Investigation of Texture Creation in Mycoprotein Products With a Focus On Fish

Abstract

A growing population and environmental pressure impose the obligation for more sustainability on food systems. Shifting from animal- and fish-based products to more environmentally benign protein sources is a crucial element in this transition. Single-cell protein refers to the edible biomass from microorganisms such as fungi, yeast or algae and is a promising way to source proteins on an industrial scale.
The following work investigates methods for structure creation in foods containing such single- cell protein grown from fungi, also referred to as mycoprotein, focusing on fish products. Two different top-down strategies for texture creation were applied and evaluated throughout the work. All experiments aimed to investigate applicable small-scale methods and finally create a product that was perceived similar to a fish product by an in-house panel.
Evaluation of textural parameters was conducted using instrumental texture analysis and in-house sensory panels. Commercial fish products and analogues were evaluated to set target parameters. These parameters could be reproduced satisfactorily by the addition of different hydrocolloid combinations to processed mycoprotein mixtures. One approach for texture creation tested was a freeze structuring process, which resulted in texture alteration in samples containing unprocessed biomass but was classified as not scalable. The resulting changes could only be measured by evaluating the mechanical texture, while evaluation of textural changes related to size, shape and orientation of constituents was unsuccessful. Samples containing the most appropriate formulations were prepared using unprocessed and processed biomass. The different physical form of the mycoprotein significantly altered instrumentally analysed mechanical texture, while both sample groups were perceived similar by the panel.
Inconsistency of raw material introduced an additional variable, and the limited ability to compare and replicate results is the major drawback of the study. However, results from various experiments led to notable findings and a better understanding of the matter. This unexploredness of the subject proves results from this investigation valuable since it can be used as a starting point for further investigations.

Popular Abstract

How can the characteristics of filamentous fungi be exploited to create new food textures to finally resemble fish?

Different methods for texture-creation in mycoprotein products were studied with the final goal to create a fish finger analogue product. Investigations have shown that filamentous fungi can form unique structures where additional ingredients and extensive processing are not inevitably necessary.

The current environmental crisis calls for a transition to more plant-based foods. Still, we're all creatures of habit and know how difficult it is to change our diet. This is where analogue products come in handy, erasing the need to change meal formats. Swapping the fish finger on our plate for a fish-less finger is more convenient than thinking about a whole new dish. However, creating such products is not an easy thing since their originals, such as meat or fish, rely on very complex structures that give them their unique texture. This is where the role of the food scientist is seen as crucial; by closing the gap between theory and application, new and improved food products can be created. This is especially important when working with novel food ingredients, where insufficient knowledge limits the use.
In contrast to the fungi we usually consume as mushrooms, mycoprotein comes from protein-rich filamentous fungi, which are grown in bioreactors. This might sound very technical and unnatural, but these microorganisms are highly resource-efficient, and their consumption has many health benefits. The taste is relatively neutral, but the texture can be very chewy. This is why the investigated mycoprotein is currently processed extensively to finally obtain a homogenous ground product, like coarse flour.
By adding so-called gelling agents to these processed and granulated mycoprotein fractions, a range of textures can be achieved. The texture of such products is mainly dependent on the characteristics of the gelling agent and can be tailored by changing the ratios between the various ingredients. However, the resulting structures are pretty homogenous, which is not suitable for all food products.
On the other hand, the filamentous nature of the fungi comes in as an excellent prerequisite to imitate animal-based products with a fibrous structure. Still, a way to get products containing only water and mycoprotein less chewy is needed. Creating a sponge-like structure by freezing mycoprotein-water mixtures slowly might sound abstract, but this so-called freeze structuring significantly changes the texture. Using the unprocessed fungi does not only reduce processing steps and reduces additional ingredients but also opens up the possibility to create more sophisticated textures by using the characteristics of the fungi.

Different methods for texture alteration in mycoprotein products were investigated. Some investigations targeted the processed and ground fraction, while others were based on the unprocessed biomass with intact fungi filaments. One approach was to add gelling agents and compare the texture to commercially available fish fingers, while the other approach focussed on exploiting the intrinsic characteristics of the fungi. The primary analysis method was texture profile analysis, and an untrained in-house sensory panel was used to evaluate acceptability.

Overall, mycoprotein is a very promising food ingredient. With the proper processing method, it can substitute the protein many people nowadays obtain from animal products, and could hence play a crucial role in making our food systems more sustainable.

• author: Tschigg, Anna Maria
• supervisor: Lars Nilsson
• organization: Food Technology and Nutrition (M.Sc.)
• course: KLGM01 20211
• year: 2021
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: mycoprotein, texture, product development, food technology
• language: English
• id: 9055216
• date added to LUP: 2021-06-29 10:47:31
• date last changed: 2021-06-29 10:47:31