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Mathematical Modeling of Fresh Green Pepper (Capsicum L.) Dried at Different Powers in Microwave Oven
2022
Fatma Coşkun Topuz
In this research, fresh green peppers were dried in a kitchen microwave oven at 600W, 700W and 800W. The drying curves of the study were compared with 5 different thin layer drying models in the literature. The changes in the moisture values of the samples against time were expressed graphically. R2, χ2 and RMSE values were used to determine the most suitable model for dried green peppers. Color values of fresh and dried peppers were determined. It was found that the L* and b* values of the dried peppers were lower, and the a* value was higher than the fresh green peppers. In addition, the rehydration rate of dried peppers was calculated. It was determined that the rehydration ability of the peppers decreased as the applied microwave power increased. For this reason, it was found that the peppers with the highest rehydration rate were those dried with 600W. Also, it was found that the most suitable model for all microwave powers among the five drying models was the Logarithmic drying model. It was calculated that the R2 values of the drying models ranged between 0.830-0.999, χ2 values between 0.0001- 0.4684 and RMSE values between 0.0014-0.6121. It was determined that the highest R2 (0.997-0.999), the lowest χ2 (0.0001-0.0002) values, and the lowest RMSE (0.0014-0.0035) values for all microwave powers belong to the Logarithmic drying model.
اظهر المزيد [+] اقل [-]Evaluation Data of Dried Vegetables and Fruits
2021
Necla Çağlarırmak | Ahmet Zeki Hepçimen
Drying is the process of removing of the water that has destroying effect in food products by evaporation and. Research project on the basis of direct sun drying and solar greenhouse. Basic operations research in food engineering, food chemistry, food quality control and toxicology has been established over such a broad spectrum. Subjects of investigation were in accordance with all of the values of dry matter basis. The study of dry matter and water activity values of each product (aw), direct sun drying, drying in the greenhouse. It was determined comparing nutrients of samples those were applied directly to the greenhouse and drying in the sun. Sampling patterns of research were explained as follow; tomatoes drying in the sun (external environment), and greenhouse, bell peppers in the greenhouse and drying in the sun, soaked raisins (sultanas) and not-soaked (raisin), sun-dried, sun-dried fig products directly. Nutrients of the samples such as; lycopene, thiamine (B1), riboflavin (B2), retinol (A), Pyridoxine (B6), ascorbic acid (C), folic acid, magnesium (Mg), potassium (K), sodium (Na), phosphorus (P), zinc (Zn), iron (Fe), copper (Cu) were quantitatively determined. The red pepper products, dried figs and dried grapes mycotoxin amounts were in safe levels, which had not created any hazard and risk for health. Red pepper and dried figs, total aflatoxins, (B1, B2, G1, G2), ochratoxin A (OTA) levels in raisin in the European Union is set well below the limits in terms of human health hazard and the risk factor has been identified.
اظهر المزيد [+] اقل [-]Kinetic and Mathematical Modeling of Drying of Asparagus officinalis in Different Drying Methods
2018
İlhami Okur | Cem Baltacıoğlu
Asparagus officinalis is a spring vegetable contains flavonoids, amino acid derivatives, glycolic acid, tyrosine, vitamins, saponins and essential oils and it has health benefits such as prevention of cancer, mutation, inflammation, and liver damage. The aim of this study is to investigate drying kinetics of Asparagus officinalis. According to R, χ2, RMSE and Error values, the model parameters at different temperatures (70°C, 80°C, 90°C), spear thickness (1 mm, 2 mm and 3mm), and microwave power (100 W, 200 W, and 300W) were compared. Midilli and Kucuk equation was found as the best equation to describe drying of Asparagus officinalis. R values of Midilli and Kucuk Equation changed between 0.8886 and 0.9989 for hot air drying and between 0.9568 and 0.9999 for a microwave drying.
اظهر المزيد [+] اقل [-]Evaluation of the Effects of Drying Methods on Post Aflatoxin Infection in Maize
2023
Erastus Dushimeyesu | Sylvestre Habimana | Fabrice Musana Rwalinda
The cultivation and the usage of maize have been significantly increased across all provinces of Rwanda. Nevertheless, the problem of aflatoxin contamination remains a major factor that renders them to be unfit for animal and human consumption. In this research, the effects of drying methods (sun drying, kitchen drying, dry shelter) post aflatoxin infection in maize were evaluated in Northern Rwanda. A randomized complete block design with four replications was used with maize variety (H628) with drying methods as the main plot. Maize samples were tested for aflatoxin using aflatest. In both seasons (2021 A and 2021 B) the aflatoxin results show that the aflatoxin infection levels were lower in maize dried with kitchen drying (1.4 ppb) compared to the samples dried with sun drying (1.6 ppb) and dry shelter (2.2). Also, it was seen that the three drying methods are good for reducing the aflatoxin infection levels lower than 10 ppb as standards limit for East African countries. The aflatoxin infection levels were found to be significant (≤10 ppb) as results of kitchen drying than sun drying and dry shelter methods. This research resulted that proper drying such as drying maize on kitchen fire (kitchen drying) produce the lower level of aflatoxin infection in maize.
