Plant Proteins

Section: Health | Vida Vertical

Summary

The assumption that adequate protein intake is possible only through animal products is not supported by scientific evidence. This article organises the principal plant protein sources—legumes, seeds, nuts, cereals and pseudocereals, and plant protein powders—and assesses their nutrient profiles, protein quality and practical uses. Particular attention is given to combining different sources to obtain a complete amino acid profile comparable to that of animal proteins. The final section relates these principles to controlled plant production in vertical and hydroponic systems.

1. Introduction

Protein is one of the three macronutrients and, at 4.1 kcal per gram, contributes to energy supply. Its primary importance, however, lies not in its calories but in its role as a structural and regulatory molecule: protein is indispensable for building and repairing muscle, skin and nerve cells, acts in metabolic signalling and forms part of the basis of immune defence (Lemon, 2000).

Public discussion often associates protein provision with animal sources such as quark, poultry and whey protein. At first glance, meeting daily protein requirements can therefore appear difficult for people following vegetarian or vegan diets. Nutritional physiology clearly contradicts this assumption: numerous plant foods provide protein amounts comparable to, or even greater than, animal sources. They also supply fibre, vitamins and minerals.

2. Legumes: The Foundation of Plant-Based Protein Provision

2.1 Nutrient Profile

Legumes—including lentils, peas, chickpeas and beans—form the backbone of plant-based protein intake. Their balanced combination of protein and carbohydrates promotes lasting satiety and provides dependable energy. Their average protein content is around 7%.

The soybean occupies a special position: at 12 g of protein per 100 g, it clearly exceeds most other legumes. Fermented soy products such as tempeh and miso also offer improved bioavailability through microbial breakdown.

The peanut —botanically also a legume—deserves particular mention: at 30 g of protein per 100 g, it not only has the highest protein content in this group but also a comparatively low calorie density.

2.2 Practical Relevance

Legumes are increasingly used as an alternative to wheat in pasta and baked goods. These products combine the carbohydrate and fibre content of legumes with a higher protein density than conventional cereal products.

3. Seeds: Compact Nutrient Sources with Added Functional Value

3.1 Chia and Flaxseed

Chia seeds, and especially the locally grown alternative flaxseed combine several nutritional advantages:

• Rich in fibre: A positive influence on intestinal motility and the microbial diversity of the gut microbiome.
• Omega-3 fatty acids: Alpha-linolenic acid (ALA), a precursor of the long-chain fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), with demonstrated anti-inflammatory effects.
• Protein content: At 21 g of protein per 100 g, seeds make a substantial contribution to daily protein intake.

3.2 Other Seed Sources

Pumpkin, hemp and sunflower seeds broaden the range. Hemp seeds contain all essential amino acids and, with around 30 g of protein per 100 g, offer particularly high nutrient density.

4. Nuts: Protein, Healthy Fats and Micronutrients in Synergy

The recommendation to eat a handful of nuts each day is well founded nutritionally. Alongside plant protein, nuts provide substantial amounts of monounsaturated and polyunsaturated fatty acids, fibre, vitamins and minerals.

Protein content of selected nuts:

Cashews are particularly versatile because of their balanced amino acid profile and mild flavour—whether eaten as a snack, used as a base for plant-based sauces or added to cereal dishes.

5. Cereals and Pseudocereals

5.1 Wholegrain Cereals

The protein content of cereals is directly related to the degree of processing. When the whole grain is retained during processing, its full protein content is also preserved. This is an important reason for preferring wholegrain products to refined flour.

Oats are an established breakfast protein source in porridge, while spelt and millet provide comparable protein density and also support digestion through their fibre content.

5.2 Pseudocereals: Amaranth and Quinoa

Botanically, amaranth and quinoa are not grasses but members of the amaranth family (Amaranthaceae). They are described as pseudocereals because they are used in similar ways and offer several advantages:

• A high content of essential amino acids, especially lysine, which is limiting in conventional cereals.
• Rich in minerals such as calcium, zinc and iron.
• Naturally gluten-free—an appropriate alternative for coeliac disease or gluten sensitivity.

