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This study aimed to investigate the single-die compression process of gluten and formulate a constitutive model. Regression models were established between indicators and significant factors with single-factor and response surface tests. The optimal parameter combination was a moisture content of 7.441%, compression speed of 0.146 mm s−1, and compression load of 1.75 kN. The relative error between each indicator's experimental and predicted values was less than 2.866%. Rheological modeling of the densification forming and stress relaxation stages was carried out using the optimal parameters. The results showed that a piecewise nonlinear elastic-viscoplastic model effectively described the gluten densification process, with a relative error between experimental and predicted values of less than 3.428%. The five-element generalized Maxwell model (R2 = 0.997) was more suitable for characterizing the stress relaxation of gluten densification. [Display omitted] • Constant time had no significant effect on the evaluation indicators. • Moisture content, compression speed and load influenced gluten densification process. • Optimum process of gluten densification forming was obtained. • Nonlinear elastic-viscoplastic model described the gluten densification. • Five-element generalized Maxwell model was suitable for gluten stress relaxation. [ABSTRACT FROM AUTHOR]

This study analyzes the influence of the number of flips on the cooking performance of burgers by heating contact using results from both experimental test and computational simulation. The analysis employs a previously developed multiphysics model that accounts for heat and moisture transfer as well as product deformation. The turning process was simulated considering two heat sources representing the cooking pan that are alternately activated and deactivated to heat either surface of the product. Furthermore, a set of experiments were carried out to validate the model outcomes recording data of temperature at the center and upper surface of the burger, weight loss, and shrinkage at different number of flips. When performing only one flip, great moisture expelling was observed at the top surface, while multiple flips facilitates moisture retention, reducing cooking losses and shrinkage since it allows for a reduction in cooking time to reach the desired temperature. However, more than five flips do not significantly improve these effects. • Increasing the number of flips reduces the volumetric shrinkage of the burger. • Cooking time significantly diminishes with three or more flips. • Late flips affect temperature prediction precision. • Burger shrinkage results from the combined effects of water loss and protein denaturation. • Frequent flipping results in more tender burgers. [ABSTRACT FROM AUTHOR]

Radio frequency (RF) heating technology is widely applied to dry agricultural products due to the advantages of fast and volumetric heating, but it lacks systematic and in-depth studies on combination drying methods. This study aimed to investigate the drying mechanism of tiger nuts with hot-air drying (HD), radio frequency drying (RFD), radio frequency assisted hot-air drying (RFHD), and radio frequency-vacuum drying (RFVD), in terms of analyzing dynamic changes of dehydration kinetics, moisture migration, and dielectric properties during the drying processes, as well as quality attributes of dried tiger nuts. The results indicated that the RF drying time (including RFD, RFHD and RFVD) was significantly reduced by 38.60–54.39%, compared with HD. Although RF drying had a positive effect on physical qualities, it caused clear changes to the microstructure. Among all drying methods, the free water content (A 23) in the tiger nuts decreased as drying processed, while the immobilized water content (A 22) increased first and then decreased. The A 23 exhibited strong positive correlations with dielectric constant (ε ′) and loss factor (ε ″). Correspondingly, ε ′ and ε ″ gradually decreased due to a reduction in the A 23 value. The results may comprehensively understand the RF drying mechanism of tiger nuts to provide high-quality products and optimize the drying process. • Drying mechanism of tiger nuts using combined radio frequency (RF) energy was studied. • Hot-air and vacuum assisted RF drying can improve RF heating uniformity of tiger nuts. • RF-dried tiger nuts had better qualities under shorter drying time than hot-air drying. • Dielectric properties of tiger nuts were positively correlated with free water content. [ABSTRACT FROM AUTHOR]

