scholarly journals Functional properties of dried tarragon affected by drying method

2018 ◽  
Author(s):  
Banu Koç ◽  
Nazan Çağlar ◽  
Gamze Atar
Keyword(s):  
Moisture Content ◽  
Color Change ◽  
Colour Change ◽  
Microwave Drying ◽  
Perennial Herb ◽  
Drying Method ◽  
Drying Time ◽  
Infrared Drying ◽  
Temperature Levels ◽  
Asteraceae Family

Tarragon is a small shrubby perennial herb in the Asteraceae family. It is cultivated for the use of its aromatic leaves in seasoning, salads, sauces, vinegars, mustard and spices. In this study, tarragon was dried in two different drying equipment (infrared (ID) and microwave dryers (MD)) to compare the drying and final product properties (moisture content, water activity and colour change). Three different output power levels of 125, 250 and 500 W were used for MD, whereas the ID treatment involved three drying temperature levels that were 60, 70 and 80°C. A comparison of the drying kinetics, MD was more effective in shortening drying time when compared with ID. Keywords: Tarragon, microwave drying, infrared drying, color change 

scholarly journals Determination of Drying Patterns of Radish Slabs under Different Drying Methods Using Hyperspectral Imaging Coupled with Multivariate Analysis

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 484 ◽  
Author(s):  
Dongyoung Lee ◽  
Santosh Lohumi ◽  
Byoung-Kwan Cho ◽  
Seung Hyun Lee ◽  
Hyunmo Jung
Keyword(s):  
Moisture Content ◽  
Hyperspectral Image ◽  
Partial Least Square ◽  
Least Square ◽  
Moisture Distribution ◽  
Microwave Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Drying Time ◽  
Hot Air

Drying kinetics and the moisture distribution map of radish slabs under different drying methods (hot-air drying (HAD), microwave drying (MD), and hot-air and microwave combination drying (HMCD)) were determined and visualized by hyperspectral image (HSI) processing coupled with a partial least square regression (PLSR)-variable importance in projection (VIP) model, respectively. Page model was the most suitable in describing the experimental moisture loss data of radish slabs regardless of the drying method. Dielectric properties (DP, ε ) of radish slices decreased with the decrease in moisture content (MC) during MD, and the penetration depth of microwaves in radish was between 0.81 and 1.15 cm. The PLSR-VIP model developed with 38 optimal variables could result in the high prediction accuracies for both the calibration ( R c a l 2 = 0.967 and RMSEC = 4.32 % ) and validation ( R v a l 2 = 0.962 and RMSEC = 4.45 % ). In visualized drying patterns, the radish slabs dried by HAD had a higher moisture content at the center than at the edges; however, the samples dried by MD contained higher moisture content at the edges. The nearly uniform drying pattern of radish slabs under HMCD was observed in hyperspectral images. Drying uniformity of radish slabs could be improved by the combination drying method, which significantly reduces drying time.

Investigation on drying characteristics of high titanium slag using microwave heating

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Xuefeng Liao ◽  
Guo Chen ◽  
Qianqian Liu ◽  
Jin Chen ◽  
Jinhui Peng
Keyword(s):  
Moisture Content ◽  
Microwave Heating ◽  
Raw Materials ◽  
Adsorbed Water ◽  
Scientific Basis ◽  
Microwave Drying ◽  
Optimum Conditions ◽  
Drying Time ◽  
Titanium Slag ◽  
Selective Heating

AbstractIn the present study, the moisture of high titanium slag was chosen as the research object. Taking advantage of selective heating of microwave and the specific inductive capacity of water, the drying experiment of high titanium slag using microwave heating have been carried out. The results revealed that the presence of moisture in the form of high titanium slag was adsorbed water, and the wet sample possesses excellent wave-adsorbing performance; the bed depth preferred was no larger than 10 mm, with moisture content at around 3%. The microwave drying process was divided into two stages: the constant-stage and the deceleration-stage. The optimum conditions were identified to be microwave power of 700 W, sample mass of 200 g, bed depth of 10 mm and drying time of 50 s. The dehydration extent can reach 90% and moisture content remains at 0.3% under the optimum conditions. The demonstration of microwave drying techniques can be applied effectively and efficiently into the treatment processing of drying of the raw materials of metallurgy and chemical industry with the theoretical and scientific basis.

