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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

O estudo avaliou a geração de metano e biodegradabilidade por meio de um ensaio anaeróbio em condições mesofílicas (37°C) de três misturas de resíduos orgânicos (resíduos de feira e fezes caninas) nas seguintes proporções volumétricas: amostra 1 (30% feira e 70% fezes); amostra 2 (20% feira e 80% fezes) e amostra 3 (10% feira e 90% fezes). O inóculo utilizado teve procedência de um digestor anaeróbio que tratava fezes suínas e foi previamente aclimatado. Para o ensaio, 6 minirreatores (volume efetivo de 0,3 l) foram montados (3 fixos e 3 sacrifícios), contendo as misturas apresentadas e o inóculo, além de 2 reatores (brancos) que só tinham o inóculo, para estimar seu efeito intrínseco. Após 41 dias de operação, houve uma remoção total de DQO de 58%, 34% e 63% e remoção de STV de 33%, 30% e 40% para as amostras 1, 2 e 3, respectivamente. As amostras 1 e 3 demonstraram uma possibilidade de tratamento desses resíduos orgânicos justificada pela biodegradabilidade dentro da faixa esperada de um biodigestor anaeróbio. A amostra 3 obteve melhor resultado, no entanto, tardou uma semana para gerar o biogás e tratou um menor volume de substrato para manter a mesma relação de nutrientes (relação C: N: P) entre as amostras. As taxas de 86 L CH4/kg DQOeliminada, 301 L CH4/kg DQOeliminada e 133 L CH4/kg DQOeliminada foram alcançadas pelas amostras respectivamente, resultados abaixo dos valores de referência.

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

A proteolytic susceptibility index was proposed to evaluate the reaction performance of different food by-products with subtilisin. Whey, salmon muscle and feather keratine were hydrolyzed at the same peptide bond concentration at 50 °C and pH 8.0 with different subtilisin concentrations. The logarithmic equation P = 1/b ln(abt+1) was fitted to estimate the kinetic constants a and b. The a/b ratio was proposed as a proteolytic susceptibility index, which was correlated with the chemical structure and conformation of protein sources in increasing order of feather keratin, salmon muscle and whey proteins with corresponding a/b values of 0.1, 8.2 and 14.4 mM2/min, respectively. The methodology proposed in this work can be used to evaluate the proteolytic susceptibility of different protein by-products to different proteases and to evaluate the changes in proteolytic susceptibility after treatment.

Crystalline material can develop on the surface of raisins during storage and transport, affecting the final acceptability of the product. In this work, a mild thermal pretreatment was applied to raisins to melt the pre-existing crystals and the effect of such thermal treatments on the development of crystals over a storage period was investigated. The raisins selected for this study were of the Thompson seedless variety from one Chilean company. The thermal pretreatment of raisins at 50 &deg, C and 70 &deg, C for 20 min in an oven and microwave (800 W) irradiation for 15 s resulted in a reduction in the percentage of crystallized raisins (w/w) from more than 50% in the control samples to less than 10% after 35 days of storage at 15 and 25 &deg, C in a 57% relative humidity environment. The results showed that some textural parameters, such as cohesiveness and chewiness, were not affected by thermal treatment and were independent of storage temperature.

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 synergistic effects of peptides in bovine skin gelatin hydrolysate (BSGH) on the water-holding capacity (WHC), measured as cooking loss, were studied. These peptides were isolated from the hydrolysate in fractions with different hydrophobicities by reversed-phase chromatography on C18 separation columns. Each peptide fraction was included in the meat matrix at various concentrations for the study of water retention. The fraction with the highest WHC (F5) was obtained. The experimental design consisted of a central compound design with axial points; the independent variables were X1 (ingredient concentration in the meat sample) and X2 (concentration of fraction F5 in the ingredient). The dependent variable was cooking loss. The WHC studies showed substantial synergistic effects occurred between the fractions within the BSGH, and the peptide fractions reduced the cooking loss by 62.96% with respect to a sample without the ingredient. However, a decrease of 42.26% was observed for the F5 fraction. This fraction corresponds to the highest WHC applied for the concentration of 3 g/100 g. The results suggest a synergistic WHC effect of the peptides present in the BSGH since this effect was significantly reduced (p ≤ 0.05) when the peptide fractions were separated.