The most abundant by-product of the brewing industry is beer bagasse (BSG); its high moisture content requires a rapid drying process to stabilize the product. The objective of this work was to carry out the analysis and mathematical modeling of the drying process of thin layer bagasse at temperatures above 60 °C in order to establish adequate processing conditions that assure its safe use and storage as a functional ingredient. The moisture sorption isotherms of BSG were determined at 10, 20 and 40 °C. Considering the most unfavorable condition tested (40 °C), the maximum residual moisture content that avoids the growth of Bacillus cereus was 15% dry basis, that corresponds to aw = 0.93. The drying curves of thin layers of BSG were obtained experimentally and mathematically modeled using Fick's law; lethality to achieve at least a 2-log reduction in Bacillus cereus population was assessed in terms of thermal inactivation kinetic parameters. Drying conditions at temperatures above 75 °C with air velocity of 3.2 m/s, increased total phenol content levels enhancing antioxidant activity. [Display omitted] • Drying experiments using thin layer of BSG at temperatures above 60 °C. • Mathematical modeling of drying process, vapor diffusivity and activation energy. • Lethality of Bacillus cereus with 2-log reduction at different drying conditions. • Higher air temperatures increased total phenol content and antioxidant activity. • BSG with a 15% moisture dry basis (aw< 0.93) inhibits growth of Bacillus cereus. [ABSTRACT FROM AUTHOR]

Drying of black pepper has been investigated in a lab-scale conventional spouted bed dryer. Spouting behavior of black pepper was studied, and the minimum spouting velocity was determined. The effect of operational conditions; drying temperature, air velocity and stagnant bed height on drying kinetics was analysed. The higher values of drying rates were achieved when the dryer was operated with moderately high temperatures, high airflow rates and shallow beds. The results show an increase in effective moisture diffusivity with increasing drying temperature. The highest effective moisture diffusivity of 2.03 × 10-10 m2/s was obtained at a hot air temperature of 75 °C. Extraction and analysis of essential oil from dried black pepper showed that the variation of oil yield with drying temperature is significant for drying temperatures from 45 °C to 75 °C 65 °C was selected as the best drying temperature for black pepper drying in the conventional spouted bed dryer. • Raw black pepper was dried in a spouted bed dryer. • The minimum spouting velocity of raw black pepper in the spouted bed was determined for different bed heights. • Higher values of drying rates were achieved when the dryer was operated with moderately high temperatures, high airflow rates and shallow beds. • 65 °C was found as the best drying temperature for black pepper drying in the spouted bed dryer in order to obtain highest yield of black pepper essential oil. [ABSTRACT FROM AUTHOR]

The effect of moisture on reduction of the flow starting temperature (T f ; i.e. start of flow through a capillary die at constant pressure conditions) in major protein ingredients used in fish feed has been assessed using a Phase Transition Analyzer. All proteins showed an initial linear reduction in T f followed by a sharp sigmoidal reduction at higher moisture content. A critical moisture level (M cr) could be defined at the onset of this transition region. Fishmeal and wheat gluten show the lowest M cr (138 and 160 g kg-1, respectively) and highest reduction in T f above M cr. Sunflower meal and soy protein concentrate demand more moisture, show higher variability in M cr (210–262 and 233–306 g kg-1, respectively) and less reduction in T f at moisture levels above M cr. The T f level corresponds to an apparent viscosity of 105 Pa s and can be combined with the William-Landel-Ferry equation to establish moisture contour plots for the effect of temperature on viscosity reduction in the rubbery state. The protein specific M cr levels and rheological profiles can be applied to determine optimal moisture and temperature conditions for plasticization and texturization of extruded food and feed products. • Sigmoidal reduction in flow starting temperature above a critical moisture level. • The critical moisture level is linked to increased effect of temperature on viscosity reduction in the rubbery state. • Comparison of flow starting temperatures in plant and fish based food proteins. • Mapping of moisture and temperature effects on viscosity reduction. • Variability in rheological properties within commercial SFM and SPC samples. [ABSTRACT FROM AUTHOR]