Convective and microwave drying characteristics, energy requirement and color retention of dehydrated nettle leaves (Urtica diocia L.)

2017 ◽  
Author(s):  
Fuat Lule ◽  
Turhan Koyuncu
Keyword(s):  
Moisture Content ◽  
Air Temperature ◽  
Energy Requirement ◽  
Color Difference ◽  
Microwave Drying ◽  
Convective Drying ◽  
Drying Time ◽  
Drying Characteristics ◽  
Color Retention ◽  
Specific Energy Requirement

In this research, convective and microwave drying characteristics, energy requirement and color changes of nettle leaves (Urtica diocia L.) were reported. Samples of freshly harvested nettle leaves were dehydrated under three air temperatures of 50 °C, 60 °C and 70 °C and at three microwave power levels of PL-1, PL-2 and PL-3. Selected drying air velocity was 0.30 m/s for all temperatures. This is coming from the fact that it was understood from the preliminary studies that the temperature less than 50 °C and the air speed more than 0.30 ms-1 increase the drying time and energy requirement, extremely for these products. Nettle leaves were dehydrated from the initial moisture content of 320 (percentage dry basis) to a final moisture content of 7 % to 9 %. During convective drying experiments, product were weighted automatically by the balance per (5 to10) min. Data were transferred to the computer and processed by a software. During microwave drying, the product were weighted and data recorded manually per (15 to 60) min. The influence of drying method, drying air temperature and microwave power level have also been studied. Hunter L, a, b values system was also used to evaluate changes in total color difference (DE) on dried products. The results showed that convective drying air temperature and microwave oven power levels influenced the total drying time, total energy requirement, specific energy requirement and color difference for nettle leaves. The minimum specific energy requirement were determined as 6.95 kWhkg-1 and 23.63 kWhkg-1 for 70 °C and PL-2 respectively. 70 °C drying air temperature and PL-3 was found to yield better quality product in terms of color retention of Hunter L, a, b and DE. As a result, to reduce drying energy consumption and to keep better color retention, convective drying can be recommended for this application.

Applications of Several Hybrid Drying Methods for a Bioproduct: Effects on Drying Kinetics and Product Colour

2007 ◽  
Vol 2 (5) ◽  
Author(s):  
Kian Jon Chua
Keyword(s):  
Colour Change ◽  
Drying Kinetics ◽  
Microwave Drying ◽  
Drying Methods ◽  
Thermal Processes ◽  
Adsorption System ◽  
Drying Time ◽  
Pressure Drops ◽  
Cyclic Pressure ◽  
Drying Techniques

In response to growing expectations for more effective drying of bioproducts with improved quality, this paper presents recent experimental results obtained from employing several hybrid drying techniques. The hybrid drying methods could be classified into thermal and non-thermal processes. The thermal processes included combined convective/infrared and convective-microwave drying while non-thermal process refers to dehydration under conditions of successive pressure drops incorporating an adsorption bed. Potato samples were taken to be the model bioproduct. A comparison of the drying kinetics with product colour degradation showed convective-microwave drying to be an effective method in shortening the drying time to achieve the desired moisture content whilst maintaining acceptable product quality. Bioproduct dehydration in a non-thermal cyclic pressure drop adsorption system resulted in substantial minimisation of the product colour change but at the expense of a longer drying time.

scholarly journals Physicochemical, Functional and Bioactive Properties of Pea (Pisum sativum L.) Pods Microwave and Convective Dried Powders

2021 ◽  
Author(s):  
Lynda Hadjout ◽  
Farid Dahmoune ◽  
Mohamed Hentabli ◽  
Giorgia Spigno ◽  
Khodir Madani
Keyword(s):  
Functional Properties ◽  
Water Retention ◽  
Color Change ◽  
Microwave Drying ◽  
Convective Drying ◽  
Total Phenolic ◽  
Drying Methods ◽  
Drying Time ◽  
Bioactive Properties ◽  
Swelling Capacity

