Taking the cream out of ice cream
By Rebecca Guenard
- Frozen dessert companies are reformulating ice cream to appeal to health and environmentally conscientious consumers.
- Replacing milk fat and protein requires completely rethinking the dessert formulations to emulate ice cream’s taste and feel.
- Current non-dairy formulations are based on empirical tinkering; the product category needs a more scientific investigation of ingredient interactions.
Want the ultimate sign that frozen desserts have changed? Spinach ice cream! In addition to the vitamin-rich main ingredient, the spinach-flavored treat has a non-dairy base to attract vegan customers (https://tinyurl.com/spinach-ice-cream). Van Leeuwen Ice Cream, the Brooklyn, New York ice cream shop that served the leafy-flavored scoop this summer, has been selling artisanal frozen desserts for a decade (https://vanleeuwenicecream.com/). They are among a group of producers on the leading edge of a resurgence of alternative ice creams. They may still be cold and scooped into a cone, but the formulation of these frozen treats is far more complicated than traditional ice cream.
Plant proteins do not exhibit the same unique properties as milk proteins, and the complexity of milk fat is difficult to duplicate with non-dairy replacements. Removing dairy from frozen desserts inevitably results in a complicated food label as more and more ingredients are needed to produce the taste and texture of traditional ice cream.
“When making non-dairy frozen desserts you have to bring in the technology and the scientific knowledge to balance the amount of sugar, the amount of protein, and the amount of fat,” says Robert F. Roberts, head of the food science department at Penn State University in University Park, Pennsylvania, USA. “And then you have to put that together in a way that is going to be stable so you can freeze it.”
Despite the formulation obstacles, vegan ice creams are growing in popularity. They are marketed toward a myriad of consumers, like those trying to avoid digestive discomfort, or concerned about the environmental strain caused by ice cream, as well as, those making the choice to avoid animal by-products for ethical reasons. In addition, some frozen desserts are aiming for a bigger health food market. Alternative ice creams now include nutritional incentives like probiotics and extra protein (https://tinyurl.com/y3unejyf). Manufacturers seem to be considering frozen desserts as a vehicle for supplementing basic nutrition to reduce the risk of certain diseases and health conditions.
Some experts feel alternative ice creams need more research to understand the molecular interactions of the ingredients before they get too established in the market. The formulation for the non-dairy frozen desserts have thus far been determined empirically. In contrast, the science of traditional ice cream is well-known. What can non-dairy ice cream producers take away from the treat humans have enjoyed since antiquity? And what can consumers expect from this rapidly changing product?
The protein predicament
Typically, traditional ice cream is composed of the following mixture: fats, proteins, sweeteners, stabilizers, emulsifiers, water, and flavors. As this mixture is whipped, air also gets incorporated. Milk proteins provide important structural functions for blending these ingredients into a creamy, smooth texture. The proteins (lactose, casein, whey, etc.) stabilize the partial coalescence of the fat phase and maintain small air bubbles. The proteins also enfold water, which gives the product body and texture while preventing ice crystallization. Finally, they add a sweetness to the ice cream, reducing the amount of added sweetener that is needed. In short, dairy is a critical ingredient that cannot be replaced with a single substitute. Multiple components are necessary to make up for all the duties dairy fulfills.
“The biggest problem I see when I talk to lay people is, they say, ‘I just replaced the cow’s milk with soymilk and it didn't work,’” Roberts says. “That is because cow’s milk and soymilk are not the same thing.” He says soymilk, almond milk, and other non-dairy beverages do not contain as much protein, and the proteins they contain function differently. “It certainly doesn't contain any lactose; it doesn't contain the right minerals,” he says.
FIG. 1. Illustration of the interplay between fat, protein, water, and air in dairy based ice cream. Source: Goff, Chapter 13 from Advanced Dairy Chemistry, volume 1B: proteins, applied aspects, McSweeney and Mahony editors, Springer, New York, 2016.
Roberts points out that using the word “milk” to describe almond and soy beverages leads manufacturers and consumers to assume such products function like dairy. “People think they can replace these things one for one and they cannot,” he says. “This absolutely does not work.”
He says the main reason for this failure is composition. Dairy protein isolates are primarily protein, about 85 or 90 percent. A pea protein flour or a soy protein flour, on the other hand, has roughly 12 percent protein. That means when you add these protein isolates to an alternative ice cream formula, you are incorporating a much higher number of unknown ingredients.
According to Roberts, in addition to having lower concentrations of protein than dairy, plant proteins grow inconsistently. The plant’s variety, where it is grown and under what conditions, all influence protein production. “We have been studying milk for a long time. There is a couple hundred years of research data on milk,” he says. “We know milk comes from a cow, so biologically there is some variation, but in general milk has a similar composition.” Even within a single plant species, he says, there is enough variability that it could affect a frozen dessert formulation. As a result, alternate ice cream producers may find they need to change their formulation when swapping out protein suppliers. Robert’s research group plans to study how functional properties change with these inconsistencies in plant protein isolates. It is one of many studies that are needed to better understand these products.
