scholarly journals Energy and Quality Aspects of Freeze-Drying Preceded by Traditional and Novel Pre-Treatment Methods as Exemplified by Red Bell Pepper

2021 ◽  
Vol 13 (4) ◽  
pp. 2035
Author(s):  
Katarzyna Rybak ◽  
Oleksii Parniakov ◽  
Katarzyna Samborska ◽  
Artur Wiktor ◽  
Dorota Witrowa-Rajchert ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Freeze Drying ◽  
Bell Pepper ◽  
Drying Process ◽  
Drying Time ◽  
Statistical Point ◽  
Quality Aspects ◽  
Bell Peppers ◽  
Pre Treatment

Freeze-drying is one of the most expensive and most energy intensive processes applied in food technology. Therefore, there have been significant efforts to reduce the freeze-drying time and decrease its energy consumption. The aim of this work was to analyze the effect of pulsed electric field (PEF), ultrasound (US), and hybrid treatment (PEF-US) and compare them with the effect of blanching (BL) on the freeze-drying kinetics, energy consumption, greenhouse gasses emission, and physical quality of the product. The freeze-drying process was applied to red bell peppers after pretreatment operations. Results showed that application of BL, PEF, US, or PEF-US reduces freeze-drying time and decreases energy consumption. Among the tested methods, the combination of PEF performed at 1 kJ/kg and US was the most effective in reduction of greenhouse gas emission. BL samples exhibited the highest porosity, but from a statistical point of view, most of the PEF-US treated materials did not differ from it. The smallest color changes were noted for US pre-treated bell peppers (ΔE = 9.4), whereas BL, PEF, and PEF-US material was characterized by ΔE of 15.2–28.5. Performed research indicates the application of pre-treatment may improve the sustainability of freeze-drying process and quality of freeze-dried bell pepper.

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 ASSESSMENT OF FREEZING PRE-TREATMENTS FOR THE FREEZE DRIED OF APPLE SLICES

2013 ◽  
Vol 17 (2) ◽  
pp. 3-14 ◽  
Author(s):  
Tamás Antal ◽  
László Sikolya ◽  
Benedek Kerekes
Keyword(s):  
Water Activity ◽  
Freeze Drying ◽  
Color Difference ◽  
Freezing Rate ◽  
Slow Freezing ◽  
Drying Process ◽  
Drying Time ◽  
Freeze Dried ◽  
Apple Slices

Abstract The effect of freezing rate on the quality of dried Jonagold and Idared was studied. Apple slices underwent various pre-treatments, i.e. freezing in household freezer (freezing rate: 0,5 °C/min), contact plate freezing (2 °C/min) and vacuum-freezing (3 °C/min). The quality of the freeze dried product was then evaluated in terms of water activity, hardness, color and rehydration. The freezing in household freezer (slow freezing rate) significantly reduces the duration of the freeze drying process and consequently the process costs. The slow freezing rate allows the growth of large ice crystals at the beginning of the freeze-drying process, this fact should consequently lead to larger pores and injured cell walls and thus to shorter freeze drying time. Quality of the freezing in household freezer product was assessed as higher than the quality of the other freezing pre-treated material. Slow freezing rate resulted softer texture and higher rehydration capacity, than that of other pre-treated samples. In all cases, slow freezing lead to lower final moisture content, total color difference and water activity.

scholarly journals The using Infrared Radiation on the Freeze-Drying of Cherry

2020 ◽  
Vol 9 (2) ◽  
pp. 1628-1630
Keyword(s):  
Energy Consumption ◽  
Infrared Radiation ◽  
Freeze Drying ◽  
Experimental Studies ◽  
Quality Characteristics ◽  
Drying Rate ◽  
Drying Time ◽  
Reduce Energy Consumption ◽  
Pre Treatment ◽  
Freeze Dryer

In this work experimentally investigated the drying rate of Cherry on the freeze-dryer (FD) and FD with infrared pretreatment (IR), and compared the quality characteristics of the cherry after rehydration. Results of experimental studies was determined that, the use of IR pre-treatment on the FD was much more effective. The use of IR waves showed that the drying time of cherries with IR pre-treatment is shorter than without pre-treatment. Especially, the application of IR pretreatment before freeze-drying, allows you to get quality products, and provides to reduce energy consumption by 15-17%.

scholarly journals Evaluation of freezing pre-treatments for the lyophilisation of apple

2013 ◽  
Vol 5 (1) ◽  
pp. 56-68
Author(s):  
Tamás Antal ◽  
László Sikolya ◽  
Benedek Kerekes
Keyword(s):  
Water Activity ◽  
Freeze Drying ◽  
Ice Crystals ◽  
Freezing Rate ◽  
Slow Freezing ◽  
Drying Process ◽  
Drying Time ◽  
Freeze Dried ◽  
Apple Slices

