This is a guest post by Carla Zarazir, a fellow food scientist, with a PhD in Food Science and Technology. You can find her on LinkedIn.
A wide variety of reasons (e.g. sustainability and health & nutrition) is shifting people’s interests from animal-based foods towards healthy and tasteful plant-based diets. Major food companies are now targeting meat eaters by filling the supermarket shelves with plant-based burgers, meatballs, and chicken nuggets.
Faux Fish is shaping up to be the next big thing on the horizon! The demand for fish alternatives has been increasing rapidly during the past years. Plant-based tuna, salmon, caviar, crab, and shrimp have already entered the market.
The most common ingredients in these products are pulses, seaweed and algae, legumes, and some vegetable oils. One of the biggest challenges is to mimic the texture, appearance, flavor, and mouthfeel of animal-based products with just these ingredients. Also, the nutrient profile of plant-based products has to be designed with the utmost care so that their consumption does not lead to harmful health effects.
The perfect recipe for Faux Fish
Fake fish is even more complex to make than fake meat due to its unique flaky structure and distinct thin layering arrangement of proteins. Appearance, texture, and flavor are the main challenges that scientists face when building the perfect plant-based foods.
One of the most important quality attributes of fish is texture, which is characterized by complex muscle fibers. Several factors should be taken into consideration when replicating the texture of fish meat.
First, fish meat has a high tensile strength, which means it can withstand a huge force while being stretched or pulled. This is due to its high myofibrillar protein (a protein common in animals) and collagen content. Secondly, when fish die their muscles soften. This is due to microbiological changes that occur which lead to myofibrillar protein degradation. Third, the texture of a fish varies with fish type, age, geographic location, growth conditions, and anatomic location.
Lastly, scientists need to keep in mind the cooking method when replicating seafood. During the cooking process, myofibrillar proteins denature, which results in changes in the fish structure as well as other sensorial properties, such as taste, smell, and color.
Fresh fish and seafood products have a wide range of unique flavors. They are also characterized by the fifth basic taste called Umami, which is savory and brothlike. Delivering an authentic fish taste and mouthfeel can be tricky. Some plant proteins are perceived as bitter and cardboardy which may lead to the generation of off-flavors.
In order to mask these unpleasant flavors, a multidisciplinary approach is required. The first option is to remove off-flavoring molecules using physical and chemical treatments. Another option is to mask unwanted flavors during production by mixing agents like gels, protein isolates, and starches with the protein base. All components must work in harmony to deliver the authentic taste of real fish.
To successfully attract consumers, plant-based seafood products should have a fresh and appealing look. However, mimicking the right colors for fish substitutes can be a real challenge, especially when not using artificial colors. For instance, salmon, shrimps, and crabs require orange or pink colors with good stability across processes. So adding a colorant like astaxanthin, which occurs in certain algae, gives seafood alternatives its traditional reddish hue. Other plant sources like paprika and carrot provide an orange shade to the end-product.
In terms of shape, fish-muscle substitutes are produced by adapting the typical flakiness from muscle fibers held together by connective tissues.
Plant-based proteins used in seafood products
Alternative seafood products mainly contain plant-based proteins, polysaccharides and lipids, and other functional ingredients such as colorants, flavorings, minerals, vitamins, and preservatives as well. The plant-based proteins play a key role. They provide the protein content and play a key role in the final structure of the product. They can be used to provide structure, emulsify (that is, stabilize a mixture of water & oils), stabilize foams, and help to hold onto fluid.
The selection of an appropriate plant protein source is necessary to create a high-quality end product with similar nutritional values to traditional fish. Up until this point, soy tends to be the first choice for manufacturers to imitate the texture and structure of animal-based products because of the soy’s high protein content and omega-3 fatty acids. On the other hand, soy is also considered an allergen which makes it not suitable for some consumers.
Pea is also used to produce fish analogs and is considered to be an allergen-free alternative, especially for higher quality products. Other popular plant-based proteins that are usually used in combination are oats, chickpea, lentils, fava, sunflower, and flaxseed.
For shellfish substitutes, proteins such as seaweed, algae, or konjac powder, mimic the texture of real shrimp and can be applied to other products such as lobster, crab, prawn, and calamari alternatives. Nevertheless, these ingredients have lower protein levels so additional protein must be added to boost the product’s nutritional content.
How do we process plant-based seafood?
The most common technique to transform plant-based proteins into the desired fibrillar structures is extrusion. This technique uses a large screw within a metal pipe through which the ingredients are pushed (it’s also used for making certain chicken replacers). The high shear forces (‘smearing’) and temperatures align the proteins in the desired structure. But, other techniques are also available.
Over the last decade, 3D food printing techniques have been evolving rapidly, and the most common method is based on syringe injection. In this process, a 3D muscle structure is formed by extruding a protein solution used as ”ink”, layer by layer, through a moving ﬁne syringe nozzle. The product collected should be homogenous and have appropriate physical and chemical properties. Fish-meat products are eaten raw or cooked. Therefore, the 3D printed model should be durable and resistant to thermal cooking processes.
Another technique called electrospinning is also used in plant-based seafood processes. In this method, the protein solution is electrically accelerated and pushed through a nozzle. The solution is then structured into nanofibers using high voltage and is finally ejected on the collector plate. This technology is able to better imitate the texture of fish meat by creating nano-sized protein fibers.
Alternative seafood companies are preserving marine life
A slew of companies has joined the plant-based seafood market (as of September-2021).
Good Catch was able to recreate the structure and texture of Tuna by using a magic formula that includes a blend of six legumes (peas, chickpeas, lentils, soy, fava beans and navy beans) – this combination replicates the flaky texture of fish. In addition, algal oil which is rich in docosahexaenoic acid (an essential omega-3 fatty acid found in fish) was added to the mix to give the product a distinctively briny flavour of tuna.
New Wave Foods and BeLeaf are perfecting plant-based shrimp alternatives made from seaweed, soy protein, and natural flavors. To recreate the taste of shrimp, NWF and BeLeaf are using natural ingredients that offer subtly sweet flavors. And finally, Cavi-art developed by accident a plant-based alternative to caviar while experimenting with seaweed.
Can plant-based seafood products be part of a healthy diet?
If you follow a vegetarian or vegan diet or have seafood allergies, plant-based seafood may be the right choice for you.
Plant-based fish products do not contain toxic metals like methylmercury, microplastics or other contaminants found in regular fish in the ocean. Moreover, developing plant-based seafood products could be the solution for overfishing. Fish substitutes are highly processed products that contain additives. The formulations and nutrient contents of those products may keep on evolving due to advances in technology. Therefore, plant-based seafood products must be further investigated by assessing their nutritional properties and safety aspects.
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