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.

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.

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.

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 aim of this work was to validate a mathematical model and evaluate hydrolysis of salmon muscle proteins by Alcalase in batch reactor. The inhibition constants were correlated with conversion and temperature thus improving dramatically the agreement between model predictions and experimental hydrolysis time courses. The standard operation in batch reactor consisting in pre-heating, isothermal stage and inactivation of enzyme was evaluated through simulation of different operational strategies based on increasing temperature gradients. Operational conditions were 7.5%(w/w) protein, 1 g/l Alcalase and different temperatures from 50 °C to 73 °C. The optimal temperature for the standard process was 68 °C with a processing time of 41 min. Different operational strategies, included temperature profiles, resulted in longer operation times. The standard process was the best reactor performance due to the maximization of the enzyme efficiency.

After prolonged storage or during the shipment of raisins, a crystalline material may be developed on their surface, affecting the final acceptability of the product. The mild thermal pretreatment (50 °C for a period of 12 h and 48 h) was applied to dissolve any potential tiny crystals and nuclei already present in the raisins. The thermal pretreatment of raisins resulted in a reduction on the percentage of crystallized raisins (w/w) from more than 46% in control samples to less than 10% after 30 days of storage at 57% and 66% of relative humidity and 15 °C and 25 °C. X-ray diffraction analysis identified d-Glucose monohydrate as the main crystalline component. All the thermal treatments increased the hardness of the raisins, when they were incubated at 57% relative humidity. To mitigate the problems of crystallization of raisins during shipping, it is recommended that the raisins are thermally pretreated and the shipping conditions are controlled.

The effects of sugar component ratio, water fraction, and storage conditions on crystallisation and glass transition temperature (Tg) of three Chilean dried raisins were examined by using differential scanning calorimetry (DSC), polarised light microscopy and X-ray diffraction (XRD) techniques. Thompson, Flame and Golden raisins differed in fructose:glucose and glucose:water ratios, impacting on their measured Tgs (P

A novel methodology for the modeling and characterization of the enzymatic hydrolysis of proteins is proposed. The hydrolysis time course can be predicted at different operating conditions for protein concentration, enzyme concentration and temperature. The hydrolysis kinetics of salmon muscle proteins and whey protein isolate by Alcalase were studied using a central composite design. A combination of the logarithmic equation P = 1/bln (abt + 1) to model the hydrolysis time course with the response surface methodology to correlate the kinetic constants a and b with the operating conditions: protein concentration, enzyme concentration and temperature were achieved. The logarithmic equation was a very good fit with the hydrolysis time courses, with both substrates achieving R2 > 0.995. The kinetic constants a and b were significantly affected by the operating conditions. Empirical models were obtained for a and b as functions of operating conditions. The kinetic constant values were predicted, and a strong correlation between predicted and experimental values was obtained for a (R2 = 0.949) and b (R2 = 0.945). The predicted and experimental time courses resulted in good correlation for both salmon muscle proteins (R2 > 0.987) and whey protein isolate (R2 > 0.978). The model allowed calculation of the hydrolysis time course of proteins from a given set of operating conditions with good predictability. This methodology can be used with different sources of proteins and enzymes to test the susceptibility of proteins to hydrolysis as well as the catalytic efficiency of proteases. Additionally, the combined model can be used as a design and optimization function.

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 apple peel, a by-product of apple processing, has a high total phenolic content (TPC); however, these compounds can be highly thermosensitive and unstable. Therefore, the aim of this study was to determine the degradation kinetics of the TPC in apple peels during drum-drying as a stabilization and recovery method. Apple peels (Granny Smith) were dried at 110, 120, 130 or 140 °C for 250 s with a constant drum clearance (0.2 mm). TPC degradation exhibited first-order kinetics and their retentions at the end of the process were 73.13% at 110 °C, 57.28% at 120 °C, 43.40% at 130 °C and 21.10% at 140 °C. Finally, empirical models were significantly fitted to predict the TPC as the apple peels reached a certain level of dehydration, which may be useful from the processing standpoint and validate the use of drum-drying as a process tool for the recovery of apple industrial wastes.

