Pro Tip: Due to its potential health claims, hemp provides a promising source of protein for the baking industry.

Since the passage of the Agriculture Improvement Act as part of the 2018 Farm Bill, the production of industrial hemp (THC < 0.3%) has been federally legal.

This has led to states adopting a variety of laws regulating the growth of hemp for several applications, such as CBD production (mostly found in hemp flowers), fiber and seed production, although the same cultivars are not commonly grown for all three of these purposes.

The newfound availability of hemp seeds has led to recent research and consumer interest in hemp-based foods, including baked goods.

Figuring out exactly how to use hemp seeds in baked goods is still under research, but structural details have been published, and some work in incorporating these ingredients in vegan cakes and protein supplementation shows promise.

Let’s explore hemp’s structural and functional properties and applications in the baking industry, especially the potential use of hemp as a supplemental protein source that is uniquely bioavailable and complementary to cereal grains’ amino acid profile.

Figure 1: A- Representation of Edestin protein (Hemp, 11S) in the hexamer form. Coloring shows three monomers that form the top half in different colors; the other half is in black; B- Edestin monomeric unit with red α-helices, green β-sheets and grey random coils; C- Molecular surface applied to Edestin monomer colored from most hydrophobic (yellow) to most hydrophilic (blue). White indicates relatively neutral hydrophobic/hydrophilic surface regions; D- Coulombic electrostatic surface approximation of Edestin monomer. Coloring is on a gradient from -10 kt/e (red) to +10 kt/e (blue). Grids indicate approximate charge magnitudes of -4 or +4 in an aqueous solvent at neutral pH. 

Typically, seeds are processed to extract the oil, which is rich in healthy omega-3 and omega-6 fatty acids.

The remaining pressed cake contains high levels of protein that are commonly isolated through isoelectric precipitation, a method that involves solubilizing the proteins around pH 10, followed by their recovery from solution by adjusting the pH to values between 4 and 6, near the isoelectric point of the protein.

The remaining protein fraction is predominantly Edestin (~80%), an 11S hexamer (Figure 1A) that denatures around 92°C (197.6°F). The relatively homogenous protein profile, coupled with an inherent defatting step, may lead to more consistency when using hemp than other more heterogenous plant-based proteins.

In terms of amino acid composition, Edestin has high levels of arginine, a positively charged amino acid that leads to unique electrostatic distributions on the surface of the protein (Figure 1D). It also contains many hydrophobic amino acids that increase the surface hydrophobicity when compared to pulses, like pea protein, which leads to good emulsification and oil absorption abilities for hemp.

Edestin is also high in sulfurous amino acids and has more available sulfhydryl groups than soy or pea protein, which may allow for the formation of disulfide bonds upon heating, shearing and other molecular rearrangements. 

Functional properties of hemp in baking are not widely established, but there has been quite a bit of research that suggests excellent health benefits of hemp protein.

The protein digestibility ranges from 90.8% to 97.5%, depending on the source and isolation method, which is much higher than other plant-based proteins such as soy (about 70% digestible).

Additionally, hemp contains substantial levels of antioxidants and phytochemicals that can lead to positive health outcomes like a reduction in hypertension. Arginine also promotes enhanced blood flow.

Hemp protein isolate has been effectively incorporated into vegan cake recipes, showing an increase in volume when substituting 20% of a gluten-free starch blend with the protein.

However, the protein substitution also led to chewier and springier products.

Hemp has also been successfully substituted at 10% replacement of wheat flour for protein supplementation in bread.

Given its potential health claims, hemp is a promising source of protein for the baking industry.

Harrison Helmick is a PhD candidate at Purdue University. Connect on LinkedIn and see his other baking tips at BakeSci.com.

His research is conducted with the support of Jozef Kokini, Andrea Liceaga, and Arun Bhunia.