Abstract A moving-boundary model is proposed for describing food isothermal drying. The model takes into account volume reduction of food materials and it is capable to predict sample shrinkage and surface deformation during the drying process. It can be applied to any sample geometry (discoid, cylindrical, cubic, parallelepiped) and to any food material since it can take into account that sample volume can decrease of a quantity that can be smaller, equal or larger than the corresponding volume of removed water. The core of the present model is the adoption of a pointwise shrinkage velocity equal (and opposite in sign) to the water diffusive flux times a shrinkage factor α (ϕ) depending on the pointwise water volume fraction ϕ (x). The shrinkage factor α (ϕ) can be assumed a priori or directly derived from experimental data of the rescaled volume V / V 0 vs the rescaled moisture content X / X 0 . For ideal shrinkage α (ϕ) = 1. The model provides good results in terms of prediction of volume reduction, surface deformation and effective water diffusivity for potato strips air-drying. Highlights • Moving-boundary model for food isothermal drying and shrinkage. • Pointwise shrinkage velocity is related to the pointwise water flux. • The shrinkage factor is introduced to model different food materials. • The shrinkage factor can be directly estimated from experimental data. • Sample volume reduction and surface deformation is accurately predicted. [ABSTRACT FROM AUTHOR]

Abstract Caking of dietary salt is a well-known problem in food industries. In this study, caking behavior of various kinds of dietary salt, including refined salt, sea salt (from South Korea and France), bamboo salt, rock salt, and sodium chloride (used as control group) was investigated. According to our results, these dietary salts had different mineral content and moisture sorption isotherm. The sea salt had more minerals than the other salts. As a result, the deliquescence relative humidity of the sea salt was significantly lower than that of the other dietary salt, which resulted in higher water sorption ability. After salts were stored in two humidity cycle conditions, the change in moisture content, caking strength, passed ratio, and morphology was determined. In the case of sea salt, the highest caking strength, the lowest passed ratio, and lots of crystal bridges caused by caking were observed. Highlights • Moisture-induced caking behavior with various dietary salts was researched. • Dietary salts had different amounts and types of minerals. • Each moisture sorption isotherm differed because of mineral content. • Caking behavior of salts was investigated in humidity cycling condition. [ABSTRACT FROM AUTHOR]

This study aims at development of a new method to form emulsion-based yoghurt like gels from, but not limited to hazelnut. For this purpose, hazelnut slurries with varying solid content were processed using a microfluidizer to obtain creamy structures possessing high consistency. Then, these slurries were processed into fermented hazelnut products (HNPs) by inoculating with lactic acid bacteria culture. Real time rheological measurements were conducted to monitor how moduli values changed during fermentation. For the sake of comparison conventional cow milk yoghurt (CMY) was also included in the study. Texture analysis experiment showed that microfluidization greatly improved physical properties of the HNPs with significant increase in firmness values. When moisture content of HNP was around 22.7%, the firmness value was close to that of CMY. Since the entire hazelnut was used in processing, the HNPs contained soluble (0.34–0.75 g/100 g) and insoluble fiber (1.58–4.12 g/100 g). Microfluidization treatment also resulted in markedly increased colloidal stability of the HNPs. Sensory evaluation studies revealed that some of the HNP formulations had comparable texture, flavor, and appearance properties with CMY. [ABSTRACT FROM AUTHOR]

Kiln-dried fruit drying time is readily predicted from initial moisture content since the environment is tightly controlled. For uncontrolled environments, such as a greenhouse solar dryer, a product's drying time varies depending on ambient conditions and is thus more difficult to predict. Prediction of the drying time is needed to better schedule dryer use. Data was obtained from a set of wireless scales that weigh the waste during solar drying after initial moisture content measurement of a sample. A set of linear and quadratic models for drying rate are tested with the best yielding a 39% reduction in RMSE over traditional models. The results indicate that the modelling approach is likely to be useful for open solar dryers where the temperature, and thus the drying rate, is not controlled. [ABSTRACT FROM AUTHOR]

