Colour, Texture, Microstructure and Nutrient Retention of Kiwifruit Slices Subjected to Combined Air-Impingement Jet Drying and Freeze Drying

2017 ◽  
Vol 13 (7) ◽  
Author(s):  
Di Huang ◽  
Wenfeng Li ◽  
Hongjun Shao ◽  
Anning Gao ◽  
Xingbin Yang
Keyword(s):  
Energy Consumption ◽  
Freeze Drying ◽  
High Efficiency ◽  
Nutrient Retention ◽  
Microwave Drying ◽  
Rehydration Ratio ◽  
Retention Capacity ◽  
Drying Time ◽  
Impingement Jet ◽  
Air Impingement

Abstract The aim of this study was to select an appropriate drying technique from air-impingement jet drying (AIJD), hot air drying (HAD) and microwave drying (MWD) which can be combined with freeze drying (FD). Results showed that AIJD with relatively high efficiency, low energy consumption and good drying quality was suitable to be combined with FD. To further improve the drying technology of kiwifruits, the energy consumption and quality of dried kiwifruit with different conversion point during combined FD and AIJD were also tested. The energy consumption obtained for AIJD+FD and FD+AIJD was lower than that obtained for FD alone. Among the products, the kiwifruit processed by AIJD+FD not only showed better attractive green colour and higher sweetness perception, but also revealed higher rehydration ratio than FD and FD+AIJD kiwifruits, which was positively related to microstructure changes. The best AIJD+FD process, from nutrient retention and antioxidant activity considerations, was the combination of 65 min AIJD pre-drying and FD finish drying. Therefore, AIJD pre-drying and FD finish drying as a promising way with short drying time and strong nutrient retention capacity may be applied to the drying processing of agricultural products.

Effects of Air-Impingement Jet Drying on Drying Kinetics, Nutrient Retention and Rehydration Characteristics of Onion (Allium cepa) Slices

2015 ◽  
Vol 11 (3) ◽  
pp. 435-446
Author(s):  
Wenfeng Li ◽  
Moyi Wang ◽  
Xulin Xiao ◽  
Baoshan Zhang ◽  
Xingbin Yang
Keyword(s):  
Effective Diffusivity ◽  
Nutrient Retention ◽  
Ascorbic Acid Content ◽  
Drying Kinetics ◽  
Total Phenolic ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Impingement Jet ◽  
Air Impingement

Abstract This study is designed to investigate drying kinetics, nutrient retention and rehydration ratio of onion slices under air-impingement jet drying (AIJD) with different drying temperatures (40, 50 and 60°C), air velocities (11, 12 and 13 m/s), and the distance between jet nozzles and material box (0, 40 and 80 mm). Additionally, the influence of AIJD and hot air drying (HAD) on drying efficiency and product quality of onion slices was comparatively investigated. It was found that the moisture effective diffusivity of onion slices under AIJD ranged from 3.51 × 10−10 to 5.51 × 10−10 m2/s, and the activation energy (E a) of onion determined from Arrhenius equation was 14.73 kJ/mol, and ascorbic acid content (AAC), total phenolic content (TPC) and DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging activity (DSA) significantly decreased in the dried onions compared to that in fresh onion. In addition, the results suggest that the Modified Page model provides the best fit for AIJD curves. Furthermore, AIJD product is better than HAD both in decreasing drying time and enhancing drying rate, AAC, TPC, DSA and rehydration ratio. Accordingly, the AIJD method has advantages in drying time and quality of products, indicating that this technology can be widely applied to food drying process.

scholarly journals Upcycling food ingredients from orange by-products by hot air-microwave drying. Impact on energy consumption.

2021 ◽  
Author(s):  
Clara Talens ◽  
Itziar Tueros ◽  
Bruno Iñarra ◽  
Carlos Bald ◽  
Marta Castro-Giraldez ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Aqueous Extract ◽  
Dietary Fibre ◽  
Ethanolic Extract ◽  
Microwave Drying ◽  
Retention Capacity ◽  
Drying Time ◽  
Food Ingredients ◽  
Hot Air ◽  
By Products

Currently industrial citrus by-products represent a relevant environmental issue. The main aim of this work was the chemical characterization of the different bioactive compounds obtained after hot air-microwave drying (HAD+MW) of orange by-products, and their further conversion into three upcycled ingredients with health-related benefits: aqueous extract, ethanolic extract and dietary fibre. Total phenolics, antioxidant capacity, individual phenolic acids, flavonoids, limonin and carotenoids were monitored during blanching and colour extraction steps by analysing fresh by-products and process co-products: an aqueous extract rich in polyphenols and an ethanolic extract rich in carotenoids. After drying, the resulting fibre was characterized in terms of chemical composition, soluble and insoluble dietary fibre content and particle size. Technological properties and colour were compared to those of commercial citrus fibre. Energy and time consumption were compared with conventional hot air drying (HAD). Most polyphenols (50-65 %) and limonin (70 %) were extracted during the blanching step. 86 % of carotenoids were removed by soaking in ethanol. The orange fibre obtained had 71.9 g DF/ 100 g and antioxidant properties (205 mg TE/ Kgdm). Whiteness, water retention capacity and oil retention capacity were similar to commercial citrus fibre. HAD+MW reduced drying time and energy consumption by up to 50 % compared to HAD.

