Research on animal-free fats presents un-fat-homable possibilities for meat alternatives
Fat is an essential part of the meat-eating experience.
The aroma, juiciness, tenderness, and overall mouthfeel from fat create a delicious and memorable product. Animal-free fats that can substitute the traditional fat experience are essential for alternative meats to compete with the taste of conventional meats. These animal fat substitutes should not only be convincing mimics but sustainable and scalable, too.
GFI’s newest cohort of grantees focuses on just this: producing the next generation of animal-free fats.
In recognition of the sustainability and technical challenges with current alternative fats, we released a call for proposals on plant-based or fermentation-derived fats for use in meat alternatives. From many excellent proposals emerged five new grantees focused on alternative fats: Salma Mohamad Yusop, Naazneen Sofeo, Kyria Boundy-Mills, Jiakai Lu, and Alejandro Marangoni.
Let’s dive deeper into the technological requirements for plant-based and fermentation-derived fat substitutes and explore the solutions developed by GFI grantee alums Ricardo San Martin and Chris Gregson as well as those on the horizon from our new cohort of grantees.
Current challenges in alternative fats
GFI was motivated to fund alternative fat projects after publishing our recent report, Plant-based meat: Anticipating 2030 production requirements where a key finding became clear to us: sustainable alternative fat innovation is crucial for the success of the alternative meat industry.
The industry currently relies on coconut oil as the primary fat in products because it is semi-solid around room temperature, making it a better substitute for solid animal fat than other plant oils. Our report found that by 2030, the plant-based meat industry will require at least 16% of the global supply of coconut oil if it grows at the rate projected by multiple market analysts. Given the growing demand for coconut oil from other sectors and its volatile sourcing, relying on a large percentage of its supply could lead to significant bottlenecks in alternative meat production.
In addition to supply chain challenges, coconut oil is not ideal as an animal fat substitute technologically. Although coconut oil is more solid than plant oils, an ideal animal fat alternative would be completely solid at room temperature and would slowly melt upon cooking—whereas coconut oil melts almost immediately when heated. Additionally, coconut oil cannot serve as an alternative for other types of desirable animal-sourced lipids. For example, omega-3 fatty acids contribute to seafood flavoring and health appeal but are usually sourced from marine fish; these types of fats are not present in high quantities in coconut fat.
What makes a good animal-free fat?
Alternative fat products should emulate the desirable traits of animal fat while improving upon undesirable properties.
Fat properties that alternatives should emulate
- Flavor, texture
- Cookability (e.g., high melting point and minimal leakage)
- Structure
- Affordability
- Scalability (e.g., commercializable, compatible with downstream processes)
- Nutritional benefits (e.g., include omega-3 fatty acids)
- Food grade quality
- Shelf stability (e.g., resistant to oxidation/rancidity)
Fat properties that alternatives can improve
- Climate impact (e.g., avoid deforestation, reduce greenhouse gas emissions from animal agriculture)
- Supply chain instability
- Animal welfare
- Risks to public health (e.g., exclude cholesterol and saturated fats- note that cholesterol is only found in animal products)
When looking for animal-free fat sources, there are a number of key considerations to keep in mind, including:
Saturated fat content
The molecular structures of saturated vs. unsaturated fats demonstrate key differences in their properties. While high saturated fat content contributes to favorable properties (texture, cookability, taste, stability), it is also associated with poor nutrition. These trade-offs are important considerations for alternative fat formulations.
Saturated fatty acid
- No double bonds on fatty chain (saturated with hydrogens)
- Straight chains -> forms organized solids at room temp (higher melting point)
- Found in high levels in animal fats
- Better oxidative stability
- Raises the risk of heart disease and stroke
Unsaturated fatty acid
- Contains 1 or more double bonds
- Bent chains -> forms liquids at room temp (lower melting point)
- Found in high levels in plant oils
- Double bond is susceptible to oxidation (rancidity)
- Generally healthier than saturated fats (see more information about cis vs. trans unsaturated fatty acids and polyunsaturated fatty acids)
Melting point range
Animal fats have higher melting points than plant oils, providing a solid structure that slowly melts while cooked. Alternative fats should melt similarly to animal fats. Higher saturated fat composition increases lipid melting point. As a result, animal fats and tropical oils have higher saturated fat content and melting points than plant oils. Other lipid properties have effects on melting point as well—for example, longer chain lengths are associated with higher melting points. Animal fats typically have longer lipid chains than plant oils.
