Jumping on the Tofutti boom, starting in 1984 I developed, produced, and marketed frozen desserts in the U.S., Japan, Australia, and Europe. Dozens of different types, almost all were nondairy [PDF].
The only dairy product, New Zealand Milk Products was a client because I developed a dry instant frozen yogurt mix that they liked.
Fruit juice concentrate, tofu, soymilk, amasake and later hempseed were the various bases.
Frozen pints and scooping tubs, liquid soft-serve mix, powdered soft-serve mix, even a concentrate to which the Australian factory added water, sugar, flavor, and fat.
I could get as much as 200% over-run from the 99% fruit ones (1 gallon liquid makes 3 gallons frozen, the rest is air); it was like eating strawberry flavored air. That’s a foam, like you see in whipped cream, ice cream, mousse, etc.
I found one trick was in the use of the right natural plant-based stabilizers and foaming agents, under 1%. Over forty years ago all I had was a foaming agent made from soya, so ever since I had my eye out for other natural foamers.
Considering that it is one-third albumin, the type of protein also found in egg whites famous for its whipping ability, I suspected hempseed was a prime candidate.
Turns out it was:
Enhancement of foaming performance of hempseed protein by limited enzymatic hydrolysis: From the viewpoint of the structural and interfacial rheological attributes
“Introduction
Foam, as an important structural element, plays a pivotal role in miscellaneous aerated food products such as meringue, milkshakes, baked foods, and ice cream, providing consumers with pleasant visual and peculiar sensory experiences (Zhan, Youssef, Shah, Li, & Li, 2022). The quality of these kinds of food products is closely related to the properties of foam. Foam represents a typical thermodynamically unstable system wherein air bubbles are dispersed within a liquid matrix. In accordance with the thermodynamic dictum, instability phenomena such as drainage, coalescence, and/or disproportionation often occur to minimize the interfacial area and interfacial free energy (Deotale, Dutta, Moses, & Anandharamakrishnan, 2023). Traditionally, animal proteins (e.g., egg white proteins and milk proteins) with amphiphilicity are the most commonly utilized agents for stabilizing foams in the food industry. However, in recent years, there has been a noticeable shift towards the use of plant-derived proteins as alternatives to animal proteins. This transition has been driven by growing concerns surrounding animal protein consumption, which include factors such as veganism, religious convictions, environmental sustainability, and human health (Amagliani, Silva, Saffon, & Dombrowski, 2021).
Hempseed protein, an emerging and highly desirable plant-derived protein, has gained increasing popularity in the food industry due to its distinctive nutritional value, excellent digestibility, and hypoallergenic qualities (Karabulut, Kahraman, Pandalaneni, Kapoor, & Feng, 2023; Wang & Xiong, 2019). It boasts a well-balanced composition of essential amino acids which are comparable to many other proteins such as soy protein and egg white (Wang, Tang, Yang, & Gao, 2008), positioning it as a prominent candidate for application as a valuable food ingredient, particularly as a foaming agent. To serve as an effective foaming agent, the competence to rapidly absorb at the air–water interface and reduce interfacial tension are required for proteins, which is closely associated with the unfolding state of protein structure and molecular flexibility; in addition, the formation of a cohesive and viscoelastic protein layer via intermolecular interactions at the air–water interface is crucial for maintaining foam stability (Janssen, Monterde, & Wouters, 2023). However, the compact structure of intact hempseed protein limits its interfacial behavior and resultant foaming properties.
