Browsing by Person "Schmitt, Christophe"

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Homogenization improves foaming properties of insoluble pea proteins
(2022) Moll, Pascal; Salminen, Hanna; Griesshaber, Elena; Schmitt, Christophe; Weiss, Jochen
Foams are essential in many food applications and require surface-active ingredients such as proteins for formation and stabilization. We investigated the influence of high-pressure homogenization on foaming properties of insoluble pea protein dispersions (5% w/w) at pH 3 and 5. Unhomogenized insoluble pea protein dispersions did not foam at either pH 3 or 5, as they consisted of large insoluble pea protein aggregates with limited surface activity. At pH 3, the homogenized pea protein dispersions generated foams due to higher protein solubility and surface activity through disruption of large protein aggregates into smaller particles. The foam stability decreased with increasing homogenization pressure and number of cycles due to a reduction in continuous phase viscosity. At pH 5, the insoluble pea proteins foamed when the homogenization resulted in formation of aggregates made of smaller protein entities, which was the case for homogenization ≥ 100 MPa and three cycles. In general, the foam capacity (amount of formed foam) was higher at pH 3 due to improved protein solubility and surface activity that facilitated incorporation of air, while the foam stability (resistance against foam collapse) was better at pH 5 because of the presence of larger protein aggregates that formed thicker and more viscous films around the air bubbles benefitting retention of gas bubbles. Overall, homogenization improved the foaming properties of insoluble pea proteins at pH 3 and 5.
Solidification of concentrated pea protein–pectin mixtures as potential binder
(2023) Moll, Pascal; Salminen, Hanna; Stadtmüller, Lucie; Schmitt, Christophe; Weiss, Jochen
BACKGROUND: Binders in plant-based meat analogues allow different components, such as extrudate and fat particles, to stick together. Typically, binders then are solidiﬁed to transform the mass into a non-sticky, solid product. As an option for a clean- label binder possessing such properties, the solidiﬁcation behavior of pea protein–pectin mixtures (250 g kg−1 , r = 2:1, pH 6) was investigated upon heating, and upon addition of calcium, transglutaminase, and laccase, or by combinations thereof. RESULTS: Mixtures of (homogenized) pea protein and apple pectin had higher elastic moduli and consistency coefﬁcients and lower frequency dependencies upon calcium addition. This indicated that calcium physically cross-linked pectin chains that formed the continuous phase in the biopolymer matrix. The highest degree of solidiﬁcation was obtained with a mixture of pea protein and sugar beet pectin upon addition of laccase that covalently cross-linked both biopolymers involved. All solidi- ﬁed mixtures lost their stickiness. A mixture of soluble pea protein and apple pectin solidiﬁed only slightly through calcium and transglutaminase, probably due to differences in the microstructural arrangement of the biopolymers.