Through decades of study, regardless the protein source, the enzymatic hydrolysis of proteins has always resulted in a hydrolysis curve with a typical shape: an initial rapid hydrolysis phase followed by a rapid decrease in the reaction rate. Several hypotheses have been proposed, such as substrate exhaustion, product inhibition and enzyme inactivation. In current study the effect of substrate, product and thermal inactivation were systematically studied using the commercial enzyme Alcalase and salmon muscle protein as the substrate. The low Km value of 4.39 mM and the stabilization of Alcalase in the presence of substrate and hydrolysis products could not explain the progressive decrease in the reaction rate. On the other hand, a strong product inhibition was observed (Ki = 2.31 mM; K ′ i = 7.12 mM ). These results along with computer simulations revealed that neither substrate exhaustion nor enzyme inactivation generated the typical hydrolysis curve; however, inhibition by hydrolysis products resulted in a remarkable and progressive decrease in the reaction rate, which satisfactorily explained the shape of the hydrolysis curve.

The basic principles of canning have not changed dramatically since Nicholas Appert and Peter Durand developed the process. The sterilization and pasteurization of foods have a long tradition, and this tradition will likely continue due to its convenience and advances in the technology as well as the packaging materials. Mathematical modeling has been gaining recognition in the food industry, particularly for applications such as thermal sterilization and pasteurization, helping the food industry to deliver safe processed products that also retain quality to a greater extent. In recent years, several researchers have been developing applications for multiobjective optimization in food processing, especially in the area of thermal food sterilization.

The combined effect of osmotic dehydration/ohmic heating (OD–OH) and vacuum impregnation/ohmic heating (VI–OH) on physicochemical and quality parameters of strawberry ( a w , color, firmness and microstructure), as well as on microbial stability of storage samples at 5 and 10 °C, was analyzed. Treatments were carried out with a 65% (w/w) sucrose solution at 30 °C, and ohmic heating at 9.2, 13, and 17 V/cm electric field strengths, corresponding to applied voltages of 70, 100, and 130 V. Dehydrated samples showed that water loss was greater in OD–OH treatments at 17 V/cm. The greatest solute gain, least firmness loss and least color loss were obtained in the VI–OH treatment at 13 V/cm. The shelf-life of strawberries treated with VI–OH at 13 V/cm and stored at 5 °C was extended from 12 d (control samples) to 25 d. Furthermore, the VI–OH treatment at 13 V/cm was the best processing condition for dehydrating strawberries.

A critical analysis of the correction factor for the come-up time (CUT) introduced by Dr. C. Olin Ball in his Formula Method for thermal process calculations is described in this manuscript. In the General Method, the effect of the CUT is included in the calculated lethality value as long as numerical integration is carried out over the entire cold spot temperature–time profile from the point when the steam is turned on. The hypothesis of this communication is that Ball’s Formula Method, just like the General Method, includes the effect of the CUT in its calculations. Ball’s Formula Method utilizes a “curve fitting” of the experimental time–temperature data regardless of where the time zero is placed within the come-up time. Therefore, the effect of the CUT is automatically included, because, as in the General Method, Ball’s Formula Method is fitting and managing experimental data. In addition, the regressed time–temperature data used for lethality calculations are exactly the same independent of the time zero location. To evaluate the rationale of the CUT correction factor, computer-simulated time–temperature data and experimental runs were evaluated with time zero shifted to different locations (100, 70, 42, 20 and 0% of the CUT). In addition, the effect of the CUT (shape and length) was studied in terms of FHeating and Tg accuracy compared to the General Method. Independent of the time shift (the location of time zero), the calculations according to the Formula Method for total heating time (Pt + CUT) were always the same. This work states that it is not necessary to shift the location of time zero in Ball’s Formula Method because the calculations over the curve fitting time–temperature data will always include the effect of the CUT regardless of where time zero is placed.