Pomace is an oil mill byproduct and the raw material for extracting olive pomace oil. The pomace is stored several months in ponds until it is processed. Tests have been carried out in stored olive pastes, malaxated with and without different coadjuvants. These pastes have been equated to the oil mill pomace. Coadjuvants increase the water pH in 0.8 units. 89.5% of the initial oil is recovered from pastes without coadjuvant; 91.1% from pastes with calcium carbonate and 80.5% from pastes with talc. The free acidity is 1.9%, 2.6% and 2.1% respectively. The maximum amount of refined pomace oil is obtained when calcium carbonate is used and the minimum when talc is used. Moisten the adjuvants affects talc and calcium carbonate differently, although both of them easily releases the original micro-powder. Moisture does not affect the technological action of the coadjuvants or modify their physical characteristics. [ABSTRACT FROM AUTHOR]

In this study, the water state and distribution of Chinese dried noodles during drying process was investigated by low-field nuclear magnetic resonance (LF-NMR). Transverse relaxation times ( T 2 ) were achieved by LF-NMR coupled with a 0.5 T permanent magnet equivalent to a proton resonance frequency of 21 MHz at 32 °C. Three populations of water state can be distinguished: strongly bound water ( T 21 , 0.04–0.40 ms; A 21 , 0.25–19.08%), weakly bound water ( T 22 , 0.96–5.34 ms; A 22 , 80.81–98.44%), and free water ( T 23 , 74.50–266.47 ms; A 23 , 0.11–1.61%). During the drying process, the transverse relaxation time of all water states followed decreasing trend. Initially, the moisture content decreased faster from the edges; however, moisture migrated rapidly from the central part during 90–180min. The moisture gradient disappeared after drying for 240min. Besides, a special method as "Oil immersion method" was introduced to address poor signal to noise ratio in samples when moisture content was low during the drying process. High signal to noise ratio was successfully achieved by this method. [ABSTRACT FROM AUTHOR]

Vacuum drying kinetics, thermal histories and quality kinetics of two rosehip leather formulations were determined, at tray temperatures between 40 and 70 °C. Data was simultaneously modelled as an ordinary differential equations system encompassing a transient water balance, a transient energy balance, and a variable-order quality kinetics equation, coupled to heat and mass transfer. A set of parameters was fitted for each formulation and satisfactory representations of the experimental data were obtained. Differences in drying rate compensated for the effect of the tray temperature on quality loss, so vacuum drying at 70 °C was recommended for rosehip leathers due to the shorter drying time required. In particular, the reaction order for ascorbic acid degradation was found to be dependent on the tray temperature. [ABSTRACT FROM AUTHOR]

Moisture diffusion in lipids has been traditionally described by generic models that do not offer complete information about its structural dependency. Due to the lack of a predictive structure-based model in literature, we do not know the crystallization conditions needed to favorably alter structure and decrease moisture transport in lipids. The objective of this study was to develop a mathematical model to predict effective moisture diffusivity based on fractal structure and void fraction in lipids. Predicted water uptakes using the proposed model were in better agreement (RMSE 0.01–0.03) with experimental data when compared to models from literature (RMSE 0.01–0.16). Clearly, accounting for the fractality of fat crystal networks and vapor phase diffusion in the void fraction were critical to the success of the proposed model over all other models. Interestingly, moisture diffusion occurred predominantly in the void fraction compared to the liquid oil fraction of all the lipid samples. [ABSTRACT FROM AUTHOR]

In this work, physical changes such as protein denaturation, cell membrane integrity, and the viscoelastic relaxation of mushrooms, as induced by drying treatments, were investigated as possible causes of the variation in moisture sorption isotherms (MSIs) and hysteresis. Our investigations involved both experimental and theoretical evaluation of MSIs. Via analysis with the Flory-Huggins (FH) theory, we concluded that 1) the protein denaturation does not significantly affect moisture sorption and hysteresis, and 2) cell membrane integrity only influences on the moisture sorption/water holding capacity at high relative humidity. Additional experiments show that mushrooms exhibit viscoelastic properties, which are temperature and moisture-dependent. As dynamic vapor sorption (DVS) experiments show signs of viscoelastic relaxation, we consider the latter to be the likely determining factor affecting the variations in MSI and hysteresis. The Flory-Rehner theory follows that one needs to include elastic stress into the driving force of drying. For viscoelastic media, a separate model, like the generalized Maxwell model, should describe the stress evolution linked to a drying model. • Moisture sorption isotherms (MSIs) and hysteresis vary with processing history. • The protein denaturation does not significantly affect MSIs and hysteresis. • The cell membrane integrity influences MSIs at high relative humidity. • The viscoelasticity is likely to be the determining factor for variations in MSIs. [ABSTRACT FROM AUTHOR]

