University of Arkansas researchers turn rice milling byproducts into high-protein plant-based cheese

Researchers at the University of Arkansas have demonstrated that proteins extracted from rice milling byproducts can be used to produce plant-based cheese alternatives, potentially opening new markets for rice growers and processors.

The study, published in the journal Future Foods, analyzed proteins derived from brown rice, rice bran, and broken rice kernels from a single rice cultivar. The research found that these proteins possess functional properties suitable for alternative cheesemaking, including meltability and structural firmness.

• Researchers at the University of Arkansas have shown that proteins from rice bran, brown rice, and broken kernels can be used to produce plant-based cheese alternatives.

• The study found rice-based cheese prototypes contained about 12% protein, addressing a common nutritional limitation in many dairy-free cheeses.

• Rice milling byproducts could supply an estimated 3.3 million tons of protein annually for the plant-based protein market in the USA.

Mahfuzur Rahman, Assistant Professor of Food Science with the Arkansas Agricultural Experiment Station and the University of Arkansas’ Dale Bumpers College of Agricultural, Food and Life Sciences, led the research alongside graduate student Ruslan Mehadi Galib.

“In a single rice grain, we have three different types of protein – from brown rice, white rice and bran,” Rahman said. “That’s the fundamental understanding we wanted to develop. When you say, ‘rice protein,’ what does that mean? Is it brown rice protein? Bran protein? Broken kernel protein?”

The research examined the composition and functional performance of these different protein sources when incorporated into plant-based cheese formulations.

Rice proteins consist primarily of four major fractions: albumin, globulin, glutelin and prolamin. The researchers found that the distribution of these proteins varies across different parts of the grain, influencing their functional properties in food applications.

Rice bran contained the highest level of albumin, while glutelin was more abundant in brown rice and broken kernels. These differences translated into varying performance characteristics when the proteins were used in prototype cheese formulations.

To test their functionality, the researchers extracted proteins from each rice fraction and produced three plant-based cheese prototypes using a standardized formulation containing coconut oil and corn starch.

The resulting products contained approximately 12% protein, a relatively high level compared with many plant-based cheese alternatives, which often contain little or no protein.

Rahman noted that improving protein content is a key challenge in alternative cheese development. Many plant-based cheeses rely primarily on starches and fats to replicate dairy textures, resulting in products with limited nutritional value.

The study also examined how each protein source influenced the texture and behavior of the cheese prototypes.

Protein extracted from broken rice kernels produced cheeses with softer textures and stronger melting characteristics, accompanied by higher oil separation. These properties were associated with the higher glutelin content of the protein fraction.

Brown rice protein, meanwhile, demonstrated the highest levels of essential amino acids and released more free amino acids during simulated digestion tests. It also showed strong solubility and emulsion stability, suggesting potential advantages for food processing applications.

Rice bran protein displayed lower solubility but significantly higher surface hydrophobicity. Its strong water-holding and foaming capabilities helped improve texture and reduce oil separation in the cheese prototypes.

Together, the findings suggest that different rice protein sources could be tailored to create a range of plant-based cheese products with varying functional properties.

Beyond cheesemaking, Rahman said the proteins may have broader applications in food systems due to their emulsifying and foaming capabilities.

“With sufficient foaming and emulsion capacities, rice-sourced protein may also be able to replace the functions that eggs and oil provide in food chemistry,” he said.

The research also highlights a potential circular economy opportunity within the rice industry by valorizing milling byproducts that are typically used for lower-value applications.

Arkansas is the largest rice-producing state in the USA. In 2024, farmers harvested a record 1.43 million acres of rice, accounting for nearly half of total US production.

According to the US Department of Agriculture, rice processing generates large volumes of byproducts each year, including an estimated 14.3 million tons of rice bran and 24.8 million tons of broken kernels.

The study estimates that these streams could collectively yield around 3.3 million tons of protein annually, representing a potentially significant supply for the growing plant-based protein market.

Currently, much of the rice protein used in the US food industry is imported, the study noted. Rahman suggested that extracting protein from domestic rice milling byproducts could expand the US rice protein sector while improving resource efficiency.

Using these materials, he said, represents a “significant opportunity to expand the USA-based rice protein market while promoting a sustainable circular economy”.

During conventional rice milling, dehulling removes the outer husk to produce brown rice. Additional processing then generates white rice while producing bran and broken kernels as secondary streams.

Although these fractions already serve some roles in industries such as animal feed, pet food, and brewing, the researchers believe they could be upgraded into higher-value food ingredients.

Future research will focus on refining formulations and evaluating sensory characteristics, shelf-life stability, and consumer acceptance of rice-based cheese products.

Rahman said further work is underway to support the transition from laboratory experiments to commercial applications.

“Current research is in progress to tackle these issues, facilitating the transition from laboratory development to practical use,” he said.

In parallel with this study, Rahman is also exploring alternative extraction technologies that could improve the nutritional quality of rice proteins. One approach under investigation involves ultrasound-based extraction methods designed to avoid chemical solvents such as hexane.

The researchers hope that improved extraction techniques could further enhance the functionality and nutritional value of rice proteins, strengthening their potential as ingredients in next-generation plant-based foods.