Maltodextrin as a Drying Adjuvant in the Lyophilization of Tropical Red Fruit Blend.

Guava, pitanga and acerola are known for their vitamin content and high levels of bioactive compounds. Thus, the preparation of combinations of these fruits comprises a blend with high nutraceutical potential, yielding a strong and attractive pigmentation material. In this study, the influence of different proportions of maltodextrin on the lyophilization of a blend of guava, acerola and pitanga was evaluated considering not only the physicochemical, physical and colorimetric parameters but also the bioactive compounds in the obtained powders. The blend was formulated from the mixture and homogenization of the three pulps in a ratio of 1:1:1 (m/m), then maltodextrin was added to the blend, resulting in four formulations: blend without adjuvant (BL0), and the others containing 10% (BL10), 20% (BL20) and 30% (BL30) maltodextrin. The formulations were lyophilized and disintegrated to obtain powders. The powders were characterized in terms of water content, water activity, pH, total titratable acidity, ash, total and reducing sugars, ascorbic acid, total phenolic content, flavonoids, anthocyanins, carotenoids, lycopene, color parameters, Hausner factor, Carr index, angle of repose, solubility, wettability and porosity. All evaluated powders showed high levels of bioactive compounds and the increase in maltodextrin concentration promoted positive effects, such as reductions in water content, water activity and porosity and improved flow, cohesiveness and solubility characteristics.

Smelling Peppers and Pout Submitted to Convective Drying: Mathematical Modeling, Thermodynamic Properties and Proximal Composition.

Pepper (Capsicum spp.) is among the oldest and most cultivated crops on the planet. Its fruits are widely used as natural condiments in the food industry for their color, flavor, and pungency properties. Peppers have abundant production; on the other hand, their fruits are perishable, deteriorating within a few days after harvesting. Therefore, they need adequate conservation methods to increase their useful life. This study aimed to mathematically model the drying kinetics of smelling peppers (Capsicum chinense) and pout peppers (Capsicum chinense Jacq.) to obtain the thermodynamic properties involved in the process and to determine the influence of drying on the proximal composition of these peppers. Whole peppers, containing the seeds, were dried in an oven with forced air circulation, at temperatures of 50, 60, 70, and 80 °C, with an air speed of 1.0 m/s. Ten models were adjusted to the experimental data, but the Midilli model was the one that provided the best values of coefficient of determination and lowest values of the mean squared deviation and chi-square value in most of the temperatures under study. The effective diffusivities were well represented by an Arrhenius equation, appearing in the order of 10-10 m2·s-1 for both materials under study, since the activation energy of the smelling pepper was 31.01 kJ·mol-1 and was 30.11 kJ·mol-1 in the pout pepper, respectively. Thermodynamic properties in both processes of drying the peppers pointed to a non-spontaneous process, with positive values of enthalpy and Gibbs free energy and negative values of entropy. Regarding the influence of drying on the proximal composition, it was observed that, with the increase in temperature, there was a decrease in the water content and the concentration of macronutrients (lipids, proteins, and carbohydrates), providing an increase in the energy value. The powders obtained in the study were presented as an alternative for the technological and industrial use of peppers, favoring obtaining a new condiment, rich in bioactives, providing the market with a new option of powdered product that can be consumed directly and even adopted by the industry as a raw material in the preparation of mixed seasonings and in the formulation of various food products.

Use of Inverse Method to Determine Thermophysical Properties of Minimally Processed Carrots during Chilling under Natural Convection.

The aim of this study was to determine the thermophysical properties and process parameters of cylindrical carrot pieces during their chilling. For this, the temperature of the central point of the product, initially at 19.9 °C, was recorded during chilling under natural convection, with the refrigerator air temperature maintained at 3.5 °C. A solver was created for the two-dimensional analytical solution of the heat conduction equation in cylindrical coordinates. This solver and the experimental data set were coupled to the LS Optimizer (V. 7.2) optimization software to simultaneously determine not only the values of thermal diffusivity (α) and heat transfer coefficient (hH), but also the uncertainties of these values. These values were consistent with those reported in the literature for carrots; in this study, the precision of these values and the confidence level of the results (95.4%) were also presented. Furthermore, the Biot numbers were greater than 0.1 and less than 40, indicating that the mathematical model presented in this study can be used to simultaneously estimate α and hH. A simulation of the chilling kinetics using the values obtained for α and hH showed good agreement with the experimental results, with a root mean square error RMSE = 9.651 × 10-3 and a chi-square χ2 = 4.378 × 10-3.

Influence of Dehydration Temperature on Obtaining Chia and Okra Powder Mucilage.

