scholarly journals Coupling of microwave radiations to convective drying for improving fruit quality

2018 ◽  
Author(s):  
Neila Bahloul ◽  
M. A. Balti ◽  
M. S. Guellouze ◽  
Nabil Kechaou
Keyword(s):  
Microwave Radiation ◽  
Power Level ◽  
Bound Water ◽  
Microwave Oven ◽  
Microwave Drying ◽  
Convective Drying ◽  
Heat Temperature ◽  
Red Color ◽  
Variable Condition

The present study aims to find the best drying method to minimize the duration of the operation while respecting the nutritional value of the product. Experiments of convective drying and microwave radiation were respectively carried out with a convective dryer (heat temperature: 65 °C and air velocity: 1.3 m/s) and a microwave oven (power level: 100 W and frequency: 2450 MHz). Six coupling tests between the convective drying and microwave radiation were conducted. The only variable condition is the time output of tomatoes from the convective dryer or the microwave oven corresponding to an intermediate mass ratio (IMR) 0.5, 0.4 and 0.3. The microwave drying removes the bound water faster than convective drying. This explains the observed time savings due to convection-microwave and microwave-convection combined drying. The combination of convection drying and microwave drying to an IMR 0.5 preserved better the red color and the antioxidants of the tomato. Thus, the convection–microwave combined drying (IMR 0.5) proved most suitable for preserving the quality of tomatoes. Keywords: convective drying; microwave; coupled drying; color. 

scholarly journals Determination of Various Drying Methods’ Impact on Odour Quality of True Lavender (Lavandula angustifolia Mill.) Flowers

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2900 ◽  
Author(s):  
Łyczko ◽  
Jałoszyński ◽  
Surma ◽  
García-Garví ◽  
Carbonell-Barrachina ◽  
...  
Keyword(s):  
Solid Phase ◽  
Microwave Drying ◽  
Convective Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Sensory Panel ◽  
Lavandula Angustifolia ◽  
Preservation Method ◽  
Vacuum Microwave

True lavender flowers (Lavandula angustifolia Mill.) is a critical source of essential oils and a flavouring agent used in numerous industries like foods, cosmetics and pharmaceuticals. Its main volatile constituents are linalool and linalyl acetate, which are commonly considered as main odour-active constituents (OACs). Nevertheless, the quality of true lavender flowers is highly dependent on its post-harvest treatment, mainly the preservation method. Recognising that drying is the most frequently used preservation method, the influence of various drying methods, including convective drying (CD) at 50, 60 and 70 °C, vacuum-microwave drying (VMD) with powers 240, 360 and 480 W and combined convective pre-drying at 60 °C followed by vacuum-microwave finish-drying with power 480 W (CPD-VMFD), on the quality of true lavender flowers was verified. The evaluation of influence was carried out by HS-SPME(HS, solid-phase microextraction), GC-MS, GC-MS-O (gas chromatography–mass spectrometry–olfactometry) techniques. Moreover, the sensory panel has assessed the sample odour quality. As a result, the optimal drying methods regarding the requirements for products were established. Overall, for total essential oil recovery, CD at 50 °C is the optimal drying method, while for odour quality concerning the sensory panel evaluation, VMD with power 360 W combined CPD-VMFD and CD at 50 °C is the optimal drying method.

scholarly journals Qualitative Traits of Dry Rose Flowers ‘Taj Mahal’ as Influenced by Dehydration Methods

2021 ◽  
pp. 173-182
Author(s):  
M. Narjinary ◽  
Arpita Mandal Khan ◽  
S. Maitra ◽  
I. Sarkar ◽  
P. K. Pal
Keyword(s):  
Silica Gel ◽  
Room Temperature ◽  
Power Level ◽  
Microwave Oven ◽  
Carotenoid Content ◽  
Oven Drying ◽  
Hot Air ◽  
Sensory Score ◽  
Taj Mahal

