Functional properties of plant proteins Part IV. Foaming properties of modified proteins from faba beans

Abstract

The foaming ability (foam capacity and stability) of protein isolates from faba beans (Vicia faba L.) depends closely on the manner of isolation and treatment of the isolates. Unmodified isolates possess a moderate foaming ability with a maximum foam capacity of 210% in alkaline solution (pH 10.0) at concentrations of about 3%. The foam capacity and stability can be improved by treatment with isopropanol or moderate temperature, as well as by denaturing by alkali or by specially heating at 80 degrees C. Thereby modified preparations are formed possessing a foam capacity of more than 400% and a foam stability of 80-100%. High concentrations of protein favour the formation of stable foams. Succinylation improves the foam formation properties of proteins. Maximum values of foam capacity (approximately equal to 400%) are produced at a high degree of succinylation, that is after blocking more than 80% of protein amino groups, in neutral solution, while the foam stability under these conditions decreases. Heating at 80 degrees C, high protein concentrations (10%) and a weak acidic milieu (pH 5.5) favour the formation of stable foams from succinylated proteins.

Structural studies on native and chemically modified storage proteins from rapeseed (Brassica napus L.) and related plant proteins

“…In most of these cases, however, the dependence of functional properties on the degree of succinylation was not studied systematically. In some papers an increase of emulsifying activity and capacity and a decrease of foam stability on the level of modification was shown [35,36]. More recently, a clear influence of the protein unfolding after reaching the critical level of succinylation on the kinetics of interface adsorption, foam and emulsion stabilization of the rapeseed 12s globulin could be shown…”

Functional properties of plant proteins Part 6. Some functional properties of succinylated protein isolates from sunflower seed (Helianthus annuus L.)

“…The samples were centrifuged at 15000 rpm and the nitrogen content in the supernatant was determined by a half-micro KJEL-IIAHL procedure. The foam capacity and stability were determined using a whipping apparatus, according to GOTTE, modified by DOWER et al [20] as described in [21].…”

Technikfolgenabsch�tzung der Gr�nen Bioraffinerie, Teil I: Endbericht

“…Ihre funktionellen Eigenschaften 36 sind ausschlaggebend für die Verarbeitung in komplexen Systemen. (Kinsella 1976;Schwenke et al 1983;1992;Zayas 1997 (Knuckles et al 1980;Bray/Humphries 1979;Baraniak et al 1989) haben den Vorteil der Erhaltung der Nativität der Proteine. Nachteilig wirkt sich das Hinzufügen zusätzlicher Chemikalien aus, da diese wieder abgetrennt werden müssen.…”

“…Da geringfügige chemische Modifikationen bereits große Effekte auf Wasseraufnahmefähigkeit, Löslichkeit, Adsorptionsverhalten, Schaumbildung, etc. haben, sind vielfältige Einsatzmöglichkeiten gegeben (Schwenke et al 1983), (Drahl/ Schwenke 1986 48 2,0*104 KbE/g FM = koloniebildende Einheiten pro Gramm Frischmasse (Idler 1994;Idler/Fuchs 1995). 49 Hier zeigt sich, dass Technologien zur Nutzung nachwachsender Rohstoffe einander ergänzen können.…”