Drying of <i>Gymnema sylvestre</i> Using Far-Infrared Radiation: Antioxidant Activity and Optimization of Drying Conditions
The leaf extracts of <i>Gymnema sylvestre</i> consist of secondary metabolites which are well known for antioxidant activity. This study aimed to measure the drying characteristics of <i>G. sylvestre</i> leaves under far-infrared radiation (FIR) and to optimize the specific e...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-03-01
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| Series: | AgriEngineering |
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| Online Access: | https://www.mdpi.com/2624-7402/5/1/38 |
| _version_ | 1797614064081305600 |
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| author | Gunaratnam Abhiram Abhiram Briyangari Rasu Eeswaran |
| author_facet | Gunaratnam Abhiram Abhiram Briyangari Rasu Eeswaran |
| author_sort | Gunaratnam Abhiram |
| collection | DOAJ |
| description | The leaf extracts of <i>Gymnema sylvestre</i> consist of secondary metabolites which are well known for antioxidant activity. This study aimed to measure the drying characteristics of <i>G. sylvestre</i> leaves under far-infrared radiation (FIR) and to optimize the specific energy consumption for drying and antioxidant activity of ethanol-water extract of dried leaves. Fresh leaves were harvested and exposed to combinations of four different temperatures (125, 150, 175 and 200 °C) and exposure times (5, 10, 15 and 20 min). Drying kinetics, energy consumption, color changes, total phenolic content (TPC) and antioxidant activities were quantified. Both temperature and drying time have significant (<i>p</i> < 0.05) effects on drying characteristics and antioxidant activity. The equilibrium moisture content was achieved at 200 °C and 18 min. The specific energy decreased and total color changes increased with temperature. Under lower temperatures (125 and 150 °C), TPC and antioxidant activity increased with exposure time, whereas higher exposure time (20 min) with high temperatures (175 and 200 °C) significantly decreased TPC and antioxidant activity. The highest TPC of 30.5 mg TAE/g leaf-fresh weight was achieved at 200 °C and 15 min. The optimal drying conditions achieved from the dissimilarity function method were 200 °C and 8.4 min. |
| first_indexed | 2024-03-11T07:03:21Z |
| format | Article |
| id | doaj.art-4b864bd81be34a3c8dba44d3f5d4302a |
| institution | Directory Open Access Journal |
| issn | 2624-7402 |
| language | English |
| last_indexed | 2024-03-11T07:03:21Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | AgriEngineering |
| spelling | doaj.art-4b864bd81be34a3c8dba44d3f5d4302a2023-11-17T09:03:27ZengMDPI AGAgriEngineering2624-74022023-03-015161162210.3390/agriengineering5010038Drying of <i>Gymnema sylvestre</i> Using Far-Infrared Radiation: Antioxidant Activity and Optimization of Drying ConditionsGunaratnam Abhiram0Abhiram Briyangari1Rasu Eeswaran2Postgraduate Institute of Science, University of Peradeniya, Peradeniya 20400, Sri LankaPostgraduate Institute of Science, University of Peradeniya, Peradeniya 20400, Sri LankaDepartment of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USAThe leaf extracts of <i>Gymnema sylvestre</i> consist of secondary metabolites which are well known for antioxidant activity. This study aimed to measure the drying characteristics of <i>G. sylvestre</i> leaves under far-infrared radiation (FIR) and to optimize the specific energy consumption for drying and antioxidant activity of ethanol-water extract of dried leaves. Fresh leaves were harvested and exposed to combinations of four different temperatures (125, 150, 175 and 200 °C) and exposure times (5, 10, 15 and 20 min). Drying kinetics, energy consumption, color changes, total phenolic content (TPC) and antioxidant activities were quantified. Both temperature and drying time have significant (<i>p</i> < 0.05) effects on drying characteristics and antioxidant activity. The equilibrium moisture content was achieved at 200 °C and 18 min. The specific energy decreased and total color changes increased with temperature. Under lower temperatures (125 and 150 °C), TPC and antioxidant activity increased with exposure time, whereas higher exposure time (20 min) with high temperatures (175 and 200 °C) significantly decreased TPC and antioxidant activity. The highest TPC of 30.5 mg TAE/g leaf-fresh weight was achieved at 200 °C and 15 min. The optimal drying conditions achieved from the dissimilarity function method were 200 °C and 8.4 min.https://www.mdpi.com/2624-7402/5/1/38antioxidant activitycolor changesenergy consumptiondrying kineticsfar-infraredresponse surface method |
| spellingShingle | Gunaratnam Abhiram Abhiram Briyangari Rasu Eeswaran Drying of <i>Gymnema sylvestre</i> Using Far-Infrared Radiation: Antioxidant Activity and Optimization of Drying Conditions AgriEngineering antioxidant activity color changes energy consumption drying kinetics far-infrared response surface method |
| title | Drying of <i>Gymnema sylvestre</i> Using Far-Infrared Radiation: Antioxidant Activity and Optimization of Drying Conditions |
| title_full | Drying of <i>Gymnema sylvestre</i> Using Far-Infrared Radiation: Antioxidant Activity and Optimization of Drying Conditions |
| title_fullStr | Drying of <i>Gymnema sylvestre</i> Using Far-Infrared Radiation: Antioxidant Activity and Optimization of Drying Conditions |
| title_full_unstemmed | Drying of <i>Gymnema sylvestre</i> Using Far-Infrared Radiation: Antioxidant Activity and Optimization of Drying Conditions |
| title_short | Drying of <i>Gymnema sylvestre</i> Using Far-Infrared Radiation: Antioxidant Activity and Optimization of Drying Conditions |
| title_sort | drying of i gymnema sylvestre i using far infrared radiation antioxidant activity and optimization of drying conditions |
| topic | antioxidant activity color changes energy consumption drying kinetics far-infrared response surface method |
| url | https://www.mdpi.com/2624-7402/5/1/38 |
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