scholarly journals Effect of Hot-Water Blanching Pretreatment on Drying Characteristics and Product Qualities for the Novel Integrated Freeze-Drying of Apple Slices

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hai-ou Wang ◽  
Qing-quan Fu ◽  
Shou-jiang Chen ◽  
Zhi-chao Hu ◽  
Huan-xiong Xie
Keyword(s):  
Electron Microscopy ◽  
Freeze Drying ◽  
Hot Water ◽  
The Novel ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Drying Characteristics ◽  
Promising Alternative ◽  
Freeze Dried ◽  
Apple Slices

The effect of hot-water blanching (HWB) on drying characteristics and product qualities of dried apple slices with the novel integrated freeze-drying (NIFD) process was investigated by comparing with 3 different FD methods. Compared with the NIFD process without HWB pretreatment (VF-FD), the NIFD process with HWB pretreatment (HWB-VF-FD) resulted in a significantly higher mass loss and more sufficient freezing in vacuum-frozen samples, significantly higher rehydration ratio (RR), higher shrinkage ratio (SR), smaller Vitamin C (VC) content and lower hardness and better apparent shape in freeze-dried samples, and fewer change to the color of the dried or rehydrated samples (p<0.05). Compared with the conventional FD process with HWB pretreatment (HWB-PF-FD), HWB-VF-FD cost significantly less processing time and FD time and obtained significantly higher RR (p<0.05), almost the equivalent SR, VC content, and hardness, and similar appearance in dried samples. The microstructure of apple cell tissues was analyzed by transmission electron microscopy and scanning electron microscopy to interpret the above differences in drying characteristics and product qualities. The results suggested that the NIFD process of apple slices with HWB pretreatment was a promising alternative method to decrease drying time, achieve similar product quality, and simplify the process steps of the conventional FD technology.

Study on a Combination Drying Technique of Shrimp

2012 ◽  
Vol 260-261 ◽  
pp. 804-807
Author(s):  
Ya Xiang Bai ◽  
Yu Cai Hu ◽  
Qiang Huang
Keyword(s):  
Freeze Drying ◽  
Sensory Properties ◽  
Drying Rate ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Air Drying ◽  
Combined Process ◽  
Highly Efficient ◽  
Sensory Qualities

In order to develop a highly efficient drying technique for shrimp, a combination of air drying (AD) and vacuum freeze drying (FD) is examined. The drying rate of combination drying, the shrinkage, rehydration ratio, and sensory properties, such as the color and trimness, of the dried product in the AD–FD method are measured. Compared with FD, the combined process consumes less drying time, compared with AD drying alone. Also the product processed by combined drying displays lower shrinkage, higher rehydration rate and better sensory qualities.

Moisture Diffusivity and Energy Consumption during Microwave Drying of Plaster of Paris

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Magesh Ganesh Pillai ◽  
Iyyasamy Regupathi ◽  
Lima Rose Miranda ◽  
Thanapalan Murugesan
Keyword(s):  
Energy Consumption ◽  
Initial Moisture Content ◽  
Moisture Diffusivity ◽  
Operating Conditions ◽  
Microwave Drying ◽  
Effective Moisture Diffusivity ◽  
Experimental Conditions ◽  
Drying Time ◽  
Plaster Of Paris ◽  
Effective Moisture

The drying characteristics of plaster of paris (POP) under microwave conditions at different microwave power input, initial moisture content, sample thickness and drying time were studied. Further the experimental data on moisture ratio of POP for different operating conditions were obtained and calculations were made using nine basic drying model equations. The appropriate model with modified constants and coefficients to represent the drying kinetics of POP was found through the analysis of the statistical analysis. The effective moisture diffusivity of the drying process was also computed for different experimental conditions and a relationship between the drying rate constant and the effective moisture diffusivity was obtained. The energy consumption for microwave drying of plaster of paris at different experimental conditions were also computed.

scholarly journals Ultrasonic-Microwave and Infrared Assisted Convective Drying of Carrot: Drying Kinetic, Quality and Energy Consumption

