scholarly journals Process intensification and process control in freeze-drying

2018 ◽  
Author(s):  
Antonello A Barresi ◽  
Roberto Pisano
Keyword(s):  
Process Control ◽  
Freeze Drying ◽  
New Technologies ◽  
Continuous Process ◽  
Process Intensification ◽  
Good Alternative ◽  
Process Efficiency ◽  
Vapor Flow ◽  
Drying Time ◽  
Product Resistance

Widespread use of advanced process control allows reduction of costs, by reducing drying time and energy consumption. The “control of the freezing stage” (by forced nucleation) also appears to be beneficial to process intensification, as it can impact the product structure and modify the product resistance to mass transfer. An alternative way to increase the drying rate is the use of organic solvents as they can lead to larger solvent crystals, hence lower product resistance to vapor flow. Atmospheric freeze-drying may be a good alternative to vacuum freeze-drying, as a way of increasing process efficiency. A further improvement can be obtained by combining atmospheric or vacuum freeze-drying with new technologies. A further step towards process intensification is given by continuous plants, as this allows a dramatic increase in throughput and product quality uniformity. Keywords: freeze-drying; process intensification; controlled nucleation; continuous process. 

scholarly journals Freeze-Drying of Blueberries: Effects of Carbon Dioxide (CO2) Laser Perforation as Skin Pretreatment to Improve Mass Transfer, Primary Drying Time, and Quality

Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 211 ◽  
Author(s):  
Pablo Munzenmayer ◽  
Jaime Ulloa ◽  
Marlene Pinto ◽  
Cristian Ramirez ◽  
Pedro Valencia ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Co2 Laser ◽  
Freeze Drying ◽  
Sharp Decrease ◽  
Linear Increase ◽  
Vapor Flow ◽  
Drying Time ◽  
Transfer Resistance ◽  
Freeze Dried ◽  
Phenomenological Perspective

Freeze-dried berry fruits are generally consumed as they are, whole and without peeling or cutting, as the conservation of their original shape and appearance is often desired for the final product. However, usually, berries are naturally wrapped by an outer skin that imparts a barrier to vapor flow during freeze-drying, causing berry busting. Photo-sequence, experimental, and theoretical methodologies were applied to evaluate the application of CO2 laser microperforations to blueberry skin. Under the same set of freeze-drying conditions, blueberries with and without perforations were processed. The results showed that the primary drying time was significantly reduced from 17 ± 0.9 h for nontreated berries to 13 ± 2.0 h when nine microperforations per berry fruit were made. Concomitantly, the quality was also significantly improved, as the percentage of nonbusted blueberries at the end of the process increased from an average of 47% to 86%. From a phenomenological perspective, the analysis of the mass transfer resistance of nontreated fruits, in agreement with reported studies, showed a Type II curvature, with a sharp decrease at low time, followed by a linear increase. In contrast, blueberries with nine perforations depicted a Type III regime, with a saturation curvature toward the time axis. It was demonstrated that CO2-laser microperforation has high potential as a skin pretreatment for the freeze-drying of blueberries.

scholarly journals The Quality of Red Bell Pepper Subjected to Freeze-Drying Preceded by Traditional and Novel Pretreatment

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 226
Author(s):  
Katarzyna Rybak ◽  
Artur Wiktor ◽  
Dorota Witrowa-Rajchert ◽  
Oleksii Parniakov ◽  
Małgorzata Nowacka
Keyword(s):  
Freeze Drying ◽  
Bell Pepper ◽  
Total Phenolic ◽  
Thermal Methods ◽  
Drying Time ◽  
Freeze Dried ◽  
Dehydration Processes ◽  
Vacuum Freezing ◽  
Better Than

It has been demonstrated previously in the literature that utilization of PEF or a combination of a pulsed electric field (PEF) and ultrasounds (US) can facilitate dehydration processes and improve the quality of dried products even better than the application of thermal methods such as blanching. The aim of the study was to evaluate the quality of red bell pepper subjected to freeze-drying preceded by blanching or PEF or US treatment applied in a single and combined mode. Furthermore, the freeze-drying was preceded by shock freezing or vacuum freezing performed inside the freeze-dryer as a result of pressure drop during the first stage of freeze-drying. All of the analyzed technological variants enhanced the drying kinetics when compared to the intact material. Freeze-dried bell pepper subjected to non-thermal pretreatment exhibited higher vitamin C, total phenolic and carotenoids content than blanched material despite the fact that blanching reduced drying time the most compared to all other analyzed methods.

