Meat is so precious that people try to reproduce it at all costs, using the most diverse technologies to create analogues. But it is not easy to replicate everything that comes from meat.

Meat is such a precious food that people try to reproduce it at all costs, creating surrogates in all sorts of ways. But imitating meat in every way is not easy. It seems impossible. This is the conclusion of a new study that analyses the molecular differences between real meat and its supposed substitutes.

The muscle structure is extremely complex, organised in levels of hierarchical units, bundles of fibres, myofibrils and myofilaments, surrounded by several layers of connective tissue and linked to endogenous components responsible for meat’s unique texture and flavour. Water, water-soluble substances and nutrients, peptides, amino acids, fats, minerals, vitamins, as well as nucleotides, blood proteins, pigments, the actin-myosin complex, organic compounds responsible for flavours, and fat-soluble compounds deposited in animal adipose tissue, are encapsulated and compartmentalised within finely articulated structural lattices.

This complexity is crucial to the texture, mouthfeel and flavour perceived by the consumer, giving the meat a unique sensory experience and juiciness when masticated, which are impossible to reproduce technologically. The difficulty of faithfully reproducing the organoleptic properties of meat is the main reason why the development of plant-based products on the market has been hampered, and all of them have failed to fully satisfy the consumer by not living up to the promises they make.

The difficulty in faithfully reproducing the #OrganolepticProperties of #meat is the main cause that hinders the development of #PlantBased products in the market. Click To Tweet

Legumes, cereals, fungi, microalgae and insect proteins are the basis of the alternative products that engineers are trying to transform using various technological strategies, such as gels, emulsions and aggregates, with the ultimate aim of simulating muscle and imitating meat. However, due to these major technical obstacles, the goal is practically unattainable, and all the efforts (and investments) made have been in vain. As a result, after rapid development, the market for meat alternatives is now in decline. And according to experts, consumers’ reluctance will continue in the future.

After trying them out of curiosity, many people have realised that these products are not as good as meat, they are not equivalent from a nutritional point of view, and their consumption is neither healthier nor more sustainable for the environment. More than 90% of these products on the market are made up of vegetable proteins isolated from legumes such as soybeans, beans, peas, lupins or lentils, with the addition of cereal proteins such as gluten and polysaccharides to act as a glue and improve the consistency of the product.

To get as close as possible to meat, vegetables, algae, and mycoproteins must be treated with intensive industrial processes, such as thermomechanical extrusion at high temperatures to achieve a vigorous breaking of the cell wall, separation by centrifugation and isolation of proteins. Extraction can be wet, with solubilisation in an alkaline aqueous medium such as caustic soda and isoelectric precipitation, or dry fractionation using high temperatures, microwaves or ultrasound.

To get as close as possible to #meat, ingredients of #PlantBased products, algae and #mycoproteins must be treated with very intense #IndustrialProcesses. Click To Tweet

The process involves a series of steps such as homogenisation, compression, heating, molecular crosslinking and alignment, shaping, and systems with gelling properties, emulsifiers and foaming activities. The aim is to achieve the ability to thicken and approach the structure of meat, adding additives, colourings, thickeners, emulsifiers, salt, flavourings and vegetable oils to provide flavour texture and compensate for the dryness commonly found in these alternatives. Soon, insect proteins will also be used, transformed into powders to destroy their morphology, which is not appreciated by consumers, and incorporated into foods such as biscuits and pastries or combined with vegetable proteins to create meat analogues.

However, the study shows that despite all the hyper-processing, it is technologically impossible to reproduce the complex hierarchical organisation of the muscle, the interconnected sarcomeres, the myosin and actin filaments and thus the succulent organoleptic properties of the meat. Fibres produced by the extrusion of plant proteins, insects and microalgae do not have the complex and well-defined orientation of muscle fibres.

From a nutritional point of view, the animal proteins in meat provide a complete profile of essential amino acids for humans, which is not the case with non-muscle proteins. Legume proteins are deficient in methionine, cereal proteins are deficient in lysine, and algae proteins are deficient in lysine and tryptophan. In addition, the high temperatures and pressures of the industrial processes to which they are subjected damage and destroy proteins and nutrients. As a result, these plant products are deficient in vitamins and essential minerals found naturally in meat, such as vitamin B12, creatine, taurine, carnosine, heme iron, zinc and iodine. Nutrients are added as additives to overcome the nutritional differences, but this has raised health concerns and chemical and microbiological safety.

#AnimalProteins in #meat provide all the #EssentialAminoacids for humans, which is not the case for #PlantBased #proteins. Click To Tweet

Ultra-high processing temperatures can promote the formation of toxins and the oxidation of fats, while some additives can induce inflammation. The transformation of non-muscular proteins into fibrous structures that microscopically resemble muscle is an over-processing and alteration that compromises their nutritional value and safety. These are ultra-processed foods, the consumption of which has been linked to cerebrovascular and cardiovascular diseases such as heart attack, ischaemia, stroke, diabetes, obesity, cancer and premature mortality.

Insect protein products also raise concerns about the natural presence of bioactive toxins, allergenic compounds, harmful pesticides and heavy metals. For microalgae, the main risks are allergens and mycotoxins. There is no scientific evidence that reducing meat consumption is good for health. At the same time, there is overwhelming evidence of its nutritional benefits and the disadvantages of replacing it with these artefacts.

The authors conclude their study by arguing that scientists tackling these technological challenges and entrepreneurs investing in this market must know that animal meat products are unique. The flavour and aroma of meat are extremely complex and cannot be successfully replicated. Alternative protein sources have metabolic systems that are drastically different from animals, so the quality and sensory attributes of meat can only be simulated, not 100% replicated. Therefore, the authors suggest that these products should not be presented as meat analogues or substitutes to avoid unrealistic expectations and consumer disappointment but should be treated as a new food group—hyper-processed industrial foods.