Physicochemical changes and bitterness of whey protein hydrolysates after transglutaminase cross-linking

Author(s)

de Carvalho, Natalia Caldeira ^{[1, 2]} ; Pessato, Tassia Batista ^[1] ; Negrao, Fernanda ^[3] ; Eberlin, Marcos Nogueira ^[3] ; Behrens, Jorge Herman ^[1] ; Zollner, Ricardo de Lima ^[4] ; Netto, Flavia Maria ^[1]

Affiliation

^[1] Univ Estadual Campinas, UNICAMP, Sch Food Engn, Rua Monteiro Lobato 80, BR-13083862 Campinas, SP - Brazil

^[2] Univ Ouro Preto, Sch Nutr, UFOP, Rua Dois, BR-35400000 Ouro Preto, MG - Brazil

^[3] Univ Estadual Campinas, UNICAMP, Inst Chem, POB 6154, BR-13083970 Campinas, SP - Brazil

^[4] Univ Estadual Campinas, UNICAMP, Sch Med Sci, Vital Brasil 300, BR-1308388Z Campinas, SP - Brazil

• Document type: Journal article
• Source: LWT-FOOD SCIENCE AND TECHNOLOGY; v. 113, OCT 2019.
• Web of Science Citations: 0

Abstract

Whey protein hydrolysates are widely used in hypoallergenic formulas. The extensive hydrolysis required to reduce the protein antigenic potential frequently generates bitter-tasting peptides. This study investigates the effect of transglutaminase (TG) catalyzed cross-linking on physicochemical characteristics and bitter taste of whey protein hydrolysates. The chromatographic analysis showed a slight increase in the relative concentration of peptides (p < 0.05) with molecular mass of 1.4-3.5 kDa (SEC-HPLC) and changes in peak intensity and peptide hydrophilicity after TG-treatment (RP-HPLC). The MALDI-MS peptide fingerprinting presented changes in relative intensities and suppression of signals after TG-treatment, suggesting that cross-linking occurred, mainly in the m/z 1600-3000 range peptides. Changes in the spatial conformation of peptides after TG-treatment were evidenced by the intrinsic fluorescence of the samples. Despite the changes in the physicochemical characteristics of peptides, no differences (p > 0.05) in the intensity (6-7, on a scale up to 9) and duration (38 s) of the bitterness sensation were observed. Possibly, the presence of free glutamine and the significant amount of short peptides with no glutamine or lysine residue may have decreased the opportunities for cross-linking formation; therefore, the presence of bitter-tasting peptides was unchanged as a consequence of TG-treatment. (AU)

• FAPESP's process: 15/26586-7 - Effect of combined treatment of hydrolysis and polymerization or complexation with phenolic compounds on whey protein allergenicity
• Grantee: Flavia Maria Netto
• Support Opportunities: Regular Research Grants