scholarly journals Comparative study of different drying methods regard to the phenols and flavonoids content of dried Citrus aurantium L. leaves

2021 ◽  
Author(s):  
Geovanni Hernandez Galvez ◽  
Margarita Castillo Téllez ◽  
Jorge de Jesús Chan González ◽  
Francisca Méndez Morales ◽  
Damianys Almenares López ◽  
...  
Keyword(s):  
Natural Convection ◽  
Forced Convection ◽  
Design Methodology ◽  
Total Phenol ◽  
Drying Methods ◽  
Total Flavonoids ◽  
Citrus Aurantium ◽  
Solar Drying ◽  
Solar Dryer ◽  
Total Flavonoids Content

Objective: To determine the effects of different thermal drying technologies on the total phenol and flavonoid contents (TPC) and total flavonoids (TFC) in sour orange (Citrus aurantium L.) leaves. Design/methodology/approach: Solar drying was carried out in outdoor sunny conditions using two direct solar dryers; one with natural convection, the other with forced convection. The total phenol and flavonoid contents in gallic acid equivalents (GAE) and quercetin (Q), respectively, of ethanolic extracts of C. aurantium were assessed with spectrophotometric techniques. Results: The results demonstrated maximum phenol values for the direct natural convection solar dryer (161.4 mg EAG/g MS) and minimum values for shade drying (61.43 mg EAG/g MS). As for flavonoids, the highest values were obtained in the direct forced convection solar dryer (32.22 ± 1.6 mg EQ/g MS), while the lowest was registered in the open air sun (11.72 mg EQ/g MS). Conclusions: Direct solar dryers are technologies effective for maintaining the phenols and total flavonoids content in dried leaves of C. aurantium.  

scholarly journals Effects of Blanching and Natural Convection Solar Drying on Quality Characteristics of Red Pepper (Capsicum annuum L.)

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
James Owusu-Kwarteng ◽  
Francis K. K. Kori ◽  
Fortune Akabanda
Keyword(s):  
Natural Convection ◽  
Quality Characteristics ◽  
Red Pepper ◽  
Plain Water ◽  
Drying Methods ◽  
Solar Drying ◽  
Drying Time ◽  
Sun Drying ◽  
Overall Acceptability ◽  
Solar Dryer

The objective of this work was to determine the effects of blanching and two drying methods, open-sun drying and natural convection solar drying, on the quality characteristics of red pepper. A 2 × 3 factorial design with experimental factors as 2 drying methods (open-sun drying and use of solar dryer) and 3 levels of pepper blanching (unblanched, blanched in plain water, and blanched in 2% NaCl) was conducted. Dried pepper samples were analysed for chemical composition, microbial load, and consumer sensory acceptability. Blanching of pepper in 2% NaCl solution followed by drying in a natural convection solar dryer reduced drying time by 15 hours. Similarly, a combination of blanching and drying in the solar dryer improved microbial quality of dried pepper. However, blanching and drying processes resulted in reduction in nutrients such as vitamin C and minerals content of pepper. Blanching followed by drying in natural convection solar dryer had the highest consumer acceptability scores for colour and overall acceptability, while texture and aroma were not significantly (p>0.05) affected by the different treatments. Therefore, natural convection solar dryer can be used to dry pepper with acceptable microbial and sensory qualities, as an alternative to open-sun drying.

scholarly journals Design of a Hexagonal Solar Fish Dryer

2019 ◽  
Vol 9 (2) ◽  
pp. 3444-3449
Keyword(s):  
Natural Convection ◽  
Solar Energy ◽  
Shelf Life ◽  
Forced Convection ◽  
Air Flow ◽  
The Other ◽  
Solar Drying ◽  
General Methodology ◽  
The World

