scholarly journals Drying characteristics and quality of lemon slices dried undergone Coulomb force assisted heat pump drying

2018 ◽  
Author(s):  
S. K. Chin ◽  
Y. H. Lee ◽  
B. K. Chung
Keyword(s):  
Vitamin C ◽  
Heat Pump ◽  
Coulomb Force ◽  
Total Phenolic ◽  
Drying Rate ◽  
Total Energy Consumption ◽  
Drying Time ◽  
Drying Characteristics ◽  
Heat Pump Drying

In this research, a Coulomb force assisted heat pump (CF-HP) dryer was invented for the purpose of improving the drying characteristics and product quality of biomaterials. As compared to heat pump drying alone, the assistance of Coulomb force in heat pump dryer enhanced the drying rates and effective moisture diffusivity of lemon slices up to 26%, which eventually shortened the total drying time to 40%. This saved the total energy consumption of HP drying by 31.5%. High retention of vitamin C and TPC were also found in CF-HP dried slices due to mild drying temperature and fast drying rate. Keywords: Coulomb force; Heat pump drying; Drying rate; Vitamin C; Total Phenolic Content (TPC).  

scholarly journals Drying characteristics and quality evaluation in convective drying of Cissus quadrangularis Linn.

2018 ◽  
Vol 192 ◽  
pp. 03041
Author(s):  
Setthawat Thanimkarn ◽  
Ekkapong Cheevitsopon ◽  
Jiraporn Sripinyowanich Jongyingcharoen
Keyword(s):  
Quality Evaluation ◽  
Moisture Diffusivity ◽  
Convective Drying ◽  
Total Phenolic ◽  
Drying Time ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Cissus Quadrangularis ◽  
Lower Bulk Density

This study aimed to investigate the effect of drying temperature (40, 60, 80, and 100°C) on drying characteristics of Cissus quadrangularis Linn. (CQ) undergoing convective drying. Physical properties and phytochemicals of the dried CQ were also evaluated. CQ with the thickness of 5 mm was dried from about 10 to 0.1 g water/g dry matter. The results showed that increasing drying temperature increased drying rate (DR) and effective moisture diffusivity (Deff) and consequently decreased drying time. The drying time, maximum DR, and Deff were in the ranges of 85-1920 min, 0.0059-0.0248 g water/g dry matter·min, and 0.7302-9.1281×10-9 m2/s, respectively. Lower drying temperature could preserve quality of the dried CQ. Decreasing drying temperature resulted in greener and lower bulk density and shrinkage. The greatest total phenolic content (TPC) and quercetin content were obtained by drying the CQ at 60°C.

scholarly journals ENERGY SAVING TECHNOLOGIES FOR DRYING OF HEAT-SENSITIVE MATERIALS

2019 ◽  
Vol 41 (4) ◽  
pp. 5-12
Author(s):  
Yu.F. Sniezhkin ◽  
Xiong Jian ◽  
D.M. Chalaev ◽  
М.М. Ulanov ◽  
N.О. Dabizha
Keyword(s):  
Heat Pump ◽  
Thermal Conditions ◽  
High Energy ◽  
Heat Pumps ◽  
Convective Drying ◽  
Drying Time ◽  
Long Duration ◽  
Heat Pump Drying ◽  
Promising Development

The promising development of convective drying of thermolabile materials is the use of heat pumps. The main advantages of heat pump drying are high energy efficiency, controlled thermal conditions of drying, high quality of the final product, environmental cleanliness of the technological process.The processes of air treatment in convective heat pumps with different schemes of dehydration of the drying agent are considered in the paper. As determined, the main disadvantage of heat pump drying is the long duration of the process due to the drying temperature limitation not exceeding 50-60 °C, and the dried material is not initially heated above the temperature of the wet thermometer, which is 25-30 °C. The possibility of using infrared radiation in combination with a heat pump was studied to intensify the process of low-temperature convective drying. It is shown that the combination of heat pump and infrared drying processes provides a synergistic effect, which leads to a shorter drying time and reduced energy consumption, as well as to obtain better quality dried products.

scholarly journals Determination of Sliced Pineapple Drying Characteristics in A Closed Loop Heat Pump Assisted Drying System

2018 ◽  
Vol 7 (1) ◽  
pp. 35 ◽  
Author(s):  
Cüneyt Tunçkal ◽  
Salih Coşkun ◽  
İbrahim Doymaz ◽  
Ernes Ergun
Keyword(s):  
Heat Pump ◽  
Closed Loop ◽  
Type Equation ◽  
Drying Rate ◽  
Diffusivity Coefficient ◽  
Axial Fan ◽  
Drying Time ◽  
Drying Characteristics ◽  
Drying System