اظهر المزيد [+] اقل [-]Comparison of Some Quality Parameters in Fresh and Dry Samples of Morus Rubra Fruits
2022
Ala Asi Mohammed Al-Salihi | Mehmetcan Olgaç | Emircan Dinçer | Hakan Polatcı | Onur Saraçoğlu
In Turkey, three species of mulberries, white (M. Alba), black (M. Nigra), and red-purple (M. Rubra) are grown commonly. These widely can be consumed fresh as well as dry. However, its rapid post-harvest decay raises major concerns about the sustainability of the fruit for both food and economic purposes. In this regard, besides the fresh consumption of black mulberry fruit, it can consume as dried it also offers an alternative way. In this study, it was aimed to compare some quality parameters in fresh and dry samples of Morus rubra fruits grown in Tokat. It was applied different temperatures to Morus rubra fruits that at collected in two different maturity levels (semi-ripe and full-ripe). In the drying process, mulberry fruits were dried in a hot air dryer at 40, 50, 60, and 70°C. Total phenol, Total phenol, total monomeric anthocyanin, total antioxidant capacity, colour values (L, a, b) chroma, hue (ho), and browning indices values will be measured in fresh and dried products. In addition, different mathematical models will be tried by constantly noting the weight drops of the products at certain time intervals and determining which mathematical model will best predict the drying kinetics
اظهر المزيد [+] اقل [-]Influence of Different Pretreatments on Hot air and Microwave-Hot Air Combined Drying of White Sweet Cherry
2021
Meric Simsek | Özge Süfer
Microwave (MW)-hot air (HA) combined drying was applied to white sweet cherries besides solely HA drying at 50, 60 and 70°C in the presence of citric acid, sucrose and freezing pretreatment in this study. Single power level of MW (90 W) was chosen, and drying behavior of all samples was modelled by using eleven thin layer equations. Two-term, rational and sigmoid models were the most suitable models for describing drying phenomena. Effective moisture diffusivities (Deff) ranged from 1.724×10-10 to 5.173×10-10 m2/s in HA drying and from 4.260×10-10 to 1.805×10-9 m2/s in MW-HA drying. Activation energies (Ea) were between 2.785 and 30.541 kJ/mol and 6.929 and 42.101 kJ/mol for HA and MW-HA drying techniques, respectively. Total color change (ΔE) levels of the outer surface of dried cherries were generally higher than the ones of inner surface. Freezing pretreatment had a comparably lower enhancing effect on the total phenolic content (TPC) of HA dried white sweet cherries compared to fresh sample. The TPC of freezing pretreated and HA dried at 50°C and HA dried at 70°C control samples were 1.481 ± 0.398 mg gallic acid equivalent (GAE)/g dry matter (DM) and 6.181 ± 0.012 mg GAE/g DM as the minimum and maximum, respectively. These values were determined as 4.183 ± 1.728 and 8.240 ± 0.502 mg GAE/g DM that were belonged to MW-HA dried at 50°C control and freezing pretreated MW-HA dried at 70°C samples in combined procedure, respectively.
اظهر المزيد [+] اقل [-]Determination of Drying Characteristics, Energy Consumption and Quality Values of Black Mulberry Fruit (Morus nigra L.) Dried Under Different Conditions
2021
Muhammed Taşova | Hakan Polatcı | Adil Koray Yıldız
There are about 68 types of mulberry fruit with a wide ecological production area. Different mulberry species are grown in large fields in Turkey. Mulberries are largely dried-consumed, but sometimes they are used as fruit juice. In this study, black mulberry fruit was collected in two different ripening levels (semi-ripe and full-ripe) and oven-dried at 50, 60 and 70°C drying temperatures. Initial moisture contents of semi-ripe and full-ripe fruits were determined as 86.74% and 82.95%, respectively. Fruits were dried to have final moisture levels of 10-15%. Drying duration, drying models, effective diffusion, activation energy, specific energy consumption, color parameters and chemical properties of dried fruits were examined and the effect of ripening levels and drying temperatures were investigated. In terms of drying duration, while full-ripe fruits dried in a shorter time, effective diffusion, activation energy and specific energy consumption values were found to be higher than semi-ripe fruits. In terms of color parameters, semi-ripe fruits are recommended to be dried at 50 or 60°C drying temperatures and full-ripe fruits should be dried at 50°C drying temperature for better preservation of color parameters. On the other hand, a common proper drying temperature could not be identified for acidity (pH), water soluble dry matter and titratable acidity.
