Meat analogues or meat hybrids are in demand. Let’s face it if we are serious about saving the planet than exploiting plant-derived foodstuffs for a variety of reasons is the way forward.
One factoid coming from Allied Market Research predicts that the meat substitute market will have a global value of $7.5bn by 2025. The compound annual growth rate is forecast at 7.7%. Euromonitor have put that figure even higher at $8bn by 2022. Whatever the case, the interest in meat alternatives is accelerating. Euromonitor also think the growth projection is $1.5 to 2.0Bn by 2024 from 2020.
At the moment the meat substitute category is still in an early phase of growth and yet we’ve been trying meat alternatives for years. Tofu and for that matter soy protein springs to mind literally as that replacement food but we also have tempeh and seitan to think of as alternatives. These three are very high protein alternatives. We shouldn’t forget wheat gluten anyway but pea proteins do seem to be taking over now. We know of projects where this particular protein is the focal point.
However it’s not enough to just slap some tofu on a plate as it needs to be structured in such a way that it actually has the texture of meat if nothing else. Even so we know it’s tofu when we bite into it. The next phase has to be how we create meaningful meat analogues that not only have the protein but somehow convince us as consumers that we are eating something akin to meat. It needs to have the sensory cues so must be visually appealing as well as smell and taste right.
The other facet is that many of the meat alternatives such as tofu etc. come with allergen warnings which makes it tricky when it comes to labelling.
At the moment a number of businesses centered in Silicon valley have pushed forward on the vegan meat burger which started appearing on veggie/vegan menus some years ago. We now have the Beyond Burger and the Impossible Burger which are on the menu as well as a mainstream player, Burger King producing their version for the whole of the country.
Looking at recent grocery showings, Beyond Meat has a plant derived ground ‘Beef’ which looks virtually like the real thing. Before we say anything it may well be the case that meat related terms for plant derived products might well be banned. Clearly this is not beef so the new offer called ‘Beyond Beef’ might not be a name for much longer.
Plant-Based Meats: A Product-Development Perspective
If you examine the literature on meat then plenty of news articles provide some useful insights into plant-based meat alternatives.
So we want to eat meat right!
If we want a plant product to convince the consumer they really are eating meat then it needs to be similar in texture and taste, to have the same sort of mouthfeel and have at least a similar if not better nutritional profile.
A typical lean meat is 75% water, 20% protein and about 2% fat with the remainder being glycogen, B vitamins and some minerals. This is a starting point for creating and mimicking a meat analogue.
A typical recipe for any wannabe vegan meat producer should consider the following factors and many now do. It should be:
- moisture content of between 50 and 70%
- a protein content of over 50% dry matter
- a protein source which is vegetable
- less than 10% fat
- a starch content of between 4 and 10%
- a vegetable fibre content which is between zero and 10% by weight.
Some meat hybrid producers want to create products which are lower in meat content but still retain a ‘real’ meat feel. In some cases the hybrid meat recipe might be more suited to those developers simply looking to create reduced meat foods if the wholly vegan meat option was not feasible. A typical recipe here would be:
- meat such as pork – 50%
- vegetable protein isolate- 40%
- starch – 5%
- vegetable fibre – 5%
- water to between 20 and 50%
Some producers of hybrid meats also incorporate other protein sources such as whey and dairy proteins, fish, egg etc. which are non-muscle proteins.
So far we’ve mentioned tofu, soya and seitan (wheat derived substitutes) but there is also pea and fungal substitutes as well which can be fashioned into something approaching this meat like product. If you then start incorporating aromas and spices, along with the right type of micronutrients and colourants then the meat analogue could really start to feel like a convincing meat food.
Lets not forget that processing is as important in creating the meat food as the ingredients. At the moment high moisture extrusion cooking is the leading method and has been since the 1990s. This method can produce a meat analogue with a passable fibrous texture.
What Type Of Protein Properties Are Required For A Meat Analogue?
Choosing the right type of protein is important in generating a high quality meat analogue. The main functional properties for any protein in this type of application is that it should have an appropriate water holding capacity as well as one for oil holding capacity. It needs to be reasonably soluble given the type of processing it should undergo, be suitable for emulsification and for gelation too.
