By KeShonna Jackson ’24
An Impossible Burger from Trillium, lentil meatballs from Martha’s Café, and soy milk lattes from Café Jennie — plant protein is found almost everywhere on Cornell University’s campus, offering more sustainable and healthy alternatives to traditional animal proteins. Three sources of plant protein currently dominate: soy, pea, and wheat. But recently, hemp has been added to the mix.
Hemp is a favorable addition to plant-based proteins. It is one of the fastest growing plants in the world, and it may be less allergenic than other sources of plant protein.
Hemp plants, like marijuana, belong to the cannabis family and produce compounds called cannabinoids. Under United States law, hemp is defined as having no more than 0.3 percent delta-9-tetrahydrocannabinol (THC), the most psychoactive cannabinoid. (In marijuana, concentrations of THC can reach 30 percent or more.) Nevertheless, hemp plants can be bred to produce other cannabinoids, such as the widely marketed cannabidiol (CBD).
Hemp was federally legalized for research purposes in 2014 and for commercial purposes in 2018. Because its legalization is fairly recent, hemp has not been thoroughly researched. Cornell PhD candidate Martin Liu is interested in how hemp might function as a food source, and particularly, as a source of protein.
Liu’s research compares distinct strains, or cultivars, of hemp that are intentionally bred for specific characteristics. With each cultivar, he looks at the type and amount of protein found in the seed and other qualities affecting how it might be used as a food.
“Hemp can be bred for a whole variety of purposes. Some cultivars are best for cannabinoids, [others are best for] food products, and you can even grow hemp for fibers which can be used in construction materials. It’s a very interesting plant,” Liu says.
Pulling Apart Hemp’s Nutritional Components
As a member of the Ali Abbaspourrad lab, Liu studies carbohydrates, proteins, and other organic molecules found in food. For his research, he receives large bags of hemp seeds harvested by the Cornell Hemp Research Team.
“[The seeds] we receive are about a third oil, a third protein, and a third fiber. First, we have to get rid of the oil, because it can interfere with the process of extracting the protein from the seed and can affect the functionality of the extracted protein. We typically do this using defatting methods. We use a food-grade solvent called hexane, which removes the oil and leaves only the fiber and protein behind,” Liu explains.
Once Liu removes the oil, he extracts the protein from the seed using an alkaline or saline solution. The protein dissolves and leaves the fiber as a solid that he can easily remove. Then Liu adds an acid or removing salt. The protein reduces in solubility and precipitates out of the solution into a tangible powder form. With the protein in powder form, Liu can conduct his analysis of the cultivar’s food-related characteristics.
“Hemp seed has a really high amount of protein; it’s somewhere between 25 to 30 percent protein. That’s similar to pea and soy. The main issue with plant proteins is that they don’t act as well as animal proteins in our food products. We need to characterize hemp proteins as an ingredient so that we can devise ways to make them more soluble or functional in a way that can replace animal proteins,” he says.
Liu’s findings can be relayed to growers to help them develop even more nutrient- and protein-packed cultivars.
“Hemp seed has a really high amount of protein; it’s somewhere between 25 to 30 percent protein.”
But hemp does have one downside.
“Hemp has got a certain nutty, grassy flavor to it,” Liu says. “In addition to our cultivar work, I want to look into different processing methods that remove these flavors so that one day down the line, a food product developer that wants to use hemp seed protein doesn’t have to deal with this strange flavor. They can just use a protein that doesn’t have much of a taste, and then flavor their product however they want.”
Liu envisions a future in which people will prefer plant-based products as a healthy and flavorful protein. “When it comes to sustainability, consuming more plant-based foods can be very helpful to the planet. If we wanted to make a change when it comes to climate change and sustainability at the personal level, food is one of the most straightforward ways we can do that. Everybody eats, and we make our own food choices, so the impact can go a long way,” he says.
CTL Practicum — Bringing Innovations to Market
Hemp is becoming a widely commercialized product, and Liu’s research has the potential to play a role in how hemp is regulated as a protein source. His work is funded by the Good Food Institute — a nonprofit to accelerate innovation of alternative proteins.
Liu has augmented his research with a position for graduate students at Cornell’s Center for Technology Licensing (CTL). CTL oversees the commercialization of technologies developed at Cornell with the goal of ensuring that Cornell research and innovations make a difference by benefiting society and fostering economic development. The CTL Practicum offers STEM and MBA graduate students an avenue to explore and build experience with key aspects of innovation assessment, commercialization strategy, and patenting and licensing agreements. Recruited as part of the first cohort of CTL practicants, Liu has been involved in the program since its launch in January 2020.
“Being a CTL practicant has given me plenty of real-world opportunities to practice skills that I’ve cultivated throughout my PhD program,” Liu says. “I’ve had to quickly learn about completely new fields of research in order to assess how a specific Cornell invention can improve or disrupt existing technologies.”
“Martin is a real asset to the CTL Practicum,” says Marie Donnelly, the business development and licensing associate for the life sciences at CTL. “He asks really insightful questions about the technologies that he works on, helping us to clarify how industrial licensees could use these inventions. I rely on him for increasingly complex assignments and technology portfolios. We’ll miss him once he graduates, but I can’t wait to see what he does next.”
Liu is working on methods of processing hemp that could alter the future of plant-based protein sources. He is excited about his work and its potential impact. He became passionate about food and food choices when he transitioned to a flexitarian diet: He treats meat as a delicacy to be consumed only occasionally. By focusing on hemp, Liu has positioned himself in two relatively new areas of research: “I’ve been very grateful to work in this crossroad of buzzwords, as I like to say. Plant-based protein is something everybody is very into right now, and hemp has huge market potential. This has a lot of value for the impact of my work. I think plant-based nutrition is the future.”