Abstract As the primary by‐product of pea processing industry, pea pods represent a rich source of various high-value molecules. The aim of this work is to investigate the effect of nine different microwave output powers (200 to 1000 W) and five different ventilated oven temperatures (40, 60, 80, 100 and 120 °C) on the quality of pea pod such as physical-chemical (water activity, total color change), functional properties (water retention capacities and swelling capacity) and bioactive properties (total phenolic content, total flavonoid content and antioxidant capacity). The results show that microwave drying reduced significantly the drying time. Convective drying led to a greater color change than microwave drying. Convective drying at 80 °C for 135.33 min appeared the best process in terms of functional properties giving the highest values of water retention capacity and swelling capacity. Both microwave and convective drying methods could increase phenolic and antioxidant compounds content of pea pods. It was suggested that the microwave method can be a promising technology for drying the pea pods due to the shorter drying time, and higher product quality.

scholarly journals Effect of Microwave Drying on the Drying Characteristics, Color, Microstructure, and Thermal Properties of Trabzon Persimmon

Foods ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 84 ◽  
Author(s):  
Soner Çelen
Keyword(s):  
Energy Consumption ◽  
Color Change ◽  
Power Level ◽  
Effective Diffusion ◽  
Microwave Energy ◽  
Microwave Drying ◽  
Slice Thickness ◽  
Fresh Sample ◽  
Drying Time ◽  
Color Changes

In this study, changes in the drying kinetics, color change, and the energy consumption for microwave energy were investigated for Trabzon persimmon. In addition to that, the microstructure of the persimmon was also investigated by considering its thermal changes. It is important to be aware of the purpose of the drying process for determining the drying system. Results of this research showed that 460 W for 7 mm slice thickness depending on energy consumption, 600 W for 5 mm slice thickness depending on drying time, and 600 W depending on color changes were found as suitable drying processes depending on drying conditions. The effective diffusion values varied between 2.97 × 10−8 m2 s−1 and 4.63 × 10−6 m2 s−1. The activation energy values for 5 mm, 7 mm and 9 mm slice thickness were estimated as 32.82, 18.64, and 12.80 W g−1, respectively. The drying time and energy consumption decreased, whereas drying rate increased with an increase in the microwave energy. The number of pores increased compared to structure of fresh sample, and the pores got to be larger for 5 mm slice thickness as the power level increased. Results showed that the applied microwave energy had an important effect on the heating of the material and the change in the microstructure.

scholarly journals Microwave Drying for Production of Rehydrated Foods: A Case Study of Stink Bean (Parkia speciosa) Seed

2021 ◽  
Vol 11 (7) ◽  
pp. 2918
Author(s):  
Mudtorlep Nisoa ◽  
Karaket Wattanasit ◽  
Arlee Tamman ◽  
Yaowarat Sirisathitkul ◽  
Chitnarong Sirisathitkul
Keyword(s):  
Moisture Content ◽  
Water Temperature ◽  
Crude Protein ◽  
Freeze Drying ◽  
Low Pressure ◽  
Microwave Drying ◽  
Convective Drying ◽  
Drying Time ◽  
Moisture Contents

The potential of microwave drying in the production of rehydrated foods is demonstrated with stink beans (Parkia speciosa), smelly legumes of Africa and Asia. Compared to stink beans dehydrated by convective drying and freeze drying, the microwave products exhibit higher moisture contents, but the distribution of microscopic pores leads to good rehydration characteristics. Dehydration by microwave drying is also achieved within a much shorter period than that commonly used in freeze drying. The dehydration time can be further reduced to 6 h comparable to convective drying, and the moisture content is dropped to 11% by decreasing the pressure during microwave drying. However, the rehydration time remains around 65 min for products from both ambient and low-pressure (400 Pa) microwave drying. In rehydration, the period is successfully reduced to 30 min by increasing the water temperature to 70 °C. The results indicate that microwave drying does not affect the value of crude protein and rehydrated products are comparable to fresh stink beans. From these findings, the microwave drying technique is an applicable technology for both manufacturers and consumers, with acceptable drying time and rehydration characteristics.

