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Acerola is a fruit rich in vitamin C and antioxidants, but it has a short shelf life. Foam-mat dehydration is a promising method for extending the shelf life, but it can change the rheological properties of the powder. Therefore, the present study aimed to evaluate the rheology of acerola fresh pulp and the reconstituted powder, obtained by drying at 60 °C using the foam-mat method with the additive Emustab (4%), to indicate which powder concentration possesses similar rheological properties to the fresh pulp. The experiment was performed with different concentrations of reconstituted powder in deionized water (2, 4, 6, 8 and 10%, w/v). The Herschel–Bulkley model was the one that adequately adjusted to the experimental rheological data, showing that the reconstituted powder and fresh pulp are non-Newtonian fluids with pseudoplastic behavior and initial shear stress. Shear stress rose and apparent viscosity decreased with increasing shear rate, regardless of the concentration. Emustab did not modify the rheological characteristics of the acerola pulp, which maintained the non-Newtonian fluid characteristic. The 2% concentration provides a reconstituted product more like the fresh pulp.

This study aimed to evaluate the physical properties of foam produced with different additives and to mathematically model foam-mat drying at different temperatures. Foams were made with 500 g of acerola pulp and 4% additives (albumin, emustab, and neutral alloy), and density and stability data were obtained. With suitable density (0.14367 g cm−3) and coalescence (0.0000 mL) values, emustab provided the best acerola pulp foam. Drying was performed at temperatures of 50, 55, 60, 65, and 70 °C, using emustab, and different mathematical models were fitted for each temperature. The fresh pulp and the dried powder were analyzed for water activity, moisture content, ash, pH, total titratable acidity, soluble solids content, reducing sugars, vitamin C, total carotenoids, and instrumental color. The logarithmic model showed the best fit for all temperatures, with increasing k-values (between 0.0021 and 0.0059 s−1) and effective diffusion coefficient (between 2.570 × 10−9 m2 s−1 and 5.060 × 10−9 m2 s−1) with increasing temperature. Temperature directly impacts the effective moisture diffusion coefficient with an activation energy of 30.88 kJ mol−1. The physicochemical properties of the foams varied significantly with increasing drying temperature. Among all the temperatures tested, 60 °C was the most appropriate to reduce changes in nutritional composition.

The objective of this work was to evaluate the influence of roasting, blending, and grinding on the nutritional, sensory and sustainable aspects of coffee. To achieve this, a systematic review of the literature was performed. The database for the selection of relevant papers was the Portal de Periódicos da Capes, with remote access via CAFe. For the elaboration of the research, a chronological criterion with period restriction was used, considering the period between 2008 and 2022, to access all possible works related to the theme of this work. The following terms were used: blending; grinding; coffee; nutritional; sensory; sustainability; and roasting. To filter the searches, the association of these terms was also used by means of links and word associations. In the terminology, the Boolean operator “AND” was used to interconnect the terms used. The roasting degree, grinding, and the amount of each coffee species impact the nutritional and sensorial aspects of coffee, while the determination of each blend influences the sustainability of the environmental, economic and social aspects of the coffee production chain.

Hygroscopic equilibrium curves or sorption isotherms are important in order to define dehydration limits of the product, estimate moisture content alterations under environment conditions and to acquire moisture content values for safe storage. This work aimed to determine desorption isotherms of cucumber seeds stored at different temperature (10, 20, 30, 40 and 50 ºC) and relative humidity (0.11 to 0.96) and the thermodynamic properties of this process. Mathematical models were fitted to experimental data in order to represent the agricultural products hygroscopicity. Net isosteric heat of desorption was performed based on the Clausius-Clapeyron thermodynamic relation and Gibbs free energy through the Van't Hoff equation. Based on statistical parameters, Modified Henderson model was the one that best represented hygroscopicity of cucumber seeds. Equilibrium moisture content of cucumber seeds decreased with temperature increment at a constant value of relative humidity. Differential enthalpy values, representing the energy required to remove moisture from the cucumber seeds, ranged from 2923 to 2469 kJ. kg-1. Values of differential entropy and Gibbs free energy decreased with moisture content increase. Enthalpy-entropy compensation theory is valid for the sorption of cucumber seeds, in which the water sorption mechanism in cucumber seeds can be considered to be enthalpy controlled.

