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Subcritical water extraction and beta-glucosidase-catalyzed hydrolysis of quercetin glycosides in onion waste

Turner, Charlotta ; Turner, Pernilla LU ; Jacobson, Gunilla ; Almgren, Knut ; Waldeback, Monica ; Sjoberg, Per ; Nordberg Karlsson, Eva LU orcid and Markides, Karin (2006) In Green Chemistry 8(11). p.949-959
Abstract
Onion waste is a renewable raw material, rich in different molecular species of the antioxidant quercetin. To utilize this resource, an environmentally sustainable procedure has been developed, using pressurized hot water to extract the quercetin species, followed by biocatalytic conversion of the quercetin glycosides to quercetin and carbohydrates. Two different recombinantly expressed thermostable beta-glucosidases, Thermotoga neapolitana beta-glucosidase A and B, were utilized as catalysts. These enzymes maintain activity at temperatures around 90 degrees C, and are therefore ideal to use in combination with hot water extraction. Our results, based on experimental design, showed that they converted quercetin glycosides to active... (More)
Onion waste is a renewable raw material, rich in different molecular species of the antioxidant quercetin. To utilize this resource, an environmentally sustainable procedure has been developed, using pressurized hot water to extract the quercetin species, followed by biocatalytic conversion of the quercetin glycosides to quercetin and carbohydrates. Two different recombinantly expressed thermostable beta-glucosidases, Thermotoga neapolitana beta-glucosidase A and B, were utilized as catalysts. These enzymes maintain activity at temperatures around 90 degrees C, and are therefore ideal to use in combination with hot water extraction. Our results, based on experimental design, showed that they converted quercetin glycosides to active quercetin in less than 10 min reaction time in water at 90 degrees C, pH 5.0. Experimental design showed that the optimal extraction conditions included three 5 min extraction cycles with water at 120 degrees C and 50 bars, giving a total extraction time of 15 min. Several different types of quercetin and isorhamnetin glycosides as well as kaempferol were detected in onion waste using LC-MS/MS analysis. After converting the different glycosidic compounds to their respective aglycones, the quercetin content was 10 to 50 mg g(-1) dry weight of onion waste (RSD 8%). In summary, our research demonstrates that subcritical water extraction followed by beta-glucosidase-catalyzed hydrolysis is a rapid method to determine the content of quercetin and isorhamnetin in onion samples, and is environmentally sustainable as it only uses water as solvent and enzymes as catalysts. (Less)
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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Green Chemistry
volume
8
issue
11
pages
949 - 959
publisher
Royal Society of Chemistry
external identifiers
  • wos:000241588000008
  • scopus:33750507897
ISSN
1463-9270
DOI
10.1039/b608011a
language
English
LU publication?
yes
id
7cc18d80-f630-4f77-b71e-c380115f0751 (old id 378853)
date added to LUP
2016-04-01 12:08:44
date last changed
2021-10-10 03:59:12
@article{7cc18d80-f630-4f77-b71e-c380115f0751,
  abstract     = {Onion waste is a renewable raw material, rich in different molecular species of the antioxidant quercetin. To utilize this resource, an environmentally sustainable procedure has been developed, using pressurized hot water to extract the quercetin species, followed by biocatalytic conversion of the quercetin glycosides to quercetin and carbohydrates. Two different recombinantly expressed thermostable beta-glucosidases, Thermotoga neapolitana beta-glucosidase A and B, were utilized as catalysts. These enzymes maintain activity at temperatures around 90 degrees C, and are therefore ideal to use in combination with hot water extraction. Our results, based on experimental design, showed that they converted quercetin glycosides to active quercetin in less than 10 min reaction time in water at 90 degrees C, pH 5.0. Experimental design showed that the optimal extraction conditions included three 5 min extraction cycles with water at 120 degrees C and 50 bars, giving a total extraction time of 15 min. Several different types of quercetin and isorhamnetin glycosides as well as kaempferol were detected in onion waste using LC-MS/MS analysis. After converting the different glycosidic compounds to their respective aglycones, the quercetin content was 10 to 50 mg g(-1) dry weight of onion waste (RSD 8%). In summary, our research demonstrates that subcritical water extraction followed by beta-glucosidase-catalyzed hydrolysis is a rapid method to determine the content of quercetin and isorhamnetin in onion samples, and is environmentally sustainable as it only uses water as solvent and enzymes as catalysts.},
  author       = {Turner, Charlotta and Turner, Pernilla and Jacobson, Gunilla and Almgren, Knut and Waldeback, Monica and Sjoberg, Per and Nordberg Karlsson, Eva and Markides, Karin},
  issn         = {1463-9270},
  language     = {eng},
  number       = {11},
  pages        = {949--959},
  publisher    = {Royal Society of Chemistry},
  series       = {Green Chemistry},
  title        = {Subcritical water extraction and beta-glucosidase-catalyzed hydrolysis of quercetin glycosides in onion waste},
  url          = {http://dx.doi.org/10.1039/b608011a},
  doi          = {10.1039/b608011a},
  volume       = {8},
  year         = {2006},
}