About this Research Topic
Many of the commercially available food products exist as colloidal systems, such as emulsions and foams, with both categories being available in a variety of formats. Emulsions include oil-in-water (O/W) (e.g., ready-to-drink beverages, coffee creamers, infant formulas, soups, salad dressings, culinary creams, and mayonnaise), water-in-oil (W/O) (e.g., butter, and margarine) and multiple ones (O/W/O or W/O/W) (e.g., reduced-fat foods, encapsulation of bioactive compounds, flavor and aroma release control). On the other hand, foams can be liquid (e.g., carbonated soft drinks, coffee beverages), semi-solid (whipped cream, aerated desserts, ice cream), or solid (e.g., bread, cakes, aerated chocolate bars, and breakfast cereals). The production and stabilization of these matrices, and thus the delivery and preservation of the desired sensory properties, require an in-depth understanding of the complex interplay between formulation and processing.
Emulsions and foams are thermodynamically unstable systems, i.e., their continuous and dispersed phases tend to separate over time to reach a more stable state that minimizes their interfacial area and free energy. The presence of a surfactant that reduces the interfacial tension between the continuous and dispersed phases is required to improve the stability of these systems. Proteins are amphiphilic macromolecules that are widely used as emulsifying and foaming agents in the food industry. This is mainly due to their ability to adsorb and reorient at the interface, form viscoelastic interfacial films through intermolecular interactions, and increase the viscosity of the continuous phase. Emulsifying and foaming properties of proteins depend on protein characteristics (amino acid composition, structure, charge, hydrophobicity/hydrophilicity, and so on) and vary with extrinsic factors, e.g. type and extent of processing and presence/absence of other ingredients.
The emulsifying and foaming properties of animal proteins, such as those derived from milk and egg, are widely described in the literature. Conversely, with a few exceptions (e.g., soy and pea proteins), less is known concerning the interfacial behavior of alternative proteins, including plants, single cells (i.e., microalgae, bacteria, fungi, and yeasts) and seaweeds, as well as that of hybrids comprising animal and alternative proteins. Increasing the use of alternative proteins in food products is of utmost importance to address global challenges such as food security and sustainability, as well as the needs of the ever-growing proportion of consumers following vegan, vegetarian, or flexitarian diets. To this end, it would be of high scientific and industrial relevance to understand the impact of formulation (e.g., pH, concentration, and type of added minerals, carbohydrates, and fats) and processing conditions (e.g., heating protocol) on the emulsifying and foaming properties of these proteins, as well as the potential of physical, chemical and enzymatic treatments to improve them.
Authors are invited to submit both research papers and literature reviews on the above-described topic to contribute to filling this knowledge gap, but are not limited to:
- Emulsifying and foaming properties of alternative proteins (i.e., plant, single cell and seaweed proteins) as well as hybrids comprising alternative and animal proteins;
- Novel methods for the characterization of the above-mentioned properties, including high throughput screening;
- Impact of formulation and processing conditions not only on the physicochemical properties of food emulsions and foams based on alternative proteins but also on the biological value of the latter;
- Investigation of the potential of physical, chemical and enzymatic treatments to improve emulsifying and foaming properties of alternative proteins.
Emulsions and foams are thermodynamically unstable systems, i.e., their continuous and dispersed phases tend to separate over time to reach a more stable state that minimizes their interfacial area and free energy. The presence of a surfactant that reduces the interfacial tension between the continuous and dispersed phases is required to improve the stability of these systems. Proteins are amphiphilic macromolecules that are widely used as emulsifying and foaming agents in the food industry. This is mainly due to their ability to adsorb and reorient at the interface, form viscoelastic interfacial films through intermolecular interactions, and increase the viscosity of the continuous phase. Emulsifying and foaming properties of proteins depend on protein characteristics (amino acid composition, structure, charge, hydrophobicity/hydrophilicity, and so on) and vary with extrinsic factors, e.g. type and extent of processing and presence/absence of other ingredients.
The emulsifying and foaming properties of animal proteins, such as those derived from milk and egg, are widely described in the literature. Conversely, with a few exceptions (e.g., soy and pea proteins), less is known concerning the interfacial behavior of alternative proteins, including plants, single cells (i.e., microalgae, bacteria, fungi, and yeasts) and seaweeds, as well as that of hybrids comprising animal and alternative proteins. Increasing the use of alternative proteins in food products is of utmost importance to address global challenges such as food security and sustainability, as well as the needs of the ever-growing proportion of consumers following vegan, vegetarian, or flexitarian diets. To this end, it would be of high scientific and industrial relevance to understand the impact of formulation (e.g., pH, concentration, and type of added minerals, carbohydrates, and fats) and processing conditions (e.g., heating protocol) on the emulsifying and foaming properties of these proteins, as well as the potential of physical, chemical and enzymatic treatments to improve them.
Authors are invited to submit both research papers and literature reviews on the above-described topic to contribute to filling this knowledge gap, but are not limited to:
- Emulsifying and foaming properties of alternative proteins (i.e., plant, single cell and seaweed proteins) as well as hybrids comprising alternative and animal proteins;
- Novel methods for the characterization of the above-mentioned properties, including high throughput screening;
- Impact of formulation and processing conditions not only on the physicochemical properties of food emulsions and foams based on alternative proteins but also on the biological value of the latter;
- Investigation of the potential of physical, chemical and enzymatic treatments to improve emulsifying and foaming properties of alternative proteins.
Keywords: Alternative proteins, Plant proteins, Single cell proteins, Seaweed proteins, Hybrids, Emulsifying properties, Foaming properties, Formulation, Processing, Physical treatments, Chemical treatments, Enzymatic treatments, Structure-function relationship
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.
