Influence of modified starches as wall materials on the properties of spray-dried lemongrass oil.

The use of lemongrass oil as food preservative present great potential, however it has high volatility and intense aroma, making them limited to be used as food additives. Microencapsulation processes become interesting alternatives to overcome these issues. This work investigated the influence of the partial replacement of gum arabic by modified starches on the microencapsulation of lemongrass oil as core material. Gum arabic and its combinations with modified starches: cassava and corn maltodextrins with different dextrose equivalent (DE) and octenyl succinic anhydride modified starch (OSA-starch) were studied. The emulsions were spray dried at controlled temperature of 170 °C. The evaluated parameters particles solubility, moisture content, and oil composition did not showed significant differences among the treatments. Replacement of gum arabic by maltodextrin DE20 and OSA-starch resulted in higher wetting times. Oil retention was increased (81.2%) when gum arabic was replaced by OSA-starch; the treatment without substitution, with only gum arabic had 67.5% of oil retention. Application of OSA-starch in association with gum arabic in microencapsulation by spray drying of lemongrass oil presented greater potential to be used due to its higher oil retention. Polymer blends should be assessed since they present advantages over individually applied polymers. Although maltodextrins show some differences compared to the treatment with only gum arabic, it may also be a viable alternative because of its lower cost.

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.

Properties of spray-dried fish oil with different carbohydrates as carriers.

This study evaluated the application of cashew gum, Arabic gum and starch on physical and thermal properties, and fatty acid profiles of spray-dried fish oil. A completely randomized design was used to evaluate the influence of the type of material on the properties of the microparticles. Hygroscopicity and solubility was higher for particles produced using cashew gum and reached 15 g/100 g and 85 g/100 g, respectively. Analyzing the thermogravimetric curves, it was found that cashew gum bulk showed two steps of degradation. For the microcapsules containing encapsulated fish oil in cashew gum, an extra degradation step at 471 °C was found. It was possible to verify the occurrence of diffused and wide peaks in the X-ray diffractograms for all three carbohydrate polymers. The particles produced presented spherical shape with cavities. The fatty acid profile for the fish oil changed only when using modified starch as wall material, where a significant loss of omega-3 fatty acids was observed. The particles produced with cashew gum had physical properties similar to those when applying materials commonly used and this biopolymer has the potential for application as a carrier in spray drying processes .

Use of prebiotic carbohydrate as wall material on lime essential oil microparticles.

The aim of this work was to study the use of different prebiotic biopolymers in lime essential oil microencapsulation. Whey protein isolate, inulin and oligofructose biopolymers were used. The addition of prebiotic biopolymers reduced emulsion viscosity, although it produced larger droplet sizes (0.31-0.32 µm). Moisture values (2.94-3.13 g/100 g dry solids) and water activity (0.152-0.185) were satisfactory, being within the appropriate range for powdered food quality. Total oil content, limonene retention values and antioxidant activity of the microparticles containing essential oil decreased in the presence of the carbohydrates. The addition of prebiotic biopolymers reduced the microparticle thermal stability. X-ray diffraction confirmed the amorphous characteristic of the microparticles and the interaction of the essential oil with the wall material. The presence of prebiotic biopolymers can be a good alternative for lime essential oil microparticles, mainly using fibre that has a functional food appeal and can improve consumer health.

Prebiotic Carbohydrates: Effect on Reconstitution, Storage, Release, and Antioxidant Properties of Lime Essential Oil Microparticles.

The aim of this study was to include prebiotic biopolymers as wall material in microparticles of lime essential oil. Whey protein isolate (WPI), inulin (IN), and oligofructose (OL) biopolymers were used in the following combinations: WPI, WPI/IN (4:1), and WPI/OL (4:1). The emulsion droplets in the presence of inulin and oligofructose showed larger sizes on reconstitution. There was no significant difference in solubility of the particles, but the wettability was improved on addition of the polysaccharides. The size of the oligofructose chains favored the adsorption of water. Prebiotic biopolymers reduced thermal and chemical stability of the encapsulated oil. Microparticles produced with WPI showed a higher bioactive compound release rate, mainly due to its structural properties, that enabled rapid diffusion of oil through the pores. The use of prebiotic biopolymers can be a good option to add value to encapsulated products, thus promoting health benefits.