Lulo is a tropical fruit with excellent organoleptic characteristics but with rapid deterioration and short shelf life. An active packaging was developed for lulo combining modified atmospheres with active O 2 removal and moisture adsorption. A mixture of iron filings (Fe) and sodium polyacrylate (SPA) powder was adjusted in sachets. Fresh fruits (0.271 ± 0,021 kg) were packaged in polylactic acid (PLA) trays sealed with a PLA film, including different amounts of active compounds, and stored at 12 ± 1 °C and 75 ± 2% RH. The best active mixture ratio of Fe/SPA was 1/1 (w/w) with an O 2 removal capacity of 0.055 mmol g−1 d−1 at 12 °C. Steady values of up to 16.8% O 2 and 5% CO 2 were obtained in the trays for 8g of active mixture besides more than 25 days of shelf life, which can make it possible to increase the market potential for the fruit. • An O 2 scavenger was prepared from a mixture of iron filings and SPA. • The O 2 removal kinetics was described with a Pseudo First-Order model. • An active packaging was configured for lulo considering the fruit respiration. • It was possible to incorporate the O 2 scavenger in an active packaging for lulo. • With 8 g of scavenger in the active packaging 25 days of shelf life were obtained. [ABSTRACT FROM AUTHOR]

This study evaluated ethyl esters as cosolvent of ethanol in the oil extraction from soybean collets containing two different levels of moisture (3 and 7 mass% of water). Extraction assays were performed in a fixed-bed column, at 60 and 70 °C, with a solid:solvent mass ratio of 1:1.5. The composition of the ethyl esters-ethanol mixture was chosen based on densities and dynamic viscosities, and Hansen solubility parameters. Using collets with 3 mass% of water and the rising temperature favored the soybean oil extraction yield. Adding 5 mass% of ethyl esters to ethanol enabled the achievement of a gain of 33% in the oil extraction yield considering collets with 7 mass% of water at 60 °C. The use of ethyl esters-ethanol mixture to extract soybean oil is promising, particularly when it is not possible or desirable to subject soybean collets to an additional drying process. [Display omitted] • Ethyl esters (EE) were added as ethanol (Et) cosolvent to extract soybean oil (SO). • Mathematical models were used to describe EtEE mixtures' densities and viscosities. • Hansen's theory and physical properties supported the EtEE composition definition. • Et with 5% EE favored SO solubility and provided low physical properties values. • EtEE only favored SO extraction when collets with 7% moisture were used at 60 °C. [ABSTRACT FROM AUTHOR]

Whey proteins can be texturized by thermo-mechanical treatment during high moisture extrusion. Thereby, protein aggregates with specific functional properties can be obtained. In this study, a heated co-rotating twin screw extruder was used to particulate whey protein concentrate. For data evaluation, process, product and system parameters affecting the extrusion process were distinguished. To characterize the process by system parameters is an important step towards an improved process understanding. The maximum product temperature (T P,max ) correlated linearly with the extruder barrel temperature and the mass flow. The specific mechanical energy input (SME) was found to be mainly affected by screw speed and mass flow. Independent of the respective adjusted process parameters, aggregate size was only affected by the resulting SME value. Equally, the degree of denaturation was only affected by the T P,max . Thus, manipulation of system parameters (SME and T P,max ) can be applied for an indirect control of micro-particle properties. [ABSTRACT FROM AUTHOR]

