Search

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

Hydrolysate cassava peel obtained from agro-industrial residues was used as a carbon source in the production of polyhydroxyalkanoates (PHAs) by Cupriavidus necator. The optimum culture conditions were pH 9, a C/N ratio of 11, and a C/P ratio of 7. Characterization of the PHA polymers by FTIR, DSC and GC–MS revealed copolymers consisting of 3HB and 3HV monomers with melting temperatures (Tm) between 100 and 150 °C. Random and aligned microfibers with average diameters of 1.56 ± 0.41 μm and 1.72 ± 0.52 μm, respectively, were produced by electrospinning. In general, it was possible to obtain PHAs from cassava peel, and PHAs could be applied to produce fibers by electrospinning. The above strategy is an alternative use of agro-industrial cassava waste and opens up potential applications in the manufacture of biopolymers for their use in industry and biomedicine.

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.

Currently, one of the fastest growing industries in the world is the poultry industry; however, the increase in demand has generated the production of various byproducts, such as bones, and these byproducts have a negative impact on the environment. The aim of the present work was to evaluate the effect of glycation on the increase in antioxidant compounds and the formation of indicators of advanced glycation end products (AGE) in chicken bone hydrolysates; it also aimed to maximize the protein content, degree of hydrolysis and antioxidant content. Through analysis of variance (ANOVA), the content of AGE products (HMF and furfural) formed in the glycation process was analyzed. The chicken bone hydrolysate (CBH) had a protein content of 1.42 g/l, a degree of hydrolysis of 17.2% and an antioxidant capacity of 8334 and 10343 μmol ETrolox/l according to ABTS and ORAC evaluations, respectively. The glycation process increased the ORAC by 6.57%. The presence of hydroxymethylfurfural and furfural was determined in the glycated samples and detected at values between 0.05 and 0.22 and 0 and 0.26 ppm, respectively. In conclusion, hydrolysis and glycation are suitable alternatives that enable the use of chicken bones in producing food ingredients with higher added value.

Pomegranate (Punica granatum) is a non-climacteric fruit with a high antioxidant content in arils and peels, of which 92% are anthocyanins and tannins. However, it is susceptible to chilling injury (CI), a physiological disorder concentrated in the peel, which can affect the organoleptic quality of the fruit. To understand the effects of modified atmosphere and ethylene in responses to stress on the antioxidant quality of the fruit and composition of fatty acids in the peel under CI conditions, the exogenous ethylene treatments (0.5, 1.0, and 1.5 μg L–1), 1-methylcyclopropene (1-MCP; 1 μl L–1), modified atmosphere packaging (MAP: XTend™ bags), combined strategy MAP/1-MCP, and package in macroperforated bags (MPB-control treatment) were evaluated. The assay was performed in cold conditions (2 ± 1°C; 85% RH) to stimulate damage and was sampled for 120 days (+3 days at 20°C). During cold storage, CI symptoms began at 20 days in MPB and at 60 days for all treatments with exogenous ethylene; CI symptoms were delayed up to 120 days in MAP, 1-MCP, and the combined MAP/1-MCP treatment. Damage was concentrated in the peel. Ethylene and MPB-control treatments induced significant electrolyte leakage, lipid peroxidation, and oxidative damage. In contrast, MAP alone or in combination with 1-MCP successfully delayed CI symptoms. However, no significant differences were observed between treatments in fatty acid content, e.g., in the peel, oleic acid, linoleic acid, palmitic acid, but a significant loss was noted after 60 days of storage. Cold storage caused an increase in anthocyanin concentration in the peel and arils, increasing up to 12 times in the peel of the fruit treated with ethylene at the final stage of storage (120 days + 3 days at 20°C), with non-significant differences in the tannin content in the peel. During long-term cold storage of pomegranate, MAP and 1-MCP treatments delay and reduce the appearance of CI symptoms. This long cold storage induces an important decrease in the unsaturated/saturated fatty acid ratio, which is not reversed by any postharvest treatment. A higher unsaturated/saturated fatty acid ratio after 1-MCP treatments showed a protective effect in peel tissues. In addition, it was possible to increase the concentration of anthocyanins in the peel of cold-storage pomegranates treated with ethylene.