scholarly journals Effect of Hot-Water Blanching Pretreatment on Drying Characteristics and Product Qualities for the Novel Integrated Freeze-Drying of Apple Slices

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hai-ou Wang ◽  
Qing-quan Fu ◽  
Shou-jiang Chen ◽  
Zhi-chao Hu ◽  
Huan-xiong Xie
Keyword(s):  
Electron Microscopy ◽  
Freeze Drying ◽  
Hot Water ◽  
The Novel ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Drying Characteristics ◽  
Promising Alternative ◽  
Freeze Dried ◽  
Apple Slices

The effect of hot-water blanching (HWB) on drying characteristics and product qualities of dried apple slices with the novel integrated freeze-drying (NIFD) process was investigated by comparing with 3 different FD methods. Compared with the NIFD process without HWB pretreatment (VF-FD), the NIFD process with HWB pretreatment (HWB-VF-FD) resulted in a significantly higher mass loss and more sufficient freezing in vacuum-frozen samples, significantly higher rehydration ratio (RR), higher shrinkage ratio (SR), smaller Vitamin C (VC) content and lower hardness and better apparent shape in freeze-dried samples, and fewer change to the color of the dried or rehydrated samples (p<0.05). Compared with the conventional FD process with HWB pretreatment (HWB-PF-FD), HWB-VF-FD cost significantly less processing time and FD time and obtained significantly higher RR (p<0.05), almost the equivalent SR, VC content, and hardness, and similar appearance in dried samples. The microstructure of apple cell tissues was analyzed by transmission electron microscopy and scanning electron microscopy to interpret the above differences in drying characteristics and product qualities. The results suggested that the NIFD process of apple slices with HWB pretreatment was a promising alternative method to decrease drying time, achieve similar product quality, and simplify the process steps of the conventional FD technology.

Study on a Combination Drying Technique of Shrimp

2012 ◽  
Vol 260-261 ◽  
pp. 804-807
Author(s):  
Ya Xiang Bai ◽  
Yu Cai Hu ◽  
Qiang Huang
Keyword(s):  
Freeze Drying ◽  
Sensory Properties ◽  
Drying Rate ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Air Drying ◽  
Combined Process ◽  
Highly Efficient ◽  
Sensory Qualities

In order to develop a highly efficient drying technique for shrimp, a combination of air drying (AD) and vacuum freeze drying (FD) is examined. The drying rate of combination drying, the shrinkage, rehydration ratio, and sensory properties, such as the color and trimness, of the dried product in the AD–FD method are measured. Compared with FD, the combined process consumes less drying time, compared with AD drying alone. Also the product processed by combined drying displays lower shrinkage, higher rehydration rate and better sensory qualities.

Allocation of Function, Adaptive Automation, and Fault Management

1998 ◽  
Vol 42 (3) ◽  
pp. 277-279
Author(s):  
Neville Moray ◽  
Toshiuki Inagaki ◽  
Makoto Itoh
Keyword(s):  
Process Control ◽  
Continuous Process ◽  
Fault Management ◽  
Control Task ◽  
Adaptive Automation ◽  
Human Control ◽  
Self Confidence ◽  
Levels Of Automation ◽  
Allocation Of Function ◽  
Different Levels

Sheridan's “Levels of Automation” were explored in an experiment on fault management of a continuous process control task which included situation adaptive automation. Levels of automation with more or less automation autonomy, and different levels of advice to the operator were compared, with automatic diagnosis whose reliability varied. The efficiency of process control and of fault management were explored under human control and automation in fault management, and aspects of the task in which human or automation were the more efficient defined. The results are related to earlier work on trust and self confidence in allocation of function by Lee, Moray, and Muir.

scholarly journals Experimental investigation on pore size distribution and drying kinetics during lyophilization of sugar solutions

2018 ◽  
Author(s):  
Petra Foerst ◽  
M. Lechner ◽  
N. Vorhauer ◽  
H. Schuchmann ◽  
E. Tsotsas
Keyword(s):  
Pore Structure ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Freeze Drying ◽  
Three Dimensional ◽  
Drying Kinetics ◽  
Process Efficiency ◽  
Freeze Dried ◽  
Pore Size Distributions

The pore structure is a decisive factor for the process efficiency and product quality of freeze dried products. In this work the two-dimensional ice crystal structure was investigated for maltodextrin solutions with different concentrations by a freeze drying microscope. The resulting drying kinetics was investigated for different pore structures. Additionally the three-dimensional pore structure of the freeze dried samples was measured by µ-computed tomography and the pore size distribution was quantified by image analysis techniques. The two- and three-dimensional pore size distributions were compared and linked to the drying kinetics.Keywords: pore size distribution; freeze drying; maltodextrin solution; freeze drying microscope   

