Newer Sources of Proteins with Emphasis on Plant Proteins

Presently, mankind is facing the biggest challenge of the growing global population. According to one WHO report, the world population was 7.6 billion in 2017 and will reach 8.6 billion in 2030, which will be 9.8 billion in 2080. India and China will be the biggest contributors to this growth. Increased population will mean more stress on many resources like Food, Housing, Infrastructure, healthcare, and jobs. The increased demand for food also means more demand for proteins which are major and important macronutrients essential for life. Rising affluence, urbanization, and awareness about healthy living are other factors for growing protein demands.

Until now plant and animal-based proteins are two major sources of dietary proteins. When we compare the requirements of resources, the plant proteins score better when it comes to sustainability. Plant-based proteins require minimal land and water as compared to animal-based proteins because animals are fed from livestock and crops like maize, soy, and cereals. Research suggests that if everyone shifts to plant-based foods, it will lead to the reduction of global land use for agriculture by 75%.

While these are the two major sources of proteins, various other sources of protein can also help meet this demand and are sustainable. It will be interesting to see how work is happening on many alternative sources.

Algae can be a good source of protein on sustainability count. The algal proteins market is gaining popularity. They do not require arable land and freshwater to grow. The protein quality is better than some of the plant sources because of their amino acid composition.  Generally, seaweed and microalgae are considered viable sources for protein extraction. Conventional methods like alkali acid extraction, and enzymatic hydrolysis are used for extraction. They have poor digestibility because of soluble fibres, lectins, and polyphenols. Novel techniques like ultrasound extraction might improve the digestibility. The sustainability is better than the conventional plant proteins.

Consumption of insects has been part of the native cultures of Asia, South America, Africa, and Europe for hundreds of years. Insects are generally used as animal feed. Edible insects can be a good alternative source of proteins. The interest in edible insects has been rapidly growing because FAO has begun promoting insects as a viable dietary option for humans. They require minimum space to grow, they have good nutritive value with proteins (50%), and Fat (20%). The main hurdle is stigma from the inexperienced customer. Proper processing should be done to take care of toxins, allergens, and microbes to make them safe to consume. Many products such as crackers, muffins, sausages, and meat loaves can be developed using edible insects.

Cultured meat or cultivated meat is produced by cultivating animal cells directly. The meat produced this way will have the same cell types in a similar structure as animal meat that will replicate the nutritional and sensory attributes of conventional meat. This will be an excellent alternative to producing meat that will also meet environmental challenges. Stem cells of animals/ fish are grown in bioreactors which will mimic the meat. Therefore, this does not require large amounts of land, or water or does not produce Greenhouse gases. The first cultivated meat demonstration was done by Dutch scientist Mark Post on live television in 2013. As of 2022, the industry has grown to more than 150 companies across six countries. Singapore Food Agency has approved its usage in 2022 and products are available in eateries.

Much work happened on the Leaf protein concentrate in nineteen eighties India using sources like alfalfa eaves. Because of a lot of other nutrients coming along with the leaf protein concentrate, it has the potential to be a food ingredient with wide applications in food supplements. The main challenge is the commercialization of this protein source. As the starting materials are leaves having high moisture (80 – 90%), they will be perishable and have procurement and storage issues for large-scale production. The extraction has to be done with the juice of leaves obtained by mechanical pressing by various techniques such as heat coagulation, acidification, flocculation, fermentation, etc. One paper published in 2013, used Moringa leaves and extracted proteins by heat coagulation. The product obtained has about 40% proteins. It has 5% fibre and so many minerals. Leaf proteins could be another contributor as an important source of alternative source of proteins. This is a potential alternative source that is untapped because of challenges in mass production.

Although the work on exploring alternative sources to meet because of rising demand is happening, today’s major sources of dietary proteins are animal and plant proteins. Looking into less requirement of land and water and the production of very less Greenhouse gases, the consumption of plant proteins must be encouraged. Of late, the consumption of plant proteins is increasing also because of ethical considerations of sacrificing animals.  Nutritionally, plant proteins have several disadvantages. They are lesser in quality as compared to animal proteins because of one or more limiting amino acids. The digestibility is also lesser because they are enmeshed into plant tissues. There are other problems like the presence of antinutritional factors. All these problems and issues are solvable. The problem of limiting amino acids can be resolved by complementing two sources of proteins. For example, cereal like rice has Lysine as a limiting amino acid, and legumes like Dahl lacks sulphur-containing amino acids. The combination of these two when consumed together will give better quality protein. Primary processing techniques such as soaking, cooking, germination, or fermentation can improve digestibility or take care of anti-nutritional factors.

Meat eaters when become vegans or vegetarians miss meat and meat-based products like burgers and other snacks. Making plant-based meat substitutes is challenging. Sensory challenges like meeting texture, flavour, juiciness, and bite, are to be matched. In a typical process; protein ingredients, vegetable oils, emulsifiers like gums, flavours, and spices are processed to make snacks like burgers, and hotdogs. Food scientists are also successful in developing products like protein bars, khakhra. The Indian market is replete with such products. The combination of cereals and legumes is successfully used to modify the original Indian snacks which will give the same taste, higher quantity, and quality of proteins. Because of higher proteins in the millet, many millet-based products are also developed.