Application of cashew tree gum on the production and stability of spray-dried fish oil.

Evaluation of cashew gum compared to conventional materials was conducted regarding properties and oxidative stability of spray-dried fish oil. Emulsions produced with cashew gum showed lower viscosity when compared to Arabic gum. The particle size was larger (29.9µm) when cashew gum was used, and the encapsulation efficiency reached 76%, similar to that of modified starch but higher than that for Arabic gum (60%). The oxidation process for the surface oil was conducted and a relative lower formation of oxidation compounds was observed for the cashew gum treatment. GAB model was chosen to describe the moisture adsorption isotherm behaviours. Microparticles produced using Arabic and cashew gums showed greater water adsorption when exposed to higher relative humidities. Microparticles produced using cashew gum were more hygroscopic however encapsulation efficiency were higher and surface oil oxidation were less pronounced. Cashew gum can be further explored as an encapuslant material for spray drying processes.

Cashew gum and inulin: New alternative for ginger essential oil microencapsulation.

This study aimed to evaluate the effect of partial replacement of cashew gum by inulin used as wall materials, on the characteristics of ginger essential oil microencapsulated by spray drying with ultrasound assisted emulsions. The characterization of particles was evaluated as encapsulation efficiency and particle size. In addition, the properties of the microcapsules were studied through FTIR analysis, adsorption isotherms, thermal gravimetric analysis, X-ray and scanning electron microscopy. It was found that the solubility of the treatments was affected by the composition of the wall material and reached higher values (89.80%) when higher inulin concentrations were applied. The encapsulation efficiency (15.8%) was lower at the highest inulin concentration. The particles presented amorphous characteristics and treatment with cashew gum as encapsulant exhibited the highest water absorption at high water activity. The cashew gum and inulin matrix (3:1(w/w) ratio) showed the best characteristics regarding the encapsulation efficiency and morphology, showing no cracks in the structure.

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.

Foam mat drying of tomato pulp / Secagem de polpa de tomate pelo método de camada de espuma

The purpose of this study was to optimize the formulation of tomato pulp foam and to evaluate the drying process using the foam mat method at temperatures of 60°C and 80°C. The optimization was conducted by analyzing the effect of the albumin concentration (expressed in %) and whipping time (expressed in minutes) in relation to the response variables of foam density and thermal stability of the foam based on the volume of remaining foam. The drying curves (moisture versus drying time ratio) for the control treatment (CT; no albumin addition) and optimized treatment (OT) were obtained. The results showed that only the whipping time variable (linear and quadratic effects) had significant influence (p < 0.05) on the foam density values. The foam stability was significantly influenced by the whipping time (p < 0.10) and albumin concentration (p < 0.10). The optimum foam formation conditions considering higher foam stability and lower density included a 4.5% albumin concentration and a 4.5 minutes of whipping time. The results of the drying curves showed that the foam formation with albumin significantly reduced (p < 0.05) the time necessary to reach moisture equilibrium during drying. The moisture equilibrium values were not significantly different (p > 0.05) among the treatments with foam application at the studied temperatures, but they were lower than the treatments without foam application.

Este trabalho foi realizado com o objetivo de otimizar a formulação de espuma da polpa de tomate e avaliar o processo de secagem através do método de camada de espuma, nas temperaturas de 60°C e 80°C. A otimização foi realizada analisando-se o efeito da concentração de albumina expressa em % e tempo de bateção expresso em minutos em relação às variáveis respostas densidade da espuma e estabilidade térmica da espuma, baseado no volume de espuma remanescente. Obteve-se a curva de secagem (razão de umidade versus tempo de secagem) para o tratamento controle (TC), sem adição de albumina, e o tratamento otimizado (TO). Os resultados mostraram que somente a variável tempo de bateção (efeito linear e quadrático) teve influência significativa (p < 0,05) nos valores de densidade de espuma. A estabilidade da espuma foi influenciada significativamente pelo tempo de bateção (p < 0,10) e concentração de albumina (p < 0,10). As condições ótimas de formação de espuma encontradas foram concentração de albumina de 4,5% e tempo de bateção de 4,5 minutos, considerando maior estabilidade de espuma e menor densidade. Os resultados das curvas de secagem mostraram que a formação de espuma com o uso de albumina reduziu significativamente (p < 0,05) o tempo para que se atingisse a umidade de equilíbrio durante a secagem. Os valores de umidade de equilíbrio não apresentaram diferença significativa (p > 0,05) entre os tratamentos com aplicação de espuma nas temperaturas estudadas, porém foram menores que os tratamentos sem aplicação de espuma.