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

2018 ◽  
Author(s):  
Atsushi Hashimoto ◽  
Ken-ichiro Suehara ◽  
Takaharu Kameoka ◽  
Kazuhiko Kawamura
Keyword(s):  
Electromagnetic Wave ◽  
Sodium Chloride ◽  
High Frequency ◽  
Freeze Drying ◽  
Infrared Heating ◽  
Drying Time ◽  
Drying Characteristics ◽  
Additive Component ◽  
Wave Heating ◽  
Food Model

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.Keywords: freeze drying, electromagnetic wave heating, food model, sucrose, sodium chloride

scholarly journals Fortified and freeze-dried kiwi fruit (Actinidia deliciosa): quality and sensory assessment

2020 ◽  
Vol 23 ◽  
Author(s):  
Niladri Chakraborty ◽  
Rajat Chakraborty ◽  
Asit Kumar Saha
Keyword(s):  
Moisture Content ◽  
Freeze Drying ◽  
Raw Materials ◽  
Food Product ◽  
Rice Flour ◽  
Actinidia Deliciosa ◽  
Crude Fibre ◽  
Kiwi Fruit ◽  
Drying Time ◽  
Freeze Dried

Abstract Kiwi fruit (Actinidia deliciosa) (KF) is one of the best fruits available due to its large amount of nutrients. Despite its many health benefits, there are no previous reports on its preparation in other readily ingestible forms. The objective of the present study was to make a new food product from KF. The KF pulp was fortified and blended with several raw materials (such as rice flour and oat flour) using a stepwise short time addition and mixing methodology since this avoids unwanted biochemical and chemical reactions. The blended and reduced moisture KF paste was freeze-dried on a round silver coated steel plate (RSCSP), supplying the heat of sublimation using a newly designed cubic heater. The freeze-drying (FD) time was 4.5 h and the drying kinetics were studied using four established models. The effective moisture diffusivity (Deff) during FD (at 50 °C) was 1.532 x 10-6 m2/s and the activation energy (E) estimated for the FD was 28.35 kJ/mol. The freeze-dried sample was ground and placed under vacuum to reduce the weathering effects. The quality of the stored product was evaluated using the proximate analysis, physicochemical analysis and a sensory evaluation using a hedonic scale. The raw, fresh KF had a moisture content of 85.07% and the final freeze-dried product one of 3%. The carbohydrate, total sugar, protein, fat, total ash, crude fibre and vitamin C contents of the final product increased by 563%, 400%, 355%, 386%, 672%, 106%, and 117% respectively. Of the 66 panelists, the % consumer acceptances for the different attributes were: sweetness (68.18%), sourness (90.91%), saltiness (100%), bitterness (100%), flavour (95.45%), texture (77.27%) and overall acceptability (81.82%). Using conventional freeze-drying (CFD) for blended KF pulp without fortification, with the same RSCSP and the same cubic heater for sublimation, the drying time was found to be 7 h to reach the same final moisture content of 3%.

scholarly journals Examination of physical properties of final product and drying properties of combined (convective pre-drying and freeze finish-drying) dehydration method

2014 ◽  
pp. 5-12
Author(s):  
Tamás Antal
Keyword(s):  
Freeze Drying ◽  
Operating Conditions ◽  
Small Scale ◽  
Case Hardening ◽  
Degree Polynomial ◽  
Hot Air Drying ◽  
Drying Time ◽  
Drying Characteristics ◽  
Hot Air ◽  
Drying Properties

In this study, the effects of freeze drying (FD), hot-air drying (HAD) and combined drying (HAD-FD) on drying characteristics, energy uptake, texture, rehydration and color of carrot were investigated. Results showed that HAD-FD significantly improved the drying time compared with FD under the same operating conditions, and the HAD-FD can reduce the total cost of dehydration. The drying kinetics was described by the Henderson-Pabis and the third degree polynomial models in the case of HAD, FD and HAD-FD. The HAD carrot samples were exhibited shrinkage, case hardening, poor rehydration and brown surface. The FD carrot cubes appeared porous structure, excellent rehydration, soft texture and loose color. The HAD-FD samples were superior to HAD products and was nearer in quality to FD products with respect to appearance, rehydration and surface resistance (texture). Finally, it is concluded that HAD-FD is effective in improving the FD drying rate. However, the combined drying has a small-scale adverse effect on product quality.

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