scholarly journals Infrared Drying as a Quick Preparation Method for Dried Tangerine Peel

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Mingyue Xu ◽  
Guifang Tian ◽  
Chengying Zhao ◽  
Aftab Ahmad ◽  
Huijuan Zhang ◽  
...  

To establish the most convenient and effective method to dry tangerine peels, different methods (sun drying, hot-air drying, freeze drying, vacuum drying, and medium- and short-wave infrared drying) were exploited. Our results indicated that medium- and short-wave infrared drying was the best method to preserve nutraceutical components; for example, vitamin C was raised to 6.77 mg/g (D.W.) from 3.39 mg/g (sun drying). Moreover, the drying time can be shortened above 96% compared with sun drying. Importantly, the efficiency of DPPH radical scavenging was enhanced from 26.66% to 55.92%. These findings would provide a reliable and time-saving methodology to produce high-quality dried tangerine peels.

Author(s):  
Yanling He ◽  
Dan Huang ◽  
Yongjia Chen ◽  
Kaiyang Men ◽  
S. A. Sherif ◽  
...  

Abstract The drying characteristics and drying quality of fresh white waxy corn were investigated under three different drying methods (sun drying, hot-air drying and far-infrared drying) and different drying temperatures (55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C). The optimal drying method and drying condition were obtained by comparing the drying time and drying quality including damage rate, rehydration capacity and the contents of protein, fatty acid and starch. The results showed that the drying time of sun drying was the longest, while the drying quality was the best, i.e., the damage rate was the lowest and the nutrient retention was the highest. The far-infrared drying time was shorter and the quality was better than that of hot air drying. The higher the temperature, the faster the drying rate. The optimal drying temperature was 60 °C under far-infrared drying, which can effectively remove the water and keep the food quality. Besides, the drying rate was faster than hot air, and the color of the dried products was brighter. When hot air drying was used, the value of fatty acids did not change much below 65 °C, but it rose sharply above 65 °C. The optimal drying temperature was 65 °C, under which the drying rate was moderate and the quality was relatively good. If the production cost was considered, sun drying was the best, following the 60 °C far-infrared drying. This conclusion can provide a reference for the drying conditions of corn after harvest in agricultural production, and to a certain extent provide suggestions for the later drying treatment methods and treatment temperatures of fresh white waxy corn.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253834
Author(s):  
Warongporn Choopan ◽  
Worawan Panpipat ◽  
Mudtorlep Nisoa ◽  
Ling-Zhi Cheong ◽  
Manat Chaijan

The objective of this research was to comparatively investigate the effect of hot air drying (HA) and hybrid microwave-infrared drying (MI) on physico-chemical characteristics of Thai fermented fish viscera, Tai-Pla, curry powder (TCP). HA was carried out at 60°C, 70°C, and 80°C and MI was carried out at a microwave power of 740, 780, and 810 W with a constant infrared heating power (500 W) for different drying times to obtain the final moisture content ≤ 12.0% and the water activity (aw) ≤ 0.6. The quality characteristics of TCP were governed by HA temperature and MI output power. TCP dried using HA and MI at all conditions had similar contents of protein, lipid, ash, fiber, and carbohydrate (p>0.05). The fastest drying rate was detected when MI at 810 W for 40 min was applied (p<0.05). In this condition, TCP had the lowest browning index (A294 and A420) and the highest lightness (L* value) (p<0.05). TCP dried with MI at all powers had higher phenolic content and lower TBARS compared to HA (p<0.05). However, no significant differences in DPPH• scavenging activity were observed among TPC made by HA and MI (p>0.05). Similar Fourier transform infrared (FTIR) spectra with different peak intensities were observed in all samples, indicating the same functional groups with different contents were found. The bulk density of all TCP ranged from 0.51 g/mL to 0.61 g/mL and the wettability ranged from 24.02% to 26.70%. MI at 810 W for 40 min effectively reduced the drying time (5-fold faster) and lowered the specific energy consumption (18-fold lower) compared to the HA at 60°C for 210 min. Therefore, MI is a promising drying technique to reduce the drying time and improve the overall quality of TCP.