Obtaining these functional benefits implies a bit more fundamental understanding about the protein. So, knowing the protein source and how it might respond to various processing conditions is critical. The key factors are:-
- chemical and amino acid composition
- its tertiary structure and conformation in various process conditions
- the level and extent of protein denaturation
- particle size
- degree of purity and does it contain in particular components such as fibre, starch and oil.
A number of plant protein ingredients are available, all with their own specific properties. In particular a product developer can look at various types of flours which have been heat treated to improve their starch gelation characteristics and have any extraneous flavours removed. Other types might by dry fractionated, oilseed press cakes which have been either defatted or not, and wet extracted concentrates or isolates. The concentrates usually have better functional benefits than the isolates based on anecdotal evidence. Isolates are used though when a particular flavour or colour modification is needed.
Some process modifications are needed to get the right type of protein for functional purposes. The ingredient supplier would use various types of fractionation to remove particular protein types along with various forms of chemical and enzymatic hydrolysis along with cross-linking.
A Little Knowledge On High Moisture Extrusion Cooking (HMEC)
Extrusion cooking has been with us for many years and it is covered much more effectively else where. Here we just give a brief overview.
A typical extruder is either a barrel with a single or double-screw arrangement which has a mixing zone, followed by a cooking zone and then a cooling zone.
The feed which is protein and any other ingredients for creating the meat analogue is fed along with water into the hopper. The water is there to create a moisture content of 40 to 70%. All these ingredients are mixed together in the first part of the extruder. The whole mass is then cooked under pressure to temperatures between 130 and 170 Centigrade where it is effectively melted. Many researchers would call this a plasticizing effect. Having cooked the meat, the whole modified mass is cooled to below 100 Centigrade which stops expansion and forces the proteins to align which creates the fibrous element. This is the critical part of the texturization process.
Shear Cell Technology Now Makes An Appearance
The Plant Meat Matters consortium has exploited a processing technology known as shear cell technology. This was developed a number of years ago as a concept at the food engineering powerhouse of Wageningen University in The Netherlands. It is a process using a device called a Couette cell which is usually used for measuring powder and particle flows.
The device allows for processing at different temperature ranges as well as inducing shear in protein mixtures. The Couette device developed at Wageningen is much larger than the usual analytical models and can produce kg quantities of meat analogues. This high temperature conical shear cell device looks like a concentric cylinder rheometer. Protein mixtures are placed inside the gap between two rotating cylinder which is known in rheology circles as the shearing zone space. The current model has a volume of about 7 litres. There is a gap of just 3cm between the surface of the two rotating cylinders. Both cylinders are heated using steam and cooled using a cold water and air system.
One benefit is that larger pieces of fibrous meat are created. It also appears to be a much milder process of manufacture than extrusion could ever offer. It’s also much simpler which implies it is a more cost-effective process.
What we are able to do nowadays is create both plant-based and cell-based meats. When you taste the meat analogues in the marketplace you can but wonder at how good they are. I’ve heard it said that this is a triumph of human centred design over philosophical and niche sectors. A sustainable and nutritional beneficial alternative to meat is possible.
So What Is The Trend For Alternative Meat Development?
Not that long ago meat alternatives were built around various meat-like single components. You had probably three main plant proteins to consider. We had soy, mycoprotein and wheat as the big three. The only process that could produce anything that had a meat resemblance was using dry extrusion.
So now we’ve come along the road with more authentic meat flavours and there is certainly a lot more variety. Think of the greater number of plant proteins available and the sources too. There are oats and legumes adding to the mix. We have pea, bean and other legumes like chickpea for example.
The flavour houses have been helping the developers with a greater range of taste maskers and enhancers because both operate cooperatively. In fact we have discussed elsewhere the steps that are needed in creating a meat alternative. From the processing point of view we have wet extrusion and as we discussed with high moisture extrusion cooking as a significant step forward.
The future is certainly going to be about extending our range of protein sources further. Can we make use of mushroom and more of the whole vegetable pieces? There is also the significant push towards sustainability and the environment which will level out our desire for meat anyway. It may become much more acceptable to enjoy a meat mimic if not a meat alternative with some of the properties of meat. Biotechnology will certainly play its part because of the developments in cell culturing.
In all we are also examining the crucial role of producing an integrated food environment. It’s probably been a trend for many years but the economics of food production are pushing us ever more to managing the supply chains better, to reducing food waste and creating more sustainable meals.