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Accounting for co-extractable compounds (blank correction) in spectrophotometric measurement of extractable and total-bound proanthocyanidin in Leucaena spp
Dalzell, S. A. and Kerven, G. L. (2002) Accounting for co-extractable compounds (blank correction) in spectrophotometric measurement of extractable and total-bound proanthocyanidin in Leucaena spp. Journal of The Science of Food and Agriculture, 82 8: 860-868.
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| Author(s) |
Dalzell, S. A.
Kerven, G. L.
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| Title |
Accounting for co-extractable compounds (blank correction) in spectrophotometric measurement of extractable and total-bound proanthocyanidin in Leucaena spp
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| Journal name |
Journal of The Science of Food and Agriculture
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| Publication date |
2002
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| Volume number |
82
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| Issue number |
8
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| ISSN |
0022-5142
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| Start page |
860
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| End page |
868
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| Total pages |
9
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| Place of publication |
Chichester, England
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| Publisher |
John Wiley & Sons on behalf of SCI
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| Collection year |
2002
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| Language |
eng
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| Subject |
C1
300201 Plant Biochemistry and Physiology
630200 Pasture, Browse and Fodder Crops
300606 Agroforestry
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| Formatted abstract |
Methods to account for the spectral interference of co-extractable compounds (blank correction) in the spectrophotometric analysis of both extractable and bound proanthocyanidin (PA) using the proanthocyanidin (butanol/HCl) assay were evaluated. Crude extractable and bound PA sample matrices of PA-free Leucaena magnifica were used. Extractable PA blanks generated in heated 95% butanol/5% H2O reagent underestimated the optical density (absorbance) of co-extractable compounds by 24% (P < 0.01), whereas unheated 95% butanol/5% HCl blanks, incubated at room temperature, accurately measured the absorbance of the background matrix (P < 0.01). Current procedures that estimate bound PA concentrations using the proanthocyanidin assay produce intensely coloured background matrices. Recovery measurements from total-bound PA extracts spiked with 1071 and 2142 µg anthocyanidin per tube indicated that existing analytical procedures that do not account for the spectral interference of co-extractable compounds overestimated (P < 0.01) bound PA concentrations by 69 and 38% respectively. An innovative technique that generated an internal correction factor for each sample, using wavelength-scanning spectrophotometry and non-linear curve-fitting computer software, was developed. This procedure recovered 100% of added anthocyanidins from bound PA matrices.
© 2002 Society of Chemical Industry
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| Keyword(s) |
Agriculture, Multidisciplinary
Chemistry, Applied
Food Science & Technology
Proanthocyanidin
Condensed Tannin
Extractable
Bound
Fibre-bound
Protein-bound
Insoluble
Methodology
Blank Correction
Co-extractable Compounds
Leucaena
Condensed Tannin Concentration
Dry-matter Degradation
Forage Legumes
Protein
Leaves
Browse
Fiber
Sheep
Reactivity
Phenolics
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