The influence of pulsed vacuum (PVOD) and ohmic heating (OH) on the osmotic dehydration (OD) kinetics and structure of apples was evaluated. Apple cubes (1 cm3) were immersed in a 65 oBrix sucrose solution at 30, 40 and 50 °C for 300 min. The PVOD treatment was conducted at 5 kPa for 5 min, and the OH treatment was conducted at 100 V (electric field of 13 V/cm). The water loss, solid gain, aw, color and firmness were measured, and the microstructure was analyzed using electronic microscopy. The largest water loss was observed with the OD/OH treatment at 50 °C. The greatest amount of solute uptake and smallest firmness loss were obtained with the PVOD/OH treatment at 50 °C. Color differences were associated with the loss of clarity and corresponded to the transparency gain. OH treatments led to changes in the microstructure, cell walls and tissues of the apples due to the electroporation effect, which explained the increase of mass transference. Industrial relevance The aim of this research was to determine the response of apple samples to osmotic dehydration using combined treatments of pulsed vacuum and ohmic heating. Two different technologies, vacuum and ohmic heating at mild temperatures, were used to determine and observe the mass transfer kinetics and microstructure of osmodehydrated apples. In several ohmic heating treatments, the time reduction reached 50% as compared to conventional heating. The increases of temperature, vacuum application and electroporation effect promoted the gain of osmotic solution into the tissue pores, thus reaching equilibrium in the sample with less water loss. Among the investigated conditions, the PVOD/OH treatment at mild temperatures was the best minimal processing method to preserve the fresh-like properties of the apples.

The objective of this work was to compare the quality of parameter estimation from experiments with protein hydrolysis of fish muscle carried out following a traditional versus D-optimal design of experiments. Traditional design was done from hydrolysis experiments using the rapid titration method, from which a large number of data points was obtained and made available for parameter estimation. D-optimal design is recommended under conditions when it would not be possible to use rapid titration with analytical tools. Such conditions would make it necessary to reduce the number of samples that would need to be taken as well as the error and variance in the estimated parameters needed for the kinetic model. Results have shown that D-optimal and traditional designs of experiments obtained accurate and reliable estimates of kinetic model parameters, with a great difference in the number of data points between both types of design: 18 points in traditional and 3 points in D-optimal design. Nevertheless, a few number of observations in D-optimal design impacted negatively the confidence interval because of a low degree of freedom. Confidence intervals ranging from 7.8% to 87% of the parameters values were obtained with D-optimal design method in contrast with traditional design where confidence intervals ranged from 6.2% to 15% of the parameters values. It is estimated that combining the advantages of both types of design will result in an optimal experimental design in terms of reliability, accuracy, and costs saving of analysis. This would be done by determining the number of observations required to achieve an appropriate confidence interval (about six or more experimental points) and, then, a selection of the best experimental points of a curve of hydrolysis by D-optimal design.

The effect of ohmic heating (OH) and vacuum impregnation (VI) on the osmotic dehydration kinetics and microstructure of pears was studied. Three different dehydration levels (30, 40 and 50 °C) were used, by applying VI or not (OD) and OH (100 V). Dehydrated samples showed that the application of OH during the osmotic treatments had significant effects on the kinetics of water loss and sugar gain as well as on the microstructure of samples. The greatest water loss was observed with the OD–OH. The largest amount of solute gain and the smallest firmness loss were obtained in the VI–OH. In some treatments, the process time was reduced by as much as 40%. The SEM observations showed that cell deformation and cell rupture were significant in the OD–OH than on the VI–OH samples. The increases in the permeability of cell by OH explain the acceleration of mass transference and process time reduction.

Apples (Malus domestica Borkh.) have been identified as one of the main dietary sources of antioxidants, mainly phenolic compounds. These compounds vary in their composition and concentration, among cultivars and fruit tissues. In this research, the total phenolic content (Folin-Ciocalteau assay), antioxidant capacity (Ferric Reducing Antioxidant Power, FRAP assay) and mineral composition in three fruit tissues (peel, pulp and whole fruit), of apple cultivars commonly used for dried apple production in Chile, were studied. In addition, the physical-chemical characteristics (dry weight, pH, titratable acidity, soluble solids content and color) were also evaluated. The results indicated that the total phenolic content, the antioxidant capacity, and the mineral composition, of peel were substantially higher than those of whole fruit, and pulp for all the cultivars studied. Among cultivars, ’Red Delicious’ apple peels have a significantly much higher content of total phenolic (11.6 mg gallic acid equivalents [GAE] g-1 FW) and a higher FRAP (209.9 µmol Fe+2 g-1 FW). Additionally, a high correlation between total phenolic content and antioxidant capacity was found in all the cultivars and fruit tissues analyzed, except in the apple pulp. On the other hand, the physical and chemical composition differed among cultivars and fruit tissues. In conclusion, our results demonstrated that the total phenolic content, antioxidant capacity, mineral composition, and physical and chemical characteristics vary considerably depending on the apple cultivars and fruit tissues analyzed.