Pineapple (Ananascomosus) slices were dried with the aid of a heat pump assisted dryer (HPD). During this process, air velocity was kept constant at 1m/s, while air temperatures were changed as 37°C, 40°C and 43°C. The drying air was also circulated by using an axial fan in a closed cycle and fresh air was not allowed into the system. The drying rate and drying time were significantly influenced by drying temperature. It was observed that drying temperatures had significant effects on the drying rate and drying time. During the conduct of the study, pineapple slices were dried at 37, 40 and 43°C for 465, 360 and 290 min, respectively. The specific moisture extraction ratio (SMER) values were observed to change as drying temperatures were changed. The drying rate curves indicated that the whole drying process occurred in the falling rate period. Seven well-known thin-layer models (Lewis, Henderson &Pabis, Logarithmic, Page, Midilli & Kucuk, Weibull and Aghbashlo et al.) were employed to make a prediction about drying kinetics through nonlinear regression analysis. The Midilli & Kucuk and Aghbashlo et al. models were consistent with the experimental data. Fick’s second law of diffusion was used to determine the moisture diffusivity coefficient ranging from 3.78×10–9 to 6.57×10-9  m2/s the each of the above mentioned temperatures. The dependence of effective diffusivity coefficient on temperature was defined by means a fan Arrhenius type equation. The activation energy of moisture diffusion was found to be 75.24kJ/mol. Article History: Received: July 18th 2017; Received: October 27th 2017; Accepted: January 16th 2018; Available onlineHow to Cite This Article: Tunçkal, C., Coşkun, S., Doymaz, I. and Ergun, E. (2018) Determination of Sliced Pineapple Drying Characteristics in A Closed Loop Heat Pump Assisted Drying System. International Journal of Renewable Energy Development, 7(1), 35-41.https://doi.org/10.14710/ijred.7.1.35-41

scholarly journals EFEK PERLAKUAN LOW TEMPERATURE LONG TIME BLANCHING TERHADAP KARAKTERISTIK CABAI KERING

Agrika ◽  
2020 ◽  
Vol 14 (2) ◽  
pp. 140
Author(s):  
Nunik Lestari ◽  
Ratnawaty Fadilah ◽  
Andi Muhammad Akram Mukhlis ◽  
Samsuar Samsuar
Keyword(s):  
Low Temperature ◽  
Vitamin C ◽  
Moisture Content ◽  
Drying Rate ◽  
Drying Process ◽  
Direct Sunlight ◽  
Drying Characteristics ◽  
Long Time ◽  
Positive Effect

ABSTRAKProses pretreatment sebelum cabai dikeringkan berperan penting untuk menghasilkan cabai kering dengan kualitas lebih baik. Penelitian ini bertujuan untuk melihat efek pretreatment LTLT blanching sebelum proses pengeringan terhadap karakteristik pengeringan dan kualitas cabai kering. Penelitian dilaksanakan dengan 12 perlakuan, yaitu pengeringan dengan pretreatment LTLT blanching pada suhu 60, 70, dan 80 oC masing-masing selama 10, 15, dan 20 menit, lalu pengeringan dengan pretreatment HTST blanching pada suhu 100 oC selama 10 detik, pengeringan tanpa pretreatment blanching di dalam alat pengering ERK, serta pengeringan tanpa pretreatment blanching di bawah sinar matahari secara langsung. Hasil penelitian menunjukkan pengaruh positif pretreatment LTLT blanching dapat mempercepat laju pengeringan, menghasilkan cabai kering dengan kadar air rendah sesuai standar SNI, menghasilkan warna cabai kering yang menarik, serta memiliki kandungan vitamin C lebih tinggi dibanding cabai kering tanpa pretreatment blanching. Secara keseluruhan, perlakuan pretreatment LTLT blanching pada suhu 80 oC selama 20 menit adalah perlakuan terbaik dari penelitian ini dengan kadar air akhir 8.17%, laju pengeringan yang tercepat, kandungan vitamin C sebesar 0.96%, dan warna yang menarik. ABSTRACTThe pretreatment before drying chilies plays an important role to produce better quality of dried chilies. This study aims to determine the pretreatment effect of LTLT blanching before the drying process on the drying characteristics and quality of dried chilies. This research was carried out with 12 treatments, namely drying with LTLT blanching pretreatment at 60, 70, and 80 oC for 10, 15, and 20 minutes respectively, then drying with HTST blanching pretreatment at 100 oC for 10 seconds, drying without pretreatment blanching in the ERK dryer, and drying without pretreatment blanching in direct sunlight. The results show the positive effect of LTLT blanching pretreatment which can accelerate the drying rate, produce dry chilies with low water content according to SNI standards, produce an attractive dried chilies color, and have a higher vitamin C than dried chilies without blanching pretreatment. Overall, pretreatment with LTLT blanching at 80 oC for 20 minutes is the best treatment in this study with a final moisture content of 8.17%, the fastest drying rate, a vitamin C content of 0.96%, and an attractive color. 

