scholarly journals Effects of different drying conditions on curcumin concentration in turmeric

Author(s):  
George Srzednicki ◽  
Qixin Li ◽  
Robert H Driscoll

Turmeric (Curcuma longa), belongs to Zingiberaceae family. The rhizomes contain bioactive compounds of the curcuminoids group (natural phenols). They are used in food and pharmaceutical industry. The aim of this research was to acquire dried turmeric with high total curcumin content. In this study, optimum turmeric drying conditions and new extraction techniques were explored. Fresh turmeric samples were subjected to constant vs changing drying air temperatures and pre-treatment (blanching). Changing drying air temperature and use of non-blanched turmeric slices resulted in the highest concentration of curcumin. Ultrasonic extraction instead of soxhlet extraction improved the extraction efficiency and decreased extraction time. Keywords: Turmeric, Curcumin; Drying; Blanching; Extraction

Author(s):  
S. FERREIRA ◽  
C. R. MALACRIDA ◽  
V. R. NICOLETTI

            Turmeric (Curcuma longa L.) oleoresin possess valuable phenolic compounds that are susceptible to degradation, and microencapsulation is a powerful technique to increase its stability. Emulsification is a preponderant step in microencapsulation of hydrophobic compounds and physical-chemical properties of the parent emulsion affects effectiveness of spray-drying process and functional properties of the produced microcapsules. The present work aimed to evaluate the influence of emulsion formulation, emulsification methods, and spray-drying operational conditions on the encapsulation efficiency of turmeric oleoresin using maltodextrin/gelatin blends as wall material. The effects of different concentrations of maltodextrin (12 - 31.7 wt %) and gelatin (0.6 - 6 wt %), combined with three methods of emulsification - high shear homogenization with and without emulsifier addition, and sonication – were evaluated regarding emulsion droplet mean diameter and stability. Based on the results, an emulsion formulated with 26 g of maltodextrin and 0.6 g of gelatin per 100 g of emulsion was selected to study the influence of spray drying conditions - drying-air temperature (124 – 190 oC), atomization airflow (275 – 536 L h-1), and emulsion feeding flow (1.4 – 8.6 mL min-1) - on encapsulation efficiency, water content, and solubility of turmeric oleoresin microcapsules. Sonication resulted in higher emulsion stability and, although drying-air temperature did not affect significantly the microcapsule properties, the best set of spray drying conditions was drying-air at 160 ºC, atomization airflow of 420 L h-1, and emulsion feeding flow of 6 mL min-1. Combinations of higher atomization airflow and lower emulsion feeding flow resulted in lower values of curcumin encapsulation efficiency.


2018 ◽  
Vol 7 (2.29) ◽  
pp. 1126
Author(s):  
Yvonne Melse Laurence ◽  
Mohammad Shaheen Khan ◽  
Mohd Sani Sarjadi

This report presents a series of different drying condition and extraction methods on Clinacanthus nutans leaves. C. nutans leaves were dried using three different drying conditions: oven (40°C, 60°C and 80°C), vacuum oven and air drying. Then, the physical properties of dried leaves obtained were analyzed in terms of the moisture content and water activity. Thus, the series of extraction was performed using three different extraction techniques: soxhlet, maceration and ultrasound-assisted solvent extraction respectively. Finally, the total phenolic content of each extracts were determined with the Folin-Ciocalteu method. The results showed that the choice of drying method and extraction technique influenced the phenolic compound yield of C. nutans extract. Excellent performance of the combination of drying C. nutans leaves using laboratory oven at 60°C and soxhlet extraction obtained the highest total phenolic content yield at 65.92 ± 2.19 mg GAE/g.  


Food Research ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 140-148
Author(s):  
P.V.C. Hong ◽  
H.D. Tan ◽  
P.T.T. Thanh ◽  
M.H. Cang ◽  
D.L. Don ◽  
...  

The objective of this study is to screen the effects of several parameters (i.e., drying aid concentration, inlet air temperatures, and feed flow rates) on the spray drying process of crocodile meat protein hydrolysate. The results showed that the experimental parameters exhibited significant effects on recovery of dry matter, recovery of proteins and the obtained powder properties (total protein content, moisture content and antioxidant capacity). Besides, inlet air temperature and drying aid concentration also significantly impacted response variables. The conditions for maximum recovery of dry matter, maximum recovery of proteins, and minimum moisture content of the spray-dried powder were found at maltodextrin concentration of 19.47% (w/w), inlet air temperature of 142.71oC, and input feed flow rate of 10 mL/min. These conditions correspond to the recovery of dry matter of 69.51%, protein recovery yield of 76.94%, powder humidity of 5.33%, and powder antioxidant activity of 1.87 mg/mL.


