Researchers want a better whiff of plant-based proteins

(Press-News.org) COLUMBUS, Ohio – Off-putting smells can make even the healthiest of foods unpalatable. 

In a new study, researchers have developed a way to remove unpleasant aromas from plant-based proteins to make them smell more appealing. They did so by designing a two-step fermentation process to counter the odors that typically form during cultivation and extraction. 

The study’s results showed that their approach could remove between 95 to 99% of key smells, significantly outperforming one-stage fermentation across all proteins. 

Ultimately, the work paves the way for consumers to embrace a wider variety of safe and nutritious food choices, said Sheryl Barringer, senior author of the study and a professor in food science and technology at The Ohio State University. 

“Plant-based proteins are becoming more and more popular, either as people become vegetarians or just want to reduce their meat consumption,” she said. “Consumers want that option, but they don't want to give up on the taste.” 

Most plant-based proteins, especially those produced as alternatives to milk and dairy products, naturally emit odors that can negatively affect their reception by consumers. Since smell greatly influences flavor perception, these scents, often described as beany, grassy, earthy, sulfurous or cereal-like, can make it difficult for consumers to choose healthier food alternatives. 

“Lots of factors all contribute to food preference, but it’s really hard to say I’m going to force myself to eat a product because it’s good for me, even if it tastes bad,” said Barringer. 

Still, as global demand shifts toward more sustainable, health-conscious and allergen-friendly foods, scientists are having to get creative about raising interest in plant-based proteins. Aside from their compatibility with vegan and lactose-intolerant diets, alternative proteins would likely also be beneficial for the long-term health of the global food supply, as well as help reduce the environmental impact of our food systems. 

The study was recently published in the journal Foods. 

Depending on the product, successful fermentation can take anywhere from a few hours to a whole day.. Adding the second step doesn’t overcomplicate this process, meaning that future plant-based proteins created using this team’s anti-smell method won’t cost consumers more or take longer to make, said Manpreet Kaur, lead author of the study and a PhD student in food science and technology at Ohio State. 

“We are using the same things that are used in the normal fermentation process,” said Kaur. “The only thing changed is how we utilize the bacteria.”

In the first stage of the experiment, researchers added a type of beneficial bacteria, Lactobacillus plantarum, to their microbial cultures, allowing it to ferment and begin breaking down the compounds responsible for foul smells. In stage two, they used a traditional yogurt culture containing a variety of common bacteria known for developing and modulating desirable aromas to complete the fermentation process. 

The team then applied this method to solutions containing eight different plant proteins: 9% soy, pea, chickpea, mung bean, faba bean, rice, barley-rice and hemp. In each test, human sensory evaluation results revealed consistent and often near-complete reductions in smells. 

Kaur and colleagues also found that adding certain ingredients could affect the outcome of the process. For example, while the natural sugar allulose could enhance Lactobacillus plantarum activity, strawberry preserves aided the performance of the bacteria in the yogurt. In contrast, non-fermentable additives, such as pectin, xanthan gum and oil, were introduced with only minimal effects on odor reduction.  

Overall, this work not only advances the field’s understanding of how fermentation can be used to mitigate unsavory sensory challenges, but also offers a practical solution for the development of flavorful plant-based dairy snack alternatives, the researchers say.

“There’s a real focus on people wanting to be healthier and more environmentally conscious, and a push for plant-based products instead of meat and dairy products,” said Barringer. “So I expect this area of research will absolutely continue to grow in the next many years.”

Charlotte Gray from Ohio State was also a co-author. 

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Contact: Sheryl Barringer, Barringer.11@osu.edu

Written by: Tatyana Woodall, Woodall.52@osu.edu 

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