A Functionality Study of Mycoprotein

Abstract

The mycoprotein was obtained from the company, Mycorena. The mycoprotein is a potential source of alternative protein of the animal origin used as the functional ingredients in the food industry. In this project, mycoprotein concentrate (MC) and mycoprotein isolate (MI) were produced by freeze-drying the biomass and pH-shift processing together with freeze-drying, respectively. Moreover, the functionality study was focused on the foaming properties, emulsifying properties, and gelling ability of mycoprotein.

This project was primarily focused on three parts: the mycoprotein isolation, the functionality impacted by factors such as salt, pH, pre-thermal treatment, and protein powder concentration, and benchmarking of the MC and MI with other plant-based proteins. MI was isolated using the pH-shift process which allowed the protein to solubilize at pH 10 and recover (precipitated) at pH 4 to reach the overall extraction yield of 37\% from biomass (dry matter basis). The soluble protein content of MC and MI did not show any significant difference at pH 7. It was found that the salt concentration could affect the foaming capacity of MC. After a pre-heat treatment at 70$^{\circ}$C of MC solution, the foaming capacity was significantly improved while the foaming stability was significantly decreased. At pH 5, 7, and the original pH (5.7), the emulsifying properties (capacity and stability) did not show any significant difference. Different salt and pH treatments lead to the different gelling performance of MC. As for benchmarking the functionality of MC and MI to other plant-based proteins, the foaming stability and emulsifying capacity of MC displayed the best performance, whereas the MI observed a relatively poor functionality in all foaming, emulsifying, and gelling experiments. It was suggested that such poor functionality of MI could result from proteolytic hydrolysis.

In conclusion, the pH-shift processing conducted in this project was not a promising approach to studying the functionality of mycoprotein. However, the native protein in MC observed a greater emulsifying capacity which has the potential for further application. Further research surrounding the optimal protein isolation method without compromising the functionality of mycoprotein is worth studying.

Popular Abstract

Protein is an important macromolecule that works on building new structural and functional proteins for both humans and animals. With the increased global population, animal protein cannot meet the nutritional demand, therefore, more alternative protein sources need to be explored. Mycoprotein is a novel protein source gaining more interest currently due to its complete essential amino acids (EAAs) composition and favorable protein utilization (NPU) value which is comparable to those of milk. For food application, study on the functionality of mycoprotein plays an important role in developing food formulations.

As the freeze-dried biomass already has a high protein content, it is also called mycoprotein concentrate (MC) which can be used for the functionality study. However, it would offer a higher protein content and steady performance for functionality study and further application if the fermentation residue and fiber content are removed by extracting mycoprotein isolate (MI) with the pH-shift method. The pH-shift method was developed in the 1990s and it isolates proteins based on the difference in solubility that proteins in water exhibit at different pH conditions. The conformational changes of protein could occur during pH shift processing.

The ability of a protein to impart beneficial properties to food in addition to its nutritional value is protein functionalities. Some factors can influence the functionality performance of protein such as salt, pH, and preheat treatment of protein solution. Studying these factors could provide a wider food application in the future. Although the protein structure changes during the pH-shift process, it is of interest to know both the functionality performance of MC and MI compared with other plant-based proteins that can be found on the market today.

As an alternative protein source to functional proteins of animal origin, the functionality study of mycoprotein is worth investigating as it impacts the physical and chemical properties of food products. Understanding the functionality of mycoprotein provides an overall view of its future applications.

• author: Zhang, Luying
• supervisor: Björn Bergenståhl
• organization: Food Technology and Nutrition (M.Sc.)
• course: KLGM01 20221
• year: 2022
• type: H2 - Master's Degree (Two Years)
• subject: Agriculture and Food Sciences
• keywords: mycoprotein, protein isolation, protein functionalities, food technology
• language: English
• id: 9089526
• date added to LUP: 2022-06-17 13:35:44
• date last changed: 2023-09-01 03:45:14