Gum and mucilage from seeds and fruits are objects of study because they have characteristics of high viscosity at low concentrations and gelling properties, which are useful characteristics for modifying the texture and stabilizing products in the food industry. Chia and okra have high concentrations of polysaccharide gums in their composition, which makes them an interesting target for use in the composition of foods that require the use of texture enhancers and stabilizers. The present study investigated the influence of dehydration temperature on the characteristics of chia and okra powder mucilage obtained at different temperatures. The mucilages were extracted using an aqueous process and dehydrated in an air circulation oven at 50, 60, and 70 °C until hydroscopic equilibrium. Then, the powdered chia mucilage (CM) and okra mucilage (OM) were analyzed for chemical and physicochemical characteristics, bioactive compounds, antioxidant activity, and physical properties. It was found that powdered mucilage had low water content and water activity, with CM standing out in terms of ash, pectin, and starch content and OM, along with higher averages of proteins, sugars, total phenolic compounds, anthocyanins, flavonoids, and antioxidant activity. As for the physical parameters, CM stood out in relation to greater solubility and lower hygroscopicity, whereas OM presented higher wettability rates. Both powdered mucilages were classified as having good fluidity and cohesiveness from low to intermediate. In relation to the dehydration temperature, the best mucilage properties were verified at 70 °C. The study revealed that mucilages have good functional properties offering great potential as raw material for industry.

The Temperature Influence on Drying Kinetics and Physico-Chemical Properties of Pomegranate Peels and Seeds.

Pomegranate is a fruit desirable for its nutritional and medicinal properties which has a great industrial potential that is yet under-explored. Notable for its integral use, the peels are used in medicinal infusions and the seeds consumed without restrictions. In this sense, the objective of this work is to determine the drying kinetics of pomegranate peels and seeds in a hot air circulation oven, at temperatures of 50, 60, and 70 °C, adjust mathematical models to experimental data, determine the effective diffusivities and thermodynamic properties of the process and the physicochemical characteristics of peels and seeds of fresh pomegranates and in their flours. Twelve models were used to adjust the drying kinetics, obtaining better results with the Diffusion Approximation model, Verma, and modified Henderson and Pabis. The effective diffusivities were well represented by an Arrhenius equation, with activation energies of 31.39 kJ/mol for seeds and 10.60 kJ/mol for peels. In the drying process, the seeds showed higher values of enthalpy, entropy, and Gibbs free energy concerning peels. Pomegranate peel and seed flours have proximal composition and distinct physicochemical characteristics, with high fiber, carbohydrate, and energy content. In addition, peel flours stand out for their mineral content, and seed flours do for their lipid and protein content.

Economic study of the cultivation of kale, coriander, lettuce, and chives in intercropping / Estudo econômico do cultivo da couve, coentro, alface e cebolinha em consórcio

Intercropping of vegetables in a poorly planned manner may not achieve the expected economic results, as it is an activity that requires a great technical and administrative capacity of the producer. This study aimed to analyze the economic feasibility of intercropping kale with coriander, lettuce, and chives in relation to monocultures. The experiment was conducted in the Center for Agri-food Science and Technology, Federal University of Campina Grande, in the municipality of Pombal, PB in the period from June 2014 to July 2015. Eleven treatments were tested: four polycultures, three bicultives, and four monocultures, in randomized blocks, with four replications. The productivity, total operating costs (TOC), gross and net revenue, rate of return, profitability index, and efficient land use were evaluated. The TOC values of intercropping were calculated with the prices of July 2015. In all the systems studied, the largest participation was referring to the cost hand of labor. The highest gross and net revenues were observed in the kale with lettuce in bicultive, the rate of return and profitability index was higher on lettuce in monoculture. Despite the increase in the TOCs of the intercropping in relation to the monocultures, the intercropping proved to be economically viable in terms of efficient land use, reaching values indicating a land-use efficiency of up to 50% more in polycultures and bicultives.

O cultivo de hortaliças de maneira mal planejada pode não alcançar os resultados econômicos esperados, pois é uma atividade que exige grande capacidade técnica e administrativa do produtor. O objetivo deste estudo foi avaliar a viabilidade econômica de cultivar couve, alface e cebolinha em consórcio. O experimento foi conduzido no Centro de Ciência e Tecnologia Agroalimentar da Universidade Federal de Campina Grande, no município de Pombal, PB, no período de junho de 2014 a julho de 2015. Foram testados onze tratamentos: quatro policultivos, três bicultivos e quatro monocultivos, em blocos casualizados, com quatro repetições. Foram avaliados: produtividade; custos operacionais totais (COT); receita bruta e líquida; taxa de retorno; índice de lucratividade e uso eficiente da terra (UET). Os valores de COT do consórcio foram calculados com os preços de julho de 2015. Em todos os sistemas estudados, a maior participação foi referente ao custo mão de obra. As maiores receita bruta e líquida foram observadas na couve com alface em bicultivo, a taxa de retorno e rentabilidade índice foram maiores na alface em monocultura. Apesar do aumento nos COT'S dos consórcios em relação às monoculturas, a consorciação mostrou-se economicamente viável em termos de uso eficiente da terra, alcançando valores que indicam uma eficiência no uso da terra de até 50% a mais em policultivos e bicultivos.