Der Einfluß von Emulgatoren auf das Verhalten von Fett im Eismix während des Reifens

Analysis of protein-network formation of different vegetable proteins during emulsification to produce solid fat substitutes

Plant-based emulsion gels can be used as solid animal fat substitutes for vegan sausages. For this reason, commercially available protein isolates with different amino acid profiles from pea, soy and potato (Pea-1, Pea-2, Soy, Potato) have been tested for their ability to form shape stable emulsions gels at neutral pH and upon heating to 72 °C. In order to obtain emulsion gels that are as solid as possible, the protein concentrations in the continuous phase (CPC, 8.0–11.5% (w/w)) and the oil mass fractions (65–80%) were varied. For leguminous proteins, a positive correlation of both parameters on emulsion rigidity was shown, indicating that both, interfacial and protein–protein interactions, are involved in structure reinforcement. Firmness increased with increasing content in cysteine (Pea-1 < Pea-2 < Soy) and the interactions were of electrostatic, hydrophobic and hydrophilic nature. Potato emulsion rigidity was independent of CPC and oil content. The emulsions showed a much higher degree in crosslinking, and very low charge density. Temperature-sweep analysis and CLSM revealed that Potato protein gelled as consequence to low temperature stability. Hence, the structure reinforcement in Potato emulsions mainly contributed to the protein network, with 70% oil and CPC 11.5% forming a hybrid gel with highest firmness. However, gelling of Potato protein also resulted in interfacial adsorption of protein aggregates and reduced interfacial stability with increasing CPC. This was demonstrated in the amount of extractable fat which was 2.0 and 0.6% for Pea-1 and 2 emulsions, 6.4% for Soy and 34.4% of total fat for Potato emulsions.

Effect of the fat globule sizes on the meltdown of ice cream

The meltdown of ice cream is influenced by its composition and additives and by fat globule size. The objective of this study was to examine the effect of fat globule size and fat agglomerate size on the meltdown stability of ice cream. Therefore, an ice cream mix (10% milk fat) was homogenized at pressures ranging from 0 to 30 MPa in single-stage, double-stage, and selective homogenization processes. The ice cream, produced on a continuous ice cream freezer, was characterized by an optimized meltdown test while, in addition, the fat globule sizes and the free fat content were determined in the mix and the molten ice cream. The meltdown was dependent on the fat agglomerate sizes in the unfrozen serum phase. Agglomerates smaller than a critical diameter led to significantly higher meltdown rates. Homogenization pressures of at least 10 MPa were sufficient to produce a stable ice cream. Furthermore, proof was provided that double-stage homogenization is not necessary for fat contents up to 10% and that selective homogenization is possible to produce stable ice creams. Based on these results a model was deduced describing the stabilizing mechanisms during the meltdown process.