Solar drying is a general methodology adopted to protect agricultural goods, fishes as well as meat in tropical as well as subtropical areas. Drying helps to maintain the quality of product and improve its shelf-life by bringing down the wastage to minimum levels. Conventional driers have lot of limitations like infestation by insect, rodents, other animals, exposure to wind-borne dirt and dust, lack of proper monitoring as well as escalated cost of the automatic dryers. Solar dryers are being used all around the world in different countries in varied models. These dryers are of two different methods one that work with natural convection with air-flow established by buoyancy and the other with air flow by a fan in forced convection mode. This is a paper on the outcome of a solar dryer designed especially for fisherman to dry fishes effectively. A different configuration with an objective to capture major amount of incident solar energy and dry fishes at a faster rate is being suggested as an alternative

scholarly journals Investigation of Solar Drying of Ginger (Zingiber officinale): Emprical Modelling, Drying Characteristics, and Quality Study

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
A. Waheed Deshmukh ◽  
Mahesh N. Varma ◽  
Chang Kyoo Yoo ◽  
Kailas L. Wasewar
Keyword(s):  
Energy Requirement ◽  
Initial Moisture Content ◽  
Food Preservation ◽  
Convective Drying ◽  
Drying Methods ◽  
Solar Drying ◽  
Drying Time ◽  
Drying Characteristics ◽  
Solar Dryer ◽  
Thin Layer Drying

Drying is a simultaneous heat and mass transfer energy intensive operation, widely used as a food preservation technique. In view of improper postharvest methods, energy constraint, and environmental impact of conventional drying methods, solar drying could be a practical, economical, and environmentally reliable alternative. In the present paper applicability of mixed mode solar cabinet dryer was investigated for drying of commercially important and export oriented ginger. Freshly harvested ginger slices were successfully dried from initial moisture content of 621.50 to 12.19% (d.b.) and their drying characteristics, quality parameters, and kinetics were evaluated. The results showed that present solar dryer could be successfully applied for drying of ginger in view of quality, reduced drying time, and zero energy requirement as compared to conventional open sun drying and convective drying techniques, respectively. Drying curves showed that drying occurred in falling rate period and no constant period was observed. The effective moisture diffusivity was determined by using Fick’s second law and found to be 1.789×10-9 m2/s. The drying data was fitted to five thin layer drying models and compared using statistical criteria. Page model was found to be most suitable to describe the drying kinetics of ginger in solar dryer under natural convection among the tested models.

scholarly journals PENGARUH METODE PENGERINGAN TERHADAP KADAR SENYAWA BIOAKTIF DAN AKTIVITAS ANTIOKSIDAN PADA HERBA SURUHAN (Peperomia pellucida L.)

2021 ◽  
Vol 6 (2) ◽  
pp. 302-311
Author(s):  
Dewi Puspita Apsari ◽  
◽  
Muhammad Nanda Aprilianto ◽  
Ni Luh Desyani ◽  
Ni Putu Widayanti ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Bioactive Compounds ◽  
Total Phenol ◽  
Drying Methods ◽  
Total Flavonoids ◽  
Total Phenols ◽  
Direct Sunlight ◽  
Oven Drying ◽  
Bioactive Content

Suruhan herb have been used globally as concoction for medical and therapeutic purposes, so that it is much needed to investigate their phytonutrients. The variations in drying methods can affect the levels of bioactive compounds and antioxidant activity, so an appropriate drying strategy is needed to produce simplicia that containing high bioactive compounds and antioxidant activity. Based on the considerations above, this study aimed to determine the effect of various drying methods strategies (direct sunlight, oven drying and wind drying) on the bioactive compounds and antioxidant activity of the suruhan herb. The extract of suruhan herb were subsequently analyzed for total flavonoids, total phenols, total tannins, and their antioxidant activity. The results showed that oven-dried suruhan herb produced the highest potential antioxidant activity, that was 94.67 ppm with total flavonoids 51.00 mgQE/g extract, total phenol 63.36 mgGAE/g extract, and total tannins 41.89 mgTAE/g extract. It can be concluded that the variety of drying strategy has a significant impact (p<0.05) on the bioactive content and antioxidant activity of the suruhan herb.