2020 ◽  
Vol 10 (18) ◽  
pp. 6309
Author(s):  
Yousef Abbaspour-Gilandeh ◽  
Mohammad Kaveh ◽  
Muhammad Aziz
Keyword(s):  
Energy Consumption ◽  
Hybrid Methods ◽  
Specific Energy Consumption ◽  
Moisture Diffusivity ◽  
Color Variation ◽  
Microwave Drying ◽  
Convective Drying ◽  
Drying Time ◽  
Drying Kinetic ◽  
The Us

In this study, the drying time, effective moisture diffusivity (Deff), specific energy consumption (SEC), and quality (color, shrinkage, and rehydration) of the ultrasound-pretreated (US) carrot slices were compared when dried by hot air drying (HD), microwave drying (MWD), infrared drying (INFD), and hybrid methods of MW–HD and INF–HD. Five mathematical models were considered to describe the drying kinetics in the carrots. The results show that US+MW–HD and INFD were the fastest and the slowest drying techniques compared to the HD technique with a 73% and 23% drying time reduction, respectively. The Deff ranged from 7.12 × 10−9 to 2.78 × 10−8 m2/s. The highest and lowest SECs were 297.29 ± 11.21 and 23.75 ± 2.22 MJ/kg which were observed in the HD and US+MWD, respectively. The color variation indices indicated that the best sample in terms of color stability was the one dried by US+MW–HD with the color variation of 11.02 ± 0.27. The lowest and highest shrinkage values were also observed in the samples dried by US+MWD and HD (31.8 ± 1.1% and 62.23 ± 1.77%), respectively. Samples dried by US+MWD and HD possessed the highest and lowest rehydration, respectively. Although the carrot slices dried at a higher pace by US+MW–HD (compared to US+MWD), the shrinkage and SEC of the samples dried by US+MWD were significantly lower than the US+MW–HD (p < 0.05). Therefore, it can be concluded that the application of the US+MWD method can be considered as a proper alternative for drying the carrot slices when compared to the HD, MWD, INFD, and hybrid methods.

scholarly journals Drying of Phyla nodiflora Leaves: Antioxidant Activity, Volatile and Phytosterol Content, Energy Consumption, and Quality Studies

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 210 ◽  
Author(s):  
Lisa Yen Wen Chua ◽  
Bee Lin Chua ◽  
Adam Figiel ◽  
Chien Hwa Chong ◽  
Aneta Wojdyło ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Energy Consumption ◽  
Drying Kinetics ◽  
Microwave Drying ◽  
Convective Drying ◽  
Total Phenolic ◽  
Drying Methods ◽  
Drying Time ◽  
Antioxidant Power ◽  
Vacuum Microwave

Drying is an important process in the preservation of antioxidants in medicinal plants. In this study, leaves of Phyla nodiflora, or commonly known as frog fruit, were dried using convective drying (CD) at 40, 50, and 60 °C; vacuum-microwave drying (VMD) at 6, 9, and 12 W/g; and convective pre-drying followed by vacuum-microwave finish drying (CPD–VMFD) at 50 °C and 9 W/g. Drying kinetics of P. nodiflora leaves was modelled, and the influences of drying methods on the antioxidant activity, total phenolic content, volatile and phytosterol contents, energy consumption, water activity, and color properties were determined. Results showed that drying kinetics was best described by modified Page model. VMD achieved highest drying rate, whereas VMFD considerably reduced the drying time of CD from 240 min to 105 min. CPD–VMFD was the best option to dry P. nodiflora in terms of retaining volatiles and phytosterols, with lower energy consumption than CD. Meanwhile, VMD at 6 W/g produced samples with the highest antioxidant activity with 2,2′-Azinobis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) value of 11.00 and 15.99 µM Trolox/100 g dw, respectively.

scholarly journals Vacuum and Infrared-Assisted Hot Air Impingement Drying for Improving the Processing Performance and Quality of Poria cocos (Schw.) Wolf Cubes

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 992
Author(s):  
Weipeng Zhang ◽  
Chang Chen ◽  
Zhongli Pan ◽  
Zhian Zheng
Keyword(s):  
Energy Consumption ◽  
Specific Energy Consumption ◽  
Moisture Diffusivity ◽  
Operating Conditions ◽  
Water Soluble ◽  
Vacuum Drying ◽  
Two Stage ◽  
Drying Time ◽  
Hot Air ◽  
Air Impingement

