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New model for the rehydration characteristics of white yam at different temperatures

  • Akinola, Akinjide
  • Ezeorah, S. N.
  • Nwoko, E. P.
[EN] A new model describing the variation in the rehydration ratio with rehydration time for yam slices is presented here. Also presented, is a new model for the rehydration kinetics of yam slices. Mass and moisture content rehydration data were collected while rehydrating 3.0 mm thick dehydrated yam slices. Regression analysis established that the mass rehydration data better fitted a two-term exponential equation rather than a second-order polynomial equation. Also, for the rehydration kinetics, the moisture content rehydration data was better fitted to a new empirical model rather than the Weibull, Peleg, and Exponential models.

Study and optimization of freeze-drying cycles of a model probiotic strain

  • Verlhac, Pierre
  • Vessot-Crastes, Séverine
  • Degobert, Ghania
  • Cogné, Claudia
  • Andrieu, Julien
  • Beney, Laurent
  • Gervais, Patrick
[EN] This work is based on the experimental study of the freeze-drying process to understand the impact of numerous factors on the survival rates of a model probiotic strain of Lactobacillus casei type. With the aim to find out if cell density in the matrix and survival rates are linked, we have studied the location of the cells after freeze drying inside a porous matrix composed of a lactose basis with a polymer, the polyvinylpyrrolidone (PVP) in various amounts. The best survival rate were obtained at slow freezing rate for a formulation containing 5% (m/V) of lactose and 5% (m/V) of PVP.

Use of a multi-vial mathematical model to design freeze-drying cycles for pharmaceuticals at known risk of failure

  • Scutellà, Bernadette
  • Trelea, Ioan Cristian
  • Bourlés, Erwan
  • Fonseca, Fernanda
  • Passot, Stephanie
[EN] Freeze-drying is a dehydration method suitable for the stabilization of heat-labile pharmaceutical products, such as vaccines. Due to the vial-to-vial variability of heat and mass transfer during the process, the value of the critical process parameters (e.g., product temperature, sublimation rate) may be different between vials and batches often present significant product quality heterogeneity. The aim of this work was the development of a dynamic, multi-vial mathematical model making it possible to predict risk of failure of the process, defined as the percentage of vials potentially rejected by quality inspection. This tool could assist the design of freeze-drying cycle., This work was sponsored by GlaxoSmithKline Biologicals SA which was involved in all stages of the study conduct and analysis

Salting kinetics, salt diffusivities and proximate composition in osmotically dehydrated Pirarucu muscle

  • Barretto, Tiago
  • Betiol, Lilian
  • Bellucci, Elisa Rafaella
  • Telis-Romero, Javier
  • Barretto, Andrea Carla
[EN] Pirarucu (Arapaima gigas Schinz) farming has been encouraged and, among meat preservation techniques, the salting process is a relatively simple and low-cost method. The objective of this work was to study the sodium chloride diffusion kinetics in Pirarucu during wet salting. Limited volumes of brine (20% w/w) were employed with wet salting assays carried at 3, 4 and 5 brine/muscle ratios, and brine temperatures of 10, 15 and 20 oC. The analytical solution of Fick's second law considering one-dimensional diffusion through an infinite slab in contact with a well-stirred solution of limited volume was used to calculate the effective salt diffusion coefficients. Salt diffusivities in muscle were found to be in the range of 2.07 and 8.80 ´ 10-10 m2/s. The wet salting of Pirarucu is greatly influenced by temperature and by the brine/muscle ratio by volume.

Ohmic heating/vacuum impregnation treatments on osmodehydrated apples enriched in polyphenols from concentrated pomegranate juice

  • Moreno, Jorge
  • Zúñiga, P.
  • Guerra, M.
  • Mella, K.
[EN] The aim of this work was to study the combination of osmodehydration (OD), coupled with Ohmic Heating (OH) and Pulsed Vacuum (PV) and to introduce natural compounds from a cryoconcentrated pomegranate juice (47°Brix) at 30, 40 and 50 °C into apple matrix, during 180 min. PV was performed at 50 mbar for 5 min at the beginning of the process and OH generates an electric field of 6.6 V/cm. The results indicated that treatments reduced water content and increase polyphenol content of apples, evidencing that the osmotic treatment improve mass transfer, especially when they are applied together at higher temperatures., Jorge Moreno is thankful for the financial aid provided by CONICYT through project FONDECYT 1160761.

Effects of ozone pretreatment on drying kinetics and quality of Granny Smith Apple dried in a fluidized bed dryer

  • Fonteles, Thatyane
  • do Nascimento, Ronnyely
  • Rodrigues, Sueli
  • Fernandes, Fabiano
[EN] Fluidized bed drying is a method for controlled and mild drying of wetThis study aimed to evaluate the effects of ozone pretreatment on drying of green apple carried out in a fluidized bed dryer to determine drying kinetics and identify operating parameters for improved product quality. Results reveal that drying temperature in different levels affected water diffusivity and retention of bioactive compounds. The ozone pretreatment showed unexpected results since the pretreatment reduced the water difusivity and promoted an increase in the enzyme activity. The treatment time strongly afftected the final polyphenoloxidase and peroxidase activities. On the other hand, the ozone treatment resulted in lower color changes compared to non-ozone treated dried apples.

