β-Lactoglobulin: A Whey Protein Fraction with Enhanced Functionality

Abstract

Infant formula manufacturers are progressively moving towards the development of the next generation of infant milk formula based on the inclusion of α-lactalbumin-enriched ingredients in order to further ‘humanise’ baby milk, as well as to reduce the allergenicity associated with the presence of β-lactoglobulin ( β-lg). Since α-lactalbumin represents one of the two major whey protein fractions in bovine milk, the viability of new fractionation processes currently under development will depend inter alia on the functional value that will attach to the remaining fraction, namely β-lg. Since this protein fraction influences whey protein functionality for the most part, it is to be expected that its availability in an enriched form should lead to further enhancement of its key functional properties, and stimulate further market opportunities. It is therefore imperative that attention is given to the processes and functionality of β-lg produced by different processing approaches. Hence, the overall objective of the project was: - To source and/or produce sufficient quantities of β-lg-enriched ingredients obtained through whey protein fractionation using different technologies, and to evaluate their functionality in model and food systems. - To investigate the influence of thermal treatments and ionic environment on the molecular structure of purified β-lg in order to understand their effect on protein functionality (gelation). - To improve the water-holding capacity of β-lg-enriched fraction so that it could compete more favourably with carbohydrate hydrocolloids in food applications. Downstream processing of β-lg was manipulated to influence the composition, and hence the functional properties of β-lg-enriched fractions. * β-Lg-enriched fractions had enhanced functional properties compared to WPC 75 and WPI. * β-Lg-enriched fraction has clear advantages over conventional whey protein products (WPC, WPI), in that it can be tailor-made to have specific functional properties desired in particular food products. * Water-binding properties of β-lg-enriched fraction could be improved by multi-stage heating.