Abstract The effect of freezing rate on the quality of dried Jonagold and Idared (Malus domestica Borkh.) was studied. Apple slices underwent various pre-treatments, i.e. freezing in household freezer (freezing speed/rate: 0,5◦C/min), contact plate freezing (2◦C/min) and vacuumfreezing (3◦C/min). The quality of the freeze-dried product was then evaluated in terms of water activity (aw), hardness, color and rehydration. The texture and color experiments were carried out with texture analyser and colorimeter. The aw of apple slices was measured by aw apparatus. It was found that drying time was influenced by freezing rate. The freezing in household freezer (slow freezing rate) significantly reduces the duration of the freeze-drying process and consequently the process costs. The slow freezing rate allows the growth of large ice crystals at the beginning of the freeze-drying process; this fact should consequently lead to larger pores and injured cell walls and thus to shorter freeze-drying time. Quality of the freezing in household freezer product was assessed as higher than the quality of the other freezing pre-treated material. Slow freezing rate resulted softer texture and higher rehydration capacity than that of other pre-treated samples. In all cases, slow freezing speed lead to lower final moisture content, total color difference and water activity. Freeze-dried samples prepared with higher freezing rates (3◦C/min) were the most white in color because small pores, originated by sublimation of small ice crystals formed by fast freezing.

scholarly journals Freeze-drying microscopy in mathematical modeling of a biomaterial freeze-drying

2012 ◽  
Vol 48 (2) ◽  
pp. 203-209 ◽  
Author(s):  
Camila Figueiredo Borgognoni ◽  
Joyce da Silva Bevilacqua ◽  
Ronaldo Nogueira de Moraes Pitombo
Keyword(s):  
Mathematical Modeling ◽  
Freeze Drying ◽  
Drying Process ◽  
Critical Temperatures ◽  
Fundamental Properties ◽  
Moving Interface ◽  
Energy Consuming ◽  
Sublimation Rates ◽  
Time And Energy

Transplantation brings hope for many patients. A multidisciplinary approach on this field aims at creating biologically functional tissues to be used as implants and prostheses. The freeze-drying process allows the fundamental properties of these materials to be preserved, making future manipulation and storage easier. Optimizing a freeze-drying cycle is of great importance since it aims at reducing process costs while increasing product quality of this time-and-energy-consuming process. Mathematical modeling comes as a tool to help a better understanding of the process variables behavior and consequently it helps optimization studies. Freeze-drying microscopy is a technique usually applied to determine critical temperatures of liquid formulations. It has been used in this work to determine the sublimation rates of a biological tissue freeze-drying. The sublimation rates were measured from the speed of the moving interface between the dried and the frozen layer under 21.33, 42.66 and 63.99 Pa. The studied variables were used in a theoretical model to simulate various temperature profiles of the freeze-drying process. Good agreement between the experimental and the simulated results was found.

scholarly journals Effect of Solar Radiation on the Drying Parameters of Mint (Mentha Spicata L.) Dried in Natural Convective Solar Dryer

2020 ◽  
Author(s):  
SEBIHA REHMAN ◽  
SEEMIN RUBAB
Keyword(s):  
Weather Conditions ◽  
Quality Parameter ◽  
Drying Process ◽  
Kashmir Valley ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Mentha Spicata ◽  
Solar Dryer ◽  
Pre Treatment ◽  
Kinetics Of

Abstract The paper presents a kinetic study of solar dried mint (Mentha spicata L.) without any pre-treatment. Mint grows effortlessly in Kashmir valley but is not obtainable throughout the year because of inconsiderate weather conditions. The genus belongs to the Labiatae family and includes large varieties with different properties. A significant quality parameter is its colour. The drying kinetics of mint leaves dried in Domestic Solar Dryer in terms of colour attributes, moisture content, drying time, non enzymatic browning, water activity, rehydration ratio was studied. This study is very useful for household scale drying of mint leaves to optimize drying process and to achieve superior quality dried product at home maintaining its colour and aroma.

scholarly journals Review: Reduction of energy consumption in TMP refining through mechanical pre-treatment of wood chips

2010 ◽  
Vol 25 (2) ◽  
pp. 156-161 ◽  
Author(s):  
Dmitri Gorski ◽  
Jan Hill ◽  
Per Engstrand ◽  
Lars Johansson
Keyword(s):  
Energy Consumption ◽  
Pilot Scale ◽  
High Ratio ◽  
Wood Chips ◽  
Chip Size ◽  
Weak Points ◽  
Pulp Properties ◽  
Pre Treatment ◽  
Reduction Of Energy Consumption

Abstract This review covers the effect of mechanical pre-treatment of wood chips on the energy consumption in refining and the quality of pulp. To understand the mechanisms of mechanical pre-treatment, a short description of relevant refining theory and reported effects of pre-treatment on wood morphology is given. Mechanical pre-treatment offers a chance to utilize the energy needed to defibrate chips in a more efficient way, minimizing the cyclic elastic deformations which are the main defibration mechanism in refining. Studies of fibre morphology indicate that compressive pretreatment mechanically introduces favorable weak points in the S1 and S2 fibre walls where defibration proceeds easier upon subsequent refining. Published results which cover the effect of the pretreatment on energy consumption and pulp properties are reviewed. Energy reduction of between 10% and 30% is reported in the literature. High ratio of volumetric compression is necessary. Pressurized conditions are required to ensure that the fibres are not damaged during the pre-treatment. Other effects of compressive pretreatment include a more uniform chip size and moisture content, better penetration of chemicals and removal of extractives from the chips. A list of equipment used for chip pre-compression is provided together with published results of pilot-scale and mill-scale operation.

