Calcium and temperature effect on structural damage of hot air dried apple slices: Nonlinear irreversible thermodynamic approach and rehydration analysis

Mathematical models traditionally employed in fitting convective drying data do not use to report information about chemical and other physical changes different from the simple decrease in moisture content. In the present study, structural damage undergone by fresh and vacuum impregnated apple slices with different calcium lactate concentrations during convective drying at 30, 40 and 50 °C was analysed by applying equations derived from nonlinear irreversible thermodynamics to experimental data. According to the results obtained, vacuum impregnation with isotonic sucrose solution before drying at 30 °C provided maximum protection to cellular structure by promoting reversible deformations against irreversible breakages. On the contrary, cell walls strengthen with calcium had severe damaged during drying. Regarding air temperature, it was directly related both to the molar energy employed in deforming structures and the drying rate. These results were confirmed by analysing dried samples behaviour during further rehydration.Barrera Puigdollers, C.; Betoret Valls, N.; Betoret Valls, ME.; Fito Maupoey, P. (2016). Calcium and temperature effect on structural damage of hot air dried apple slices: Nonlinear irreversible thermodynamic approach and rehydration analysis. Journal of Food Engineering. 189:106-114. doi:10.1016/j.jfoodeng.2016.05.024S10611418

Homogenization pressures applied to citrus juice manufacturing. Functional properties and application

[EN] Homogenization is a unit operation that can be incorporated in citrus juice manufacturing to improve chemical and physical characteristics relevant for use in subsequent processing operations. The aim of this study was to evaluate the effect of different homogenization pressures on suspended solids and antiradical activity in mandarin low pulp juice (LPJ) and to understand their influence on a posterior vacuum impregnation operation. We found the pressure treatments applied to LPJ do not have negative effects on antiradical activity or functional compounds in the juice. In the vacuum impregnation study we found that more LPJ was introduced into the structural matrix of apples when homogenized at higher pressures and therefore more functional compounds may be introduced due to pulp stability and particle size reduction. © 2012 Elsevier Ltd. All rights reservedThe authors acknowledge the Ministerio de Ciencia e Innovacion of Spain for its contribution to projects AGL2009-09905, AGL2009-11805 and PET2008_0015.Betoret Valls, ME.; Sentandreu Vicente, E.; Betoret Valls, N.; Fito Maupoey, P. (2012). Homogenization pressures applied to citrus juice manufacturing. Functional properties and application. Journal of Food Engineering. 111(1):28-33. https://doi.org/10.1016/j.jfoodeng.2012.01.035S2833111

Vacuum impregnation and air drying temperature effect on individual anthocyanins and antiradical capacity of blueberry juice included into an apple matrix

Blueberries are an important source of bioactive compounds that can be consumed as fresh or processed fruit. The aim of this work was to study the addition of blueberry juice into apple discs by vacuum impregnation and further stabilization of the impregnated apple by air-drying and freeze-drying in order to produce a low-humidity fruit-like natural snack. The effect of processing operations was studied in terms of functional properties. Results indicated that it was possible to add blueberry juice into the structure of fresh apple slices without a negative effect on bioactive compounds. While air-drying operation implied a significant loss of the initial anthocyanin content, the final product stabilization by freeze-drying did not cause any loss of individual anthocyanin content. Results of the different analyses showed the best final product was obtained by freeze-drying or air-drying stabilization at 40 \ub0C

Analysis by non-linear irreversible thermodynamics of compositional and structural changes occurred during air drying of vacuum impregnated apple (cv. Granny smith): Calcium and trehalose effects

Apple discs were impregnated with isotonic solutions of sucrose and trehalose with and without calcium addition and after air dried. In the vacuum impregnation experiments, the calcium and the replacement of sucrose by trehalose did not have significant effect on the final volumetric deformation of the samples. During air drying two stages of changes were considered. The first one lasted until the saturation of the intracellular liquid phase, and the second one from the saturation of the intracellular liquid phase until the end of the drying process. Mass transfer has been analysed applying nonlinear irreversible thermodynamics. Water flux, water chemical potential and tissue shrinkage have been taken into account in order to accurately describe the mass transfer phenomena during air drying. A precise definition of chemical potential allowed estimating the partial molar energy needed for breakages and the reversible and irreversible deformations of tissue structure coupled with mass transfer during air drying of apple

Impact of processing on the nutritional and functional value of mandarin juice

BACKGROUND: Although phenolic compounds have a role in the health benefits of fruit juice consumption, little is known about the effect of processing on their bioaccessibility. The release of phenolic compounds from the food matrix during digestion is an important pre-requisite for their effectiveness within the human body, and so it is fundamental to identify technological treatments able to preserve not only the concentration of phytochemicals, but also their bioaccessibility. In the present study, we investigated the impact of high-pressure homogenization (HPH), alone and in the presence of 100 g kg 121 trehalose or Lactobacillus salivarius, on the bioaccessibility of flavonoids in mandarin juice. In addition, digested mandarin juices were supplemented to liver cultured cells in basal and stressed conditions to evaluate their protective effect in a biological system. RESULTS: HPH reduced the concentration of total phenolics and main flavonoids but increased their bioaccessibility after in vitro digestion (P < 0.001). In the basal condition, supplementation with all digested juices significantly reduced intracellular reactive oxygen species (ROS) concentration (P < 0.001). Thiobarbituric acid reactive substances concentration in the medium was also reduced by supplementation with HPH-treated juices. Although pre-treatment with juices did not completely counteract the applied oxidative stress, it preserved cell viability, and cells pre-treated with juices submitted to HPH in the presence of probiotics showed the lowest ROS concentration. CONCLUSION: The present study represents an important step ahead in the evaluation of the impact of processing on the nutritional and functional value of food, which cannot simply be assessed based on chemical composition. \ua9 2020 Society of Chemical Industry

Metabolomic studies after high pressure homogenization processed low pulp mandarin juice with trehalose addition. Functional and technological properties

This work aimed to determine the effect of homogenization pressures (HPH) and addition of trehalose on the functional and technological properties of low pulp mandarin juice (LPJ). A set of experiments was designed, combining a non-targeted metabolomic1H NMR based approach together with suspended pulp and transmittance, hesperidin, vitamin C and antioxidant activity analysis. Suspended pulp increased with HPH and trehalose addition. Flavonoid hesperidin initially decreased with HPH but trehalose addition resulted in less flavonoid degradation during storage, increasing the effect with the HPH. Vitamin C was not affected by trehalose and pressure treatment but more Vitamin C degradation was observed in trehalose samples during storage. Antiradical activity improvement by trehalose was conditioned by homogenization pressures and specific bioactive compounds.1H NMR based approach highlighted the HPH effect on the microbiological aspects of low pulp mandarin juice by the identification of key molecules responsible of the microorganism profile evolution during storage