The spent coffee ground is a by-product of the coffee industry with high potential because of its beneficial properties for health, however, due to high water content, it is necessary to stabilize it without affecting bioactive capacities. The main objective of this work was to evaluate the effect of different convective drying conditions, on some technological and functional properties of the spent coffee ground and to determine the thermal degradation kinetics of chlorogenic acids. The methodology included the optimization of the drying process conditions of spent coffee ground: temperature (40–60 °C), air flow (1.0–2.0 m/s) and cake thickness (0.01–0.02 m). Effective diffusion coefficient, moisture, water activity, water and oil holding capacity, antioxidant capacity, caffeine, and seven chlorogenic acids were determined. The results showed that the best drying conditions were 60 °C, 2.0 m/s, 1.28 cm which allows retaining 84.24% of total polyphenols and 66.00% of the antioxidant capacity. Chlorogenic acids showed thermal degradation kinetics of first order under the optimal process conditions. In general, it is concluded that the convective drying process is a valid technique for processing of coffee grounds, as it allows the preservation of antioxidant compounds with a potentially beneficial effect on health, providing a stabilized low moisture content that can be used in food applications.

The aim of this research was to study the use of Refractance window™ (RW™) in the dehydration of salmon (Atlantic salmon), beef (lean), and apples (Granny Smith) through the analysis of the effective diffusivity determined through the Fick's model and the anomalous model. Salmon, beef, and apple slices were dried at 55 and 95 °C, using either a conventional drying process or RW™. Water activity (aw) was measured periodically by drying, and the effective diffusion (Deff) was measured using Fick's second law and an anomalous model. Color changes (∆E) and firmness were also measured. The results showed that mass transfer in salmon and beef was not improved by RW™. In contrast, in apple slices dehydrated using RW™, the Deff and processing times were significantly (p RW™ is a powerful tool that allows for the dehydration of fruit using temperatures of 95 °C and provides a 50% reduction in drying time.

In this chapter, material balance and its importance in the field of food science/engineering have been discussed. To do this, first, material balance is explained in detail using mass, i.e., mass flows and not volumetric flows. It must be remembered that masses are additive, but volumes are not always additive. Then, we provide a brief explanation of what is a process and state that the chapter focuses on continuous material balance problems under steady-state conditions. The core of the chapter details a proposed strategy to solve simple and complex material balance problems. We developed a five-step procedure, which is explained and then applied in examples. The chapter concludes with 3 solved problems and then proposes 24 problems, each one with the corresponding answer.

Chemical and Bioprocess Engineering Fundamental Concepts for First-Year Students

Salting is one of the oldest methods of preserving food. The main limitation of salting is its extended processing time due to slow salt diffusion. A moderate electric field (MEF) can improve the mass transfer rate through electroporation. Regularly, mass transfer processes are modeled with Fick’s second law. However, due to the anisotropic nature of food microstructures, it might be more appropriate to use an anomalous model. The main objective of this study was to search for a phenomenological explanation for salt and water diffusion in the salmon brining process coupled with MEF. Salmon fillets were cut into finite cylinders (0.025 × 0.025 m) and brined in two salt concentrations (6 and 24% w/w NaCl) at 6 °C for 20 h. MEFs were applied in the range of 0 to 2 V/cm. The salt and water contents of the salmon were measured during the process. Fick’s second law and anomalous model based on fractional calculus were used to describe the diffusion phenomena. The results showed that an MEF tended to reduce the brining processing time and increase the salt content of salmon. This effect is predominantly due to an increase in the equilibrium salt concentration in the salmon tissue. Mathematical analysis shows that the anomalous diffusion model is more suitable for representing the brining process, exhibiting superdiffusion behavior (α > 1). An MEF accelerates the salt mass transfer into salmon tissue even at lower temperatures, significantly reducing the processing time. In addition, the diffusion process can be characterized with an anomalous model.

