Ultrasonic Extraction of Mycoprotein

Mycoprotein are fungus-derived protein produced for human consumption, which are mainly used to prepare meat substitutes or “fake meat”. Ultrasonic extraction and homogenization is a highly efficient method to release mycoprotein from the fungus achieving very high protein yields in a short processing time.

Mycoprotein

Mycoprotein is a single cell protein present in fungi. Offering a high amount of protein and fibre, mycoprotein is considered as a healthy and sustainable source of nutritionally valuable amino acids. Mycoprotein contains typically about 45% protein and 25% fiber by dry weight. Mycoprotein is rich in essential amino acids and with a composition of approx. 41% total protein it offer a similar protein content to spirulina. This makes mycoprotein an interesting protein source for vegetarians and vegans. Mycoprotein is rich in fibre. Its fiber content comprises approx. one-third chitin (N-acetylglucosamine) and two-thirds β-glucans (1,3-glucan and 1,6-glucan). Offering a high protein and fibre content, mycoprotein is a healthy and sustainable food source.
(cf. Finnigan et al. 2019)

Ultrasonic Mycoprotein Extraction

In order to produce mycoprotein, edible fungus species are grown and cultured in bioreactors. This means the protein is entrapped in the fungus species, e.g. Fusarium venenatum. In order to release the mycoprotein, a powerful cell disruption and extraction technique is required, which lyses the fungus. During lysis, the cell walls of the microorganism is disrupted and broken up so that the intracellular material such as proteins, lipids and other nutrient are released. Ultrasonication is a well-established technique used in food production and biotechnology to disrupt cells and tissues and to extract valuable compounds. Furthermore, the uniform homogenization achieved by ultrasonification makes it easy to turn the mycoprotein into innovative food products with various textures, flavours, and uses, including meat analogues, protein-rich snacks, dairy-free milk substitutes and desserts.

Kinetics of protein release from Fusarium Venenatum by sonication with grinding
source: Prakash et al. 2014

Case Study – Ultrasonic Mycoprotein Release

Prakash et al. (2014) investigated the effects of ultrasonication on the mycoprotein release from Fusarium Venenatum. They achieved a maximum protein release rate K of 0.680 min with 580μg of extracted mycoprotein.

Effect of sonication with grinding method on protein release of Fusarium venenatum
source: Prakash et al. 2014

Ultrasonic Extraction – Working Principle and Benefits

Ultrasonic extraction is based on the phenomenon of acoustic (ultrasonic) cavitation. When powerful ultrasound waves are coupled into a liquid or slurry, alternating high-pressure and low-pressure cycles compress and expand the liquid creating minute vacuum bubbles in the medium. Those vacuum bubbles grow over several high-pressure/low-pressure cycles until they reach a point when the gas bubble cannot absorb any further energy. At the point of maximum growth, the bubble implodes violently during a high-pressure cycle. During the bubble implosion, locally extreme conditions such as very high temperature, pressures and corresponding pressure and temperature differentials as well as liquid jets with up to 280m/sec occur. These intense forces perforate and break cell walls and promote the mass transfer between the cell interior and the surrounding liquid. The intracellular material such as proteins, lipids and other bioactive compounds are transferred to the liquid from where it can be easily separated for downstream processes.

Benefits of Ultrasonic Extraction

Ultrasonically assisted extraction (UAE) is a highly efficient technique to release and isolate intracellular material such as proteins, lipids, and bioactive substances (e.g., vitamins and polyphenols). Sonification is a process intensification, which increases the mass transfer between cell interior and liquid. Ultrasonic extraction results in higher yields, reduced processing time, superior extract quality, and reduced processing costs and lower energy consumption.

Ultrasonic Homogenizers for Mycoprotein Processing

Ultrasonic cell disruptors and extractors are well established tools in food processing facilities. Providing cavitational high-shear forces, ultrasonicators are used to isolate bioactive compounds from plant material and to homogenise two or more phases into a uniform mixture.
Hielscher Ultrasonics offers a broad portfolio of high-performance ultrasonicators from lab to industrial size.
Hielscher Ultrasonics’ industrial ultrasonic processors can deliver very high amplitudes. Amplitudes of up to 200µm can be easily continuously run in 24/7 operation. For even higher amplitudes, customized ultrasonic sonotrodes are available. The robustness of Hielscher’s ultrasonic equipment allows for 24/7 operation at heavy duty and in demanding environments.

Process Standardization with Hielscher Ultrasonics

Extracts, which are used in food or pharmaceuticals, should be produced in accordance to Good Manufacturing Practices (GMP) and under standardised processing specifications. Hielscher Ultrasonics’ digital extraction systems come with intelligent software, which makes it easy to set and control the sonication process precisely. Automatic data recording writes all ultrasonic process parameters such as ultrasound energy (total and net energy), amplitude, temperature, pressure (when temp and pressure sensors are mounted) with date and time stamp on the built-in SD-card. This allows you to revise each ultrasonically processed lot. At the same time, reproducibility and continuously high product quality are ensured.

The table below gives you an indication of the approximate processing capacity of our ultrasonicators: