of inlet air temperature, oil load, and carrier substitution (whey protein isolate by inulin) on the physical properties of particles containing fish oil was investigated. Increasing the oil load caused an increase in the surface oil; however, the presence of inulin favorably decreased the particle surface oil when a high oil lad was applied. The parameters hygroscopicity and wettability were also influenced by the inulin fraction. The higher inlet air temperature produced larger particles with lower densities. The best operating conditions were determined to be an air temperature of 185°C, a 40% inulin fraction, and a 6% oil load. The results indicate that inulin is an alternative carrier in the fish oil spray-drying process.

Influence of spray drying conditions on the physical properties of dried pulp tomato.

A complet factorial experimental design was applied to determinate the influence of the variable inlet air temperature, feed flow rate, and atomizer speed on the physical properties of the tomato pulp powder. Results showed that these variables had a significant positive effect on the moisture content, apparent density, and particle size and no significant effects on the porosity and true density. The best spray drying conditions to produce lower moisture content and higher apparent density tomato powder were inlet air temperature of 200 °C, feed flow rate of 276 g/min, and atomizer speed of 30000 rpm.

Development of chitosan/montmorillonite nanocomposites with encapsulated α-tocopherol.

Nanocomposites of chitosan (CS) were developed and characterized in a full factorial design with varying levels of montmorillonite (MMTNa) and encapsulated tocopherol (toc-encap). The structural properties (XRD, FTIR), morphology (TEM), hygroscopic properties (water vapour permeability, hydrophobicity, sorption isotherms) and optical properties (haze, CIELab parameters) of the resulting materials were evaluated. Toc-encap contents up to 10% influenced the intercalation of MMTNa in the CS matrix, resulting in films with reduced water vapour permeability (3.48×10(-11)(g/msPa)), increased hydrophobicity (ΔGHydroph |7.93-59.54|mJm(-2)) and lower equilibrium moisture content (EMC), thus showing potential for active food packaging materials. At levels above 10%, toc-encap agglomerates occurred, which deteriorated the properties of the resulting films, as shown with the TEM. As the toc-encap content increased, the films became slightly more yellow, more irregular and less transparent, with a higher haze index.

Influência da secagem do pequi (Caryocar brasiliense Camb.) na qualidade do óleo extraído

Pequi (Caryocar brasiliense Camb) has stood out for being an oleaginous fruit rich in carotenoids. Drying is widely used technique in the oil extraction process using hexane, but the degradation of oil and carotenoids may occur. The objective of this study was to evaluate the influence of different drying methods (sun, air-circulated drier at 40 and 60 °C) and time (4 hours and up to constant weight) on the yield and quality of the oil extracted using hexane using a soxhlet apparatus. When the pequi pulp was dried up to 3% or even lower, more oil yield was obtained (52-59%, dry basis). The total carotenoids contents obtained were higher and the peroxide index was lower for the pulp dried at 40 °C in an air-circulated drier when compared to drying at 60 °C in an air-ventilated drier and to sun drying technique. These results indicate that drying in an air-circulated drier at 40 °C for 19 hours resulted in higher oil yields with less heat degradation.