Freeze-dried berry fruits are generally consumed as they are, whole and without peeling or cutting, as the conservation of their original shape and appearance is often desired for the final product. However, usually, berries are naturally wrapped by an outer skin that imparts a barrier to vapor flow during freeze-drying, causing berry busting. Photo-sequence, experimental, and theoretical methodologies were applied to evaluate the application of CO2 laser microperforations to blueberry skin. Under the same set of freeze-drying conditions, blueberries with and without perforations were processed. The results showed that the primary drying time was significantly reduced from 17 &plusmn, 0.9 h for nontreated berries to 13 &plusmn, 2.0 h when nine microperforations per berry fruit were made. Concomitantly, the quality was also significantly improved, as the percentage of nonbusted blueberries at the end of the process increased from an average of 47% to 86%. From a phenomenological perspective, the analysis of the mass transfer resistance of nontreated fruits, in agreement with reported studies, showed a Type II curvature, with a sharp decrease at low time, followed by a linear increase. In contrast, blueberries with nine perforations depicted a Type III regime, with a saturation curvature toward the time axis. It was demonstrated that CO2-laser microperforation has high potential as a skin pretreatment for the freeze-drying of blueberries.

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.

Pomegranate (Punica granatum) is a non-climacteric fruit susceptible to chilling injury (CI) at temperatures below 5 °C. To understand the influences of ethylene and modified atmosphere on CI physiological disorders of pomegranate, exogenous ethrel (0.5, 1 and 1.5 µg L-1 ) treatments, 1-methylcyclopropene (1-MCP) (1 µL L-1 ) exposure, packaging in a modified atmosphere (MAP) (XTend™ bags; StePac, Sao Paulo, Brazil), a MAP/1-MCP combination, and packaging in macro-perforated bags (MPB) were applied. The treated fruits were cold stored (2 ± 1 °C; 85% relative humidity) and sampled during 120 + 3 days at 20 °C.; Results: During cold storage, CI symptoms started at 20 days in MPB and at 60 days for all exogenous ethylene treatments, and were delayed to 120 days in MAP, 1-MCP and MAP/1-MCP treatments. MPB and ethylene treatments induced significant electrolyte leakage, oxidative damage, lipid peroxidation, ethylene and CO2 production, and 1-aminocyclopropane-1-carboxylic acid oxidase activity, without any change in total soluble solids, titratable acidity or skin and aril colours. Conversely, MAP by itself, or in combination with 1-MCP application, effectively delayed CI symptoms.; Conclusion: During long-term cold storage of this non-climacteric fruit, ethrel application induced endogenous ethylene biosynthesis, accelerating the appearance of CI symptoms in contrast to the observations made for MAP and 1-MCP treatments. © 2018 Society of Chemical Industry.; © 2018 Society of Chemical Industry.

Osmotic dehydration (OD) typically requires a long processing time, so the incorporation of CO2-laser microperforations could reduce it. The aims of this study were 1) to explore the potential acceleration of the OD process coupled with CO2-laser microperforations and 2) to mathematically evaluate the diffusion process through a complementary error function (erfc). Apple slices pretreated with two micropore sizes and two configurations were immersed in a solution of 45° Brix at 40 °C for 10 h. The total solid content in the apple slices was measured. A model based on erfc was used to determine the effective diffusion coefficient (Deff). The results showed a significant increase in Deff for microperforated samples, especially for those with the largest pores compared with control (R2 > 0.92). Additionally, pores were able to reduce the processing time by up to 63% for big pores (600 μm) and between 22% and 45% for small pores (23 μm).

Page's equation is one of the most successful empirical equations applied to describe water migration throughout food drying processes. However, when analyzed in detail, the mathematical derivation shows a number of inconsistencies. The hypothesis is that the noteworthy success of Page's equation could be explained by its mathematical similarity with the solution of an anomalous diffusion phenomenon. In addition, the extraordinary success of Page's equation has induced other researchers to search for similar equations, but without a phenomenological comprehension. The objectives are: 1) demonstrate that Page's equation presents some inconsistences in its mathematical derivation; 2) demonstrate that the goodness of fit of Page's equation could be explained by its similarity with the mathematical solution of anomalous diffusion model. A comprehensive examination of Page's thesis was performed by analyzing its theoretical development and experimental data. Also, data reported in the literature were analyzed to test the application of Page's equation, Fick's second law and anomalous diffusion model. This study demonstrates that Page's equation was raised from a misinterpretation of Fick's second law. In addition, anomalous diffusion solution has remarkable similarities with Page's equation, mainly because of the inclusion of time exponential parameter (n). One important outcome from the apple drying data was that n must be constant and independent of temperature, given that n is related with the microstructure of the food matrix. In conclusion, the mathematical solution of anomalous diffusion model through the fractional calculus approach may, in part, explain the goodness of fit of Page's equation to drying data.

