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 4D Micro-Computed X-ray Tomography as a Tool to Determine Critical Process and Product Information of Spin Freeze-Dried Unit Doses

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 430 ◽  
Author(s):  
Brecht Vanbillemont ◽  
Joris Lammens ◽  
Wannes Goethals ◽  
Chris Vervaet ◽  
Matthieu N. Boone ◽  
...  
Keyword(s):  
Thermal Imaging ◽  
Time Distribution ◽  
Freeze Drying ◽  
Product Information ◽  
Mechanistic Model ◽  
Physical Stability ◽  
Mechanistic Models ◽  
Drying Time ◽  
Transfer Resistance ◽  
Freeze Dried

Maintaining chemical and physical stability of the product during freeze-drying is important but challenging. In addition, freeze-drying is typically associated with long process times. Therefore, mechanistic models have been developed to maximize drying efficiency without altering the chemical or physical stability of the product. Dried product mass transfer resistance ( R p ) is a critical input for these mechanistic models. Currently available techniques to determine R p only provide an estimation of the mean R p and do not allow measuring and determining essential local (i.e., intra-vial) R p differences. In this study, we present an analytical method, based on four-dimensional micro-computed tomography (4D- μ CT), which enables the possibility to determine intra-vial R p differences. Subsequently, these obtained R p values are used in a mechanistic model to predict the drying time distribution of a spin-frozen vial. Finally, this predicted primary drying time distribution is experimentally verified via thermal imaging during drying. It was further found during this study that 4D- μ CT uniquely allows measuring and determining other essential freeze-drying process parameters such as the moving direction(s) of the sublimation front and frozen product layer thickness, which allows gaining accurate process knowledge. To conclude, the study reveals that the variation in the end of primary drying time of a single vial could be predicted accurately using 4D- μ CT as similar results were found during the verification using thermal imaging.

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.

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 Effect of Size and Drying Time on the Rehydration and Sensory Properties of Freeze-Dried Snails (Achatina achatina)

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Matthew A. Achaglinkame ◽  
Eric Owusu-Mensah ◽  
Abena A. Boakye ◽  
Ibok Oduro
Keyword(s):  
Moisture Content ◽  
Nutritional Value ◽  
Freeze Drying ◽  
Consumer Preference ◽  
Sensory Properties ◽  
Temperature Dependent ◽  
Drying Time ◽  
Standard Methods ◽  
Freeze Dried ◽  
Hedonic Scale

Snails, a delicacy in most tropical communities, are highly perishable and seasonal. Employed preservative methods are highly temperature dependent, adversely affecting their nutritional value and sensory properties. This study was aimed at determining the effect of size and drying time on the rehydration and sensory properties of freeze-dried snails. Snails were sized into three categories with average weights: 7.59 g (quarter-sized), 14.41 g (half-sized), and 30.71 g (whole), and freeze-dried for 15, 20, and 25 h. The moisture content and percent rehydration of the dried samples were determined by standard methods and sensory properties assessed by an in-house panel of 30 using a 5-point hedonic scale. The moisture content of the fresh and freeze-dried samples ranged from 65.80 to 75.20% and 3.25 to 10.24%, respectively. Freeze-dried samples had higher percent rehydration (27 to 102%) than the control; smoked snails (21 to 32%). Size had a significant (P<0.05) effect on the rehydration ability of the samples with the half-sized and freeze-dried for 15 h samples having the highest. The freeze-dried samples generally had higher consumer preference than the control in all attributes assessed. The findings show that freeze-drying snails (approximate weight of 14.4 g) for 15 h could be a consumer-preferred alternative preservative method for extending the shelf life of snails.

scholarly journals Effects of Drying Parameters on Dehydration of Green Banana (Musa sepientum) and its Use in Potato (Solanum tuberosum) Chips Formulation

2012 ◽  
Vol 10 (1) ◽  
pp. 87-97 ◽  
Author(s):  
M. S. Islam ◽  
M. A. Haque ◽  
M. N. Islam
Keyword(s):  
Mass Transfer ◽  
Rate Constant ◽  
Moisture Diffusivity ◽  
Drying Rate ◽  
Drying Time ◽  
Transfer Resistance ◽  
Air Temperatures ◽  
Model Mixing ◽  
Two Parameters ◽  
Green Banana

The present study quantifies the drying kinetics of green banana during mechanical dehydration. The effect of loading density (sample thickness) and the temperature on the drying rate constant and drying time were investigated and quantified. Drying rate increased with increasing temperature but decreased with increase in loading density. The values of exponent ‘n’ of the two parameters power law model describing the drying rate constant (as a function of thickness) were less than 2 which indicated the presence of significant external resistance to mass transfer despite the dominance of internal mass transfer resistance.  Investigation with three drying air temperatures (55, 60 and 65oC) at constant air velocity (0.6 m/sec) resulted that the increase in drying air temperature increased the drying process.  The moisture diffusivity values were 1.25×10-10, 1.67×10-10 and 2.19×10-10 m2/sec at 55, 60 and 65oC respectively. The activation energy (Ea) indicating the temperature dependence of the diffusivity was 51.21 KJ/mole obtained using Arrhenius model. Mixing of green banana flour in the potato chips formulation enhanced the fiber and mineral content in the product.DOI: http://dx.doi.org/10.3329/agric.v10i1.11069The Agriculturists 2012; 10(1): 87-97

