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In order to develop a mathematical model to simulate mass transfer occurring between the crumb and the crust during bread staling, water vapor sorption properties, i.e., moisture diffusivity, WVP and sorption of bread crumb and crust were investigated at 15 °C. Two types of bread baked with two heating rates (7.39 °C/min and 6.32 °C/min) were considered. Sorption and desorption isotherms were determined using Dynamic Vapor Sorption (DVS) and FF and GAB models were applied in the range of 0–0.95 aw, to fit isotherm curves. Diffusivity was determined from sorption isotherms by using Fick's law and WVP was measured by two methods (gravimetric and from sorption data). Results exhibited maximum values of Deff in the range of 0.1 and 0.14 g/g d.b. moisture contents. They varied between 0.88 × 10− 10 and 0.92 × 10− 10 m2/s for the crust and between 2.24 × 10− 10 and 2.64 × 10− 10 m2/s for the crumb, baked respectively at 220 °C and 240 °C. Results of WVP showed that the crust baked at 240 °C was significantly more permeable than the crust baked at 220 °C. This fact was attributed to the difference in porosity and the molecular structure due to heating effects. Also, the presence of steam in the oven atmosphere enhanced the development of higher porosity in the crust, leading to different structures and properties. Moreover, SEM images showed that starch granules were intact and less swelled in the upper crust when baking at 240 °C, resulting in higher WVP.

The freezing process at different steps of breadmaking is widely used to improve fresh bread availability for the consumer. The consequences of a freezing step on wheat dough and bread, and the way to reduce its negative impacts have been studied for years. Nevertheless, few works report studies on gluten-free doughs and breads. This work investigates the effect of unfermented frozen dough process on the properties of gluten-free dough and the quality of bread. Rheological oscillation tests showed that viscoelastic properties were unchanged for fresh and thawed doughs. However flow tests exhibit an effect of freezing on consistency index and flow behaviour index. Regarding the quality of bread, gluten-free breads obtained by frozen dough process had lower specific volumes and harder crumbs than conventional gluten-free breads (unfrozen breads). Distribution of gas cells was more homogeneous with a freezing step. Crust colour characteristics were also modified by the freezing step.

The thermal conductivity of food is usually measured in isothermal conditions with a line-heat source probe. The thermal conductivity of bread during the baking phase is function of temperature and is an important parameter to assess. This work aims at (i) developing a measurement method of thermal conductivity in pseudo-non-isothermal conditions, usable during the part baked bread thawing–baking phase, and (ii) establishing models to predict the change of the thermal conductivity as function of the temperature. The line-heat source probe method has been used, the probe temperature being corrected by subtracting the temperature increase due to the baking. Values obtained in pseudo-non-isothermal conditions during the thawing–baking phase are similar to these ones obtained in isothermal conditions. A parallel model has been successfully used to fit the experimental values of the thermal conductivity of bread during the baking phase.

The amount of ice nuclei formed during the pressure release is important for the final formation and development of ice crystals in pressure shift freezing (PSF) frozen products. In this study, a high-pressure (HP) calorimeter was used to evaluate the ratio of ice crystals instantaneously formed by rapid depressurization during PSF of pure water and pork muscle tissue. Experiments were carried out initial pressure levels of 62, 115, 157 and 199 MPa, with corresponding phase change temperatures of −5, −10, −15 and −20 °C, respectively (slightly higher than phase change point of water–ice I). The ice crystal ratio was determined based on calorimetric peak measured and heat balance. The evaluated regression relationship between observed ice crystal ratio ( R ice in %) and pressure ( P , MPa) was R ice–water = 0.115 P + 0.00013 P 2 ( R 2 = 0.96, n = 9) for pure water, and R ice–pork = 0.080 P + 0.00012 P 2 ( R 2 = 0.95, n = 11) for pork muscle. Compared to other methods, the calorimetric evaluation does not require any of the pressure-related properties of the test sample. HP calorimetry can thus be used to evaluate ice crystal ratio for PSF of foods even though their pressure related properties may be unknown.

Few data are available on the thermophysical properties of the frozen partly baked breads. In this paper, thermophysical properties, including apparent and true densities, specific heat, enthalpy and effective thermal conductivity were determined separately for crumb and crust of partly baked bread. Total enthalpy of fusion, unfrozen water and solid specific heat were determined by differential scanning calorimetry. The apparent specific heats were estimated in base of the unfrozen water at −40 °C and initial freezing point. The effective thermal conductivity was measured with a line source probe in the range −35 to 25 °C. Four predictive models of the effective thermal conductivity of porous food were developed (parallel, series, Krischer and Maxwell models). The effective thermal conductivity predicted by Krischer model was in good agreement with the experimental data.

To understand the phenomena governing the heat and mass transfers during the freezing of par-baked bread, simulation of freezing in an infinite two-layer cylinder was performed. A fixed grid finite difference method was used in the solution of simultaneous heat and moisture transfer (SHMT) equations according to Lees' three-level scheme. The model accommodates the effects of temperature dependent variables such as apparent specific heat, enthalpy, thermal conductivity, and water activity, and predicts the temperature profiles and weight losses. The model was verified by freezing of par-backed breads with cylindrical shape within an experimental freezer. The RMSE between experimental results and model predictions is 0.505 °C for surface temperature, and 1.8 °C for center temperature. The precision on the loss water is 10%. These results indicate that the method could be successfully applied to SHMT operations in foods freezing.

Turbot fillets were subjected to high pressure treatments at 100, 140, 180 and 200 MPa for 15 and 30 min at 4°C. The influence of such treatments on the lipid and protein stability and on color was studied. It appeared that color, protein stability and lipid oxidation phenomena were influenced both by the pressure level and pressure holding time. The oxidative stability of lipids was particularly affected from 180 MPa as measured by the thiobarbituric acid number. Differential scanning calorimetry showed a full denaturation of myosin at 200 MPa and the appearance of a new structure from the treatment at 100 MPa for 30 min.