Because the quality and shelf life of a frozen food greatly depend on the freezing processing time, its accurate estimation is highly relevant. In addition, the estimation of the freezing time is an enormous task due to the difficulty in developing a robust and accurate mathematical model and the need for appropriate thermophysical properties for an immense variety of foods. The objective of this study was to explore, via simulation, the capability of an inverse method to simultaneously determine the thermal conductivity ( k(T) ) and apparent volumetric specific heat ( C(T) ) of foods in the freezing temperature range (i.e., initial freezing point to −40 °C). Experiments and validation experiments were designed with the purpose of a systematic analysis and assessment of the potential capability of an inverse procedure for simultaneously determining the thermophysical properties of foods in the freezing temperature range. Assuming a one-dimensional freezing process and known thermophysical properties of the food material, temperatures were generated at different locations of the food sample by numerically solving the partial differential equation for heat conduction. The inverse method was designed to obtain the unknown parameters for the equations of the thermophysical properties C(T) and k(T) . The ability of the inverse method to simultaneously determine C(T) and k(T) in the freezing temperature range was investigated, and it was determined that the technique is accurate, rapid and robust to typical measurement errors. This fact was supported by a sensitivity coefficient analysis, which compared the direct-adjustment to the inverse method.

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.

An interesting potential improvement and challenge in thermal processing of packaged foods is the implementation of simultaneous multi-product sterilization. The aim of this research was to analyze, explore, and optimize simultaneous multi-product sterilization through thermal processing simulation of packaged foods considering both constant (CRT) and variable retort temperature (VRT) profiles. The research was approached through three main tasks, which were defined to discover potential opportunities for simultaneous multi-product sterilization with the attempt to recommend the steps to follow to practically implement it. In most cases, simultaneous multi-product sterilization for CRT processing was feasible, however, it was limited to low retort temperature and restricted to products with similar fh. In contrast, in VRT profiles a higher flexibility for simultaneous multi-product sterilization was found. The opportunity to carry out simultaneous multi-product sterilization provides flexibility to optimize retort utilization, reduce energy consumption, and increase processing plant productivity.

The marination of meat takes many hours to attain the required salt content. Vacuum impregnation (VI) and CO2-laser microperforation have been studied to accelerate the mass transfer process and show promising results. The objective of this study was to investigate the feasibility of reducing the pork marinating time by coupling CO2-laser microperforation and VI processes and mathematically with Fick's second law and anomalous diffusion models. Pork cylinders were microperforated and marinated with a solution containing NaCl (8% w/w) and Na5P3O10 (0.3% w/w) at 6 °C for 60 h. The marinating process was modeled using Fick's second law and anomalous diffusion models. The marinating process coupling VI and microperforations significantly accelerated the mass transfer compared with that of the conventional salting process, reducing the marinating processing time by 47.8%. The anomalous diffusion model was better at representing and adjusting the experimental data compared than the model based on Fick's second law. Industrial application The marinating of meat is a process commonly applied in the meat industry, which focuses on enhancing the flavor, tenderness and juiciness of meat. However, it is a time-consuming process. Laser microperforation is a pretreatment performed on the meat in which the laser acts as a drill, creating micropores in the meat, which coupled with vacuum impregnation can be applied to accelerate the marinating process of pork meat. Applying both technologies, it is possible to reduce the processing time by almost 48%, which can relevantly and significantly increase plant productivity.