An alternative method to improve treatment efficiency for industrial applications of mid-high moisture potato starch was explored based on radio frequency (RF) heating, but the large cold spot area during RF treatment was the biggest obstacle for technology development. The purpose of this study was to develop a new method to reduce the cold spot area and improve RF heating uniformity for mid-high moisture potato starch by modifying the electromagnetic field distribution in the sample with a Electromagnetic Wave Conductor (EWC). The simulation model of RF heating was established to study the temperature distribution using commercial COMSOL software. Dielectric properties of potato starch with moisture content of 31.55% w.b. were measured for computer simulation, and the associated RF experiments were conducted as the validation of the EWC method. The results showed that the parameters of EWC (width and height) had a positive correlation with the RF heating uniformity. The improved target uniformity index (TUI) and the decreased heating time indicated significant effects of EWC. Finally, optimizing EWC parameter equations were developed and could be used for improving RF heating uniformity in future applications. [ABSTRACT FROM AUTHOR]

Caking of lactose and other dry ingredients is a common problem in the dairy and food industries. The lactose production process includes different purification steps, depending on the type of lactose produced. The aim of this study was therefore to investigate how the remaining impurities (i.e. non-lactose components) affect the caking tendency of the final powder. The results from a combination of different methods, including dynamic vapor sorption, characterization of the physicochemical composition and assessment of caking with a ring shear tester, suggested humidity caking. Larger amounts of impurities in the lactose powder resulted in enhanced moisture sorption and greater caking tendency. These findings emphasize the importance of controlling the washing and purification steps throughout the production process in order to limit caking in the final product. [ABSTRACT FROM AUTHOR]

Cherry pomace, a by-product of juice production, is rich in health beneficial anthocyanins (ACY). This study aimed to determine ACY retention in 25, 41, and 70% moisture content (MC) pomace at elevated temperatures. Pomace was heated in sealed metal cans at 105 °C and 127 °C in a steam retort up to 125 min. ACY levels were measured by the pH-differential method. A first-order degradation model with an Arrhenius dependence for the rate constant was used for modeling ACY levels. The rate constant and activation energy for the pomace at each moisture level were estimated by two inverse methods. For 70% MC, k 115.8°C = 0.0129 min −1 and Ea = 75.7 kJ/mol. MC had no significant effect on the parameter estimates. Sequential estimation showed that the experiment had to be run to ≤25% ACY retention to obtain accurate parameter estimates. The estimation methods presented will be helpful for designing dynamic processes. [ABSTRACT FROM AUTHOR]

Moisture content is a fundamental parameter in peanut production and storage. Moisture content information is essential for crop analysis. Crop analysis is significant for production planning and improving yield. Thus, developing a moisture content measurement system with high precision and low cost can benefit peanut production, processing, and storage. To achieve accurate and rapid nondestructive testing of shelled peanuts and peanut pods, this study proposes a new method for measuring moisture content based on the microwave scattering coefficient. The microwave free-space method was used to measure the scattering parameters of peanut samples with different moisture contents (8.11–45.59% wet basis) at different temperatures and sample thicknesses. Moreover, a peanut moisture measurement model using S-parameters was developed. Using the amplitude, phase, and real part and imaginary part combinations of the S 11 and S 21 parameters of the peanut samples as the input and peanut moisture content as the output, moisture content and S-parameter prediction models based on the gradient boost regression trees (GBRT), extreme gradient boost (XGBoost), and fully connected deep neural network (FC-DNN) were established. Test results verified that the FC-DNN-based model had the best prediction performance, with a coefficient of determination (R2) = 0.9998, mean absolute error (MAE) = 0.0891, mean square error (MSE) = 0.0254, and root mean square error (RMSE) = 0.1593. This study provides a new method for the nondestructive measurement of moisture content during peanut production and storage. Moreover, the proposed model can be applied for moisture content measurement of other agricultural products in the food processing industry. • A platform for measuring the moisture content of shelled peanuts was constructed, with a measurement range of 8–45% w. b. • Moisture content, temperature and material thickness are inversely proportional to S 21 amplitude. • The accurate measurement of moisture is realized through fitting. • The prediction model R2 = 0.9998 based on FC-DNN can be used for the actual measurement of peanut moisture. [ABSTRACT FROM AUTHOR]

