Creating realistic, healthy meat substitutes

In seeking to eat healthier food, more consumers are turning to vegetable-based meat substitutes that resemble chicken and beef. However, while many meat substitutes can be made to taste like beef or chicken, the texture is often mushy or flaky. A team of researchers at the University of Missouri-Columbia is helping create vegetable-based meat substitutes that are remarkably similar to the texture, appearance and feel of actual meat.

Researchers Fu-hung Hsieh, professor of biological engineering and food science, and Keshun Liu, adjunct associated professor in food science, are perfecting a manufacturing process that mixes powdered vegetable proteins in a high-moisture setting to create fibrous structures that look and feel like real meat. This process ultimately will allow consumers to purchase healthier meat substitutes without sacrificing the experience of eating a steak or chicken breast, the researches said.

"Food makers have been creating vegetable protein-based meat substitutes that taste like real meat for years, but have not been as successful at recreating the texture of meat," Hsieh said. "Consumers will want these vegetable protein-based products because the textures will be more appealing to them."

The process involves combining different types of powdered vegetable proteins, which are combined with water and processed through a heated extruder. After leaving the extruder, the substance is cooled in a controlled manner. The process facilitates the creation of the meat substitute, and the formation of the desired fibrous structures.

To perform quality-control measures, the researchers collaborated with Gang Yao, assistant professor of biological engineering. Yao used a novel, non-invasive approach adapted from a method commonly used in chemistry studies: fluorescence polarisation spectroscopy. The method uses polarised, or directional, light to generate fluorescence, or luminescence, in the sample. An instrument then reads the signal generated by the fluorescence. If the signal is strong, fibre structure is good. If it's weak, this signals that adjustments need to be made in the extrusion and/or cooling process. The researchers are the first to use fluorescence polarisation spectroscopy to measure fibre structure in meat substitutes. Using this method, food manufacturers will be able to make quality control adjustments on the fly.

"This method is desirable because it's effective, small, relatively inexpensive and offers the most accurate readings of any method while never coming into contact with the food product, thereby minimising the opportunity for contamination," Yao said.

The findings will be featured in an upcoming issues of the Journal of Food Science.