The changes of lifestyle and eating habits of consumers have induced a growth in the demand for functional food. The aim of this work was to study the incorporation of folic acid into apple slices by using ohmic heating (OH) and vacuum impregnation (VI) at 30, 40 and 50 °C and air drying at 50, 60 and 70 °C to obtain an apple snack that is rich in folic acid. The kinetic impregnation of folic acid, texture and color were evaluated. The impregnated samples (VI) at 40 °C and vacuum-impregnated samples with ohmic heating (VI/OH) at 50 °C presented a high content of folic acid, whereas the samples air dried at 60 °C presented an important retention of folic acid. The lowest loss of firmness and color was obtained with the VI/OH treatment at 50 °C with drying at 60 °C. Therefore, the VI/OH treatment at 50 °C followed by drying at 60 °C was determined to be the best process for creating dehydrated apple slices that are rich in folic acid. Industrial relevance The aim of this research was to study the incorporation of folic acid into dehydrated sliced apples by using vacuum impregnation/ohmic heating (VI/OH) treatments and air drying technologies and evaluating the mechanical and optical properties of the resulting product. Two technologies, vacuum impregnation (VI) and ohmic heating (OH) were performed at 30, 40 or 50 °C with an electric field intensity of 13 V/cm using conventional heating. The results showed that the samples impregnated of apple slices by VI and VI/OH treatments reached the highest content of folic acid. However, the samples that were dried at 60 °C after impregnation by the VI/OH treatment at 50 °C exhibited an increase in folic acid due to the electropermeabilization effect, which induces retention of folic acid and an increase in the folic acid concentration by decreasing the water content. Under the investigated conditions, the VI/OH treatment at 50 °C followed by air drying at 60 °C may be considered the best processing method to obtain an apple snack that is rich in folic acid.

Osmotic dehydration is a process wherein foods are partially dehydrated by immersion in an aqueous hypertonic solution. Osmotic dehydration reduces the water activity of the food, thereby minimizing the potential growth of microorganisms and extending the shelf life of food products. A major disadvantage of the osmotic dehydration process is the long time required to reduce the water activity, which makes its industrial implementation impractical. The aim of this research is to determine the diffusion mechanisms in Granny Smith apples exposed to different electric fields varying from 0 to 17 V/cm. Osmotic dehydration was performed at 40 °C for both the conventional treatment and for the MEF treatment. The fruit/solution ratio used was 1:11 w/w to prevent and minimize the change in concentration of the solution during the experiment. The osmotic solution was exposed to electric fields of 0, 9, 13 or 17 V/cm, respectively. To determine the diffusion mechanisms two phenomenological models were tested: Fick’s second law and Anomalous diffusion model. Sucrose diffusion in Granny Smith apples is highly influenced by the application of a MEF, meaning that as the application of the electric field increases, the higher the effective diffusion coefficient (Deff) becomes. The exponential decay from the Fick law, in the tail of the diffusion profile, does not represent the shape of the data. However, as the application of the electric field increases the fit of Fick’s model improves, and specifically for an electric field of 17 V/cm it is observed that the behavior of the experimental data resembles the behavior predicted by Fick’s second law. The empirical parameter α for the anomalous diffusion model was always greater than one, but as the MEF increased, α was monotonically tending to one.

Thermal processing has been used for packaged foods for many years and remains one of the most common and safe processes to preserve foods and extend their shelf life. Advances in thermal processing in the last two decades have helped maintain its relevance in international food trades. In this study, we aimed to gain a better understanding of thermal food processing using variable retort temperature profiles (VRTPs). VRTPs were assessed to optimize processes, either by ensuring high quality level or minimizing the operating process time. Based on the research results, VRTPs could improve quality retention; however, the improvement was not sufficient to be detectable by consumers and to justify implementation of VRTPs at the industrial level. Our general assessment provided a preliminary guide for processors to discover real opportunities for VRTPs, e.g., increased productivity by reducing operating process time and energy consumption.

Currently, the food industry generates large amounts of agroindustry waste. Specifically, the coffee and cheese industry produce spent coffee ground and whey respectively. Therefore, it is important to find applications for these residues allowing the food industry to be friendly with the environment. The main goal of this research was to evaluate some morphological and thermodynamic properties of a powder product obtained by spray drying, from the mixture of Spent Coffee Ground (SCG) with Whey Concentrated (WC). The methodology includes the mixture of different combinations of SCG (4, 10 & 16%) with WC; afterward, the mixture was spray dried using an inlet temperature of 170 °C. The powder characterization includes: Moisture, Water Activity (Aw), Glass Transition temperature (Tg). In addition, isothermal curves were obtained. As a result, the moisture content and Aw of the powder were 3.25 ± 0.18 and 0.252 ± 0.01, while the bulk density was 0.495 ± 0.10 g/cm3, showing a significant correlation (p

