Influence of Air-Drying on the Quality Characteristics of Spearmint: Effects of Air Temperature and Velocity

2016 ◽  
Vol 41 (2) ◽  
pp. e12817 ◽  
Author(s):  
Antia Orphanides ◽  
Vlasios Goulas ◽  
George Botsaris ◽  
Vassilis Gekas
Keyword(s):  
Air Temperature ◽  
Quality Characteristics ◽  
Air Drying

scholarly journals Optimisation of energy consumption of a solar-electric dryer during hot air drying of tomato slices

2019 ◽  
Vol 50 (3) ◽  
pp. 150-158 ◽  
Author(s):  
Nnaemeka R. Nwakuba
Keyword(s):  
Energy Consumption ◽  
Air Temperature ◽  
High Energy ◽  
Slice Thickness ◽  
Air Velocity ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Drying Conditions ◽  
Desirability Index

High-energy demand of convective crop dryers has prompted study on optimisation of dryer energy consumption for optimal and cost effective drying operation. This paper presents response surface optimisation of energy consumption of a solar-electric dryer during hot air drying of tomato slices. Drying experiments were conducted with 1 kg batch of tomato samples using a 33 central composite design of Design Expert 7.0 Statistical Package. Three levels of air velocity (1.0, 1.5 and 2.0 ms–1), slice thickness (10, 15 and 20 mm) and air temperature (50, 60 and 70°C) were used to investigate their effects on energy consumption. A quadratic model was obtained with a high coefficient of determination (R2) of 0.9825. The model was validated using the statistical analysis of the experimental parameters and normal probability plot of the energy consumption residuals. Results obtained indicate that the process parameters had significant quadratic effects (P<0.05) on the energy consumption. The energy consumption varied between 5.42 kWh and 99.78 kWh; whereas the specific energy consumption varied between 5.53 kWhkg–1 and 150.61 kWhkg–1. The desirability index method was applied in predicting the ideal energy consumption and drying conditions for tomato slices in a solar-electric dryer. At optimum drying conditions of 1.94 ms–1 air velocity, 10.36 mm slice thickness and 68.4°C drying air temperature, the corresponding energy consumption was 5.6 8kWh for maximum desirability index of 0.989. Thermal utilisation efficiency (TUE) of the sliced tomato samples ranged between 15 ≤TUE ≤58%. The maximum TUE value was obtained at 70°C air temperature, 1.0 ms–1 air velocity and 10 mm slice thickness treatment combination, whereas the minimum TUE was obtained at 50°C air temperature, 2.0 ms–1 air velocity and 20 mm slice thickness. Recommendation and prospect for further improvement of the dryer system were stated.

Effect of air temperature on drying kinetics and quality characteristics of osmo-treated jumbo squid (Dosidicus gigas)

LWT ◽  
2011 ◽  
Vol 44 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Antonio Vega-Gálvez ◽  
Margarita Miranda ◽  
Rodrigo Clavería ◽  
Issis Quispe ◽  
Judith Vergara ◽  
...  
Keyword(s):  
Air Temperature ◽  
Quality Characteristics ◽  
Drying Kinetics ◽  
Dosidicus Gigas ◽  
Jumbo Squid

scholarly journals Optimization of energy consumption of a solar-electric dryer during hot air drying of tomato slices

2019 ◽  
Author(s):  
Nnaemeka R. Nwakuba
Keyword(s):  
Energy Consumption ◽  
Air Temperature ◽  
High Energy ◽  
Utilization Efficiency ◽  
Slice Thickness ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Drying Conditions ◽  
Desirability Index

High-energy demand of convective crop dryers has prompted study on optimization of dryer energy consumption for optimal and cost effective drying operation. This paper presents response surface optimization of energy consumption of a solar-electric dryer during hot air drying of tomato slices. Drying experiments were conducted with 1kg batch of tomato samples using a 33Central Composite Design (CCD) of Design Expert 7.0 Statistical Package. Three levels of air velocity (1.0, 1.5 and 2.0ms–1), slice thickness (10, 15 and 20mm) and air temperature (50, 60 and 70oC) were used to investigate their effects on energy consumption. A quadratic model was obtained with a high coefficient of determination (R2) of 0.9825. The model was validated using the statistical analysis of the experimental parameters and normal probability plot of the energy consumption residuals. Results obtained indicate that the process parameters had significant quadratic effects (p < 0.05) on the energy consumption. The energy consumption varied between 5.42kWh and 99.78kWh; whereas the specific energy consumption varied between 5.53kWhkg–1and 150.61kWhkg–1. The desirability index method was applied in predicting the ideal energy consumption and drying conditions for tomato slices in a solar-electric dryer. At optimum drying conditions of 1.94ms–1air velocity, 10.36mm slice thickness and 68.4oC drying air temperature, the corresponding energy consumption was 5.68kWh for maximum desirability index of 0.989. Thermal utilization efficiency (TUE) of the sliced tomato samples ranged between 15 ≤ TUE ≤ 58%. The maximum TUE value was obtained at 70oC air temperature, 1.0ms–1air velocity and 10mm slice thickness treatment combination, whereas the minimum TUE was obtained at 50oC air temperature, 2.0ms–1air velocity and 20mm slice thickness. Recommendation and prospect for further improvement of the dryer system were stated.

