Effect of Ohmic heating on functionality of sodium caseinate – A relationship with protein gelation. (February 2019)

• Record Type: Journal Article
• Authors: Moreira, Thais Caldas Paiva; Pereira, Ricardo N.; Vicente, António A.; da Cunha, Rosiane Lopes
• Is Part Of: Food research international. Volume 116(2019)
• Page Start: 628
• Page End: 636
• Publication Date: 2019-02
• Subjects: Ohmic heating -- Protein functionality -- Sodium caseinate -- Acid systems -- Moderate electric fields -- Water holding capacity; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2018.08.087
• Languages: English
• ISSNs: 0963-9969

Abstract

Abstract: Sodium caseinate (NaCAS) is widely used in the food industry to provide nutritional and functional benefits. This work deals with the effects of applying moderate electric fields (MEF) of different intensity - ranging from 2 V·cm −1 to 17 V·cm −1 - on the physical and functional properties of NaCAS solutions during Ohmic heating (OH) at 95 °C. Self-standing gels were produced regardless the heating technique applied (i.e. conventional or OH), and these gels were much more prone to physical rupture when compared with the ones produced from unheated NaCAS. Interestingly, OH treatment formed gels with lower values of strain at rupture and water holding capacity than unheated samples; this pattern was not observed for gels obtained through the conventional heating treatment (at 0 V·cm −1 ). These effects may be linked with disturbances of the distribution of random coil structures and enhanced solubility of NaCAS at its isoelectric point, reducing aggregation and impairing the development of a more compact protein network. Results show that OH presents potential to be used as volumetric heating tool for NaCAS solubilization and for the production of distinctive acidified systems. Graphical abstract: Unlabelled Image Highlights: Heating can influence physical properties of sodium caseinate (NaCAS). Subtle conformational changes on protein structure were observed after Ohmic heating (OH) treatment. The intensity of the electric fields applied seems to influence protein solubility at the isoelectric point. OH offers potential to produce self-supported NaCAS gels with distinguishing features.