Determination of poly(ethylene glycol)-binding to browse foliage, as an assay of tannin, by near-infrared reflectance spectroscopy.
Nutritionists are interested in functional assays of tannins that do not require time-consuming and expensive extraction, such as the (14)C-labeled poly(ethylene glycol) (PEG)-binding (PEG-b) assay. This paper reports the application of near-infrared (NIR) spectroscopy to determine the percentage of PEG binding, in place of the (14)C-labeled PEG-b assay of tannin, in Mediterranean woodland vegetation. Calibration was done with 53 samples from 14 species and was validated on 25 samples from 10 species. PEG-b ranged between 1.4 and 20.7% in the samples. The calibration obtained by using the modified partial least-squares (MPLS) method, with all wavelengths in the 1100-2500 nm range combined, and the validation were reasonably linear (R (2) = 0.96 and 0.91, respectively). The accuracies, estimated from the standard errors of cross-validation and prediction, were +/-1.6 and +/-1.7% PEG-b, respectively. The NIRS-aided procedure proposed here can serve as an accurate, inexpensive, time-saving, and environment-friendly functional assay of tannin in Mediterranean browse.
Landau
Serge
S
Institute of Field and Garden Crops, Department of Natural Resources, Agricultural Research Organization, The Volcani Center, P.O. Box 6, Bet Dagan 50 250, Israel. vclandau@agri.gov.il
Dvash
Levana
L
Decandia
Mauro
M
Cabiddu
Andrea
A
Shapiro
Fira
F
Molle
Giovanni
G
Silanikove
Nissim
N
D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002250:Carbon Radioisotopes; D007887:Fabaceae / Q000737:chemistry*; D006041:Goats; D047348:Hydrolyzable Tannins / Q000032:analysis*; D011092:Polyethylene Glycols / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared
D002250:Carbon Radioisotopes; D047348:Hydrolyzable Tannins; D011092:Polyethylene Glycols