scholarly journals Description of atmospheric freeze-drying process of organic apples using thermo-physical properties

2018 ◽  
Author(s):  
Ignat Tolstorebrov ◽  
Trygve Magne Eikevik ◽  
Inna Petrova ◽  
Yulia Shokina ◽  
Michael Bantle
Keyword(s):  
Glass Transition ◽  
Moisture Content ◽  
Physical Properties ◽  
Freeze Drying ◽  
Ice Formation ◽  
Drying Process ◽  
Influence Of Temperature ◽  
Thermo Physical Properties ◽  
Total Moisture Content ◽  
Ice Fraction

This study discusses the influence of temperature and total moisture content on ice fraction in organic apples during atmospheric freeze-drying process. The ice formation of glass transition events were described by Clausius-Clapeyron and Gordon Taylor equations. The obtained data is essential for design the drying process and for understanding the limiting factors.Keywords: ice fraction, organic apples, atmospheric freeze/drying, glass transition

scholarly journals Modeling and Simulation of the Drying of Beech Timber (Fagus sylvatica)Using Oscillating Regimes

2014 ◽  
Vol 08 (2) ◽  
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Modeling And Simulation ◽  
Fagus Sylvatica ◽  
Numerical Study ◽  
Numerical Test ◽  
Drying Process ◽  
Transfer Coefficients ◽  
Convective Transfer ◽  
Thermo Physical Properties

This paper represents a numerical study of the massive (60mm) and thin (38mm) wood drying using oscillating drying regimes applied on beech timber (Fagus sylvatica). All thermo-physical properties relative of studied wood are taken from the literature on appropriate experiments. We showed that Luikov’s model can be used to predict temperature and moisture content evolutions using oscillating regimes. First numerically tests on 60mm timber wood consists in increasing and decreasing alternation of the drying parameters (temperature), at the rising 12-15°C and at the descent 10- 12°C, every alternation being higher than the precedent with 2-4°C. Second numerical test consists to oscillate the values of equilibrium moisture content with the oscillation amplitudes of ±10% and ±20% at the frequencies of 6hours. These practical experiments are detailed in the literature. Luikov’s model gives satisfactory results, according to the experiments obtained in the literature. But, convective transfer coefficients are function of each experiment and we observed a short difference between oscillation amplitudes of ±10% and ±20% on moisture content evolution. Thus, Luikov’s model can be a tool to study oscillation drying timber in order to reduce consumption of energy during the drying process.

Heat and Mass Diffusion Including Shrinkage and Hygrothermal Stress during Drying of Holed Ceramics Bricks

2011 ◽  
Vol 312-315 ◽  
pp. 971-976 ◽  
Author(s):  
J. Barbosa da Silva ◽  
G. Silva Almeida ◽  
W.C.P. Barbosa de Lima ◽  
Gelmires Araújo Neves ◽  
Antônio Gilson Barbosa de Lima
Keyword(s):  
Moisture Content ◽  
Three Dimensional ◽  
Average Moisture Content ◽  
Stress Distributions ◽  
Drying Process ◽  
Convective Boundary ◽  
Volume Method ◽  
Hygrothermal Stress ◽  
Thermo Physical Properties ◽  
Good Agreement

The Aim of this Work Is to Present a Three-Dimensional Mathematical Modelling to Predict Heat and Mass Transport inside the Industrial Brick with Rectangular Holes during the Drying Including Shrinkage and Hygrothermalelastic Stress Analysis. the Numerical Solution of the Diffusion Equation, Being Used the Finite-Volume Method, Considering Constant Thermo-Physical Properties and Convective Boundary Conditions at the Surface of the Solid, it Is Presented and Analyzed. Results of the Temperature, Moisture Content and Stress Distributions, and Drying and Heating Kinetics Are Shown and Analyzed. Results of the Average Moisture Content and Surface Temperature of the Brick along the Drying Process Are Compared with Experimental Data (T = 80.0oC and RH = 4.6 %) and Good Agreement Was Obtained. it Was Verified that the Largest Temperature, Moisture Content and Stress Gradients Are Located in the Intern and External Vertexes of the Brick.

