Oxidation of whey protein isolate after thermal convection and microwave heating and freeze-drying: Correlation among physicochemical and NIR spectroscopy analyses

Author(s)

Bordignon, Juliany Cristiny Sonda ; Badaro, Amanda Teixeira ; Barbin, Douglas Fernandes ; Mariutti, Lilian Regina Barros ; Netto, Flavia Maria

• Document type: Journal article
• Source: HELIYON; v. 9, n. 7, p. 9-pg., 2023-07-01.

Abstract

This study investigated the oxidative susceptibility of whey protein isolate (WPI) dispersions treated by microwave or thermal convection before freeze-drying. WPI (20 mg protein/mL) in distilled water (DW) was heated at 63 & PLUSMN; 2 degrees C for 30 min by microwave (WPI-MW) or convection heating (WPI-CH) and freeze-dried. Untreated WPI (WPI-C), WPI solubilized in DW and freeze-dried (WPI-FD), and WPI solubilized in DW, heated at 98 & PLUSMN; 2 degrees C for 2 min and freeze-dried (WPI-B) were also evaluated. Structural changes (turbidity, & zeta; potential, SDS-PAGE, and near -infrared spectroscopy (NIR)) and protein oxidation (dityrosine, protein carbonylation, and SH groups) were investigated. WPI-FD showed alterations compared to WPI-C, mainly concerning carbonyl groups. Microwave heating increased carbonyl groups and dityrosine formation compared to conventional heating. NIR spectrum indicated changes related to the formation of carbonyl groups and PCA analysis allowed us to distinguish the samples according to carbonyl group content. The results suggest that NIR may contribute to monitoring oxidative changes in proteins resulting from processing. (AU)

• FAPESP's process: 15/24351-2 - Applications of image analyses and NIR spectroscopy for quality assessment and authentication of food products
• Grantee: Douglas Fernandes Barbin
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 19/06842-0 - Imaging techniques for determination of pasta composition during cooking
• Grantee: Amanda Teixeira Badaró
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• FAPESP's process: 17/17628-3 - Applications of image analyses and NIR spectroscopy for quality assessment and authentication of food products
• Grantee: Amanda Teixeira Badaró
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)