RT Journal Article
SR Electronic
T1 Advantages of the KDS/BCA Assay over the Bradford Assay for Protein Quantification in White Wine and Grape Juice
JF American Journal of Enology and Viticulture
JO Am J Enol Vitic.
FD American Society for Enology and Viticulture
SP 227
OP 233
DO 10.5344/ajev.2014.14076
VO 66
IS 2
A1 Diana Gazzola
A1 Simone Vincenzi
A1 Gabriella Pasini
A1 Giovanna Lomolino
A1 Andrea Curioni
YR 2015
UL http://www.ajevonline.org/content/66/2/227.abstract
AB The present study compared the performance of two colorimetric protein assays, the Bradford and the potassium dodecyl sulfate/bicinchoninic acid (KDS/BCA) assays, for use in wine and grape juice analysis. The Bradford assay was affected by protein type, whereas the KDS/BCA assay had lower protein-to-protein variation. Bovine serum albumin and lysozyme yielded an absorbance (562 nm) vs. protein concentration slope (dose–response curve) similar to that of wine proteins. In the Bradford assay, the presence of 12% ethanol and 200 mg/L of wine polyphenols decreased the protein absorbance by 28 and 16%, respectively, whereas in the KDS/BCA assay such interference was not significant. Among 64 white wines, the correlation between protein haze potential, determined by a heat test, and protein content was better for the KDS/BCA assay. This study confirmed the superiority of the KDS/BCA assay over the Bradford assay for quantifying protein in white grape juice and wine, and it yielded better predictive value with respect to the risk of white wine protein instability.