Aims: To optimize drying technique for the popular Dutch rose cultivar, Taj Mahal, by evaluating different drying methods and appraising the physical, biochemical and sensory quality of the product. Study Design: Completely Randomized Design. Place and Duration of Study: Department of Floriculture, Medicinal and Aromatic Plants, Faculty of Horticulture, Uttar Banga Krishi Viswavidyalaya, during 2019-2020 Methodology: Flowers of rose cultivar ‘Taj Mahal’, at their prime beauty i.e., half-opened bud stage, were subjected to embedded drying in silica gel at six different conditions viz. at room temperature (T1), in hot air oven at 45°C, (T2) and at 60°C, (T3) in micro-wave oven at 100% power level (T4), 80% power level (T5) and at 60% power level (T6). The quality of the ensuing dehydrated flowers was judged with respect to colour, weight, volume shrinkage and anthocyanin and carotenoid contents. Temperature during drying and time to reach optimum dehydrated condition under different drying techniques were recorded. Sensory evaluation for the quality of the products was done after six months of storage. Results: The time taken for optimum drying ranged from 120 hours in case of room temperature drying (25.1°C) to 3 minutes in microwave oven on high power i.e., 100% (130.4°C). Significant variation in final weight of the product was recorded between 18.34% to 28% of the fresh weight. Minimum shrinkage (42.85%) was noted in room drying (T1) and hot air oven drying at 60°C (43.53%). Maximum anthocyanin concentration (3.528 mg/g) was recorded in flowers dried at room temperature, whereas, minimum among the dried flowers, was recorded in microwave oven drying at 100% power level (1.439 mg/g). Maximum Carotenoid content (16.780 µg/g) was recorded in flowers dried in hot air oven at 45°C. Out of six treatments in the present study, maximum sensory score (30.38 out of 36) was gathered by T2, which was at par with T1 and T5. Conclusion: Dehydrating ‘Taj Mahal’ rose flowers by embedding in silica gel and drying under room temperature (25°C) for 120 hours or hot air oven at 45°C for 27.5 hours or microwave oven at 80% power level for 3.5 minutes can be recommended for commercial dry flower production.

scholarly journals Potential of microwave drying technology for increase drying rate and physical quality of kaffir lime (Citrus hystrix DC) leaves

2021 ◽  
Vol 924 (1) ◽  
pp. 012045
Author(s):  
F Su’aidah ◽  
I Taruna
Keyword(s):  
Moisture Content ◽  
Power Level ◽  
Preference Test ◽  
Color Difference ◽  
Microwave Drying ◽  
Drying Rate ◽  
Physical Quality ◽  
Oven Drying ◽  
Drying Rates

Abstract The effects of microwave power on microwave drying rates and the physical quality of kaffir lime leaves were studied. Three power levels were used in this study, high (723 watts), medium (537 watts), and low (420 watts). The moisture content, drying rate, color (L, a, b), and organoleptic parameters of each power level will be compared with the oven drying method (60°C). The result shows that the final moisture content of the high, medium, and low power of microwave drying are 6.06, 4.26%, and 6.16%db respectively, which is lower than oven drying, 16.62%db. Besides, the drying rate of microwave drying is 26.39-48.71%db/minute, higher than oven drying 0.32%db/minute. Dried kaffir lime leaves with medium level power (537 watt) has the lowest color difference (ΔE = 1.0 ± 0.29) compared to fresh leaves. While, the color and aromatic preference test dried kaffir lime leaves by microwave drying was preferable than oven drying.

scholarly journals Comparative Study of the Effect of Five Drying Methods on Bioactive Compounds, Antioxidant Potential and Organoleptic Properties of Zingiber officinale (Ginger) Rhizome

2021 ◽  
pp. 22-33
Author(s):  
Yves M. T. Tientcheu ◽  
Ruth E. K. Dibacto ◽  
Ferdinand L. E. Edoun ◽  
Elsa F. K. Matueno ◽  
Alex D. K. Tchuenchieu ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Power Level ◽  
Zingiber Officinale ◽  
Hot Water ◽  
Antioxidant Potential ◽  
Microwave Drying ◽  
Drying Methods ◽  
Significant Difference ◽  
Ginger Rhizome

