Written by Arya Hakimian, Laboratory Scientist (BSc, MSc); and Chedi Mbaga, Regional Manager (BSc. Engg)

The meat alternatives market has grown exponentially over the course of the past decade. Driving this expansion are factors like changing consumer preferences, shifting global supply chains and lower production costs.^[i] But as the market continues to grow, so will the number of market entrants. For this reason, there is now – more than ever – a need for producers to differentiate themselves and to understand how that differentiation affects their products’ performance. 

The Importance of Thermal Conductivity 

When evaluating the impact of meat analogue composition, one key physical property to keep in mind is thermal conductivity. Consider the following: Thermal processing centers around heating foods for a specific time under a particular set of conditions. And thermal conductivity is an important input for thermal processing as it helps to ensure adequate cooking times – which is important for health and safety considerations. In addition, thermal conductivity also affects regulation during storage and transport. Factors such as chemical composition, moisture, fat content, etc., can all influence the product’s thermal conductivity. ^{[ii] [iii]}

Putting Meat and Plant-based Protein to the Test 

To demonstrate this, lean ground beef and a leading plant-based alternative were tested on the Trident Thermal Conductivity Analyzer with the Modified Transient Plane Source (MTPS) method. Samples were formed into small balls (~5g each) and pressed into the MTPS small volume test cell. All samples were tested at RT (~21ºC) under consistent, minimal applied force (75g). Results indicated that under similar conditions, the ground beef sample had a significantly higher thermal conductivity, compared to the meat alternative – which might come as a surprise to those who wouldn’t expect beef to require a lower cooking temperature and slightly shorter cook time. ^[iv]

Closing Thoughts

One hypothesis behind the differences in observed thermal conductivity is the excreted “fluid” from the plant-based sample, which appeared to be “oilier” in nature. Natural oils have a much lower thermal conductivity compared to water, and depending on overall composition, this may have contributed to the lower thermal conductivity results (ground beef can have water content of ~55%). Further investigation at below freezing and above cooking temperatures would be a logical next step for experimentation.

If you found this article interesting, see C-Therm’s past work with fruits, honey and cold chain technologies for additional insight into MTPS testing on food-related applications.

Recommended Reading / Works Cited

[i] Gelski, J. (2021). Global plant protein market could hit $162 billion by 2030. Food Business News RSS. Retrieved from https://www.foodbusinessnews.net/articles/19347-global-plant-protein-market-could-hit-162-billion-by-2030

[ii] Ahmed, J., Mulla, M., Siddiq, M., & Dolan, K. (2021). Micromeritic, thermal, dielectric, and microstructural properties of legume ingredients: A review. Legume Science, e123. https://doi.org/10.1002/leg3.123

[iii] Verheyen, D., Govaert, M., Seow, T. K., Ruvina, J., Mukherjee, V., Baka, M., Skåra, T., & Van Impe, J. (2020). The Complex Effect of Food Matrix Fat Content on Thermal Inactivation of Listeria monocytogenes: Case Study in Emulsion and Gelled Emulsion Model Systems. Frontiers in microbiology, 10, 3149. https://doi.org/10.3389/fmicb.2019.03149

[iv] N.A. Cooking and Hot Holding Food. Florida Department of Agriculture & Consumer Services. Retrieved from https://www.fdacs.gov/content/download/67385/file/Cooking-and-Hot-Holding-Food.pdf