Apples (Malus domestica Borkh.) have been identified as one of the main dietary sources of antioxidants, mainly phenolic compounds. These compounds vary in their composition and concentration, among cultivars and fruit tissues. In this research, the total phenolic content (Folin-Ciocalteau assay), antioxidant capacity (Ferric Reducing Antioxidant Power, FRAP assay) and mineral composition in three fruit tissues (peel, pulp and whole fruit), of apple cultivars commonly used for dried apple production in Chile, were studied. In addition, the physical-chemical characteristics (dry weight, pH, titratable acidity, soluble solids content and color) were also evaluated. The results indicated that the total phenolic content, the antioxidant capacity, and the mineral composition, of peel were substantially higher than those of whole fruit, and pulp for all the cultivars studied. Among cultivars, ‘Red Delicious’ apple peels have a significantly much higher content of total phenolic (11.6 mg gallic acid equivalents [GAE] g-1 FW) and a higher FRAP (209.9 µmol Fe+2 g-1 FW). Additionally, a high correlation between total phenolic content and antioxidant capacity was found in all the cultivars and fruit tissues analyzed, except in the apple pulp. On the other hand, the physical and chemical composition differed among cultivars and fruit tissues. In conclusion, our results demonstrated that the total phenolic content, antioxidant capacity, mineral composition, and physical and chemical characteristics vary considerably depending on the apple cultivars and fruit tissues analyzed.Las manzanas (Malus domestica Borkh.) han sido identificadas como una de las principales fuentes de antioxidantes en la dieta, principalmente de compuestos fenólicos. Estos compuestos varían en su composición y concentración según el cultivar y el tejido del fruto. En esta investigación se determinó: el contenido de fenoles totales (ensayo de Folin-Ciocalteau), la capacidad antioxidante (ensayo FRAP, Ferric Reducing Antioxidant Power) y la composición mineral en tres tejidos del fruto (piel, pulpa y fruto entero) de las principales variedades usadas en la producción de manzana deshidratada en Chile. Adicionalmente se evaluaron las características físico-químicas (materia seca, pH, acidez titulable, contenido de sólidos solubles y color). Los resultados indican que en todas las variedades estudiadas, el contenido de fenoles totales, la capacidad antioxidante, y la composición mineral de la piel fueron substancialmente mayores que los valores obtenidos en el fruto entero y la pulpa. Entre las variedades analizadas, la piel del cv. Red Delicious presentó significativamente mayor contenido de fenoles totales (11,6 mg equivalentes ácido gálico [EAG] g-1 PF) y mayor valor FRAP (209,9 µmol Fe+2 g-1 PF). Adicionalmente, se encontró una alta correlación entre el contenido de fenoles totales y la capacidad antioxidante en todas las variedades y los tejidos del fruto analizados, excepto en la pulpa. Por otro lado, la composición física y química varió. En conclusión, el contenido de fenoles totales, la capacidad antioxidante, la composición mineral, y las características físicas y químicas varían considerablemente, dependiendo de la variedad de manzana y el tejido del fruto analizado.