Aims: Ginger (Zingiber officinale) is one of the most popular and widely used spice, known for its health benefits. This study aimed at assessing the potential impact of a Handcrafted dryer (HCD) on the quality of ginger in comparison to the most common drying methods. Methodology: Fresh ginger originating from 2 regions were dried using the following techniques: HCD; Air Drying (AD); Ventilator Oven (VO) at 50°C, 60°C and 80°C; Freeze Drying (FD) and Microwave drying (MD) at 700 and 900 W) methods. Dried products were ground and infused in hot water and the total flavonoid contents, and antioxidant potential through different mechanisms (DPPH radical, FRAP and TAC assays) as well as the sensory properties of the infusions were assessed. Results: TFC of the samples significantly varied with regard to the origin of the Ginger. Infusions deriving from the dried ginger from HCD and VO at 80°C exhibited the highest TPC, TFC and antioxidant activities. While the rise of temperature with VO led to an increase of TPC, it was rather a decrease that was observed with the rise of microwave power level but which did not have a significative effect on the antioxidant potential. No significant difference was noticed in the acceptance of infusions by consumers except MD samples, which received the lowest score by panelists. Conclusion: Heat-based processes appears to be useful in the optimization of the nutritional value of dried ginger, and HCD appropriate for farmers as it is easy and not expensive to put into practice.

scholarly journals Evaluasi Pengaruh Volume Minyak Simplah Terhadap Kualitasnya Pada Pemanasan Menggunakan Energi Mikrowave

2020 ◽  
Vol 13 (1) ◽  
pp. 13-23
Author(s):  
Rita Khathir ◽  
Mustaqimah Mustaqimah ◽  
Raida Agustina ◽  
Sri Hartuti ◽  
Azmil Azmil
Keyword(s):  
Fatty Acids ◽  
Microwave Heating ◽  
Power Level ◽  
Oil Quality ◽  
Coconut Oil ◽  
Microwave Oven ◽  
Virgin Coconut Oil ◽  
Before And After ◽  
Temperature Water

Abstract. Minyak simplah adalah produk lokal Aceh dari proses fermentasi kelapa yang mempunyai manfaat seperti minyak kelapa murni (VCO). Tujuan penelitian ini adalah untuk mengetahui pengaruh pemanasan energi mikrowave terhadap kualitas minyak simplah berdasarkan variasi volume minyak. Metode yang dilakukan adalah memanaskan minyak simplah dalam mikrowave oven frekuensi 2,450 MHz selama 60 detik dengan energi 800W pada variasi volume yakni 20, 40,dan 60 ml, dengan 3x ulangan. Pengamatan dilakukan terhadap suhu, kadar air, derajat keasaman, asam lemak bebas, bilangan peroksida dan warna. Hasil penelitian menunjukkan bahwa perlakuan variasi volume minyak pada pemanasan mikrowave selama 60 detik meningkatkan suhu minyak secara signifikan, namun perlakuan tersebut tidak memberikan pengaruh nyata terhadap kadar air, pH, asam lemak bebas dan bilangan peroksida. Kualitas minyak simplah sebelum dan setelah pemanasan dengan mikrowave belum memenuhi standar sehingga penelitian lanjutan sangat diperlukan untuk mengkaji kemungkinan peningkatan kualitas minyak menggunakan energi mikrowave dengan memperlama waktu pemanasan.The Influence of Oil Simplah Volume to Its Quality under Microwave HeatingAbstract. The simplah oil, contained a lot of benefits as virgin coconut oil (VCO), is traditionally produced during fermentation of coconut by Acehnese. The purpose of this study is to determine the influence of microwave heating on the simplah oil quality based on the variation of its volume. The study was conducted by heating the simplah oil by using a microwave oven at frequency of 2.450MHz for 60s at power level 800W under the variation of oil volume i.e. 20, 40, and 60 ml in three replications. The parameters observed were temperature, water content, degree of acidity, free fatty acids, peroxide number and color. Results showed that the variation of oil volume after microwave heating had significant effect on temperature, but did not significantly influence the rest parameters. Since the quality of simplah oil before and after treatment did not meet the standard yet, it is very important to conduct the further study by extending the exposure time of the oil under microwave heating.  

scholarly journals Convective and microwave drying of onion slices regarding texture attributes

2018 ◽  
Vol 36 (No. 2) ◽  
pp. 187-193 ◽  
Author(s):  
Süfer Özge ◽  
Demir Hande ◽  
Sezer Seda
Keyword(s):  
Profile Analysis ◽  
Power Level ◽  
Microwave Drying ◽  
Convective Drying ◽  
Effective Power ◽  
Brine Solution ◽  
Texture Profile ◽  
Allium Cepa L ◽  
Pre Treatment ◽  
Texture Attributes