Glass Transition Temperature, Mechanical Properties of Rice and their Relationships with Milling Quality

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Kobra Tajaddodi Talab ◽  
Mohd. Nordin Ibrahim ◽  
Sergey Spotar ◽  
Rosnita A. Talib ◽  
Kharidah Muhammad
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Moisture Content ◽  
Bending Strength ◽  
Bending Test ◽  
Transition Line ◽  
Transition Temperatures ◽  
Drying Process ◽  
Glass Transition Temperatures ◽  
Grain Moisture

Abstract Glass transition temperatures (Tg) of MR219 rice variety were measured by differential scanning calorimeter (DSC). State diagram was developed and used to evaluate drying process in this study. Glass transition temperatures range of 9.65- 61.79°C were observed for gains with moisture content of 26.8 – 7.4% (w.b.). For mechanical properties and milling test, statistical analysis was performed by using a two factor experiment in completely randomized design (CRD). Two selected factors were drying temperatures at 5 levels (40, 45, 50, 55, and 60°C) and final moisture content (FMC) at 4 levels (10-10.5, 11-11.5, 12-12.5 and 13-13.5%). Three–point bending test was applied to measure the mechanical properties of rice kernel. Generally, bending strength, apparent modulus of elasticity and fracture energy of brown rice kernel increased with decreasing the grain moisture content. Maximum bending strength was 35.69 and 33.64 MPa for 55, and 60°C, respectively. All samples that were dried at 55 and 60°C experienced to go through the glass transition line after reaching their temperature to the room temperature at the end of drying process. The effect of drying temperature, paddy FMC and their interactions on whole kernel percentage (WKP) and mechanical properties were significant (α = 0.05). An inverse relationship was observed between WKP and the percentage of strong kernels for all treatments.

scholarly journals Effect of the Freeze-Drying Process on the Physicochemical and Microbiological Properties of Mexican Kefir Grains

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 127 ◽  
Author(s):  
Alicia Conde-Islas ◽  
Maribel Jiménez-Fernández ◽  
Denis Cantú-Lozano ◽  
Galo Urrea-García ◽  
Guadalupe Luna-Solano
Keyword(s):  
Moisture Content ◽  
Water Activity ◽  
Freeze Drying ◽  
Survival Rates ◽  
Freezing Temperature ◽  
Freezing Time ◽  
Residual Moisture Content ◽  
Drying Process ◽  
Residual Moisture ◽  
Kefir Grains

The purpose of this study was to investigate how the properties of Mexican kefir grains (MKG) are affected by the operating parameters used in the freeze-drying process. The factors investigated were the freezing time (3–9 h), freezing temperature (−20 to −80 °C), pressure (0.2–0.8 mbar), and lyophilization time (5–20 h). The maximum range of change and one-way analysis of variance showed that lyophilization time and freezing time significant affects (p < 0.05) the response variables, residual moisture content and water activity, and pressure had a significant effect on the color difference and survival rate of probiotic microorganisms. The best drying conditions were a freezing time of 3 h, a freezing temperature of −20 °C, a pressure of 0.6 mbar, and a lyophilization time of 15 h. Under these conditions, we obtained a product with residual moisture content below 6%, water activity below 0.2, and survival rates above 8.5 log cfu per gram of lactic acid bacteria and above 8.6 log for yeast.

Effects of annealing on the physical properties of therapeutic proteins during freeze drying process

2018 ◽  
Vol 107 ◽  
pp. 730-740 ◽  
Author(s):  
Jun Yeul Lim ◽  
Dae Gon Lim ◽  
Ki Hyun Kim ◽  
Sang-Koo Park ◽  
Seong Hoon Jeong
Keyword(s):  
Physical Properties ◽  
Freeze Drying ◽  
Therapeutic Proteins ◽  
Drying Process

scholarly journals GUAR GUM ADDITION ON PHYSICAL CHARACTERISTICS OF EXTRUDED DRY CORN NOODLE FROM MIXTURE OF WET AND DRY CORN FLOURS

2020 ◽  
Vol 11 (1) ◽  
pp. 39
Author(s):  
Aminullah Aminullah ◽  
Tjahja Muhandri ◽  
Subarna Subarna
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Shelf Life ◽  
Guar Gum ◽  
Physical Characteristics ◽  
Cooking Loss ◽  
Drying Process ◽  
Corn Flour ◽  
Physical Quality

The drying process of corn noodles was an effort to increase the shelf life and it was a form of noodles diversification. The objective of this research was to study and analyze the effect of guar gum addition on the physical quality of the extruded dry corn noodle made from a mixture of wet and dry corn flour. Manufacturing dry corn noodles was conducted using wet corn noodles from a mixture of wet and dry corn flour, which was then dried in a tray dryer at a temperature of 60-70 °C for 1 - 1.5 hours. The treatments used were a combination of alum levels of 0.01%; moisture content of 80% (dry base); and guar gum concentration of 0%, 1%, and 2%. Physical properties of dry corn noodles included rehydration time, hardness, adhesiveness, suppleness, elongation, and cooking loss. The results showed that the optimum rehydration time for dry corn noodles was about 9 minutes. The addition of guar gum to the physical qualities of dry corn noodles tended not to be significant statistically, but as a score, an increase in guar gum levels tended to increase the elongation of dry corn noodles. While, increasing levels of guar gum tended to reduce the stickiness and cooking loss levels of them.

