Fluorescence spectroscopy and principal component analysis of soy protein hydrolysate fractions and the potential to assess their antioxidant capacity characteristics.
The potential of intrinsic fluorescence and principal component analysis (PCA) to characterize the antioxidant capacity of soy protein hydrolysates (SPH) during sequential ultrafiltration (UF) and nanofiltration (NF) was evaluated. SPH was obtained by enzymatic hydrolysis of soy protein isolate. Antioxidant capacity was measured by Oxygen Radical Absorbance Capacity (ORAC) and Folin Ciocalteau Reagent (FCR) assays together with fluorescence excitation-emission matrices (EEM). PCA of the fluorescence EEMs revealed two principal components (PC1-tryptophan, PC2-tyrosine) that captured significant variance in the fluorescence spectra. Regression models between antioxidant capacity and PC1 and PC2 displayed strong linear correlations for NF fractions and a weak linear correlation for UF fractions. Clustering of UF and NF fractions according to ORACFPCA and FCRFPCA was observed. The ability of this method to extract information on contributions by tryptophan and tyrosine amino acid residues to the antioxidant capacity of SPH fractions was demonstrated.
Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Sahan A
SA
Ranamukhaarachchi
Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Ramila H
RH
Peiris
Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada. Electronic address: cmoresol@uwaterloo.ca.
Christine
C
Moresoli
D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry; D006868:Hydrolysis; D007529:Isoflavones / Q000032:analysis / Q000737:chemistry; D025341:Principal Component Analysis; D011492:Protein Hydrolysates / Q000032:analysis* / Q000737:chemistry; D030262:Soybean Proteins / Q000032:analysis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D014462:Ultrafiltration
D000975:Antioxidants; D007529:Isoflavones; D011492:Protein Hydrolysates; D030262:Soybean Proteins
Antioxidant capacity; Intrinsic fluorescence; Nanofiltration; Principal component analysis; Soy protein hydrolysate; Ultrafiltration