scholarly journals A comparison of the kinetics of mango drying in open-air, solar, and forced-air dryers

2012 ◽  
Vol 12 (55) ◽  
pp. 6835-6852
Author(s):  
DG Mercer ◽  
Keyword(s):  
Air Temperature ◽  
Operating Conditions ◽  
Wire Mesh ◽  
Solar Drying ◽  
Drying Method ◽  
Air Drying ◽  
Sub Saharan ◽  
Forced Air ◽  
Air Dryer ◽  
Kinetics Of

Mangoes are under-utilized fruits that grow naturally in many sub-Saharan African countries. At the present time most mangoes are sold fresh in local markets. There is little done to preserve them for use during the off-season. Drying is one way in which the economic potential of mangoes could be exploited. This study was undertaken to investigate and compare the kinetics of mango drying using three basic drying methods: open-air drying on wire mesh racks; solar drying in a prototype dryer equipped with solar-powered exhaust fans; and forced-air drying in an Armfield Model UOP8 laboratory-scale tray dryer. Results could then be used to determine appropriate drying techniques for mango processing in sub-Saharan Africa on both local and commercial scales. Of these methods, forced air drying was found to provide the best overall results, based on water removal rates and general control over the drying process. Solar drying, while viewed as a promising technology for application in developing countries, was considerably slower than forced- air drying and is severely restricted by climatic conditions. A similar situation was observed for open-air drying, which was the slowest drying method of the three. Based upon mathematical models developed for each drying method, 11.6 hours was predicted as being required for mangoes in the forced-air dryer to a final moisture content of 10% (wet basis). Sixteen (16) hours and 24 hours of exposure to appropriate drying conditions were predicted as being required for solar drying and open-air drying, respectively. This could take three or four days to achieve under actual operating conditions. These times were supported by experimentally determined values. The impact of air temperature and linear air velocity on the drying kinetics of sliced mangoes were also investigated using the forced-air dryer. A linear velocity of 0.5 m/s was found to be sufficient for satisfactory drying of the mango slices when combined with an air temperature in the range of 50ΕC to 60ΕC. It is recommended that forced-air drying be utilized whenever possible for the drying of mango slices for both food safety and food quality reasons.

Study on the splitting by hot-air drying of Camellia oleifera fruit

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Fenghe Wang ◽  
Zongxin Liu ◽  
Yechun Ding ◽  
Deyong Yang
Keyword(s):  
Air Temperature ◽  
Seed Quality ◽  
Seed Color ◽  
Camellia Oleifera ◽  
Hot Air Drying ◽  
Air Drying ◽  
Moisture Migration ◽  
Hot Air ◽  
Micro Channels ◽  
Drying Kinetic

Abstract In order to explore the feasibility of hot air splitting of Camellia oleifera fruit, the effect of hot air temperature on peel splitting, the moisture state and moisture migration in peel, the peel microstructure and the seed color were studied. The results showed that higher hot air temperature could accelerate the splitting rate, the optimum temperature for splitting C. oleifera fruit was 90–110 °C considering the seed quality. Page model was the most suitable for describing the drying kinetic characteristics of C. oleifera fruit. Nuclear magnetic resonance (NMR) revealed the changing of the dehydration rate, the migration rate of bound water, immobilized water and free water in peel during hot air drying. The expansion of micro-channels in peel was conducive to moisture migration in the early splitting stage, but microstructure damaged in the late splitting stage accompanied by loose disorder of micro pores, serious shrinkage and deformation of peel.

