Resumo O objetivo deste trabalho foi otimizar a secagem por atomização da polpa de juçara, utilizando-se misturas de amido modificado (AM), concentrado proteico de soro de leite (CPL) ou isolado proteico de soja (IPS), como agentes carreadores. Dois delineamentos compostos centrais rotacionais foram realizados para avaliar o efeito das variáveis independentes: temperatura do ar de entrada (140 °C a 200 °C), concentração de agente carreador ‒ CAC (0,5 a 2 g de carreador/g de sólidos de polpa juçara) e proporções de AM:CPL ou AM:IPS (5 a 30 g de CPL ou IPS/100 g carreador) sobre as seguintes respostas para pós formulados com AM:CPL e AM:IPS, respectivamente: teor de umidade (0,3% a 1,4% e 0,6% a 1,2%), solubilidade (78,0% a 92,9% e 78,9% a 83,8%), retenção de antocianinas totais (49,2% a 82,9% e 34,1% a 96,9%), eficiência de encapsulação (98,5% a 99,7% e 98,5 a 99,5%), ângulo de tonalidade (9,1 a 44,0 e 3,7 a 42,6), croma (10,0 a 15,3 e 9,2 a 14,3) e rendimento do processo (33,2% a 55,5% e 49,9% a 78,5%). A temperatura do ar de entrada de 170 °C, CAC de 1,25 e 2, e a proporção de AM:CPL ou AM:IPS de 17,5 e 30 foram recomendadas como condições selecionadas.

Abstract The objective of this work was to optimize the spray drying of jussara pulp using mixtures of modified starch (MS) with whey protein concentrate (WPC) or soy protein isolate (SPI) as the carrier agents. Two central composite rotatable designs were used to evaluate the effect of the independent variables of inlet air temperature (140 °C to 200 °C), carrier agent concentration - CAC (0.5 to 2 g carrier agent/g jussara pulp solids) and the proportions of MS:WPC or MS:SPI (5 to 30 g WPC or SPI/100 g carrier agent) on the following responses for powders formulated with MS:WPC and MS:SPI, respectively: moisture content (0.3% to 1.4% and 0.6% to 1.2%), solubility (78.0% to 92.9% and 78.9% to 83.8%), retention of total anthocyanins (49.2% to 82.9% and 34.1% to 96.9%), encapsulation efficiency (98.5% to 99.7% and 98.5% to 99.5%), hue angle (9.1 to 44.0 and 3.7 to 42.6), chroma (10.0 to 15.3 and 9.2 to 14.3) and process yield (33.2% to 55.5% and 49.9% to 78.5%). The inlet air temperature 170 °C, CAC of 1.25 and 2 g/g jussara pulp solids and proportion of MS:WPC or MS:SPI of 17.5 and 30 g/100 g were recommended as the selected conditions.

The objective of this work was to optimize the spray drying of pequi pulp using maltodextrin as carrier agent and Tween 80 as surfactant agent. A central composite rotatable design was used to evaluate the influence of inlet air temperature (140 to 200°C), maltodextrin (15 to 30%) and surfactant (0 to 5%) concentration on the process performance and physicochemical and nutritional properties of the dried powdered pulp. The dependent variables were process yield (27.4 - 51.7%), outlet air temperature (106.5 - 135°C), energetic efficiency (29.9 - 44.8%), moisture content (0.25 - 1.43%), water activity (0.09 to 0.21), hygroscopicity (9.1 - 12.1 g adsorbed moisture/100g dry matter), vitamin C content (129.8 - 303.0 mg/g solids pequi) and total carotenoids content (8.2 - 94.9 mg carotenoids/g solids pequi). The spray drying of pequi pulp was optimized for maximum vitamin C and total carotenoids content using response surface methodology, which were attained at 152°C, surfactant concentration of 1% and maltodextrin concentration of 18%. The characterization of the pequi pulp powder obtained at the optimized condition evaluating the particles sizes, bulk density and porosity. The morphology showed spherical and smooth particles with several sizes.

O objetivo deste trabalho foi avaliar a microencapsulação de polpa de pequi por spray drying. Um delineamento composto central rotacional foi utilizado para avaliar o efeito das variáveis independentes: temperatura do ar de entrada, concentração de surfactante e concentração de amido modificado sobre o rendimento do processo e as características do produto microencapsulado. A seleção da melhor condição de processo foi baseada na obtenção de um produto com maior teor de vitamina C e de carotenoides. Todos os pós produzidos mostraram teores de umidade inferiores a 2%. Os valores experimentais de higroscopicidade, rendimento de secagem, atividade de água, vitamina C e carotenoides totais dos pós variaram de 7,96 a 10,67 g de água adsorvida/ 100 g sólidos, 24,34 a 49,80%, 0,13 a 0,30, 145,78 a 292,11 mg de ácido ascórbico/g de sólidos de pequi e 15,51 a 123,42 mg de carotenoides/g de sólidos de pequi, respectivamente. Temperatura de ar de entrada de 140°C, concentração de surfactante de 2,5% e concentração de amido modificado de 22,5% foram recomendadas como sendo a condição selecionada. Através da microscopia eletrônica de varredura, observou-se que a maioria das partículas apresentou formato esférico e superfície lisa.

The aim of this study was to evaluate the microencapsulation of pequi pulp by spray drying. A central composite rotational design was used in order to evaluate the effect of the independent variables: inlet air temperature, surfactant concentration and modified starch concentration. The dependent variables were assumed as yield of the process and the product features microencapsulated. A selection of the best process condition was performed to obtain the best condition of a product with the highest vitamin C and carotenoids content. Powders showed moisture content below 2%. The experimental values of hygroscopicity, yield, water activity, total carotenoids and vitamin C powders ranged from 7.96 to 10.67 g of adsorbed water/100g of solids, 24.34 to 49.80%, 0.13 to 0.30, 145.78 to 292.11 mg of ascorbic acid/g of pequi solids and 15.51 to 123.42 mg of carotenoids/g of pequi solids, respectively. The inlet air temperature 140°C, the surfactant concentration of 2.5% and the modified starch concentration of 22.5% was recommended as the selected condition. By the scanning electron microscopy, it was observed that most of the particles had spherical shape and smooth surface.

The objective of this study was to obtain babassu coconut milk powder microencapsulated by spray drying process using gum Arabic as wall material. Coconut milk was extracted by babassu peeling, grinding (with two parts of water), and vacuum filtration. The milk was pasteurized at 85 ºC for 15 minutes and homogenized to break up the fat globules, rendering the milk a uniform consistency. A central composite rotatable design with a range of independent variables was used: inlet air temperature in the dryer (170-220 ºC) and gum Arabic concentration (10-20%, w/w) on the responses: moisture content (0.52-2.39%), hygroscopicity (6.98-9.86 g adsorbed water/100g solids), water activity (0.14-0.58), lipid oxidation (0.012-0.064 meq peroxide/kg oil), and process yield (20.33-30.19%). All variables influenced significantly the responses evaluated. Microencapsulation was optimized for maximum process yield and minimal lipid oxidation. The coconut milk powder obtained at optimum conditions was characterized in terms of morphology, particle size distribution, bulk and absolute density, porosity, and wettability.