Overall structure
Animal adipose tissues are composed of fatty cells in a collagen fiber network, making their structure challenging to replicate with other lipids. Alternative fats must have similar structures to reach taste and texture parity with animal fats. GFI grantee, Professor Jiakai Lu uses high internal phase emulsions of soybean protein and soybean oil to mimic beef adipose tissue.
Omega-3 content
Omega-3 fatty acids are mainly sourced from fish oil, so nutritious animal-free omega-3 fatty acid alternatives, such as algae oil, are necessary. α-Linolenic acid (ALA) is the omega-3 fatty acid mainly found in plants, while eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the omega-3 sources mostly found in marine seafood and algae. ALA can be converted into EPA and DHA, but this process is inefficient in humans. EPA and DHA are associated with health benefits and, in humans, ALA is mostly stored or used for energy. Good omega-3 alternatives will focus on producing animal-free EPA and DHA fatty acids.
GFI’s newest grantee cohort is focused on making appealing alternative fat products from plant-based and fermentation-derived ingredients.
Plant-based fat alternatives
While native plant lipids typically lack the functionalities of animal fats, their molecular structures can be modified or separated to create solid fats more akin to their animal counterparts. Alternatively, native plant lipids can be combined with other ingredients—like proteins, phosopholipids, or carbohydrates—to form emulsion- or gel-based fat alternatives.
Traditionally, plant-based alternative fats have been made through hydrogenation or lipid fractionation. Hydrogenation is a chemical reaction that directly modifies plant oils by converting double bonds into single bonds. This transforms plant oils into solid, saturated lipids with high melting points. Hydrogenated vegetable oil is the key ingredient to plant-based butter substitutes, margarine, and shortening. While hydrogenation is scalable, partial hydrogentation forms trans fat byproducts which promote heart disease and, as a result, is no longer deemed as GRAS (“Generally Recognized as Safe”) by the FDA.
As an alternative to creating saturated and trans fats, plant oils that contain mixtures of fats can be separated to create more pure fractions of desirable types of fats. Lipid fractionation is a separation technique that can extract saturated lipids (e.g., stearic acid-containing solids) from unsaturated lipids (e.g., oleic acid-containing liquids). This is generally not a high-yielding process for plant oils given their low saturated lipid content. Lipid fractionation, like hydrogenation, can successfully create alternative fats with ideal structures and melting temperatures, but they both rely on saturated lipids that would have similar nutritional issues as animal fats.
Professor Alejandro Marangoni
Professor of Food Science at University of Guelph
Focus: Enzymatic conversion of oils into functional fats using glycerolysis
Professor Jiakai Lu
Professor of Food Science at University of Massachusetts, Amherst
Focus: Production of omega-3 enriched plant-based adipose tissue using advanced emulsion technology
Learn more about Professor Marangoni’s work
Professor Alejandro Marangoni and his team (Dr. Saeed M. Ghazani and Dr. Erica Pensini) are taking a biological approach to modifying plant lipids with promising scalability and nutritional properties.
Using a mild enzymatic reaction similar to interesterification, Marangoni’s lab is converting triacylglycerides (TAGs) into mono- (MAGs) and di- (DAGs) acylglyercerides. MAGs and DAGs have higher melting points and are, therefore, more solid at room temperatures than TAGs with the same fatty acids. The group plans to optimize the fat crystallization and enzymolysis process at scale. Oils do not need to be refined before undergoing this enzymatic process, so less-refined oils can be used, supporting the commercial viability of this process. The mild nature of the enzymatic process also preserves lipid saturation content, micronutrients, and natural antioxidants.