The textural characteristics of onion slices (Allium cepa L.) of 3- and 7-mm thicknesses undergoing convective drying (50, 60, and 70°C) and microwave drying (68, 204, and 340 W real effective power levels) techniques with or without pre-treatment were evaluated. Pre-treatment consisted of dipping into brine solution (8% NaCl). Texture profile analysis at 25% compression was applied and hardness, chewiness, springiness and gumminess values of onions were recorded. As the temperature (convective) or real effective power level (microwave) increased, the hardness and chewiness levels of dried onion slices were enhanced. The values of these parameters were higher in response to microwave application compared to convective drying. Pre-treatment had an additive effect on hardness and chewiness in convectively dried samples. Maximum springiness was observed in response to convective drying. Dipping in brine solution generally caused no significant changes among slices of the same thickness (P < 0.05). With respect to gumminess, the results were quite similar to those for hardness and chewiness, i.e., markedly higher in microwave-dried onions.

scholarly journals Effect of microwave radiation on seed viability, survival of Aspergillus niger van Tieghem and oil quality of oilseeds crops canola, soybean and safflower

2016 ◽  
Vol 107 (1) ◽  
pp. 73
Author(s):  
Ahad MOTALLEBI
Keyword(s):  
Aspergillus Niger ◽  
Microwave Radiation ◽  
Radiation Power ◽  
Power Level ◽  
Oil Quality ◽  
Negative Relationship ◽  
Seed Viability ◽  
Treatment Technique ◽  
Environmental Treatment

The effect of microwave's radiation on seed viability of three different oilseed crops, spores of <em>Aspergillus niger </em>and quality of extracted oil from treated seeds over various exposure times was evaluated. The seeds were exposed to 2450 MHz. at five different power levels of 0, 100, 200, 400, 600 and 800 W for two exposure times of three and five minutes. At a given time, a direct negative relationship between seed viability and microwave's radiation power level was detected. Substantial variation in the lethality of tested seeds to microwave's power levels was apparent in the fiducial limits of the estimated LD<sub>50 </sub>values in probit analysis approach. A similar trend of <em>A. niger</em> spores’ susceptibility to microwave radiation was detected. The microwaves' radiation and exposure time did not impact one another and a significant interaction was not detected. Short term fungal infection did not cause substantial quantitative and qualitative damage to the oilseeds. The oil quality was generally unaffected by microwave radiation and fungal infestation for tested oilseeds. Moreover, microwave radiation decreased seed germination percentage and vigor index. The microwave radiation could provide an effective and friendly environmental treatment technique for improving the dietary consumption of the oil in any seed disinfestation program.

scholarly journals Performa dan Analisis Konsumsi Energi Pengeringan Rumput Laut Menggunakan Energi Gelombang Mikro

2020 ◽  
Vol 15 (1) ◽  
pp. 85
Author(s):  
Arif Rahman Hakim ◽  
Wahyu Tri Handoyo ◽  
Adrianto Widi Prasetyo
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Specific Energy ◽  
Power Level ◽  
Effective Diffusion ◽  
Specific Energy Consumption ◽  
Microwave Oven ◽  
Moisture Ratio ◽  
Microwave Drying ◽  
Drying Rates