Analysis of Freeze-Drying and Rehydration of Açai (Euterpe oleracea Martius)

2015 ◽  
Vol 365 ◽  
pp. 11-16
Author(s):  
R.J. Brandão ◽  
M.M. Prado ◽  
L.G. Marques
Keyword(s):  
Mass Transfer ◽  
Energy Demand ◽  
Freeze Drying ◽  
Moisture Diffusion ◽  
Euterpe Oleracea ◽  
Power Ultrasound ◽  
Ultrasound Waves ◽  
Freeze Dried ◽  
Peleg’S Equation ◽  
Kinetics Of

The freeze-drying rate is essentially low, since it is controlled by internal moisture diffusion. In addition, the application of vacuum and low temperature during the process presents a higher energy demand. Therefore, the search for new strategies to improve water mobility during freeze-drying constitutes a topic of relevant research. The aim of this work was to evaluate the use of power ultrasound to improve freeze-drying characteristics of açai, quantifying the influence of the applied power on both the drying and rehydration kinetics of the material. Açai (Euterpe oleracea Martius) samples were sonicated with two different frequency levels, 20 kHz and 40 kHz, and two sonication times, 3 min and 10 min. Page’s equation considering internal and external resistances to mass transfer provided a good fit of freeze-drying kinetics, while the Peleg’s equation was found to be suitable for describing the rehydration kinetics of freeze-dried açai. Pretreatment of açai with ultrasound waves was not effective. Ultrasound-induced structural disruption in the açai skin hindered the mass transfer during both freeze-drying and rehydration processes.

scholarly journals Evaluation of Packaging Materials in Freeze-Drying: Use of Polymer Caps and Nested Vials and Their Impact on Process and Product Attributes

2021 ◽  
Vol 22 (3) ◽  
Author(s):  
Tim Wenzel ◽  
Henning Gieseler
Keyword(s):  
Water Vapor ◽  
Product Quality ◽  
Flexible Manufacturing ◽  
Freeze Drying ◽  
Thermal Environment ◽  
Quality Attributes ◽  
Vapor Flow ◽  
Drying Process ◽  
Process Data ◽  
Freeze Dried

AbstractCurrent trends in the pharmaceutical industry led to a demand for more flexible manufacturing processes with smaller batch sizes. Prepackaged nested vials that can be processed as a unit were introduced into the market to fulfill this need. However, vial nests provide a different thermal environment for the vials compared to a hexagonal packaging array and could therefore influence product temperature profiles, primary drying times, and product quality attributes. Polymer caps with the possibility of vial closure inside the freeze-drying chamber were developed to remove the risks and need of a crimping process. A general concern with the use of such caps is the possibility of an increase in resistance to water vapor flow out of the vial. This case study investigated the effect of the LyoSeal® and PLASCAP® polymer caps and EZ-fill® nests on the freeze-drying process. Amorphous and partially crystalline model formulations were freeze-dried. Process data and product quality attributes were compared for regularly stoppered vials and vials with polymer caps as well as vials in a hexagonal packaging array and nested vials. The results indicated no increased resistance or impeded water vapor flow by the polymer caps. Differences in the macro- and microscopic appearances of products and a trend towards lower product temperatures were observed for the investigated nest type compared to a regular hexagonal packaging array. Consequently, the polymer caps could be used as an alternative to regular stoppers without affecting freeze-drying process data or product quality attributes, while the different thermal environment of nested vials should be considered.

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 Study of vacuum and freeze drying of bee honey

2020 ◽  
Vol 24 (6 Part B) ◽  
pp. 4241-4251
Author(s):  
Nebojsa Nedic ◽  
Milan Gojak ◽  
Ivan Zlatanovic ◽  
Nedzad Rudonja ◽  
Kristina Lazarevic ◽  
...  
Keyword(s):  
Water Activity ◽  
High Performance ◽  
Freeze Drying ◽  
Soluble Solids ◽  
Diffusivity Coefficient ◽  
Chromatography Method ◽  
Drying Time ◽  
Freeze Dried ◽  
Acacia Honey ◽  
The Impact

The aim of this research is to study the drying kinetics of vacuum-dried and freeze-dried bee honey produced from two different varieties: Sunflower honey (Helianthus Annuus L.) and Acacia honey (Robinia pseudo acacia L.). Vacuum drying treatments were carried out with the honey samples? initial temperatures of +25?C, ?20?C, and ?40?C. Water content, total soluble solids, as well as the water activity of fresh and dried honey samples were determined. Freeze-drying of bee honey with initial sample temperature of ?40?C has resulted in shorter drying time (7-9 hours), moisture content (10%-12%), water activity (0.405-0.427 aW) and effective moisture diffusivity coefficient (8.26?10?7-9.51?10-7 m2/s). The high-performance liquid chromatography method was used when analyzing the impact that drying pre-treatments had on honey quality. The application of pre-treatments has led to an increase in hydroxy-methyl-furfural by 39-71%, and a decrease in diastase activity by 17-36%, all compared to fresh honey samples. The solutions of Verma model proved to be the best fit with the experimental results.

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