Professor Marangoni also emphasized that less conventional, more sustainable oils could be used in the process.
Learn more about Professor Lu’s work
Instead of modifying or separating plant lipids directly, some researchers are instead using other ingredients to structure native plant oils. One method is emulsifying, i.e., mixing liquids that would otherwise not combine well. Oil-in-water and water-in-oil emulsions are structurally similar to adipose tissue because they are liquid droplets suspended within a matrix.
Professor Jiakai Lu and his team (Professor David Julian McClements, Professor Eric Decker, Professor Alissa Nolden, and Xiaoyan Hu) plan to leverage oil-in-water and water-in-oil emulsions to create an omega-3-rich adipose tissue alternative.
Specifically, the Lu lab uses high internal phase emulsification (e.g., an emulsion with tightly packed droplets) to combine seaweed-derived polysaccharide gelling agents with plant-based emulsifiers and algal, flaxseed, and other plant oils. Algal and flaxseed oils are rich in unsaturated lipids, including omega-3 fatty acids, which could be enticing for health-conscious consumers. To prevent omega-3 fatty acid oxidation, the Lu lab plans to add antioxidants and confirm the product’s shelf-stability. Professor Lu described some of the current challenges and budding potential of these next generation emulsion-based fats.
“You can use a variety of locally grown oils (peanut, cottonseed, rice bran, tigernut) and novel, more sustainable oils could be used for this purpose. No need to stick to canola, soy and sunflower only.”
Alejandro Marangoni
“Our existing prototypes are much softer than real adipose tissue at low temperatures and do not melt when heated. In this project, we therefore aim to optimize these [emulsions] so they can be fortified with plant-based omega-3 rich oils, be successfully incorporated into protein-rich muscle analogs, and exhibit the texture and melting properties exhibited by real adipose tissue.”
Jiakai Lu
For more information about the need for alternative omega-3 fatty acid efforts, see GFI’s Advancing Solutions for Alternative Proteins (ASAP) initiative’s notes on preventing oxidation, novel production, enhancing affordability, and understanding the uptake by cultivated fish cell of omega-3 fatty acids.
Oleogelation
Oleogelation is an oil structuring technique that leverages oleogelators—molecules that can self-assemble into crystalline fibers—to confine oil. There is a wide range of food-grade oleogelators, such as proteins, polysaccharides, small molecules like phytosterols, and waxes and other lipids, that can entrap oils without modifying their chemical traits. As a result, oil nutritional value is retained, and oil leakage during cooking is reduced.
GFI grantee alums Dr. Christopher Gregson and Professor Ricardo San Martin both create oleogels using different materials. Dr. Gregson uses wax as an oleogelator and Dr. San Martin applies small molecule saponin as an emulsifier.
Dr. Gregson
CEO and Pioneer of Paragon Pure
Focus: Rice bran oil oleogels for plant-based meat
Professor San Martin
Professor of Engineering at University of California, Berkeley
Focus: Adding encapsulated fats to plant-based meat
Learn more about Dr. Gregson’s work
To understand how his wax-based oleogels should function in meat, Dr. Gregson, CEO and Pioneer of Paragon Pure, worked with Toronto Metropolitan University and Silpakorn University researchers to pinpoint key microstructure and thermal properties as well as rheological and texture attributes of adipose tissue from conventional animal sources. These are the properties Gregson aims to mimic using rice bran ingredients. Dr. Gregson described the advantage of Paragon Pure’s approach using rice bran oil and rice bran wax mixtures for their alternative fats. He emphasized the low cost of rice bran oil, its rich antioxidant content, and its sustainable sourcing.