Single layer solar drying behaviour of Citrus aurantium leaves under forced convection

2005 ◽  
Vol 46 (9-10) ◽  
pp. 1473-1483 ◽  
Author(s):  
L. Ait Mohamed ◽  
M. Kouhila ◽  
A. Jamali ◽  
S. Lahsasni ◽  
N. Kechaou ◽  
...  
Keyword(s):  
Forced Convection ◽  
Single Layer ◽  
Citrus Aurantium ◽  
Solar Drying ◽  
Drying Behaviour

scholarly journals Experimental Studies on Natural Convection Open and Closed Solar Drying Using External Reflector

2021 ◽  
Author(s):  
Abd Elnaby Kabeel ◽  
Paul Durai Leon Dharmadurai ◽  
Sathiyaseelan Vasanthaseelan ◽  
Prof. Dr. Ravishankar Sathyamurthy ◽  
Bharathwaaj Ramani ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Natural Convection ◽  
Removal Rate ◽  
Experimental Studies ◽  
Heat Energy ◽  
Moisture Removal ◽  
Solar Drying ◽  
Solar Dryer ◽  
Drying Efficiency ◽  
Food Dryer

Abstract This work presents the experimental investigation on a solar food dryer equipped with external reflectors to enhance the rate of drying efficiency by removing the moisture content available in the anchovy fish. A comparison on conventional open solar drying is carried out to assess the parameters such as drying efficiency, moisture removal rate, and heat energy required for drying the anchovy fish using the modified solar dryer using natural convection technique. The physical examination results on the dried products proved that using modified solar dryer, the dried product are free from insects, dust. Also, it is found that the loss of colour from the product is minimum while compared to conventional open solar drying. The results showed that the thermal efficiency of dryer 1 and dryer 2 are comparatively higher as compared to that of conventional open solar drying and found as 16.73 and 19.34 % respectively.

scholarly journals Development of Solar Drying Model for Selected Cambodian Fish Species

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Anna Hubackova ◽  
Iva Kucerova ◽  
Rithy Chrun ◽  
Petra Chaloupkova ◽  
Jan Banout
Keyword(s):  
Natural Convection ◽  
Fish Species ◽  
Nile Tilapia ◽  
Drying Kinetics ◽  
Solar Drying ◽  
Fish Processing ◽  
Climbing Perch ◽  
Term Model ◽  
Solar Dryer ◽  
Electric Oven

A solar drying was investigated as one of perspective techniques for fish processing in Cambodia. The solar drying was compared to conventional drying in electric oven. Five typical Cambodian fish species were selected for this study. Mean solar drying temperature and drying air relative humidity were 55.6°C and 19.9%, respectively. The overall solar dryer efficiency was 12.37%, which is typical for natural convection solar dryers. An average evaporative capacity of solar dryer was 0.049 kg·h−1. Based on coefficient of determination (R2), chi-square (χ2) test, and root-mean-square error (RMSE), the most suitable models describing natural convection solar drying kinetics were Logarithmic model, Diffusion approximate model, and Two-term model for climbing perch and Nile tilapia, swamp eel and walking catfish and Channa fish, respectively. In case of electric oven drying, the Modified Page 1 model shows the best results for all investigated fish species except Channa fish where the two-term model is the best one. Sensory evaluation shows that most preferable fish is climbing perch, followed by Nile tilapia and walking catfish. This study brings new knowledge about drying kinetics of fresh water fish species in Cambodia and confirms the solar drying as acceptable technology for fish processing.

scholarly journals Comparative Study of Three Solar Drying Methods of Adensonia digitate L. (Baobab Leaves using Drying Kinetics and Empirical Drying Models)