Wet basis moisture content (MC wb) is an important quality parameter of green coffee as it affects the coffee's physical, chemical, and sensory characteristics. Accurate estimation of green coffee MC wb after dry hulling, long-term storage, and transportation is imperative to prevent quantitative and qualitative losses. Thus, this study aimed to design, develop, calibrate and validate a prototype inline system capable of accurately measuring the MC wb of green coffee beans, using a commercially available time-domain reflectometry (TDR) probe. The TDR probe was calibrated and validated with green coffee within a MC wb range of 9–21%. A calibration linear regression model correlating the TDR probe output (dielectric constant) to reference MC wb measurements obtained by a halogen moisture analyzer, yielded a high coefficient of correlation (R2 = 0.99). Model validation yielded a high R2, and a low Root Mean Squared Error equal to 0.93, and 0.9% MC wb , subsequently. Results indicate that the TDR inline green coffee moisture estimation system has the potential to be applied in real-time, industrial-scale operations. • An inline unit was built to measure green coffee moisture by time-domain reflectometry. • The system was calibrated and validated with reference to a halogen moisture analyzer. • Model validation yielded a high correlation (R 2 = 0.93) with accuracy up to 91%. • The system performance is comparable to existing methods of moisture measurement. • The system has the potential to be applied in real-time, industrial-scale operations. [ABSTRACT FROM AUTHOR]

Drying plant-based food materials can be time consuming and energy intensive, making optimization of its processes essential. However, current mathematical models are plagued with condition-dependent diffusivities restricting their performance in developing optimal drying strategies. Multiscale modeling is one technique which can help transition towards a more physics-based approach, improving model's predictive capabilities. This research constructs a multiscale food drying model utilizing a generalized moisture diffusivity to investigate its predictive capabilities. The study investigates two food materials (apple and potato) convective drying at two different temperatures (47 °C and 64 °C). Additionally, to be able to utilize the generalized diffusivity, cell rupturing must be considered. Therefore, a theoretical rupturing threshold was developed exploiting the equilibrium vapor pressure to recognize which transport mechanisms were occurring. The generalized diffusivity was able to distinguish between the two materials and was able to describe the experimental data accurately at both drying temperatures. The generalized property resulted in diffusivities with the range of 1.94 × 10−10-5.14 × 10−10 m2/s. • A multiscale model with a generalized diffusivity for food drying is investigated. • Multiscale model investigates two materials drying at low and medium temperatures. • Theoretical cell rupturing threshold is developed using equilibrium vapor pressure. • Multiscale model can predict if and when cell rupturing occurs. [ABSTRACT FROM AUTHOR]

Thermophysical properties and hygroscopic behavior of unripe banana ( Musa cavendishii ) were studied. The sorption isotherms were measured at 25 °C, 40 °C, 50 °C and 60 °C and the observed sigmoid curves were modeled with GAB equation which satisfactorily fitted the experimental data. The mean value of monolayer moisture content ( X m ) estimated was (5.5 ± 0.6) g/100 g d.b. Drying experiments were conducted at temperatures of 40 °C, 50 °C and 60 °C and the apparent density, specific heat, thermal conductivity and thermal diffusivity – were directly measured as a function of moisture content and porosity. Empirical models obtained by nonlinear regression were successfully fitted to the thermophysical properties, important data to model and simulate the drying process. [ABSTRACT FROM AUTHOR]

