Drying Behavior and Curcuminoids Changes in Turmeric Slices during Drying under Simulated Solar Radiation as Influenced by Different Transparent Cover Materials
Dried turmeric is used as a spice and traditional medicine. The common drying methods for turmeric (<i>Curcuma longa</i> L.) are sun drying and solar drying. In this study, turmeric slices with a thickness of 2 mm were dried at 40, 50, 60, and 70 °C in a laboratory hot-air dryer with a s...
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MDPI AG
2022-02-01
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| Series: | Foods |
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| Online Access: | https://www.mdpi.com/2304-8158/11/5/696 |
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| author | Nilobon Komonsing Sebastian Reyer Pramote Khuwijitjaru Busarakorn Mahayothee Joachim Müller |
| author_facet | Nilobon Komonsing Sebastian Reyer Pramote Khuwijitjaru Busarakorn Mahayothee Joachim Müller |
| author_sort | Nilobon Komonsing |
| collection | DOAJ |
| description | Dried turmeric is used as a spice and traditional medicine. The common drying methods for turmeric (<i>Curcuma longa</i> L.) are sun drying and solar drying. In this study, turmeric slices with a thickness of 2 mm were dried at 40, 50, 60, and 70 °C in a laboratory hot-air dryer with a simulated solar radiation applied through transparent polycarbonate cover (UV impermeable) and PMMA cover (UV permeable). Air velocity and relative humidity of drying air were fixed at 1.0 M·s<sup>−1</sup> and 25 g H<sub>2</sub>O kg<sup>−1</sup> dry air, respectively. Light significantly increased the sample temperature under both covers. Page was the best model to predict the drying characteristics of turmeric slices. Drying rate correlated with the effective moisture diffusivity, which increased at higher temperature. The hue angle (<i>h</i>°) of turmeric was distinctly lower at 70 °C under both covers. The dried products were of intensive orange color. Curcumin, demethoxycurcumin, and total curcuminoids were affected by the cumulated thermal load (<i>CTL</i>). The lowest curcumin content was found at 40 °C under PMMA (highest <i>CTL</i>). The optimum drying condition was 70 °C under polycarbonate cover due to shorter drying time and better preservation of color and curcuminoids in the dried product. |
| first_indexed | 2024-03-09T20:39:50Z |
| format | Article |
| id | doaj.art-62fffdd87bf443c99e1fe55a40d23596 |
| institution | Directory Open Access Journal |
| issn | 2304-8158 |
| language | English |
| last_indexed | 2024-03-09T20:39:50Z |
| publishDate | 2022-02-01 |
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| series | Foods |
| spelling | doaj.art-62fffdd87bf443c99e1fe55a40d235962023-11-23T23:01:07ZengMDPI AGFoods2304-81582022-02-0111569610.3390/foods11050696Drying Behavior and Curcuminoids Changes in Turmeric Slices during Drying under Simulated Solar Radiation as Influenced by Different Transparent Cover MaterialsNilobon Komonsing0Sebastian Reyer1Pramote Khuwijitjaru2Busarakorn Mahayothee3Joachim Müller4Department of Food Technology, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom 73000, ThailandTropics and Subtropics Group, Institute of Agricultural Engineering, University of Hohenheim, 70599 Stuttgart, GermanyDepartment of Food Technology, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom 73000, ThailandDepartment of Food Technology, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom 73000, ThailandTropics and Subtropics Group, Institute of Agricultural Engineering, University of Hohenheim, 70599 Stuttgart, GermanyDried turmeric is used as a spice and traditional medicine. The common drying methods for turmeric (<i>Curcuma longa</i> L.) are sun drying and solar drying. In this study, turmeric slices with a thickness of 2 mm were dried at 40, 50, 60, and 70 °C in a laboratory hot-air dryer with a simulated solar radiation applied through transparent polycarbonate cover (UV impermeable) and PMMA cover (UV permeable). Air velocity and relative humidity of drying air were fixed at 1.0 M·s<sup>−1</sup> and 25 g H<sub>2</sub>O kg<sup>−1</sup> dry air, respectively. Light significantly increased the sample temperature under both covers. Page was the best model to predict the drying characteristics of turmeric slices. Drying rate correlated with the effective moisture diffusivity, which increased at higher temperature. The hue angle (<i>h</i>°) of turmeric was distinctly lower at 70 °C under both covers. The dried products were of intensive orange color. Curcumin, demethoxycurcumin, and total curcuminoids were affected by the cumulated thermal load (<i>CTL</i>). The lowest curcumin content was found at 40 °C under PMMA (highest <i>CTL</i>). The optimum drying condition was 70 °C under polycarbonate cover due to shorter drying time and better preservation of color and curcuminoids in the dried product.https://www.mdpi.com/2304-8158/11/5/696<i>Curcuma longa</i>herbdrying characteristicultravioletsolar drying |
| spellingShingle | Nilobon Komonsing Sebastian Reyer Pramote Khuwijitjaru Busarakorn Mahayothee Joachim Müller Drying Behavior and Curcuminoids Changes in Turmeric Slices during Drying under Simulated Solar Radiation as Influenced by Different Transparent Cover Materials Foods <i>Curcuma longa</i> herb drying characteristic ultraviolet solar drying |
| title | Drying Behavior and Curcuminoids Changes in Turmeric Slices during Drying under Simulated Solar Radiation as Influenced by Different Transparent Cover Materials |
| title_full | Drying Behavior and Curcuminoids Changes in Turmeric Slices during Drying under Simulated Solar Radiation as Influenced by Different Transparent Cover Materials |
| title_fullStr | Drying Behavior and Curcuminoids Changes in Turmeric Slices during Drying under Simulated Solar Radiation as Influenced by Different Transparent Cover Materials |
| title_full_unstemmed | Drying Behavior and Curcuminoids Changes in Turmeric Slices during Drying under Simulated Solar Radiation as Influenced by Different Transparent Cover Materials |
| title_short | Drying Behavior and Curcuminoids Changes in Turmeric Slices during Drying under Simulated Solar Radiation as Influenced by Different Transparent Cover Materials |
| title_sort | drying behavior and curcuminoids changes in turmeric slices during drying under simulated solar radiation as influenced by different transparent cover materials |
| topic | <i>Curcuma longa</i> herb drying characteristic ultraviolet solar drying |
| url | https://www.mdpi.com/2304-8158/11/5/696 |
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