2021 ◽  
pp. 77-85
Author(s):  
S. A. Okaiyeto ◽  
Nathaniel Oji ◽  
Y. A. Unguwanrimi
Keyword(s):  
Comparative Study ◽  
Mixed Mode ◽  
Moisture Diffusivity ◽  
Drying Methods ◽  
Solar Drying ◽  
Drying Time ◽  
Effective Moisture ◽  
Solar Dryer ◽  
Drying Models ◽  
On Farm

A comparative study of three drying methods of baobab leaves have been conducted and reported. Mixed mode solar drying, indirect mode solar drying and open sun drying of baobab leaves were conducted based on three drying models viz a viz Lewis,. Page and Henderson and Pabis models were employed in this research. Baobab leaves dried faster when dried under the mixed mode on-farm solar dryer. Drying time reduced considerably using the mixed mode on-farm solar dryer. Drying data were fitted into Lewis, Page and Henderson and Pabis models. Henderson and Pabis model (R2=0.9999, 0.9611, 0.9656; X2= 1.0297, 0.7931, 0.7710; RMSE= 0.5859, 0.6898, 0.6802 and MBE= -0.4.135, -0.4.231, -0.4176) gave the best prediction for the mixed mode drying). In the same way Henderson and Pabis model (R2=0.7450, 0.7699, 0.8243; X2= 1.9025, 0.4026, 0.2006; RMSE= 1.0684, 0.5181, 0.4058 and MBE= -0.8966, -0.3823, 0.2789) gave the best prediction for the indirect mode drying of baobab leaves. Effective moisture diffusivity of baobab leaves varied between -6.382 X 10-04 and -1.108 X 10-03 m2/s.

scholarly journals Experimental Research of Drying Characteristics of Red Banana in a Single Slope Solar Dryer Based on Natural and Forced Convection

2021 ◽  
Vol 59 (2) ◽  
Author(s):  
Elavarasan Elangovan ◽  
Sendhil Kumar Natarajan
Keyword(s):  
Activation Energy ◽  
Correlation Coefficient ◽  
Forced Convection ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Solar Drying ◽  
Solar Dryer ◽  
Proposed Model ◽  
Thin Layer Drying ◽  
Drying Technology

Research background. Traditionally, open sun drying method is used to dry the products for long time preservation. For the same products, solar drying technology is being employed to minimize the drying time for achieving the required moisture content. This solar drying technology, which inherently contains complex heat and mass transfer mechanism, which makes difficult to describe drying kinetics at the micro level. Experimental approach. In this present paper, research work is carried out to investigate the drying of 5 mm thickness of red banana (Musa acuminata “Red Dacca”) in a single slope solar dryer based on natural and forced convection. Based on the experiments, development of new semi-empirical thin layer drying kinetics correlation for red banana is proposed. The proposed correlation is also compared with other existing models. The proposed model is in very good agreement with well-known other models and the correlation coefficient (R2) of 0.997 is obtained. Based on the model, the moisture diffusivity and activation energy of the red banana are also obtained. Results and conclusions. It is found that, the moisture diffusivity of the red banana samples is in the range of 8.74·10-10-1.56·10-9 m2/s for natural convection solar drying and 8.43·10-9-2.61·10-8 m2/s for forced convection solar drying. The activation energy of the red banana is varied from 24.58 to 45.20 kJ/mol for passive mode and 22.56 to 35.49 kJ/mol for active mode. Besides, energy and exergy analysis of red banana in a dryer are also carried out. It is found that the average exergy losses for the forced and natural convections are obtained as 16.1 kJ/kg and 6.63 kJ/kg and the average exergic efficiency for the natural and forced convection dryer was obtained as 57.7 % and 70.9 %, respectively. Novelty and scientific contribution. A single slope direct type solar dryer was designed and fabricated to maintain the desired temperature for a specified period in both natural and forced convection phenomena. A novel drying kinetics model is proposed to preserve red banana. The proposed model given a superior correlation coefficient (R2) when compared to other drying kinetics models.

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