Revestimento ativo de amido na conservação pós-colheita de pera Williams minimamente processada / Starch-based edible coating on extending shelf life of fresh-cut pear

A pera é uma das frutas de clima temperado mais consumidas no Brasil, no entanto sua conservação é limitada devido ao seu escurecimento quando sofre danos ou tratamentos físicos. Os revestimentos comestíveis interagem favoravelmente com o alimento, aumentando sua vida de prateleira. Este trabalho objetivou avaliar a ação de revestimento de amido adicionado de lactato de cálcio e L-cisteína na inibição do escurecimento enzimático, na redução do crescimento de psicrotrófilos e enterobactérias e na manutenção da textura. As peras fatiadas foram cobertas com revestimentos comestíveis à base de amido incorporados com cisteína e lactato de cálcio, exceto o controle - sem revestimento (C). Os tratamentos foram: apenas revestimento (T1); 2,0 por cento lactato de cálcio e 1,0 por cento L-cisteína (T2) e 2,0 por cento lactato de cálcio e 1,5 por cento L-cisteína (T3). As amostragens foram feitas nos tempos zero, dois, quatro e seis dias. As amostras foram mantidas sob refrigeração (7°C±2°C). As peras submetidas aos tratamentos T2 e T3 apresentaram-se significativamente mais firmes (P<0,05) que as dos tratamentos C e T1. A ação da cisteína sobre a inibição do escurecimento enzimático foi observada nos tratamentos T2 e T3, que não apresentaram diferença significativa (P≥0,05) entre si para os valores de ∆E, no entanto esses valores foram significativamente menores em relação ao controle. No tempo 6, a redução decimal na contagem de psicrotrófilos chegou a 3,03 e 2,43 para T3 e T2, em comparação com o controle. A contagem de enterobactérias apresentou comportamento semelhante, sendo o valor da redução de 3,16 e 3,05 para T2 e T3 em relação ao controle. Verificou-se que a vida de prateleira de pera minimamente processada pode ser mantida por mais tempo com o uso desse revestimento.

Pear is one of the most consumed temperate fruits in Brazil; however their conservation is limited due to browning when it suffers injuries or physical treatments. The edibles coating interact with the food positively extending its shelf life. This research aimed to evaluate the action of starch edible coating incorporated with calcium lactate and L-cysteine on enzymatic browning inhibition, on psychrotrophs and enterobacteriaceae growing reduction and on firmness maintenance. The sliced pears were coated with starch edible coating incorporated with L-cysteine and calcium lactate, except control, without coating (C). The treatment were: only coating (T1); 2,0 percent calcium lactate and 1,0 percent L-cysteine (T2); 2,0 percent calcium lactate and 1,5 percent L-cysteine (T3). The samples were taken at 0, 2, 4 and 6 days. Pears were keeped under refrigeration (7°C±2°C). Pears submitted to treatments T2 and T3 show significantly more firms (P<0,05) compared to treatments C and T1. Cysteine action over enzymatic browning inhibition was observed in treatments T2 and T3 which do not differed significantly each other (P≥0,05) to ∆E values however these were significantly lower than control (C). At time 6, decimal reduction on psychrotrophs counting reached 3,03 and 2,43 to T3 e T2 compared to control. Enterobacteriaceae counting showed similar behavior where the reduction values were 3,16 and 3,05 to T2 e T3 compared to control. It was verified that using the studied edible coating on fresh cut pear can extend its shelf life.