2014 ◽  
Vol 30 (6) ◽  
Author(s):  
Jibrin Mohammed Danlami ◽  
Agus Arsad ◽  
Muhammad Abbas Ahmad Zaini ◽  
Hanizam Sulaiman

AbstractResearchers have shown that techniques such as microwave-assisted extraction, ultrasound-assisted extraction, pressurized liquid extraction, and supercritical fluid extraction developed for extraction of valuable components from plants and seed materials have been successfully used to effectively reduce the major shortcomings of the traditional method such as Soxhlet extraction. These include shorter extraction time, increase in yield of extracted components, decrease in solvent consumption, and improvement of the quality of extracts. This review presents a detailed description of the principles and mechanisms of the various extraction techniques for better understanding and summarizes the potential of these techniques in the extraction of oil from plants and seed materials. Discussions on some of the parameters affecting the extraction efficiency are also highlighted, with special emphasis on supercritical fluid extraction. A comparison of the performance of traditional Soxhlet extraction with that of other extraction techniques is also presented.


2018 ◽  
Vol 14 (1) ◽  
pp. 44-57
Author(s):  
S. N. Shumov

The spatial analysis of distribution and quantity of Hyphantria cunea Drury, 1973 across Ukraine since 1952 till 2016 regarding the values of annual absolute temperatures of ground air is performed using the Gis-technologies. The long-term pest dissemination data (Annual reports…, 1951–1985; Surveys of the distribution of quarantine pests ..., 1986–2017) and meteorological information (Meteorological Yearbooks of air temperature the surface layer of the atmosphere in Ukraine for the period 1951-2016; Branch State of the Hydrometeorological Service at the Central Geophysical Observatory of the Ministry for Emergencies) were used in the present research. The values of boundary negative temperatures of winter diapause of Hyphantria cunea, that unable the development of species’ subsequent generation, are received. Data analyses suggests almost complete elimination of winter diapausing individuals of White American Butterfly (especially pupae) under the air temperature of −32°С. Because of arising questions on the time of action of absolute minimal air temperatures, it is necessary to ascertain the boundary negative temperatures of winter diapause for White American Butterfly. It is also necessary to perform the more detailed research of a corresponding biological material with application to the freezing technics, giving temperature up to −50°С, with the subsequent analysis of the received results by the punched-analysis.


2017 ◽  
Vol 6 (04) ◽  
pp. 5343
Author(s):  
Ragni Vora ◽  
Ambika N. Joshi* ◽  
Nitesh C. Joshi

Mucuna pruriens seeds are noted to be a natural source of L-DOPA and are also used as a substitute for the synthetic L-DOPA. In the present study; attempts are made to develop suitable method(s) for extraction of L-DOPA from the powdered seeds of Mucuna pruriens using different solvents and conditions. The Seed powder was subjected to 7 different extraction methods and Method 1 was subjected to various solvent concentrations. Some methods used de-fatting procedure, either the method was cold maceration or in high temperature. Soxhlet extraction was also used in one of the extraction methods. All the extracts were analyzed using RP-HPLC. Mobile Phase used was Water: Methanol: AcetoNitrile (100:60:40) (v/v) containing 0.2% Triethylamine, pH = 3.3 and monitored at 280 nm with variable wavelength UV detector. The extraction was best with Methanol Water mixture in a cold maceration technique and overall gives good extraction efficiency of 13.36 % L-DOPA and id the best method giving highest extraction efficiency. The De-fatting method was the 2nd best methods giving approximately 8.8% L-DOPA and Method 5 viz, heat reflux method gives 8.7% L-DOPA making it the 3rd best method. There are not many studies done for optimization of extraction technique for L-DOPA despite an extensive work is reported for isolation, identification and pharmacological activities of L-DOPA from various plant sources. Keeping this in view, present investigation was done to study the extraction efficiency of various extraction methods of L-DOPA content in seed extracts of Mucuna pruriens and compare it.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 292 ◽  
Author(s):  
Ana Oliveira ◽  
António Lopes ◽  
Ezequiel Correia ◽  
Samuel Niza ◽  
Amílcar Soares