Learn more about Professor San Martin’s work
Professor San Martin creates plant-based oleogels for plant-based meat with saponin emulsifiers and sunflower and canola oils. San Martin particularly emphasized that saponins are excellent emulsifiers, which ultimately prevents oil leaching during cooking by acting as an organogelator
“Rice bran oil and rice bran wax are upcycled ingredients extracted from rice bran, an abundant by-product of rice polishing (the conversion of whole grain rice to white rice). As such, rice bran oil and rice bran wax have very positive sustainability footprints, particularly given their ability to replace animal fats and tropical oils like palm, coconut, and shea.”
Christopher Gregson
“Saponins are unique because with very small amounts, the network that surrounds the oil droplets is much stronger than that obtained with traditional surfactants, such as soy lecithin or proteins. This has processing advantages, as well as reducing oil leakage from the foods, therefore enhancing a desirable mouthfeel.”
Ricardo San Martin
For more information about plant-based alternative fats, see GFI’s Advancing Solutions for Alternative Proteins (ASAP) initiative’s notes on fat and moisture encapsulation for alternative protein products.
Fermentation-derived fat alternatives
Some microbes, like microalgae and oleaginous yeasts, have high-quality and high-quantity lipid content, which makes them attractive for alternative fat technology. For example, marine microalga Aurantiochytrium sp. SW1, native to Malaysia, can produce lipids up to 60% of the cell weight with 35-50% of the lipids being omega-3 fatty acid DHA.
Dr. Salma Mohamad Yusop
Senior Lecturer of Food Sciences at Universiti Kebangsaan Malaysia
Focus: Utilization of microalgal fermentation product to produce structured plant-based fat for meat analogue
Professor Kyria Boundy-Mills
Professor of Food Science and Technology at University of California, Davis
Focus: Production of animal fat substitutes by oleaginous yeasts
Dr. Naazneen Sofeo
Postdoctoral Research Fellow at Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology, and Research (A*STAR)
Focus: Chicken and sheep TAG production from food waste streams with yeast
Learn more about Dr. Salma’s work
Dr. Salma Mohamad Yusop and her team (Dr. Mohamed Yusuf Bin Mohamed Nazir, Professor Aidil Abdul Hamid, Ahmad Syafik Jaafar, and Amirah Mohd Noh) plan to use fermentation technology to grow this microalgae and optimize the production of its DHA-rich lipids. The Yusop lab then plans to emulsify and structure the resulting algal oil with soy proteins and transglutaminase. Dr. Yusop explained the process further and emphasized the importance of analyzing costs.
Learn more about Professor Boundy-Mills’ work
Oleaginous yeasts have high lipid content (up to 70% dry weight) and were previously optimized for petroleum replacements. The Boundy-Mills lab (with additional team members, Dr. Payam Vahmani, Dr. Irnayuli Sitepu, Dr. David Block, and Dr. Anita Oberholster) is identifying wild (non-GMO) oleaginous yeast strains which accumulate fat at high yields and with compositions and properties similar to animal fats. Boundy-Mills plans to further optimize oleaginous yeast fatty acid content
Learn more about Dr. Sofeo’s work
Because of carbon’s key role in enhancing oil concentration, carbon-rich feedstocks like glucose or other carbohydrates are applied to grow oleaginous yeasts. A project at A*STAR, led by Dr. Naazneen Sofeo (with collaborators Dr. Aaron Thong, Dr. Prakash Arumugam, and Dr. Eric Charles Peterson), is evolving oleaginous yeast strains to grow on cheaper sources than pure carbohydrates. Specifically, A*STAR is aiming to sustainably produce yeast lipid profiles similar to the triacylglycerides found in chicken and sheep fats. Dr. Sofeo is using carbon-rich agri-industrial waste streams from cocoa processing in her work and described the environmental and cost benefits of this method.
Dr. Sofeo sang praises for other traits of this microbial fat production process: the high lipid content of oleaginous yeast, yeast’s high growth rate, the tunability of microbial growth, and a lower consumption of water and land resources make microbes a promising source for alternative fats.