The processing of squid generates nearly 50% of raw material as a waste by-product rich in protein. Use of this by-product as a raw material in the manufacture of a squid protein hydrolysate would add considerable product value to the industry. Enzyme hydrolysis of squid waste protein is a complex process because of a number of inherent simultaneous inhibition and enzyme inactivation reactions which occur during hydrolysis. Artificial neural networks (ANNs) are very effective in developing predictive models for processes involving complex reaction kinetics that would otherwise be difficult to develop by more traditional deterministic approaches. The objective of this work was to develop a kinetic model to describe the kinetics of enzyme hydrolysis of squid waste protein using ANNs. A series of enzyme hydrolysis experiments were carried out on samples of squid waste under specified conditions of temperature, pH, and initial enzyme and substrate concentrations. Experimental data in the form of substrate concentration over time were taken as real time course data. These data were fitted with a cubic spline procedure for use in an ANNs training process to estimate reaction rates for the model. The effect of a number of hidden processing elements on the error in prediction was studied, and the ANN showing necessary prediction performance was constructed. Maximum differences between experimental and predicted values of substrate concentration at any point in time ranged from 0.098 to 0.29 g/L (3–4%). Correlation coefficients between predicted and experimental results were also, respectively, high, ranging from 0.988 to 0.992. PRACTICAL APPLICATIONS Results from this study would suggest that artificial neural networks (ANNs) can be very effective in developing predictive models for processes involving complex reaction kinetics. Enzyme hydrolysis of squid waste protein is an example of such a process because of a number of inherent simultaneous inhibition and enzyme inactivation reactions occurring during hydrolysis. This work resulted in the successful development of a kinetic model to describe the kinetics of enzyme hydrolysis of squid waste protein using ANNs.

Apple peel is a waste product from dried apple manufacture. The content of phenolic compounds, dietary fiber, and mineral are higher in apple peel, compared to other edible parts of this fruits. The objective of this study was to develop an ingredient from Granny Smith apple peel, using a pilot scale double drum-dryer, as drying technology. The control of all steps to maximize the retention of phenolic compounds and dietary fiber was considered. Operational conditions, such as drying temperature and time were determined, as well as important preprocessing steps like grinding and PPO inhibition. In addition, the physical-chemical characteristics, mineral and sugar content, and technological functional properties such as water retention capacity, solubility index, and dispersability among others, were analyzed. A simple, economical, and suitable pilot scale process, to produce a powder ingredient from apple peel by-product, was obtained. The drying process includes the application of ascorbic acid at 0.5% in the fresh apple peel slurry, drum-dryer operational conditions were 110 degrees C, 0.15 rpm and 0.2 mm drum clearance. The ingredient developed could be considered as a source of phenolic compounds (38.6 mg gallic acid equivalent/g dry base) and dietary fiber (39.7% dry base) in the formulation of foods. Practical Application: A method to develop an ingredient from Granny Smith apple peel using a pilot scale double drum-dryer as drying technology was developed. The method is simple, economical, feasible, and suitable and maximizes the retention of phenolic compounds and dietary fiber present in the raw matter. The ingredient could be used in the formulation of foods.

The uncertainty of shelf-life estimations for refrigerated foods exposed to changing temperature was quantified by considering the contribution of the experimental variability of the model parameters. Assuming the real distribution of the parameters can be replaced by an unknown empirical distribution, this uncertainty was analyzed by a bootstrap methodology. Independent sets of heat transfer and microbial growth parameters were chosen randomly from experimental values. Shelf-life values were estimated for each set, with the variability evaluated using an SD value. The procedure was repeated 10 times to obtain 10 shelf-life SDs. The variation coefficient of these SDs is an absolute measurement of shelf-life variability. At the recommended variation coefficient of 0.1, a sample size of 25 was found acceptable. The shelf-life variability estimated was similar (±1 day) for surimi in cardboard and expanded polystyrene containers with different shelf life and temperature profiles. The method is applicable to other predictions of food stability. PRACTICAL APPLICATIONS The effect of the experimental variability of model parameters on shelf-life estimations confirmed the need to assess the uncertainty of model predictions. Another beneficial aspect of the approach presented is that it encourages an integrated approach to food safety and shelf life. Decisions on raw materials and modifications to processing operations affect the initial microbial load of a product. Improvement of storage, distribution and retail facilities reduces temperature abuse. Product size, geometry and packaging choice are also aspects that should be considered. The impact on shelf life of all these factors can be examined by the integrated microbial and heat-transfer models of the type here presented. The increasing availability of microbial growth parameters and electronic recorders to monitor temperature during processing, storage and distribution facilitate their implementation. The impact of the experimental variability of model parameters is important. For example, this study suggested the need for microbial determinations with lower experimental variability.