Study on Drying Technology of Sargassum Fusiforme

2011 ◽  
Vol 361-363 ◽  
pp. 764-769
Author(s):  
Shu Xing Liu ◽  
Li Li Zhu ◽  
Shu Meng Zhang
Keyword(s):  
Wind Speed ◽  
Air Temperature ◽  
Raw Materials ◽  
Variable Temperature ◽  
High Quality ◽  
Hot Air Drying ◽  
Air Drying ◽  
Sargassum Fusiforme ◽  
Hot Air ◽  
Drying Technology

A convenient and nutritious dried instant Sargassum fusiforme was developed by the study on the technology of drying with the raw materials of Sargassum fusiforme. The result indicated that the optimum drying technology of Sargassum fusiforme is: on the condition of 95°C for 90s,to blanching, then by means of variable temperature for hot air drying at the 3m/s wind speed, which is air temperature 80°C in first hour,70°C for another 3.5 hours, that we can get high quality Sargassum fusiforme in Rehydration shape,color, and taste .etc.

Air drying kinetics and quality characteristics of osmodehydrated-candied pumpkins using alternative sweeteners

2020 ◽  
pp. 1-12
Author(s):  
Stamatina Katsoufi ◽  
Andriana E. Lazou ◽  
Maria C. Giannakourou ◽  
Magdalini K. Krokida
Keyword(s):  
Quality Characteristics ◽  
Drying Kinetics ◽  
Air Drying

Analysis of Microclimate and Cucumber Fruit Yield in a Screenhouse and an Evaporatively Cooled Greenhouse in a Semi-Arid Location

2018 ◽  
Vol 61 (2) ◽  
pp. 619-629 ◽  
Author(s):  
Yaseen A. Al-Mulla ◽  
Mohammed I. Al-Balushi ◽  
Hamad A. Al-Busaidi ◽  
Adil A. Al-Mahdouri ◽  
Constantinos Kittas ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Air Temperature ◽  
Fruit Quality ◽  
Evaporative Cooling ◽  
Quality Characteristics ◽  
Summer Period ◽  
Air Temperatures ◽  
Use Efficiency ◽  
The Mean

Abstract. The microclimate and cucumber crop response in a screenhouse and in an evaporatively cooled greenhouse were studied in Oman during winter/spring and spring/summer cultivation periods. Measurements were carried out in two similarly shaped structures: (1) a greenhouse equipped with a pad-and-fan system for evaporative cooling of the greenhouse environment and (2) a screenhouse with no cooling system. Analysis of the spring/summer period climate data showed that the evaporative cooling in the greenhouse reduced the mean air temperature by about 4.5°C compared to outside and maintained the leaf temperature close to the greenhouse air temperature. The 24 h mean leaf and air temperatures in the greenhouse reached 25.8°C ±1.3°C and 25.9°C ±0.8°C, respectively. On the other hand, the 24 h mean leaf and air temperatures in the screenhouse were higher by 1.0°C and 1.3°C, respectively, compared to outside. The 24 h mean leaf and air temperatures in the screenhouse reached 32.8°C ±1.2°C and 31.8°C ±1.5°C, respectively. Furthermore, the evaporative cooling in the greenhouse maintained the 24 h mean air vapor pressure deficit (VPD) values at levels lower than 1.1 kPa, while the 24 h mean air VPD in the screenhouse reached values up to 4.5 kPa. These differences resulted in a 50% decrease in crop fruit yield during the spring/summer period. The radiation and water use efficiency (WUE) values observed in the two structures were similar during the winter/spring period but were higher in the greenhouse during the spring/summer period. However, for the greenhouse, when the water evaporated in the wet pad was also considered, the overall WUE was at the same level in both structures during summer. Furthermore, the evaporative cooling applied in the greenhouse enhanced the mean values of fruit quality characteristics measured during the spring/summer, such as fruit dry matter content (5.6%), fruit firmness (5.0 kg cm-2), and chroma (18.6), compared to that of the screenhouse (5.0%, 4.9 kg cm-2 and 16.3, respectively), but did not significantly affect other fruit quality characteristics, such as mean fruit weight (128 g for greenhouse and 123 g for screenhouse), total soluble solids content (3.9 °Brix for both structures), and juice pH (5.7 for greenhouse and 5.6 for screenhouse). Overall, it can be concluded that under the weather conditions of Oman, although greenhouses are still needed during spring/summer, screenhouses can be used during winter without jeopardizing crop production quantity and quality. Keywords: Evaporative cooling, Evapotranspiration, Radiation use efficiency, Water user efficiency. Total water use efficiency, Climate.

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