اظهر المزيد [+] اقل [-]The Effect of Vacuum Impregnation Pretreatment on Air-Drying Kinetics of Pears
2020
Şeyma Uysal | Fikret Pazır
The aim of this study was to examine the drying kinetics of pears (Pyrus communis L.) with and without vacuum impregnation and under the different temperature by using tray dryer. Vacuum impregnation were applied to the the pears (15 mm thickness, 65 mm outer and 20 mm inner dimensions respectively) with the conditions of 50⁰ Brix impregnation solution concentration, 225 mbar vacuum pressure and 45 min vacuum time. Drying process was carried out at temperatures of 55, 65 and 75°C. Drying time of non-vacuum impregnated pears was determined 640, 500 and 340 min and vacuum impregnated pears was determined 700, 540 and 560 min respectively. Page, Exponential, Henderson and Pabis, Diffusion Approach were examined for testing the drying kinetics. Experimental values are in accordance with the expected values resulted Page and Difussion models of with and without vacuum impregnated pears. Effective diffusion coefficient (Deff) was varying 2.74×10-11 to 7.31×10-11 m2/s. m2/s with respect to the drying temperatures. The activation energy for the non-vacuum impregnated and vacuum impregnated pears was 32.93 kJ / mol and 24.25 kJ / mol, respectively.
اظهر المزيد [+] اقل [-]The Effect of Drying Methods on Color and Chlorophyll Content of Parsley Leaves
2019
Ilknur Alibas | Mahrukh Parveez Zia | Aslihan Yilmaz
Parsley leaves (Petroselinum crispum L.) weighing 100 ± 0.09 g were dehydrated from moisture content of 82.24 ± 0.07% to 10.01 ± 0.02 % (wet basis) using the microwave (MD), convective (CD), solar oven (SOD), sun (SD) and natural (ND) drying. Drying in MD, CD, SOD, SD, and ND was completed at 18±1.15, 61±0.58, 255±10, 330±5.29, and 1530±11.55 min, respectively. The energy consumption of MD and CD was measured as 0.213±0.009 and 0.427±0.015 kWh, respectively. In microwave drying, 700 W microwave output power was applied while convective drying was used with 50°C temperature and 1m/s air velocity. The sun and solar oven drying processes were carried out under the same conditions at the same time. The average temperature of the system during the solar oven drying was 81.7±1.5°C whereas the airflow in the system was 0.5 m/s. The data obtained from the experiments were also modeled using twelve different thin-layer drying equations, and thus the theoretical data were obtained. According to these theoretical data, the best model in the microwave and natural drying was Alibas’s equation while the most suitable model in the solar and convective drying was modified Henderson and Pabis’s model. On the other hand, it was seen that the best model in the solar oven drying was the Page equation. As a result, considering both quality and drying parameters, it was determined that MD and SOD were the most suitable method for drying of parsley leaves.
اظهر المزيد [+] اقل [-]Effects of Different Drying Methods on Modelling, Energy Consumption and Final Quality of Tomato (Lycopersicum esculentum Mill)
2019
Hakan Polatcı | Yücel Erkmen
Agricultural developments mostly depend on rapidly increasing world population. Tomato is a highly nutritious vegetable. Post-harvest technologies are often applied to prolong the consumption periods of tomato. Drying is one of the oldest methods of conservation. In this study, five different drying methods (oven drying, vacuum oven drying, sensitive drying, shaded-open atmosphere drying and sun drying) was used. Drying processes were carried out with dryers at 55°C, 60°C, 65°C and 70°C temperatures. All drying trials were performed in three replications. Drying performance (drying duration, final moisture content), drying kinetics, colour analysis, energy consumption, chemical analyses were performed for all drying methods. Fresh samples reached to desired moisture contents in 20-300 hours. To define time-dependent changes in moisture contents, Page, Logarithmic and Midilli-Küçük equations were used. Page equation yielded the worst estimations. There were not significant differences in “a” redness values of fresh samples, 65-70C of oven dryer and all temperatures of sensitive dryer. Sensitive dryer yielded the closet pH values to fresh samples. Based on current findings, it was concluded that oven drying, and sensitive drying were suitable for drying Selinus tomato variety.
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