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 pomegranate peel, an agro-industrial waste, has a high content of antioxidant polyphenolic compounds with proven health-benefiting and technological properties. Polyphenol stability might be affected by heat treatments that are required during drying. Thus, the aim of this study was to analyze the drying kinetics of pomegranate peel dried by double drum drying and to evaluate its effect on polyphenolic compounds. Pomegranate peel was dried at 100, 110 and 120 °C using a constant clearance (2 mm); the processes were modeled and the physiochemical and antioxidant properties were analyzed. Drum drying at 100, 110 and 120 °C were very fast processes that required short drying times (422 s, 400 s and 257 s, respectively) to reach low moisture contents (5.0, 1.6 and 2.6 g water/100 g peel, respectively). At these short drying times, the total polyphenolic content and antioxidant activity were not significantly decreased at any temperature, and the hydrolysable tannins content was maintained by drum drying at 100 and 110 °C. Thus, the drum drying results demonstrate an efficient alternative to obtain a high quality product from pomegranate peel and thereby reuse and add value to this agro-industrial waste.

The combined effect of ohmic heating (OH) and osmotic dehydration (OD) with vacuum impregnation (VI), on the polyphenoloxidase (PPO) inactivation, physical properties and microbial stability of apples stored at 5 °C or 10 °C was analyzed. The treatments were performed using a 65% (w/w) sucrose solution and with ohmic heating at 13 V/cm at 30 °C, 40 °C or 50 °C for 90 min. Examination of the dehydrated samples showed that the water loss and the solid gain were greater with the OD/OH and VI/OH treatments at 50 °C. PPO was completely inactivated by the OD/OH and VI/OH treatments at 50 °C. There was a correlation between the PPO activity, the color change and the browning index of the treated and stored samples; the values for these parameters were stable when PPO was inactivated. The lowest loss of firmness and color was obtained with the VI/OH treatment at 50 °C. The shelf-life of the apples treated with VI/OH at 50 °C and stored at 5 °C was extended to more than 4 weeks. Therefore, the VI/OH treatment at 50 °C was determined to be the best process for dehydrating apples. Industrial relevance The aim of this research was 1 to study the combined effect of ohmic heating (OH) and osmotic dehydration (OD) with vacuum impregnation (VI) on the polyphenoloxidase inactivation and microbial stability of osmotically dehydrated apples stored at either 5 °C or 10 °C. Two technologies, OH and OD were performed at 30, 40 or 50 °C with an electric field intensity of 13 V/cm and conventional heating for 90 min. The results showed a correlation between the PPO activity, the color change and the browning index of the treated and stored samples; the values were stable when PPO was inactivated. PPO was completely inactivated by the OD/OH and VI/OH treatments at 50 °C. The shelf-life of the apples treated was extended to more than 4 weeks. Under the investigated conditions, VI/OH treatment at 50 °C and stored at 5 °C may be considered the better minimal processing that preserves the fresh-like properties.

Research, innovations and applications in the food industry are always delayed relative to other areas of engineering, in part because modeling, simulation and optimization of food processes face additional challenges due to the nature of biological materials. In addition, researchers and scientists in other engineering fields tend to have better mathematical training in relation to researchers in biological sciences. Our hypothesis is that the diffusion process within food materials which are non-Fickian, that is, anomalous, can be characterized using a fractional calculus formulation. There is currently strong experimental and theoretical evidence that the diffusion process in food materials generally departs from the Fickian diffusion model which comes from the random walk displacement of the diffusants. In biological materials the heterogeneity due to the cellular structure produces regions in which the diffusants can travel anomalous length distances or be stopped in compartments, which produces a departure from the expected results of the random walk, resulting in anomalous diffusion. The introduction and application of fractional calculus to the field of food science/engineering could lead to many uses, primarily in heat and mass transfer processes. Fractional calculus is a powerful tool for solving and understanding complex natural phenomena; therefore, we believe it is necessary to exploit it to the utmost to obtain realistic and practical solutions for the mass transfer phenomena and to demonstrate its potential to other food science/engineering problems.

Heat Transfer.- Kinetics of Thermal Processing.- Sterilization, Pasteurization and Cooking Criteria.- Heat Penetration in Packaged Foods.- Process Evaluation Techniques.- Quality Optimization.- Engineering Aspects of Thermal Processing.- Retort Control.- Safety Aspects of Thermal Processing.