“Not much has been published on the science of plant-based ice creams,” says Finn Hjort Christensen of DuPont Nutrition Biosciences in Denmark.
Christensen is working on emulsifiers for vegan ice creams. Without the stabilizing properties of milk proteins, alternative ice creams rely on emulsifiers to distribute air in small bubbles throughout the product. A traditional ice cream might use egg yolk as the emulsifier, which is not possible with vegan, or even low-fat ice creams. He says emulsifiers are crucial to making these alternative ice creams with vegetable-based proteins. “If you have very poor air incorporation that means that you are trying to force in air and it is not being distributed,” says Christensen. “The air bubbles would be really big, and when it comes out of the freezer it looks like Swiss cheese.”
Working empirically, he has found that mono- and diglycerides, and acetylated diglycerides work well as emulsifiers for vegan ice creams. However, he admits that he does not understand the interactions between these emulsifiers and plant proteins enough to achieve better air incorporation. Christensen echoes Robert’s statement that scientific studies of plant-based frozen desserts are not available yet. “We have been making dairy based ice cream for the last two hundred years, whereas it has only been within the last 5 years that we have seen a growing interest in the plant-based version,” he says. Though, with all the large, international companies launching products within this segment of the industry he says he believes a lot of research will be published soon.
Desserts as health food
One factor that may push research forward is the rebranding of these desserts as functional foods. Such foods are intended to provide a benefit beyond basic nutrition, like minimizing a consumer’s risk for type-2 diabetes. Low-fat or sugar-free options have now evolved into ice cream with prebiotics, probiotics, or higher protein. For some of these formulations, not having cow’s milk is an advantage.
One of the first modern-day alternative ice creams to come on the scene, in 2012, was Halo Top, a US company headquartered in Los Angeles, California. Within 5 years, Halo Top became the top-selling pint of ice cream in the United States while also gathering a long list of competitors. Well-established brands like Häagen-Dazs, Magnum, and Ben&Jerry’s have developed more healthy options, and start-ups focused on healthy alternatives are regularly cropping up.
The latest is a brand from the Netherlands called Koupe. In an interview with Food Navigator, Koupe founder, Jaco Pieper, said that in addition to having reduced sugar, fat, and calories his product offers something extra for your health: protein and prebiotic fiber (https://tinyurl.com/y52wpa69). Koupe touts the energy boost its consumers will get from the addition of lean protein and fiber, but it is less and less novel to find these ingredients in snacks and desserts. Even candy bars are being sold with added protein (https://tinyurl.com/yyhm3824). Halo Top has protein- and fiber-containing varieties among their products as well.
A unique approach to providing a healthy treat is allowing the growth of bacteria that benefit the gut. The idea of fermented ice cream mirrors yogurt, which harbors strains like Lactobacillus acidophilus and Bifidobacterium Bifidum that enhance digestion and overall health. However, probiotic cultures do not grow rapidly in ice cream made from cow’s milk. Similarly, not all frozen yogurt has the same probiotic concentration as standard yogurt; if it has any at all.
Research shows that replacing cow’s milk with plant products, such as soy or coconut, promotes better probiotic growth (https://doi.org/10.1016/j.lwt.2016.02.056). In a collaboration between the University of Malaya, Lumpur, Malaysia, and King Abdulaziz University in Jeddah, Saudi Arabia, researchers found that the population of Lactobacillus acidophilus bacteria increased more than Bifidobacterium Bifidum in both soy and coconut milk, but both cultures were higher than in cow’s milk. In addition, a mixture of 75% soy milk and 25% coconut milk grew nearly double the amount of these bacteria that grows in cow’s milk. The investigators point out that the sugars and amino acids the bacteria need to grow are more abundant in these mediums than in cow’s milk.
Alternative ice creams are now suited for a wide range of consumers’ dietary needs. A frozen dessert with vegetables, protein, and gut-healthy bacteria evokes less guilt than traditional ice cream. Sustainability studies provide one more reason for consumers to gravitate to dairy-free frozen treats.
An environmental concern
Adisa Azapagic, a researcher at the University of Manchester in Manchester, U.K., recently coordinated a study of dairy ice cream’s effect on the environment. “What we wanted to do was evaluate and estimate the life-cycle environmental impact of ice cream which had not been done previously,” she says. Her research team evaluated ice cream production from start to finish. They considered everything from the production of raw materials, to the manufacturing process, to the energy used for refrigeration, to end-of-life packaging, and disposal. They also considered the effect of all the transportation steps in between, and the waste produced across ice cream’s entire lifecycle.
Of all the processes she studied, Azapagic found that the production of milk had the biggest impact on the environment. She says the methane produced on dairy farms adds to the greenhouse gases in the environment that contribute to climate change. “Anything that eliminates milk will have a lower environmental impact,” she says.