Author(s):  
Pranabendu Mitra ◽  
Venkatesh Meda ◽  
Rick Green

The main objective of this research was to compare the retention of antioxidant activity and total anthocyanin content of Saskatoon berries dried by freeze drying, microwave-vacuum drying, thin layer hot air drying and vacuum drying. Antioxidant activity of berry samples was determined by DPPH radical scavenging and ABTS radical scavenging, and the pH differential method was used to determine total anthocyanin content of the berry samples. The results showed that the freeze dried Saskatoon berries exhibited the highest retention of anthocyanin and antioxidant activity among the dried samples, followed by microwave-vacuum dried berries, thin layer hot air dried berries and vacuum dried berries. There were significant differences between the berry samples at P<0.05.  DPPH radical scavenging and ABTS radical scavenging were correlated linearly with an R2 value of 0.99 at P<0.05 showing their effectiveness for the determination of the antioxidant activity of the Saskatoon berries. However, the DPPH radical scavenging assay was more effective than the ABTS radical scavenging assay. The results also showed that antioxidant activity of the berries was highly correlated with the total anthocyanin content of the fruit. The reduction of anthocyanin in dried berry samples was linearly correlated with the reduction of DPPH radical scavenging with an R2 value of 0.97 at P<0.05 and, also, linearly correlated with the reduction of ABTS radical scavenging with an R2 value of 0.88 at P<0.05.


2014 ◽  
pp. 5-12
Author(s):  
Tamás Antal

In this study, the effects of freeze drying (FD), hot-air drying (HAD) and combined drying (HAD-FD) on drying characteristics, energy uptake, texture, rehydration and color of carrot were investigated. Results showed that HAD-FD significantly improved the drying time compared with FD under the same operating conditions, and the HAD-FD can reduce the total cost of dehydration. The drying kinetics was described by the Henderson-Pabis and the third degree polynomial models in the case of HAD, FD and HAD-FD. The HAD carrot samples were exhibited shrinkage, case hardening, poor rehydration and brown surface. The FD carrot cubes appeared porous structure, excellent rehydration, soft texture and loose color. The HAD-FD samples were superior to HAD products and was nearer in quality to FD products with respect to appearance, rehydration and surface resistance (texture). Finally, it is concluded that HAD-FD is effective in improving the FD drying rate. However, the combined drying has a small-scale adverse effect on product quality.


2013 ◽  
Vol 2 (2) ◽  
Author(s):  
Pranabendu Mitra ◽  
Venkatesh Meda ◽  
Rick Green

The main objective of this research was to compare the retention of antioxidant activity and total anthocyanin content of Saskatoon berries dried by freeze drying, microwave-vacuum drying, thin layer hot air drying and vacuum drying. Antioxidant activity of berry samples was determined by DPPH radical scavenging and ABTS radical scavenging, and the pH differential method was used to determine total anthocyanin content of the berry samples. The results showed that the freeze dried Saskatoon berries exhibited the highest retention of anthocyanin and antioxidant activity among the dried samples, followed by microwave-vacuum dried berries, thin layer hot air dried berries and vacuum dried berries. There were significant differences between the berry samples at P<0.05.  DPPH radical scavenging and ABTS radical scavenging were correlated linearly with an R2 value of 0.99 at P<0.05 showing their effectiveness for the determination of the antioxidant activity of the Saskatoon berries. However, the DPPH radical scavenging assay was more effective than the ABTS radical scavenging assay. The results also showed that antioxidant activity of the berries was highly correlated with the total anthocyanin content of the fruit. The reduction of anthocyanin in dried berry samples was linearly correlated with the reduction of DPPH radical scavenging with an R2 value of 0.97 at P<0.05 and, also, linearly correlated with the reduction of ABTS radical scavenging with an R2 value of 0.88 at P<0.05.


