Foaming properties of whey protein isolate and [lambda]-carrageenan mixed systems

Heating protein with polysaccharide under a net negative condition can induce the formation of soluble complex with improved functional properties. Studies on foaming properties of whey protein isolate (WPI) with polysaccharide mostly focused on the effects of polysaccharide on native WPI or heated WPI, while little has been done on heated WPI-polysaccharide soluble complex. The objective of our research was to investigate effects of different [lambda]-carrageenan ([lambda]C) concentrations and pH on foaming properties of heated WPI and [lambda]C soluble complex. Three WPI and [lambda]C systems were prepared: 1) heated WPI and [lambda]C soluble complex (h-cpx), (2) heated WPI with added [lambda]C (pWPI - [lambda]C), and (3) unheated WPI with [lambda]C (WPI-[lambda]C). Foams were generated by beating the solution using a KitchenAid mixer. Foamability and foam stability were determined by measuring the foam overrun and drainage 1/5 life, respectively. Foam rheological properties were determined using a Kinexus Pro Rheometer, while foam microstructures were visualized by confocal laser scanning microscopy (CLSM). For native WPI and [lambda]C mixed system, [lambda]C was needed in order for 5% WPI to form measurable foams. In all three WPI- [lambda]C systems at neutral pH, increasing [lambda]C concentration led to improved foamability which increased with increasing [lambda]C concentration until a certain concentration before it decreased. Interestingly, despite their higher viscosity, both heated systems (pWPI-[lambda]C and h-cpx) showed significantly better foamability and foam stability compared to WPI-[lambda]C. Results of rheological properties of foams made from treatments with 0.25% [lambda]C at neutral pH suggested that higher elasticity and viscous films were produced in h-cpx and pWPI-[lambda]C systems corresponding to better foam stability. Heating WPI and [lambda]C together to form heated soluble complex resulted in thicker and viscoelastic interfacial film surrounding the air bubbles and thus better foam

Name thesis:degree_name

M.S.

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Food science (MU)

Grantor dc:publisher

University of Missouri--Columbia

Year dc:date.issued

2013

Author dc:creator

• Wang, Zhengshan

Advisor dc:contributor.advisor

• Vardhanabhuti, Bongkosh, 1967-

Language dc:language.iso

eng, English

DOI

https://doi.org/10.32469/10355/44714

OAI identifier oai:identifier

oai:mospace.umsystem.edu:10355/44714