Effects of Assistance of High Frequency Dielectric and Infrared Heating on Vacuum Freeze Drying Characteristics of Food Model

  • Hashimoto, Atsushi
  • Suehara, Ken-ichiro
  • Kameoka, Takaharu
  • Kawamura, Kazuhiko
[EN] By combining vacuum freeze drying combined with high-frequency dielectric and/or infrared heating, the drying time for frozen gels containing 1% agar with sucrose or sodium chloride was successfully shorten, and the drying time was influenced by the heating methods and by the additive component to the sample. Additionally, it was experimentally confirmed that the power consumption for freeze drying combined with electromagnetic wave heating could be reduced because of the shortened drying time. Consequently, this study could be a very important step for designing a vacuum freeze drying process optimally combining electromagnetic wave heating for each sample component.

Modeling of kinetics of drying process of polycaproamide granules considering its sorption properties

  • Kosheleva, Maria
  • Dornyak, Olga
  • Maklusova, Marina
[EN] The object of research is a fiber-forming polymer - polycaproamide. The process of drying of polycaproamide granules, after aqueous extraction of low-molecular compounds from them, is an important stage of producing of polyamide fiber nylon and largely determines the quality of the target product. To obtain a high-quality fiber, the drying of the granules should provide a sufficiently high degree of its dehydration. The average final moisture content of the material should be no more than 0.1%. With a low moisture content, the drying process slows down, so the calculation of the kinetics of dewatering of granules can not be carried out using a constant effective mass-transfer coefficient (moisture diffusion). In this paper we present a calculation technique for determining two local parameters of mass transfer: the water diffusion coefficient in polycaproamide (as a liquid) and the so-called criterion for phase transitions, which depend on the moisture content of the material and are determined by its sorption properties. The report presents the results of numerical calculations illustrating the development of two-dimensional fields of moisture content, temperature, pressure and vapor concentration in the vapor-gas phase for cylindrical granules in convective drying. To describe the processes of heat and mass transfer during the drying of granules, a nonstationary nonlinear 2D model is used that includes transport equations averaged over the microvolume of the material: the liquid phase transfer equation; heat equation; equation for vapor-gas phase pressure; equation for the concentration of the vapor component. The nonstationary nonlinear conjugate mathematical model is studied numerically. A feature of the presented model is the possibility of an analytical calculation of the local mass transfer coefficients of a liquid, taking into account the sorption properties of the material, the permeability coefficient and the local values ​​of humidity and temperature. Determination of the local coefficients of moisture transfer is carried out on the basis of the formulas obtained in the analysis of a more general mathematical model of heat and mass transfer carried out based on the mechanics of multiphase systems developed in the works of R.I. Nigmatulin, and S. Whitaker. The structure of the samples was investigated by three independent methods in order to obtain the most complete idea of ​​it and to compare the obtained characteristics. The isotherms of the sorption of polycaproamide were obtained experimentally on a vacuum sorption plant with Mac-Ben-Bakr weights. Comparison of the results of mathematical modeling of heat and mass transfer in the granule and data of the laboratory experiment on the kinetics of polycaproamide granule drying showed good agreement between the calculated and experimental data. The constructed mathematical model allows to form energy-efficient resource-saving regimes for drying granules of polycaproamide.

Thermal stability of amorphous sugar matrix, dried from methanol, as an amorphous solid dispersion carrier

  • Imamura, Koreyoshi
  • Takeda, K.
  • Yamamoto, K.
  • Imanaka, H.
  • Ishida, N.
[EN] Developing a technique to disperse hydrophobic ingredients homogeneously in a water-soluble solid matrix (solid dispersion) is one of the topics that have been extensively investigated in the pharmaceutical and food industries. Recently, we have devised a novel solid dispersion technique (surfactant-free solid dispersion), in which a preliminarily amorphized sugar was dissolved in an organic media containing hydrophobic component, without using any surface active substances, and then vacuum dried into the amorphous solid mixture [Food Chem., 197 (2016) 1136; Mol. Pharm., 14 (2017) 791]. In this study, the physicochemical properties, especially thermal stability of the surfactant-free amorphous solid dispersion, were investigated.

Drying of algae by various drying methods

  • Bheda, Bhaumik
  • Shinde, Manoj
  • Ghadge, Rajaram
  • Thorat, Bhaskar
[EN] Algae drying was carried out using Vacuum Tray Dryer and an Innovative Solar Conduction Dryer. Algae was dried in a Vacuum Tray Dryer at 60°C under varied pressure conditions and makes use of specially designed double condenser system. The open sun drying and solar conduction dryer (SCD) was also used for algae drying. Comparison between open sun drying and solar conduction dryer were done and it was found that the solar conduction dryer gives high performance than the open sun drying. It was also found that, the conductive heat transfer mode plays a crucial role in the solar conduction dryer.

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