Author(s):  
Dat Q Tran

Dried vegetables are considered convenient for storage, transportation and preservation. The different drying techniques could influence the quality of resulting products. This study aimed to evaluate the effects of three distinguish drying methods as hot-air drying, foam-mat drying and microwave drying on the color retention and chlorophyll of green vegetables powder. Fresh spinach(Spinacia oleraceaL.), celery (Apium graveolensL.), Malabar spinach (Basella albaL.) were dried by different methods: hot air at 60oC, foam-mat at 60oC and microwave at 270 W until the samples reached approximately 9% of moisture content (wb). The drying time of the dried samples by microwave, foam-mat and hot-air method were 60, 210 and 240 min, respectively. Foam-mat dried vegetables were found to have the best quality in terms of color and the residual chlorophyll content. The findings suggest that foam-mat drying is promising in dried vegetable processing


2018 ◽  
Vol 26 (4) ◽  
pp. 202-208
Author(s):  
Sang Im Oh ◽  
Seo Young Kim ◽  
Ja Hee Lee ◽  
Ae Kyung Lee

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Lihui Zhang ◽  
Yu Qiao ◽  
Chao Wang ◽  
Li Liao ◽  
Lu Liu ◽  
...  

In this study, freeze vacuum drying (FVD), hot air drying (AD), and FVD combined with AD (FVD-AD) were used to dry kiwifruits. Dried products were analyzed comprehensively on their sensory quality, active components, moisture mobility, odors, and microstructure. Results showed that the FVD-AD saved time by 38.22% compared with FVD while maintaining an acceptable product quality. The antioxidant properties of FVD-AD were lower than those of FVD but significantly higher than those of AD. Moreover, compared with FVD products, FVD-AD products were moderately hard (5252.71 ± 33.53 g) and improved in color, bound water, and microstructure. Additionally, FVD-AD consumed lesser drying time and energy than FD. According to cluster analysis, the odors of FVD-AD products were similar to those of the fresh ones. Principal component analysis of physicochemical and drying cost indicated that FVD-AD was a promising processing technique for functional kiwifruit snacks.


2020 ◽  
Vol 1003 ◽  
pp. 260-267
Author(s):  
Xian Feng Wu ◽  
Xu Jia Li ◽  
Xin Zhi Bei

Based on the drying technology principle of lithium-ion battery cathode coating, the variation law of dry base moisture content and drying rate in the process of hot-air drying and infrared drying was studied. The experimental results show that the cathode coating of lithium-ion battery dried under hot-air and infrared conditions can be divided into three stages: increasing-rate, constant-rate, and falling-rate. The constant-rate stage is the main drying stage, accounting for more than 50% of the weight loss, the falling-rate stage is the main energy consumption stage, accounting for more than 50% of the time. Under the condition of hot-air, the change level of airspeed is the main influencing factor of the drying process, and the drying time can be reduced by about 35% for each 0.7 m/s increase in airspeed. Under infrared conditions, the change level of radiation power is the main influencing factor of the drying process, and the drying time can be reduced by about 34.1% for every 100W of power increase. The optimal drying conditions under hot-air conditions are: air temperature 90 °C, airspeed 2.3 m/s; the optimal drying conditions under infrared conditions are: radiation distance 13 cm, radiation power 200 W. By comparing the best conditions of hot-air and infrared, it can be known that the drying efficiency is higher in the infrared condition and the drying duration is 160 s, but the energy utilization rate in the falling-rate stage in the infrared condition is lower than that in the hot-air condition. Therefore, when infrared drying enters the falling-rate stage, it can be supplemented by hot-air drying to further improve the drying efficiency.


Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 101 ◽  
Author(s):  
Senadeera ◽  
Adiletta ◽  
Önal ◽  
Di Matteo ◽  
Russo

Drying characteristics of persimmon, cv. “Rojo Brillante”, slabs were experimentally determined in a hot air convective drier at drying temperatures of 45, 50, 55, 60, and 65 °C at a fixed air velocity of 2.3 m/s. It was observed that the drying temperature affected the drying time, shrinkage, and colour. Four empirical mathematical models namely, Enderson and Pabis, Page, Logarithmic, and Two term, were evaluated in order to deeply understand the drying process (moisture ratio). The Page model described the best representation of the experimental drying data at all investigated temperatures (45, 50, 55, 60, 65 °C). According to the evaluation of the shrinkage models, the Quadratic model provided the best representation of the volumetric shrinkage of persimmons as a function of moisture content. Overall, higher drying temperature (65 °C) improved the colour retention of dried persimmon slabs.


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