Fluorescence spectroscopy and principal component analysis of soy protein hydrolysate fractions and the potential to assess their antioxidant capacity characteristics. (15th February 2017)

• Record Type: Journal Article
• Authors: Ranamukhaarachchi, Sahan A.; Peiris, Ramila H.; Moresoli, Christine
• Is Part Of: Food chemistry. Volume 217(2017)
• Page Start: 469
• Page End: 475
• Publication Date: 2017-02-15
• Subjects: Soy protein hydrolysate -- Antioxidant capacity -- Intrinsic fluorescence -- Principal component analysis -- Ultrafiltration -- Nanofiltration; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2016.08.029
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Antioxidant capacity of soy peptides was improved by sequential membrane filtration. Fluorescence and PCA captured fluorescing amino acids in antioxidant soy peptides. Tryptophan and tyrosine are fluorescing and contributed to antioxidant capacity. Rapid, non-destructive method extracted information on bioactive peptides. Abstract: 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.