scholarly journals Effect of Drying Temperature of Small Scale Spray Dryer on Physical Properties of Coffee Powder

2020 ◽  
Vol 28 (4) ◽  
Author(s):  
Joko Nugroho Wahyu Karyadi ◽  
Dwi Ayuni ◽  
Tsania Ayu Rohani ◽  
Devi Yuni Susanti
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Spray Drying ◽  
Product Yield ◽  
Feed Solution ◽  
Small Scale ◽  
Inlet Temperature ◽  
Spray Dryer ◽  
Drying Process ◽  
High Product Yield

Nowadays, coffee has become one of the most favorable commodities for beverages, flavoring as well as for cosmetic industries. In Indonesia, coffee becomes more popular, especially among youngsters. In this study, the spray drying process was evaluated, giving the potential of how simple spray dryer can help local farmers of Indonesia to produce their coffee powders. One small scale of spray dryer was constructed with the total dimensions of 2.85 x 0.64 for length x width, with a height of 2.32 m. The spray dryer was equipped with a digital thermo regulator, the pneumatic nozzle system, and 4 finned heaters with the power of 2700 watt for each. The spray drying constructed was revealed to be able to produce coffee powders with fine quality. The inlet temperature of the drying chamber, as well as the initial Brix content of feed solution, were proven to affect the physical properties of powder produced such as moisture content, product yield, and solubility. The final moisture content of powders was ranged from 3 - 7% db, with the high product yield of the drying process, which could reach up to 70%.

scholarly journals The Freeze-Drying of Foods—The Characteristic of the Process Course and the Effect of Its Parameters on the Physical Properties of Food Materials

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1488 ◽  
Author(s):  
Dorota Nowak ◽  
Ewa Jakubczyk
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Structural Properties ◽  
Freeze Drying ◽  
Process Conditions ◽  
Drying Process ◽  
High Quality ◽  
Freeze Dried ◽  
Secondary Drying ◽  
Selection Of

Freeze-drying, also known as lyophilization, is a process in which water in the form of ice under low pressure is removed from a material by sublimation. This process has found many applications for the production of high quality food and pharmaceuticals. The main steps of the freeze-drying process, such as the freezing of the product and primary and secondary drying, are described in this paper. The problems and mechanisms of each step of the freeze-drying process are also analyzed. The methods necessary for the selection of the primary and secondary end processes are characterized. The review contains a description of the effects of process conditions and the selected physical properties of freeze-dried materials, such as structural properties (shrinkage and density porosity), color, and texture. The study shows that little attention is given to the mechanical properties and texture of freeze-dried materials obtained from different conditions of the lyophilization process.

scholarly journals Effect of Freeze-Drying on Quality and Grinding Process of Food Produce: A Review

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 354 ◽  
Author(s):  
Timilehin Martins Oyinloye ◽  
Won Byong Yoon
Keyword(s):  
Glass Transition ◽  
Freeze Drying ◽  
Structural Changes ◽  
Morphological Changes ◽  
Energy Requirement ◽  
Quality Attributes ◽  
Processing Unit ◽  
Drying Process ◽  
Drying Time ◽  
Freeze Dried

Freeze-drying is an important processing unit operation in food powder production. It offers dehydrated products with extended shelf life and high quality. Unfortunately, food quality attributes and grinding characteristics are affected significantly during the drying process due to the glass transition temperature (during drying operation) and stress generated (during grinding operation) in the food structure. However, it has been successfully applied to several biological materials ranging from animal products to plants products owning to its specific advantages. Recently, the market demands for freeze-dried and ground food products such as spices, vegetables, and fruits are on the increase. In this study, the effect of the freeze-drying process on quality attributes, such as structural changes, the influence of glass transition during grinding, together with the effect on grinding efficiency in terms of energy requirement, grinding yield, and morphological changes in the powder as a result of temperature, drying time were discussed. An overview of models for drying kinetics for freeze-dried food sample, and grinding characteristics developed to optimize the drying processes, and a prediction of the grinding characteristics are also provided. Some limitations of the drying process during grinding are also discussed together with innovative methods to improve the drying and grinding processes.

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