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The main limitation of salting is its extended processing time, mainly caused by the slow diffusion of salt into the muscle tissue. The diffusion process can be accelerated by different technologies such as moderate electric fields (MEF) and CO2-laser microperforations. The main objective of this research was to evaluate the implementation of a combined MEF-CO2-laser-microperforation treatment on the acceleration of the salting process in Atlantic salmon (Salmo salar) and its influence on the effective diffusion coefficient (Deff). Salmon fillets were cut in cylinders. Microperforations at 50 and 100% depth into salmon tissue were produced axially with a 100 W CO2 laser. For MEF treatment an electric field strength of 1 V/cm was used. Salt concentrations along time were analyzed through Fick’s second law and anomalous diffusion models, considering a finite cylindrical geometry. As a result, treatment with micropores-MEF achieved a salt concentration of 3.5% after 4 h, while the control required 12 h to reach the same salt concentration. When both technologies were simultaneously applied, both Deff and final equilibrium salt concentration were increased, thus resulting in a significant reduction in salting time. The mathematical analysis showed good fit through the anomalous, presenting a sub-diffusive (α

A simple method to study the diffusion of a probe molecule into muscle tissue, which considers real composite architecture and anisotropy, was proposed. An anisotropic diffusion study of methylene blue (MB) as a probe molecule into the composite muscle tissue of salmon (Salmo salar) was performed using an image-processing technique. The concentration profile was determined in the middle sagittal plane by considering the muscle fiber orientation angle (θ). The mean value of the angle was θ = 31 ± 1.2°, and the fractional anisotropy values showed an anisotropic behavior for all samples tested. The presence of the discontinuity between muscle and connective tissue was characterized by the distribution coefficient. The simulation using the generalized minimum residual method iterative solver in COMSOL Multiphysics™ software described the anisotropic condition of the tissue with root mean square values of less than 27%. Significant differences were found in effective diffusion coefficient values between the muscle and connective tissue at 2 °C (p-value

Free fatty acid (FFA) release from the in vitro digestion of an emulsion-filled gel using three different particle size distributions and its modeling using the Weibull function and Gallagher–Corrigan model were investigated. To produce the emulsion-filled gel, an oil/water mix was prepared and blended with sodium alginate to finally produce small calcium alginate gel cubes. Three different particle size area distributions were generated by comminuting the cubes applying 5, 10, and 15 cycles of compression/shearing. The particles were intestinally in vitro digested, and the fraction of FFA released was calculated and analyzed using the Weibull function and Gallagher–Corrigan model. The FFA release showed a sigmoidal behavior for the three particle distributions; the Weibull function did not show a good fit. The Gallagher–Corrigan model presented a good fit to the FFA data, reinforced with a random error distribution. The model parameters were able to explain the kinetic processes related to both surface emulsion release and emulsion release by matrix dissolution. In addition, some parameters were linearly correlated (R2 > 0.99) with particle size, which established a relationship between particle size and the kinetics of release attained during the first stage of the digestion curve.

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The objective of this research was to explore the advantages of apple slices dehydration (cv. Granny Smith) using a Refractance Window (RW) with and without osmotic dehydration as pretreatment and compared with conventional hot‐air drying considering the quality attributes such as color and texture. For pretreatment, the apple slices were osmotically dehydrated and coupled to a moderate electric field (9.3 V/cm) using a sucrose solution (45°Brix) at 40°C until an Aw = 0.95 was achieved. Then, apple slices (with and without pretreatment) were dehydrated using RW at 55, 75, and 95°C and compared with conventional hot‐air drying at 55°C as a control. The results showed that with dehydration using RW, both with and without pretreatment at 95°C, it was possible to achieve a similar quality of apple slices when compared with conventional hot‐air drying at 55°C, but with a significant reduction in processing time. Additionally, the dehydration process using RW presented anomalous diffusion behavior on apple slices with an α > 1. PRACTICAL APPLICATIONS: Refractance Window (RW) is a technology used for dehydration of fruit and vegetables slices and pulp based on the refractance properties of wet materials. RW has reported promising results in processing time reduction as compared with conventional dehydration methods. In addition, the quality of the end products by RW is higher as compared with conventional drying methods. In this research, we have showed that the final product (dehydrated apple slices) using RW attained quality values (color and texture) similar to those obtained with osmotic dehydration (OD) coupled with moderate electric field (MEF)/hot‐air drying. However, the time spent by RW (50 min) was much lower than OD coupled with MEF/hot‐air drying (240 min). Then, the main advantage of RW is the capacity to dehydrate fruit and vegetables materials using temperatures around 100°C, which allow both, reduce processing time and also attain high‐quality retention.

The design and development of gluten-free foods requires a comprehensive understanding of the behavior of the raw materials to attain the same cooking and nutritional quality as gluten-based food. The objective of this study was to determine the optimal hot-air drying conditions for elaboration of cassava flour to be used in a gluten-free pasta formulation. The results showed that the operational conditions to minimize the hot-air drying time (57 min) to produce cassava flour with higher water holding capacity was 57 ℃ at 3 m/s. Then, the optimal formulation for the pasta was found to be cassava (26 g/100 g), amaranth flour (12 g/100 g), and carboxymethyl cellulose (0.23 g/100 g), which maximized the Aw (0.160), moisture content (3.10 g/100 g), hardness (5.02 N), and protein content (9.30 g/100 g), and it is used for the sensorial analysis, which showed that an earthy taste was the main problem with consumer satisfaction.