The objective of this study was to model the kinetics of water sorption in roasted and ground coffee. Crude Arabica coffee beans with an initial moisture content of 0.1234 kgwkgdm-1 were used. These beans were roasted to a medium roast level (SCCA # 55) and ground at three particle sizes: coarse (1.19 mm), medium (0.84 mm) and fine (0.59 mm). To obtain the water sorption isotherms and the isosteric heat, different conditions of temperature and relative humidity were analyzed using the dynamic method at 25ºC (0.50, 0.60, 0.70, and 0.80 of RH) and 30°C (0.30, 0.40, 0.50, 0.60, 0.70, and 0.80 of RH) and using the static method at 25ºC (0.332 and 0.438 of RH). The GAB model best represented the hygroscopic equilibrium of roasted coffee at every particle size. Isosteric heat of sorption for the fine particle size increased with increments of equilibrium moisture content, indicating a strong bond energy between water molecules and the product components. The Gibbs free energy decreased with the increase in equilibrium moisture content and with temperature.

This study investigated the thermodynamic properties of water sorption in soybean using the DM 68I69 Ipro variety from Campo Verde, Mato Grosso, Brazil. Grains with initial moisture contents of 21.95% (w.b.) and 3.50% (w.b.) were used for desorption and adsorption analyses, respectively. The static-gravimetric method determined equilibrium moisture content at various temperatures (10, 20, 30, 40, and 50°C) and relative humidity (between 0.11 and 0.92 ± 2%). The Modified Halsey model quantified the hygroscopicity of soybean. Key findings include: (a) desorption equilibrium moisture content exceeded adsorption values, demonstrating hysteresis; (b) decreasing equilibrium moisture content increased the energy required for water removal and its release during adsorption; (c) differential entropy of desorption and adsorption increased with decreasing equilibrium moisture content; (d) Gibbs free energy decreased with increasing temperature for both desorption and adsorption. The enthalpy-entropy compensation theory effectively described the observed phenomena.

Knowledge of the relationship between the equilibrium moisture content of the product and the air that involves it is essential to guarantee product quality and preserve its characteristics during storage. This trend can be studied by sorption isotherms. Thus, this study aimed to obtain desorption and adsorption isotherms of soybean grains to determine the mathematical model that best fits the experimental data and analyze the hysteresis phenomenon. Soybean grains with a moisture content of 21.95% (db) were used to verify the desorption process. The grains were dried until 3.50% (db) for the adsorption process. The static-gravimetric method was employed to determine the equilibrium moisture content of the grain at different temperatures (10, 20, 30, 40, and 50°C) and relative humidity levels (0.10 to 0.92%). Eight mathematical models were fitted to the experimental data. The modified Halsey model satisfactorily represented the desorption and adsorption phenomena of soybean grains. The equilibrium moisture content of soybean grains increased along with an increment in water activity. The increase in temperature led to a reduction in the equilibrium moisture content of soybean grains at a constant water activity. The equilibrium moisture content values obtained by desorption are higher than those obtained by adsorption, indicating the hysteresis phenomenon at the studied temperature range. The isotherms obtained for the desorption and adsorption process were classified as type III because of the high oil content in soybean grains.

The powdered products industry demands certain parameters for the transport of these products, such as flowability. This has a direct impact on actions within the industry and in machinery development. For Coffea canephora, this information is absent in the relevant literature. Thus, the present study aimed to analyze alterations in the flow properties of Coffea canephora due to the degree of roasting, particle size, and storage temperature. Two degrees of roasting were used: medium light (ML) and moderately dark (MD). Later, the coffee was divided into four particle size categories: whole roasted coffee and coffee ground to fine, medium, and coarse sizes. These lots were kept at 10 °C and 30 °C and the flowability parameters were studied throughout the storage period (0, 30, 60, 120, and 180 days). The angle of internal friction presented higher values for higher degrees of roasting and lower values for larger particle sizes. The MD and fine coffee samples presented higher values for the wall friction angle. Steel provided the lowest values for the wall friction angle. Unground roasted coffee was classified as free-flowing, whilst coffee with a coarse or fine particle size was classified as having an easy flow and a cohesive flow, respectively. According to the K coefficient, coffee roasted to MD required storage containers that were more robust, such as having thicker silo walls or being constructed of a material with a higher resistance, to prevent the storage container from collapsing during transport.

This study aimed to obtain the drying and water absorption curves of husk rice grain (Oryza sativa L.), cv. Urucuia, as well as the thermodynamic properties. Five temperatures (35°C, 45°C, 55°C, 65°C and 75°C) were used. Two terms, logarithmic, modified Midilli, Page and Verma models were used to model the drying process, and the Peleg model was used to model the soaking process. The modified Midilli and Peleg models satisfactorily accounted for the processes of drying and absorption of water, respectively. The activation energy for the drying and soaking was 51.03 and 37.06 kJ mol −1 , respectively. The enthalpy and entropy decreased with increasing temperature, regardless of the process. Their values ranged between −6.60 and 48.47 kJ mol −1 and between −0.1084 and −0.2464 kJ mol −1 K −1 for enthalpy and entropy, respectively. The Gibbs free energy increased with increasing temperature, with values between 69.36 and 86.22 kJ mol −1 .