Sunflower proteins : overview of their physicochemical, structural and functional properties
González-Pérez, S. ; Vereijken, J.M. - \ 2007
Journal of the Science of Food and Agriculture 87 (2007)12. - ISSN 0022-5142 - p. 2173 - 2191.
helianthus-annuus l - seed storage proteins - low-molecular-weight - reduced soy glycinin - chlorogenic acid - foaming properties - ionic-strength - defatted sunflower - globulin fraction - oilseed proteins
There is increasing worldwide demand for proteins of both animal and plant origin. However, animal proteins are expensive in terms of both market price and environmental impact. Among alternative plant proteins, sunflower seeds are particularly interesting in view of their widespread availability in areas where soy is not or only sparsely produced. Compared with other sources of vegetable proteins, sunflower seeds have been reported to have a low content of antinutritional factors. Although the absence of these factors is important, the functionality of the protein preparations will mainly determine their applicability. This review provides detailed information about sunflower seed composition and processing, including processes to remove phenolic compounds from meals. The main part of the review concerns the structure and functionality of the two major protein fractions, helianthinin and 2S albumins. Regarding functionality, emphasis is on solubility, thermal behaviour and surface activity. Protein structure and functionality are discussed as a function of extrinsic factors such as pH, ionic strength, temperature and the presence of other seed components, particularly chlorogenic acid. In addition, sunflower proteins are compared from a structural and functional point of view with other plant proteins, particularly soy proteins.
Formation and Stability of Foams Made with Sunflower (Helianthus annuus) Proteins
Gonzalez-Perez, S. ; Vereijken, J.M. ; Koningsveld, G.A. van; Gruppen, H. ; Voragen, A.G.J. - \ 2005
Journal of Agricultural and Food Chemistry 53 (2005)16. - ISSN 0021-8561 - p. 6469 - 6476.
seed storage proteins - functional-properties - defatted sunflower - oilseed proteins - chlorogenic acid - soy glycinin - albumin - meal - isolate - whey
Foam properties of a sunflower isolate (SI), as well as those of helianthinin and sunflower albumins (SFAs), were studied at various pH values and ionic strengths and after heat treatment. Less foam could be formed from helianthinin than from SFAs, but foam prepared with helianthinin was more stable against Ostwald ripening and drainage than foam prepared with SFAs. Foams made with SFAs suffered from extensive coalescence. The formation and stability of foams made from reconstituted mixtures of both proteins and from SI showed the deteriorating effect of SFAs on foam stability. Foam stability against Ostwald ripening increased after acid and heat treatment of helianthinin. Partial unfolding of sunflower proteins, resulting in increased structural flexibility, improved protein performance at the air/water interface. Furthermore, it was observed that the protein available is used inefficiently and that typically only ~20% of the protein present is incorporated in the foam.