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An on-line method f...
An on-line method for pressurized hot water extraction and enzymatic hydrolysis of quercetin glucosides from onions.
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- Lindahl, Sofia (författare)
- Lund University,Lunds universitet,Centrum för analys och syntes,Kemiska institutionen,Institutioner vid LTH,Lunds Tekniska Högskola,Centre for Analysis and Synthesis,Department of Chemistry,Departments at LTH,Faculty of Engineering, LTH
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- Liu, Jiayin (författare)
- Lund University,Lunds universitet,Centrum för analys och syntes,Kemiska institutionen,Institutioner vid LTH,Lunds Tekniska Högskola,Centre for Analysis and Synthesis,Department of Chemistry,Departments at LTH,Faculty of Engineering, LTH
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- Khan, Sami (författare)
- Lund University,Lunds universitet,Bioteknik,Centrum för tillämpade biovetenskaper,Kemiska institutionen,Institutioner vid LTH,Lunds Tekniska Högskola,Biotechnology,Center for Applied Life Sciences,Department of Chemistry,Departments at LTH,Faculty of Engineering, LTH
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- Nordberg Karlsson, Eva (författare)
- Lund University,Lunds universitet,Bioteknik,Centrum för tillämpade biovetenskaper,Kemiska institutionen,Institutioner vid LTH,Lunds Tekniska Högskola,Biotechnology,Center for Applied Life Sciences,Department of Chemistry,Departments at LTH,Faculty of Engineering, LTH
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- Turner, Charlotta (författare)
- Lund University,Lunds universitet,Centrum för analys och syntes,Kemiska institutionen,Institutioner vid LTH,Lunds Tekniska Högskola,Centre for Analysis and Synthesis,Department of Chemistry,Departments at LTH,Faculty of Engineering, LTH
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(creator_code:org_t)
- Elsevier BV, 2013
- 2013
- Engelska.
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 1873-4324 .- 0003-2670. ; 785, s. 50-59
- Relaterad länk:
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http://dx.doi.org/10...
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https://lup.lub.lu.s...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- A novel environmentally sound continuous-flow hot water extraction and enzymatic hydrolysis method for determination of quercetin in onion raw materials was successfully constructed using a stepwise optimization approach. In the first step, enzymatic hydrolysis of quercetin-3,4'-diglucoside to quercetin was optimized using a three level central composite design considering temperature (75-95°C), pH (3-6) and volume concentration of ethanol (5-15%). The enzyme used was a thermostable β-glucosidase variant (termed TnBgl1A_N221S/P342L) covalently immobilized on either of two acrylic support-materials (Eupergit(®) C 250L or monolithic cryogel). Optimal reaction conditions were irrespective of support 84°C, 5% ethanol and pH 5.5, and at these conditions, no significant loss of enzyme activity was observed during 72h of use. In a second step, hot water extractions from chopped yellow onions, run at the optimal temperature for hydrolysis, were optimized in a two level design with respect to pH (2.6 and 5.5), ethanol concentration (0 and 5%) and flow rate (1 and 3mLmin(-1)) Obtained results showed that the total quercetin extraction yield was 1.7 times higher using a flow rate of 3mLmin(-1) (extraction time 90min), compared to a flow rate of 1mLmin(-1) (extraction time 240min). Presence of 5% ethanol was favorable for the extraction yield, while a further decrease in pH was not, not even for the extraction step alone. Finally, the complete continuous flow method (84°C, 5% ethanol, pH 5.5, 3mLmin(-1)) was used to extract quercetin from yellow, red and shallot onions and resulted in higher or similar yield (e.g. 8.4±0.7μmolg(-1) fresh weight yellow onion) compared to a conventional batch extraction method using methanol as extraction solvent.
Ämnesord
- NATURVETENSKAP -- Kemi -- Analytisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Analytical Chemistry (hsv//eng)
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