Although biofilm formation is a very effective mechanism to sustain bacterial life, it is detrimental in medical and industrial sectors. Current strategies to control biofilm proliferation are typically based on biocides, which exhibit a negative environmental impact. In the search for environmentally friendly solutions, nanotechnology opens the possibility to control the interaction between biological systems and colonized surfaces by introducing nanostructured coatings that have the potential to affect bacterial adhesion by modifying surface properties at the same scale. In this work, we present a study on the performance of graphene and hexagonal boron nitride coatings (h-BN) to reduce biofilm formation. In contraposition to planktonic state, we focused on evaluating the efficiency of graphene and h-BN at the irreversible stage of biofilm formation, where most of the biocide solutions have a poor performance. A wild Enterobacter cloacae strain was isolated, from fouling found in a natural environment, and used in these experiments. According to our results, graphene and h-BN coatings modify surface energy and electrostatic interactions with biological systems. This nanoscale modification determines a significant reduction in biofilm formation at its irreversible stage. No bactericidal effects were found, suggesting both coatings offer a biocompatible solution for biofilm and fouling control in a wide range of applications.

The aim of this research was to investigate the acceleration of brine-salting process of salmon when coupling it with moderate electric field (MEF). Salmon samples were cut into cylinder shape (0.025 +/- 0.001 m diameter and 0.025 +/- 0.001 m height), an

Foods are complex matrices formed by many compounds whose nutritional properties vary when they are mixed. Therefore, the study of ingredients interactions that occur during food formulation is necessary to understand the final behavior of food during digestion. This study examined the effects of sodium alginate mixed with a starch solution (3.0 g/100 g) on glucose release during in vitro digestion. To evaluate the effect of alginate, three concentrations were used (0.5, 1.0 and 2.0 g/100 g), and the in vitro digestion was carried out in two stages: gastric and intestinal digestion. The glucose release was evaluated by colorimetric. In order to understand the behavior of this mixture, complex index (CI), viscosity analysis and differential scanning calorimetry were performed to study the alginate–starch interaction. The results showed that starch hydrolysis began during intestinal digestion, reaching a hydrolysis percentage of 72% during the first 15 min. A significant reduction in starch hydrolysis was observed when 1.0 and 2.0 g/100 g of sodium alginate was incorporated, with hydrolysis percentages around 55% during the first 15 min. The CI varied from 34.34% to 57.11% when alginate was increased from 0.5 to 2.0 g/100 g. Also, the sodium alginate affected the viscosity which can be attributed to a protector role of alginate on the starch granules that diminishes the swelling and amylose leaching. Through this study it was possible to show the importance of molecular interaction between different ingredients used in food formulation and how these interactions can be relevant in the regulation of the glycemic response in carbohydrate based food.

The objective of this research was to evaluate the diffusion mechanism based on Fick's second law and anomalous diffusion modifying the drying operating conditions temperature (T) and relative humidity (RH) on apple slices (cv. Granny smith). Drying was performed at 30 °C, 40 °C, 50 °C and 30%, 50%, 70%RH based on a 32 experimental design. The drying curves were analyzed to determine the effective diffusion (Deff) using two methods: Fick's second law and anomalous diffusion model based on fractional calculus approach. Our results showed that the anomalous diffusion mechanism fit the experimental data better and revealed a super-diffusive behavior (α > 1). Therefore, Deff values were estimated using the anomalous diffusion model with α = 1.735. With respect to the use of anomalous diffusion model solution based on fractional calculus at different operations conditions allow to get better fitting of drying data than second Fick's law model, even keeping the Arrhenius behavior of Deff with temperature. Practical applications Diffusion process is typically analyzed using models based on Fick's second law. However, several assumptions inherent in Fick's second law are not fulfilled in food materials (e.g., structural heterogeneity). In addition, Fick's second law does not consider structural variations during the drying process, and it is well known that fruits such as apples experience significant structural changes during drying. Fractional calculus is a tool for mathematically representing the anomalous diffusion of solutes whose movements can be faster or slower than postulated in Fick's second law due to food structure. In general, with second Fick's law model not good fitting to data are obtained, therefore the prediction capacity of the model is limited. Based on this, anomalous diffusion solution based on fractional calculus was applied. The results showed good fit the data to the model, and also by the time exponent (α) is possible to identify the kind of diffusion process.

Passion fruit peel constitutes 50% of the whole fruit; therefore, a method to transform it to an active ingredient would be useful. Hot air drying is the most common process applied to extend the shelf life by reducing water activity. However, the processing conditions must be carefully selected to retain bioactive compounds. The goal of this study was to investigate the effects of blanching, temperature and airflow rate during hot air drying on the physicochemical and technological properties of passion fruit peel. A 32 experimental design with replicates in the central point was used. Three temperatures (50–55–60°C) and three airflow rates (2.4–2.7–3.0 m/s) were used, and the drying curves were analyzed to estimate the effective diffusion (Deff) and drying time. The dried peels were milled and their physicochemical properties (total fiber content and total polyphenol content), and technological properties (water holding capacity, the swelling capacity and the oil holding capacity) were measured. The results showed that the shortest drying time (∼2.5 h) was obtained at 60°C and 2.7 m/s for both control and blanched fruits. The physicochemical and technological properties were not affected by the drying conditions, because the temperatures used were not high enough to be detrimental. In addition, Deff and the physicochemical and technological properties were not affected by blanching due to preserve the samples a slower freezing process (freezing rate