The objective of this study was to develop an efficient drying technology for poria cubes in order to improve product quality. Poria cubes were dried using different methods, including air impingement drying, infrared-assisted air impingement drying, vacuum drying, two-stage vacuum drying, and infrared-assisted air impingement drying. The results were compared with those from hot air drying. For the two-stage drying, the tested conditions were the first stage of vacuum drying with temperatures between 65–85 °C and a switching moisture ratio of 70–90%. The second stage infrared-assisted air impingement drying also had temperatures 65–85 °C. The drying kinetics (effective moisture diffusivity (Deff), Biot number (Bi), and mass transfer coefficient (k) were studied via the product qualities (broken ratio, firmness, microstructure, and water-soluble polysaccharide content) and specific energy consumption (SEC) of the drying processes. The results showed that two-stage drying led to the lowest drying time and energy consumption, and also obtained the best qualities. Box–Behnken experimental design with response surface methodology (RSM) was used to optimize the two-stage operating conditions as 82 °C under vacuum drying until a moisture content of 81% and a temperature of 69 °C with infrared-assisted air impingement drying was achieved. These findings suggested that two-stage vacuum and infrared-assisted air impingement drying is a promising method for producing high quality and energy efficient dried poria cubes.

scholarly journals Microwave drying of corn seeds: Effect of Temperature on Drying Time, Energy Consuption and Germination Rate

2019 ◽  
Author(s):  
Ángel Hernández Moreno ◽  
Rafael Hernández-Maqueda ◽  
Isabel Ballesterios ◽  
Carlos Torres-Miño
Keyword(s):  
Energy Consumption ◽  
Germination Rate ◽  
Petri Dish ◽  
Electrical Energy ◽  
Microwave Drying ◽  
Effect Of Temperature ◽  
Total Output ◽  
Drying Process ◽  
Drying Time ◽  
Drying Temperature

Previous studies on the microwave drying of corn seeds have shown that the process parameters employed play a very important role in determining the properties and quality of this grain (Gürsoy et al, 2013). Among these parameters, the drying temperature has a fundamental role (Nair et al, 2011). The main objective of this work is to evaluate the effect of temperature on drying time, energy consumption and germination rate of corn seeds after they have been dried with microwave energy. To achieve the proposed objective, the drying process of these seeds was carried out in a rotating turntable domestic microwave oven (LACOR Model 69330), with a capacity of 30 liters and a total output power of 900 W, fitted with a PID temperature controller Eurotherm 3216 L. In this oven, 100 g of corn seeds, with an initial humidity of approximately 20%, was heated up to 3 drying temperatures (35, 55 and 75 °C). The seeds were weighed every 30 minutes and the drying process was considered completed when a humidity of 12 % was obtained. For each drying temperature studied, the experiments were carried out in duplicate. In each experiment, the electrical energy consumption was measured using a FLUKE 1735 energy analyzer. A sample of the dried seeds was subject to germination tests in a petri dish using filter paper and a volume of distillate water of 20mL to achieve sufficient humidity for them to sprout. Table 1 shows the average values obtained from the variables evaluated for each drying temperature.   Table 1. Results of the microwave drying experiments of the corn seeds at different temperatures and their germination tests. Drying temperature (ºC) Drying time to reach a humidity of 12% (min) Energy consumption (Wh) Germination rate (%) 35 345,0 880,3 90,0 55 118,5 330,0 81,3 75 73,5 183,9 12,0   As can be seen in Table 1, the temperature exerts a significant influence on the drying process and the germination rate of the corn seeds. An increase in the drying temperature causes a simultaneous decrease in drying time (∿ 78%) and in energy consumption (∿ 79%), which are very positive aspects. However, there is also an unacceptable decrease (∿ 87%) in the germination rate of the corn seeds.   References Gürsoy, S., Choudhary, R., Watson, D.G. Int. J Agric. &amp; Biol. Eng., 2013, 6, 1, 90–99.Nair, G.R., Li, Z., Gariepy, Y., Raghavan, V. Drying Technology, 2011, 29, 11, 1291-1296.

Effect of microwave, infrared, and convection hot-air on drying kinetics and quality properties of okra pods

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hany S. EL-Mesery ◽  
Mona A. Elabd
Keyword(s):  
Energy Consumption ◽  
Air Temperature ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Drying Methods ◽  
Air Velocity ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Shrinkage Ratio ◽  
Hot Air

Abstract Okra pods were dried using the following drying regimes; microwave (MWD), infrared (IRD) and convective hot-air drying (CHD). The objective of this investigate was to report the influences of drying methods on okra quality under different drying conditions. Data analysis showed that rehydration ratio and colour change increased with increase in drying air temperature and air velocity while specific energy consumption and shrinkage ratio decreased with increase in drying air temperature under (CHD). The rehydration ratio and colour of dried okra increased with increase in both infrared intensity but it also increased with a decrease in air velocity under (IRD). In the MWD method, drying time, specific energy consumption and shrinkage ratio decreased with increases in microwave power while the rehydration ratio and colour increased. Optimum drying period, specific energy consumption, colour, shrinkage and rehydration ratio were obtained for microwave drying. The model of Midilli et al. is the greatest for describing the drying curves of okra under all the drying processing conditions.

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