scholarly journals Air drying of macauba fruits: maintaining oil quality for biodiesel production

2019 ◽  
Vol 42 ◽  
pp. e43451 ◽  
Author(s):  
Gutierres Nelson Silva ◽  
José Antônio Saraiva Grossi ◽  
Marcela Silva Carvalho ◽  
Kacilda Naomi Kuki ◽  
Samuel de Melo Goulart ◽  
...  
Keyword(s):  
Oil Quality ◽  
Chemical Properties ◽  
Biodiesel Production ◽  
Drying Process ◽  
Drying Time ◽  
Dried Fruits ◽  
Efficient Storage ◽  
Fruit Samples ◽  
Low Levels

Macauba fruits are oil-rich drupes with high moisture content at harvest. This feature can affect the chemical properties of the oil and increase the costs of biodiesel production. Therefore, it is necessary to adopt postharvest strategies to ensure oil quality. The aim of this work was to evaluate the effect of drying macauba fruit on the quality of the pulp oil. Husked and dehusked fruits were dried at 60°C and then stored. At 0, 15, 45, 100, and 180 days after storage, fruit samples were retrieved, and the oil from the pulp was evaluated for physicochemical parameters. The removal of the husk from the fruits considerably reduced the drying time compared to that of the husked fruits. Drying prevented deterioration of the fruit even after 180 days of storage, regardless of the presence of the husk. The drying process allowed for efficient storage of the macauba fruit while maintaining low levels of oil acidity. Furthermore, the oxidative stability of the pulp oil from the dehusked dried fruits lasted longer than that from the husked dried fruits. Therefore, drying is a viable alternative for the postharvest of macauba fruits to maintain the quality of the oil for biodiesel production.

A numerical simulation of a line-type paint drying furnace

2019 ◽  
Vol 30 (5) ◽  
pp. 2639-2653
Author(s):  
Jongrak Choi ◽  
Giyeob Yang ◽  
Nahmkeon Hur
Keyword(s):  
Numerical Results ◽  
Drying Process ◽  
Drying Time ◽  
Content Type ◽  
Hot Air ◽  
Air Supply ◽  
Nozzle Configuration ◽  
Paint Drying ◽  
Line Type

Purpose Paint drying is a very important process in an industry where shorter drying time for productivity and lower energy consumption for production cost are required while maintaining the product’s painting quality. In the present study, a drying process in a line-type paint drying furnace equipped with nozzles for hot air supply and moving conveyer belt to dry painted automotive parts is numerically simulated for the flow and heat transfer inside the furnace to evaluate the quality of the drying or baking at the end of the drying process in a production line. Design/methodology/approach A baking window for a specific paint is used for judging the local degree of baking (DOB) of the painted parts, which can be useful to identify under-baked or over-baked locations of the painted parts, and hence the quality of the baking process. Findings Numerical results of a time history of temperatures at two monitoring points on the painted parts were obtained and compared to the measured data in an actual furnace and showed good agreement. Three types of paints were considered in the present study and numerical results showed different drying characteristics. In addition to the original furnace nozzle configuration, two more furnace nozzle configurations with different numbers, direction and speed of hot air supply were simulated to improve the furnace’s drying performance. As a result, a newly suggested nozzle configuration with quick drying paint can give us a remarkable improvement in surface averaged DOB compared to the original nozzle configuration with original paint. Originality/value The present simulation technique and DOB methodology can be used for the optimal design of a drying furnace.

Ultrasound as Pre-Treatment for Drying of Genipap (Genipa americana L.)

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Fabiano An. Fernandes ◽  
Sueli Rodrigues
Keyword(s):  
Ultrasonic Treatment ◽  
Sugar Content ◽  
Drying Process ◽  
Drying Time ◽  
Air Drying ◽  
Tropical Fruit ◽  
Dried Fruits ◽  
Water Diffusivity ◽  
Pre Treatment

Abstract Genipap (Genipa americana L.) is an exotic tropical fruit that can be used in production of sweets, liqueurs, and several other foodstuffs. In this work the effect of ultrasonic pre-treatment prior to air-drying on dehydration of genipap was investigated. The study allowed estimating the water diffusivity in the air-drying process for genipaps submitted to ultrasound. Results showed that the water diffusivity increased after application of ultrasound and that the overall drying time was reduced by 28.2%. During the ultrasonic treatment, genipaps lost sugar showing that the ultrasonic pre-treatment can be a valuable process to produce dried fruits with lower sugar content.

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