Pengeringan menggunakan energi gelombang mikro menjadi alternatif agar pengeringan berjalan lebih cepat tanpa terpengaruh kondisi cuaca. Namun performa dan efisiensi energi dalam mengeringkan rumput laut belum diketahui. Tujuan penelitian ini adalah untuk mengetahui performansi pengeringan rumput laut menggunakan energi gelombang mikro (microwave) dan analisa konsumsi energinya. Metode yang digunakan ialah mengeringkan rumput laut segar dalam oven gelombang mikro secara batch. Dalam proses pengeringan dilakukan variasi level daya (400, 500, 600 watt) ke dalam oven gelombang mikro dan variasi ketebalan rumput laut (3, 5, 7 cm). Parameter yang diamati meliputi rasio kadar air (moisture ratio/MR), laju pengeringan (g/menit), difusi efektif air/Deff (mm2/detik), specific energy consumption/SEC (J/g H2O) dan efisiensi energi (%). Hasil penelitian menunjukkan, level daya magnetron 600 watt menghasilkan MR terendah (0,19), laju pengeringan tertinggi (13,15 g/menit) dan Deff tertinggi (2,28 x 10-2 mm2/detik). Rumput laut ketebalan 3 cm memperoleh MR terendah (0,05), laju pengeringan tertinggi (6,42 g/menit) dan Deff tertinggi (9,42 x 10-2 mm2/detik). SEC pengeringan sebesar 4,38-4,51 J/g H2O dan efisiensi energi 22,56-23,42% untuk level daya 400-600 watt. Perbedaaan level daya tidak memberikan pengaruh signifikan terhadap SEC dan efisiensi. Sedangkan variasi ketebalan rumput laut antara 3 cm dan 7 cm memberi hasil yang berbeda. SEC terendah diperoleh pada perlakuan rumput laut tebal 3 cm yaitu 2,96 J/g H2O sementara efisiensi tertinggi pada rumput laut dengan tebal 5 cm yaitu 22,93%.Oleh karena itu pengeringan rumput laut menggunakan energi gelombang mikro dengan level daya 600 watt dan ketebalan 3 cm menghasilkan performasi dan konsumsi energi yang lebih baik. AbstractMicrowave drying becomes alternative method to get faster process without being influenced by weather. However performance and energy efficiency of microwave drying for seaweed are still unknown. This research aims to find out performance of seaweed drying in microwave oven as well as energy consumption analysis. The method used was drying seaweed in microwave oven. Seaweed drying was conducted at various power level (400, 500, 600 watt) and thickness of seaweed (3, 5, 7 cm). Observed parameters were moisture ratio/MR, drying rates (g/min), effective diffusion/Deff (mm2/s), specific energy consumption/SEC (J/g H2O) and energy efficiency (%). Result of research showed that power level, 600 watt of magnetron produced lowest MR (0,19), highest drying rate and Deff i.e 13.15 g/min and 2.28 x 10-2 mm2/s respectively. Seaweed 3 cm thickness achieved lowest MR (0.05), highest drying rates 6.42 g/min and Deff 9.42 x 10-2 mm2/s. SEC of drying were 4.38-4.51 J/g H2O while energy efficiency were 22.56-23.42 % for 400-600 watt. Differences of power level have not given significant effect to SEC and efficiency values. Whereas differences of seaweed thickness between 3 cm and 7 cm have given significant effect. Seaweed in 3 cm thickness resulted in the lowest SEC i.e 2.96 J/g H2O, however, the highest efficiency energy was 5 cm thickness i.e 22.93%. Therefore drying seaweed utilize microwave energy of 600 watt power level and 3 cm thickness generated better performance and energy consumption.

scholarly journals Application of microwaves in the convective drying of ceramic

2018 ◽  
Author(s):  
Kinga Rajewska ◽  
Andrzej Pawłowski
Keyword(s):  
Strength Test ◽  
Microwave Drying ◽  
Convective Drying ◽  
Scale Analysis ◽  
Strength Tests ◽  
The Moment ◽  
Cylindrical Samples ◽  
Brazilian Method ◽  
Drying Curve

The paper demonstrates microwave and convective drying processes in different combinations of kaolin cylindrical samples in laboratory scale. Analysis of the kinetics and sample temperature evolution show that the moment of application and electromagnetic field duration have the biggest influence on characteristics of the drying curve and quality of dried material. Dried samples were subjected to strength tests using the Brazilian method in order to determine the relation between its quality and different drying programs. Keywords: ceramic, convective drying, microwave drying, strength test. 

Microwave Drying Characteristics of Kidney Beans and the Effect of Different Microwave Powers on the Dried Quality of Kidney Beans

2013 ◽  
Vol 781-784 ◽  
pp. 1469-1473
Author(s):  
Jin Shuang Wang ◽  
Yong Sen Xiong
Keyword(s):  
Energy Consumption ◽  
Sensory Quality ◽  
Power Level ◽  
Microwave Drying ◽  
Drying Characteristics ◽  
Second Stage ◽  
Dehydration Rate ◽  
Kidney Beans ◽  
Two Factors

The experiments are designed to study influence of different loading mass and microwave power on drying kidney beans. A conclusion is obtained that all the two factors significantly affect dehydration and power consumption. When the power level increased, the dehydration rate increased while the drying energy consumption decreased. The same water loss will consume more energy when the moisture content is less than about 300 (w%,d.b.). The sensory quality of the dried samples decreased with increase first-stage of power and second-stage power when the power was more than 1.6kW/kg and 1.0kW/kg.

Sign in / Sign up

Export Citation Format

Share Document