This research suggests a modification of the adaptive random search method. The proposed modification is based on the utilization of the well-known logistic function or logistic curve in order to improve the random search adaptation characteristics. The algorithm tested results show the advantage of the random search modification over the previous random search organization, especially in the case of solving the multi-modal optimization problems. An interesting and important food industry optimization problem, such as thermal processing, was solved by the new organization of adaptive random search.

The use of technologies that modify food environment for preservation purposes has been extensively studied in the past two decades. Even though technological advances have been made, most of the modified atmosphere packaging (MAP) development has been empirical. In this short communication, a revision of general equations of mass transfer and criteria to design MAP systems was carried out. Mathematical relationships and models to evaluate the flux of CO 2 for the packaging of non-respiring foods are discussed. Data to predict CO 2 uptake for the food, such as solubility and diffusion in refrigerated MAP systems are given.

In this study, the use of artificial neural networks (ANN) for estimating reaction rates in enzymatic hydrolysis of squid waste protein was investigated. This is a complex process because a number of inherent simultaneous inhibition and enzyme inactivation reactions occur during hydrolysis that make it difficult to develop a reliable kinetic model by more traditional deterministic approaches. A series of 12 enzyme hydrolysis experiments were carried out on samples of squid waste under specified conditions of temperature, pH, and initial enzyme and substrate concentrations. Experimental data in the form of substrate concentration over time were taken as real time course data (TCD), and divided into three groups for respective use in training, validating, and testing the model. A feed-forward architecture was utilized to construct the necessary predictive model. The network was trained until the mean squared error function between target and actual output values reached a desired minimum. Data sets from the remaining two groups were used for subsequent validation and testing of the model. The model performed well when tested against experimental data in the third group (not used in its development) and taken over a wide range of initial conditions. Maximum differences between experimental and predicted values of substrate concentration at any point in time ranged from 0.3 to 0.5 g L-1 (1% to 3% of initial substrate concentration), with correlation coefficients between predicted and experimental results ranging from 0.95 to 0.97.

This paper presents a review of recent developments over the past 10 years that have further advanced the state of the art in improving food safety, quality and manufacturing efficiency in the canned food industry worldwide. The review focuses initially on retort control systems, and the various approaches that have been taken to help canned food processors accomplish on-line correction of unexpected process deviations, the major cause of lost productivity. Important features of each approach are discussed, along with suggested industry applications that would be appropriate for each method. The review also describes recent advances in industrial automation, including new retort systems for flexible and semi-rigid retortable packages, and automated materials handling systems for loading and unloading of batch retorts. The review concludes with a discussion of future trends to be expected in the industry.

Mussel aquaculture is the main source of this valuable seafood. China, Spain, Chile, and Thailand are the largest producers, whose total average harvest in 2010 was 1,272,131 t accounted for 65% of the total world production. Assuming that when a food compound contributes 20% or more of a nutrient’s Recommended Daily Allowance, the food can be taken as a good source of that component; mussel meat is a good source of proteins, vitamin B12, Fe, P, and omega-3 fatty acids (DHA + EPA). Mussels are not consumed raw but rather are processed through pre-cooking, followed by freezing or sterilization. The processing effects on mussel composition are mainly caused by two mechanisms: material exchange between mussel meat and processing media (water, steam, brine, air), and thermal inactivation by high temperature (molecular lysis or reaction) when mussels are sterilized. The main effect of processing on mussel components is their concentration due to water loss. Leaching and reaction have a minor influence.

The basic principles of canning have not changed dramatically since Nicholas Appert and Peter Durand developed the process. The sterilization and pasteurization of foods have a long tradition, and this tradition will likely continue due to its convenience and advances in packaging materials. Mathematical modeling has been gaining recognition in the food industry, particularly for applications such as thermal sterilization and pasteurization, helping the food industry to deliver safe processed products that also have very high quality. In recent years, several researchers have been developing applications for multiobjective optimization in food processing, especially in the area of thermal food sterilization.