Study on the Effect of Vacuum Microwave Drying on Quality of Okra

2013 ◽  
Vol 791-793 ◽  
pp. 132-136 ◽  
Author(s):  
Jing Yi Li ◽  
Zhen Hua Duan
Keyword(s):  
Microwave Power ◽  
Fracture Resistance ◽  
Colour Change ◽  
Microwave Drying ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Vacuum Degree ◽  
Vacuum Microwave ◽  
The Impact

The purpose of this paper is to investigate the impact of vacuum microwave drying on the quality of okra. The curves of colour, fracture resistance, rehydration ratio and the content of vitaminC were obtained at various drying times, vacuum degrees and microwave powers. Results showed that an increase in drying time and microwave power resulted in serious colour change when compare the dry product to fresh okra. However, the higher the vacuum, the slighter the colour changed. The fracture resistance decreased and the brittleness was good when drying time was increased to high level of 14min and 16min. Increasing vacuum degree also made fracture resistance decreased; rehydration ratio increased with the time and microwave power increased, but decreased if the time exceeds 14min. The rehydration ratio of okra is also affected by the vacuum degree, increasing which led the rehydration ratio increased significantly at the beginning of drying and then slowly; the greater the drying time and microwave power, the more lost of vitaminC, however, higher vacuum degree was found to be beneficial to save the vitaminC.

Experimental optimization of microwave drying zinc oxide leach residues by response surface methodology

2017 ◽  
Vol 6 (5) ◽  
Author(s):  
Weifeng Zhang ◽  
Junruo Chen ◽  
Guo Lin ◽  
Libo Zhang
Keyword(s):  
Zinc Oxide ◽  
Response Surface Methodology ◽  
Moisture Content ◽  
Response Surface ◽  
Multivariate Regression Analysis ◽  
Microwave Drying ◽  
Drying Time ◽  
Spectra Analysis ◽  
Dehydration Rate ◽  
Material Thickness

AbstractResponse surface methodology (RSM) and Box-Behnken design (BBD) were applied to experiment optimization of microwave drying zinc oxide leach residues (ZOLR). The effects of different factors involving temperature, drying time, material mass, material thickness and their interaction on moisture content and dehydration rate of ZOLR were investigated. Two second-order polynomial models for moisture content and dehydration rate of ZOLR were established by multivariate regression analysis. Analysis of variance shows that all independent variable and quadratic terms of the four factors have significant influence on moisture content and dehydration rate of ZOLR. The optimum drying conditions are as follows: temperature is 93.41°C, drying time is 15.9 min, sample mass is 77.91 g and material thickness is 17 mm. The predicted values of moisture content and dehydration rate were 10.98% and 1 g/min, which were close to experimental values 11±0.03% and 1±0.01 g/min under the optimal conditions. Infrared spectra analysis show that no chemical reactions took place in the process of microwave dying ZOLR and only a part of the absorbed water was removed in the sample.

Calculation of Moisture Content and Drying Rate during Microwave Drying

2013 ◽  
Vol 423-426 ◽  
pp. 746-749
Author(s):  
Samad Khani Moghanaki ◽  
Behnam Khoshandam ◽  
Mohammad Hosein Mirhaj
Keyword(s):  
High Temperature ◽  
Moisture Content ◽  
Microwave Power ◽  
Operating Temperature ◽  
Irradiation Time ◽  
Microwave Drying ◽  
Drying Rate ◽  
Microwave Method ◽  
Drying Process ◽  
Drying Time

Convectional dryerswork at high temperature and usually lead to loss of quality for sensitivebiomaterial products (especially in nutrition). In this way the researchersfound the microwave power more effective and suitable for drying processes. Someof microwave drying advantages include the following: short drying time, highquality of product, low operating temperature, flexibility in producing widerange of products and easier process controlling. The article calculated themoisture content and drying rate during drying process. Microwave power, holdertray speed, dimension of samples, irradiation time were considered; under theseconditions experiments were done and the results show that microwave method hasmore advantages as comparing with convectional methods.

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