Defined functional properties of whey proteins can be achieved by controlling thermal unfolding and subsequent aggregation. To achieve a controlled formation of micro-particles, thermo-mechanical treatment by high moisture twin screw extrusion was used. The aim was to control the degree of denaturation as well as the particle size by variation of the process parameters. The temperature of the extruder has a strong impact on the maximum product temperature and increasing the extruder temperature increases the degree of denaturation. An increasing mass flow in contrast decreases the specific heat transfer to the product and leads to a decrease in denaturation. Increasing the screw speed has almost no effect on the degree of denaturation, but results in an exponential decrease in particle size due to increasing mechanical shear stress. Thus, the degree of irreversible protein denaturation as well as the particle size distribution can be controlled by these process parameters and aggregates with specific properties can be produced. [ABSTRACT FROM AUTHOR]

Dielectric measurements were carried out on the soybean oil that already used for frying dough of different moisture or heating the oil without dough (blank oil) over a frequency range of 40 Hz–100 MHz to evaluate the deterioration of the oil with frying time. A distinct dielectric relaxation caused by the dipole orientation polarization was observed at about 10 MHz. Dielectric parameters characterizing the relaxation feature were obtained by fitting Cole–Cole equation to the dielectric data. The relaxation time stayed around at 10 −8 s with frying time, indicating that the size of the polar components have no change during the frying. Dielectric increment and dielectric loss increased linearly with frying time and the moisture contents of the dough, which was in agreement with the density of oil (measured in a separate experiment) that is in proportion to the deterioration. The time dependence of conductivity was different for the blank oil and that of oil used to fry dough, leading to the conclusion that the conductivity was mainly affected by the volatile decomposition products. The results show that dielectric spectroscopy could be a useful tool to evaluate frying oil. [ABSTRACT FROM AUTHOR]

Quantitative neutron imaging was applied for the dynamic monitoring of the internal moisture distribution of fruit slices during convective drying in a drying tunnel. The impact of several process conditions was evaluated, including airflow temperature, air speed and incident radiation. This technique also unveiled that anisotropic shrinkage was caused, in part, by spatially heterogeneous dehydration, as induced by the presence of the peel. Neutron imaging provided unique graphical and quantitative insights on how the internal water distribution evolved. Thereby, this imaging technique has large potential to complement conventional techniques for monitoring, controlling and optimising drying processes of complex biomaterials, or to generate high-resolution validation data for numerical simulations. [ABSTRACT FROM AUTHOR]

The moisture sorption isotherms of three different infant formulas (denoted as P1, P2 and P3) that contained almost the same amount, but different types, of protein were analysed and their physicochemical changes characterised. Although P3 showed a different trend as compared to both P1 and P2, all the powders had the highest moisture content at 0.428 a w , signifying the occurrence of lactose crystallisation as confirmed by both XRD analysis and glass transition temperature ( T g ) analysis. The particle size (D 90 ) decreased for all the powders due to distortion of particle structure. Caking was observed in all samples conditioned between 0.330 and 0.753 a w . The caking strength of P2 was significantly higher as compared to the other powders at 0.529 a w , which suggests that magnesium content played a significant role in the hygroscopicity of the powders. These results demonstrate that small compositional differences have a profound effect on the moisture sorption behaviour and caking strength of the infant formulas. [ABSTRACT FROM AUTHOR]

Total acid content (TAC) and moisture content (MC) are very important parameters during Solid-State Fermentation (SSF) processes. The feasibility of using hyperspectral imaging (HSI) technology for predicting TAC and MC in vinegar cultures during SSF processes was investigated. Prediction models were constructed using variables selected from spectral and spatial data from associated 3-D hyperspectral datacubes to predict the relative content of TAC and MC for each pixel in the hyperspectral image. Models were developed using genetic algorithm (GA) optimization combined with partial least squares regression (PLS) dependent on the spectral variables yielded good prediction results for both TAC and MC. The determination coefficients ( R p 2 ) for TAC and MC were 0.8565 and 0.8162, respectively. Finally, the distribution maps of TAC and MC for a vinegar culture sample were obtained. These distribution maps could be implemented to estimate the uniformity of fermentation products during SSF. [ABSTRACT FROM AUTHOR]