“Using a variety of methods to incorporate the algal oils into a network of plant fat crystals and crosslinked proteins, the functional properties of the resulting mixtures will be tested against animal fats as well as plant-based sources such as palm oil. The research team also plans to model costs for industrial-scale versions of this process.”
Salma Mohamad Yusop
“[Oleaginous] yeasts are low in fat (below 20% dry weight) when they are actively growing. When the growth medium runs out of nitrogen, but carbon is still present, the yeasts continue eating the carbon source (sugar, alcohol, organic acid, etc.). They convert it into oil—swelling to 4-5 times their former size, and filling with lipid storage bodies made of triacylglycerols (TAG, the same storage oil used by plants and animals). Some yeasts reach over 65% oil by dry weight!”
Kyria Boundy-Mills
“Use of pure carbohydrate sources during fermentation for producing microbial lipids is one of the major production costs. Alternative low cost carbon sources from agri-industrial waste streams can reduce the production costs significantly. Such waste streams are abundantly available and have potential to contribute to environmental pollution. Hence recycling and transformation of these agri-industrial wastes enhances sustainability.”
Naazneen Sofeo
For more information about fermentation-derived alternative fats, see GFI’s Advancing Solutions for Alternative Proteins (ASAP) initiative’s notes on producing animal fats through fermentation and fat production and encapsulation within oleaginous yeast.
Cultivated fat mimics
While our 2022 grant cycle did not include a call for cultivated alternative fat proposals, there are notable advances by companies (e.g., Mission Barns, Hoxton Farms, and MeaTech) and academic labs. For example, GFI grantee alumna and subsequent recipient of grants from both USDA and NSF, Professor Amy Rowat, is creating marbled meat by co-culturing muscle-forming and fat-forming cells. Cultivated fat is made from animal adipose tissue-forming cells, so it has all the characteristics of animal-derived fat without animal agriculture.
For more information about cultivated alternative fats, see GFI’s Advancing Solutions for Alternative Proteins (ASAP) initiative’s note on uptake and biosynthesis of fat in cultivated meat cells.
Alternative fat commercialization and hybrids
Companies are also taking advantage of these fat opportunities. Lypid is a startup that uses microencapsulation to make solid plant-based fats with sunflower and olive oils, gums, and fibers. Another startup, Melt&Marble, uses precision yeast fermentation to make a plant-based fat with melting and mouthfeel similar to beef fat. CUBIQ Foods just partnered with Cargill to promote and sell their omega-3-rich plant-based and cultivated fat ingredients.
These alternative fat products are already being used for hybrid products that combine the best of plant-based, fermentation-derived, and cultivated ingredients to create the ultimate alternative protein experiences. Mission Barns teamed up with Silva Sausage Co. to combine their cultivated fats with Silva Sausage’s plant proteins.
Another cultivated fat company, MeaTech, is creating a cultivated-fermentation hybrid product with Enough’s mycoprotein product. Hybrid products like these will bring the best of all worlds by combining ingredients to optimize cost, taste, and texture. Recent updates on hybrid products and other industry developments in alternative fats can be found in GFI’s annual State of the Industry reports.
The fate of meat alternatives may rely on fat
When it comes to animal-free meat, alternative proteins are only part of the story. Proteins may be the central theme, but fats set the tone: they determine our feelings toward the product from the first bite.
Currently available animal-free fats fall short on one or many important characteristics including function, organoleptics, cost, sustainability, and nutrition, and future growth of the plant-based industry is sure to render them in limited supply. But as the research projects above show, scientists are working on breakthrough technologies to solve all of these challenges with the next generation of animal-free fats.
Whether using plants, microbes, animal cells, or some combination of the three, research to create animal-free fats is bringing us one step closer to craveable, affordable, and nutritious meat alternatives.
Author
Priera Panescu, Ph.D.
Priera Panescu is focused on analyzing plant-based meat and proteins and how to best expedite their progress. Areas of Expertise: food and agriculture systems, materials science, polymer chemistry, plant-based ingredients