Enzymatic hydrolysis with proteases has garnered massive attention as an effective, highly sensitive, and environmentally friendly method for modifying proteins. It generates protein hydrolysates (peptides) with reduced molecular weight and increased hydrophobic and ionizable groups, consequently contributing to the readily absorption of protein molecules at the air–water interface (Qoms et al., 2023). This structure-modifying technique has been widely employed to ameliorate the foaming properties of numerous proteins, including those from legume, cereal, and animal (Mookerjee & Tanaka, 2023; Ryan, O’Regan, & FitzGerald, 2023; Thirulogasundar et al., 2024). However, limited research has been conducted on the enzymatic modification of hempseed protein for improved techno-functionality, including those by Chen, Pangloli, and Dia (2024), Isinguzo (2011), Shahbal, Jing, Bhandari, Dayananda, and Prakash (2023), and Yin et al. (2008). Hereinto, Yin et al. (2008) found that trypsin proteolysis led to a significant reduction in the foaming capacity and foam stability of hempseed protein. Similarly, adverse effects on the foaming properties were also observed in hempseed protein hydrolyzed by alcalase, pepsin, and thermolysin (Isinguzo, 2011). The possible reason for this phenomenon could be excessive hydrolysis of hempseed protein caused an increase in the net charge of peptides and enhancement of electrostatic repulsion between molecules as well as the destruction of hydrophilic/hydrophobic balance, which was unfavorable for the adsorption of peptide molecules and intermolecular interactions at the interface, eventually resulting in decreased viscoelasticity of the interfacial film and deteriorated foam stability (Tang et al., 2023). Additionally, while the small peptides produced by excessive hydrolysis may exhibit good solubility and rapidly migrate to the air–water interface, their diminutive size may be insufficient to provide the necessary structural integrity for stabilizing air bubbles (Vogelsang-O’Dwyer, Sahin, Arendt, & Zannini, 2022). Hence, in order to achieve optimal foaming performance, it is crucial to control the implementation of enzymatic hydrolysis (e.g., degree of hydrolysis and enzyme specificity) to moderately modify protein structure and regulate interfacial behaviors. Nevertheless, only a limited number of studies have focused on the characterization of the interfacial film formed by hydrolyzed proteins and the impact of proteolysis on the interfacial properties, particularly in relation to foaming capacity and stability.
The objective of this study was to explore the impacts of limited enzymatic hydrolysis-induced structural modification on the foaming characteristics of hempseed protein. Specifically, two serine endopeptidases, Alcalase and Protamex, with distinct cleavage specificities were selected for protein modification in this study. Ulteriorly, the adsorption behavior of the obtained hydrolysates at air–water interface and the consequent interfacial rheological properties, which are closely associated with the intermolecular interactions at the air–water interface and the nature of the interfacial film formed, were examined to gain a comprehensive understanding of the foaming properties of the hydrolysate derivatives. This work would provide valuable insights into the potential utilization of hempseed protein as a sustainable alternative to animal protein as a foaming agent in the food industry.
Section snippets
Materials
Hempseed protein isolate (HPI) was obtained from raw dehulled hempseeds using an alkaline extraction (pH 10.0)–isoelectric precipitation (pH 4.5) procedure according to our previous protocol (Wang, Jin, & Xiong, 2018). The protein content in the freeze-dried powder was 90.5 % as measured using the Kjeldahl method. Alcalase 2.4 L (2.4 AU/g) and Protamex (1.5 AU/g) were acquired from Novozymes (Bagsværd, Denmark). All chemicals or reagents of at least analytical grade were purchased from…
Secondary structure
Proteins exhibit characteristic CD spectra in the far-ultraviolet region (typically 190–250 nm) due to the presence of peptide bond chromophores. Hence, the CD spectra in this region were analyzed to characterize alterations in the secondary structures of HPI samples after hydrolysis. Typically, α-helix is distinguished by a positive band near 190 nm and two negative bands at approximately 208 nm and 222 nm, whereas β-sheet exhibits a broad negative band in the vicinity of 220 nm and a positive…
Conclusions
Enzymolysis treatment, notably with Alcalase, effectively altered the protein structure, thus influencing interfacial rheological properties and foaming performance of hemp proteins. In comparison with the intact HPI, proteolysis stimulated the conformational conversion of proteins from α-helix and β-sheet into random coil and disrupted the hydrophobic regions, resulting in a more disordered molecular structure with increased flexibility, particularly evident for Alcalase. Moreover, Alcalase…”
Read the study at: https://www.sciencedirect.com/science/article/abs/pii/S0308814624038329