Lisbon is a European Mediterranean city, greatly exposed to heatwaves (HW), according to recent trends and climate change prospects. Considering the Atlantic influence, air temperature observations from Lisbon’s mesoscale network are used to investigate the interactions between background weather and the urban thermal signal (UTS) in summer. Days are classified according to the prevailing regional wind direction, and hourly UTS is compared between HW and non-HW conditions. Northern-wind days predominate, revealing greater maximum air temperatures (up to 40 °C) and greater thermal amplitudes (approximately 10 °C), and account for 37 out of 49 HW days; southern-wind days have milder temperatures, and no HWs occur. Results show that the wind direction groups are significantly different. While southern-wind days have minor UTS variations, northern-wind days have a consistent UTS daily cycle: a diurnal urban cooling island (UCI) (often lower than –1.0 °C), a late afternoon peak urban heat island (UHI) (occasionally surpassing 4.0 °C), and a stable nocturnal UHI (1.5 °C median intensity). UHI/UCI intensities are not significantly different between HW and non-HW conditions, although the synoptic influence is noted. Results indicate that, in Lisbon, the UHI intensity does not increase during HW events, although it is significantly affected by wind. As such, local climate change adaptation strategies must be based on scenarios that account for the synergies between potential changes in regional air temperature and wind.


2020 ◽  
Vol 1008 ◽  
pp. 128-138
Author(s):  
Ahmed M. Salman ◽  
Ibrahim A. Ibrahim ◽  
Hamada M. Gad ◽  
Tharwat M. Farag

In the present study, the combustion characteristics of LPG gaseous fuel diffusion flame at elevated air temperatures were experimentally investigated. An experimental test rig was manufactured to examine a wide range of operating conditions. The investigated parameters are the air temperatures of 300, 350, 400, 450, and 500 K with constant percentage of nitrogen addition in combustion air stream of 5 % to give low oxygen concentration of 18.3 % by mass at constant air swirl number, air to fuel mass ratio, and thermal load of 1.5, 30, and 23 kW, respectively. The gaseous combustion characteristics were represented as axial and radial temperatures distributions, temperatures gradient, visible flame length and species concentrations. The results indicated that as the air temperature increased, the chemical reaction rate increased and flame volume decreased, the combustion time reduced leading to a reduction in flame length. The NO concentration reaches its maximum values near the location of the maximum centerline axial temperature. Increasing the combustion air temperature by 200 K, the NO consequently O2 concentrations are increased by about % 355 and 20 % respectively, while CO2 and CO concentrations are decreased by about % 21 and 99 % respectively, at the combustor end.


Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1377
Author(s):  
Weifang Shi ◽  
Nan Wang ◽  
Aixuan Xin ◽  
Linglan Liu ◽  
Jiaqi Hou ◽  
...  

Mitigating high air temperatures and heat waves is vital for decreasing air pollution and protecting public health. To improve understanding of microscale urban air temperature variation, this paper performed measurements of air temperature and relative humidity in a field of Wuhan City in the afternoon of hot summer days, and used path analysis and genetic support vector regression (SVR) to quantify the independent influences of land cover and humidity on air temperature variation. The path analysis shows that most effect of the land cover is mediated through relative humidity difference, more than four times as much as the direct effect, and that the direct effect of relative humidity difference is nearly six times that of land cover, even larger than the total effect of the land cover. The SVR simulation illustrates that land cover and relative humidity independently contribute 16.3% and 83.7%, on average, to the rise of the air temperature over the land without vegetation in the study site. An alternative strategy of increasing the humidity artificially is proposed to reduce high air temperatures in urban areas. The study would provide scientific support for the regulation of the microclimate and the mitigation of the high air temperature in urban areas.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Vyacheslav N. Baklagin

The paper shows the changes in the dates (complete freeze-up, ±5 days/°C and complete ice clearance, ±3 days/°C) of the ice regime in Lake Onego depending on changes in average air temperature within the preceding two-month periods (autumn and spring). The regression equations for their calculation based on previous three- and four-month periods according to the 2000-2018 data are also provided. Indicative dates of ice regime based on accumulated air temperatures within the ice period of Lake Onego were also established (early formation of ice phenomena, complete freeze-up phase, beginning of the break-up phase and complete ice clearance). Together with the data on expected air temperature above the lake’s surface, these dependencies enable us to predict the indicative dates of the ice regime.


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