Frozen desserts that eliminate milk, such as sorbets, are one thing, but Azapagic says consumers cannot assume that substituting with plant-based ingredients is more environmentally friendly. Her group’s impact study included cocoa cultivation for chocolate flavored ice cream. “Farmers open up new lands and plant new cocoa beans. We call that land use change,” says Azapagic. “This is typically associated with high carbon emissions.” She says that if there was increased land use associated with cultivating soybean, for example, non-dairy frozen desserts based on soy could have a similar environmental impact as that of dairy ice cream. Without impact studies, it is impossible to claim that alternative ice creams are better or worse for the environment than dairy based.
“I have not seen studies which look at these new types of ice cream and estimate the environmental impact of replacing the milk with some of the alternatives,” Azapagic says. “Unless you have captured some numbers, it is dangerous to speculate.”
The future of frozen deserts
For all the ice cream innovation that has occurred in the past five years, more work remains. For many consumers the flavor and texture of plant-based frozen desserts is still unappealing.
Despite the added protein and fiber that some Halo Top flavors offer, the legumes used as the source for these ingredients reportedly leave a dry taste in the mouth (https://tinyurl.com/y65gctz3). The addition of plant materials and the removal of milk fat makes mouth feel a continued challenge for alternative ice creams. “Milk fat has hundreds of fatty acids in it, with about twenty in abundance” says Roberts. “Most typical vegetable fats only have three or four.” The complexity of fatty acids in milk translates into a complex freezing profile that inhibits traditional ice cream from crystalizing at a single temperature, he says. This, in turn, leads to the smooth, creamy feeling in the mouth when it melts. Alternative frozen desserts still face the challenge of feeling watery and icy in the mouth (https://tinyurl.com/y5k9k6n6).
Then there is the obstacle of taste. Roberts says that with dairy formulations manufacturers can make a neutral base that does not impart a flavor. “You can make a white background for people to add their strawberry or vanilla or whatever flavor they want to put into the product, he says. “Folks in the plant-derived industry would like to do the same thing.” However, plant products have an inherent taste that formulators must mask to create a neutral base.
“You definitely see more and more of these plant-based products coming on to the market,” says Christensen. “If we have found the holy grail yet, with regards to formulation, I don't know. It’s still an area where there is not a lot of research on how to improve.” In July 2019, a new kind of dairy-free ice cream hit the market with the potential to displace all the new alternative brands. The ice cream contains milk proteins that were not produced from an animal (https://tinyurl.com/y2qs3q9r). The product is made by Perfect Day, a San Francisco, California company using the fermentation of microflora to produce milk proteins. The proteins function like those in traditional ice cream. If consumers accept this animal-free source, the world of ice cream could change yet again.
Rebecca Guenard is the associate editor of Inform at AOCS. She can be contacted at firstname.lastname@example.org.
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- Ice cream, 7th ed., Goff and Hartel editors, Springer, New York, 2013.
- Advanced Dairy Chemistry, volume 1B: proteins, applied aspects, McSweeney and Mahony editors, Springer, New York, 2016.
- Effects of soy proteins and hydrolysates on fat globule coalescence and meltdown properties of ice cream, Chen, J., et al., Food Hydrocolloids 94: 279–286, 2019.
- Influence of cellulose nanofibrils on the structural elements of ice cream, Zuluaga, R., et al., Food Hydrocolloids 87: 204–213, 2019.
- Environmental impacts of ice cream, Antonios Konstantas, et al., J. Clean. Prod. 209: 259–272, 2019.
Biotech ice cream
In April 2019, Inform reported on biotech companies that were using fermentation as a new way to manufacture proteins (https://tinyurl.com/y2al3h8s). One of these companies, Perfect Day, has released a limited supply of ice cream made from the whey protein they develop without cows.
Perfect Day was founded in San Francisco, California, USA, by two vegans with experience working in the biopharmaceutical sector. They established their company in 2014, with the goal of creating milk proteins through the fermentation practices used by biopharma. In doing so, they fulfilled their vegan belief of avoiding animal byproducts, while still eating foods they enjoy, like cheese, yogurt, and ice cream.
The company has no plans to enter the manufacturing realm itself but will partner with companies who will formulate their proteins into food products (their most notable joint venture was in 2018, with Archer Daniel Midland). However, Perfect Day produced an ice cream for limited release that was only available through their website. The sample pack consisted of three pints of different flavors at a cost of $60 (closer to $100 with shipping). Within hours the company sold out of the one thousand packets of “animal-free” ice cream it made available. (https://www.perfectdayfoods.com/taste-the-magic/).
Those that had the opportunity to try it before it was gone report that they could not tell the difference between Perfect Day and traditional ice cream (https://tinyurl.com/yxe6flgh). Instead of the gritty, wateriness that non-dairy ice cream consumers usually say they experience with alternative ice creams, Perfect Day’s ice cream was described as smooth and creamy. Milk proteins, even if they are lab-grown, provide the crucial bridge that combines all the ingredients in the frozen treat.
If this temporary release was a test of consumer acceptance of lab-grown dairy proteins, the ice cream’s rapid sell out could be taken as a sign of success.