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 The influence of ethanol on the convective drying and on the nutritional quality of dekopon slices

2018 ◽  
Author(s):  
Ronaldo Elias de Mello-Júnior ◽  
Nathane Silva Resende ◽  
Jefferson Luiz Gomes Corrêa ◽  
Leila Aparecida Salles Pio ◽  
Elisângela Elena Nunes Carvalho
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Vitamin C ◽  
Nutritional Quality ◽  
Quality Parameters ◽  
Nutritional Composition ◽  
Convective Drying ◽  
Total Phenolic ◽  
Drying Time ◽  
Citrus Reticulate

Dekopon or Hallabong (Citrus reticulate “Shiranui”) is a hybrid fruit that belongs to the citrus fruits. The scientific and commercial interests in dekopon is due to its nutritional composition. The objective of the study was to verify the influence of ethanol as a pretreatment in reducing drying time as well as maintaining nutritional quality (vitamin C, total phenolic compounds, and antioxidant activity) of dekopon slices. The drying with ethanol at 70 °C promoted the greatest reduction in drying time, but the processed pretreated samples at 50 °C presented the highest level of nutritional quality parameters. Keywords: drying time; vitamin C; phenolic compounds; antioxidant activity 

scholarly journals Drying Modelling, Moisture Diffusivity and Sensory quality of Thin Layer dried Beef

2018 ◽  
Vol 6 (2) ◽  
pp. 552-565 ◽  
Author(s):  
Eunice Akello Mewa ◽  
Michael Wandayi Okoth ◽  
Catherine Nkirote Kunyanga ◽  
Musa Njue Rugiri
Keyword(s):  
Thin Layer ◽  
Sensory Quality ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Effect Of Temperature ◽  
Slice Thickness ◽  
Drying Time ◽  
Drying Characteristics ◽  
Thin Layer Drying

The objective of the present study was to determine the drying kinetics, moisture diffusivity and sensory quality of convective air dried beef. The effect of temperature of drying (30-60°C) and thickness of samples (2.5-10 mm) on the convective thin-layer drying kinetics of beefdried in a cabinet dryer was evaluated. Five semi-theoretical models were fit to the drying experimentaldata with the aim of predicting drying characteristics of beef and fitting quality of models determined using the standard error of estimate (SEE)and coefficient of determination (R2). Determination ofeffective moisture diffusivity (Deff) from the experimental drying datawas done and sensory quality of the optimized dried cooked and uncookedbeef samplesevaluated. Drying time and rate of drying increased with an increasing temperature but decreased with increased slice thickness. However, there was overlapping of drying curves at 40-50°C. Among the selected models, Page model gave the best prediction of beef drying characteristics. Effective moisture diffusivity (Deff) ranged between 4.2337 x 10-11 and 5.5899 x 10-10 m2/s, increasing with an increase in air temperature and beef slice thickness.Of all the sensory parameters evaluated, texture was the only attribute that gave significantly different (P > 0.05) scores between the cooked and uncooked dried beef samples.

scholarly journals Drying kinetics and quality aspects during heat pump drying of onion (Allium cepa L.)

2012 ◽  
Vol 1 (2) ◽  
Author(s):  
Nihar Ranjan Sahoo ◽  
Uma Sankar Pal ◽  
Sanjaya Kumar Dash ◽  
M.D. K. Khan
Keyword(s):  
Heat Pump ◽  
Air Temperature ◽  
Colour Change ◽  
Coefficient Of Determination ◽  
Drying Time ◽  
Hot Air ◽  
Thin Layer Drying ◽  
Quality Aspects ◽  
Heat Pump Drying ◽  
Air Dryer

A prototype heat pump dryer has been developed for drying of fruits and vegetables at low temperature and relative humidity to maintain the quality of dried product. Onions, of Nasik red variety were peeled, trimmed and sliced to 2 mm thickness. The onion slices were dried in the heat pump dryer at 35ºC (32 % R.H.), 40ºC (26 % R.H.), 45ºC (19 % R.H.) and 50ºC (15 % R.H.). Samples were also dried in a hot air dryer at 50ºC (52 % R.H.) for comparison. The drying rate increased with increase in drying air temperature, associated with reduced R.H., in the heat pump dryer. Drying took place mainly under the falling rate period. The Page equation, resulting in a higher coefficient of determination and lower root mean square error, better described the thin-layer drying of onion slices than the Henderson and Pabis equation. Heat pump drying took less drying time of 360 min and yielded better quality dried product, with higher retention of ascorbic acid and pyruvic acid and lower colour change, as compared to a hot air dryer at the same drying air temperature of 50ºC.

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