6. Plant Protein Powders: Concentrated Protein Sources

Plant protein powders can be a practical supplement for people with higher protein requirements, particularly strength athletes and athletes during calorie-restricted phases.

6.1 Rice Protein

Rice protein is derived from rice bran and concentrated through natural germination and fermentation processes to approximately 86% protein, while the carbohydrate content falls to around 15%. Compared with widely used whey protein, rice protein contains a higher proportion of the essential amino acids isoleucine and valine . Its slightly gritty texture can take some getting used to.

6.2 Pea Protein

Pea protein has a relatively neutral flavour with a slightly nutty note. It provides about 82 g of protein per 100 g of powder and offers a high-quality combination of essential and non-essential amino acids. Its unusually high levels of arginine and lysineare especially noteworthy.

Pea protein is also rich in iron, a trace element involved in numerous enzymatic reactions and oxygen transport.

6.3 Protein Blends and Protein Quality

Protein quality describes how efficiently the amino acids in a food can be converted into the body’s own proteins. Individual plant sources often have a limiting amino acid profile—for example, cereals tend to be low in lysine and legumes in methionine.

Combining different protein sources deliberately can compensate for these limitations. The amino acids in pea protein, for example, complement those in rice protein to create an overall profile whose protein quality can approach that of animal proteins. Blended products combine several high-quality sources and remove the need to rely on a single protein source.

7. Nutrients of Concern with an Exclusively Plant-Based Protein Intake

People who avoid all animal products should monitor not only protein intake but also nutrients that may require particular attention:

• Vitamin B12: It occurs almost exclusively in animal-derived products. Supplementation is essential with an exclusively vegan diet.
• Iron: Plant-derived non-haem iron has lower bioavailability than haem iron. Combining it with vitamin C, for example from citrus fruits or sweet peppers, substantially improves absorption.
• Zinc and calcium: They occur in legumes and cereals, but phytic acid can inhibit their absorption. Soaking, germinating and fermenting reduce the phytic acid content.

8. Relevance to Controlled Plant Production: Vida Vertical

One essential point for Vida Vertical readers is that the quality and protein content of plant products depend directly on growing conditions. Crop nutrition can be controlled precisely in vertical and hydroponic systems.

Practical implications:

• Sprouts and microgreens from hydroponic cultivation may offer greater bioavailability of proteins and micronutrients than dry seed because germination breaks down antinutrients such as phytic acid.
• Legumes and leafy vegetables from controlled cultivation benefit from an optimised nutrient solution that supports protein synthesis in the plant.
• Short harvest-to-consumption intervals preserve amino acid integrity and minimise oxidative losses.
• Vertical self-provisioning allows direct control over fertilisation, light spectrum and harvest timing—factors that substantially influence the nutrient content of the harvest.

Growing your own protein sources—whether sprouts, leafy vegetables or herbs—in vertical systems combines sustainability with maximum nutrient freshness.

9. Conclusion

Plant-based protein provision is not a compromise but a complete dietary strategy that, when planned appropriately, can reliably meet the protein needs of adults ranging from recreational to competitive athletes. Its key principles are:

1. Variety: Combine different protein sources to ensure a complete amino acid spectrum.
2. Processing: Prefer fermented, germinated and whole-food products to maximise bioavailability.
3. Supplementation: When requirements are higher, use plant protein powders such as rice, pea or blended products as a practical addition.
4. Monitor micronutrients: Pay particular attention to vitamin B12, iron and zinc on an exclusively plant-based diet.

Sound nutritional knowledge combined with a high-quality, fresh food supply forms the foundation of a healthy diet that supports performance—whether the food comes from a supermarket or your own vertical garden.

Note: These recommendations apply to healthy adults. Individual advice from a qualified nutrition or medical professional is indicated in the presence of illness, during pregnancy or breastfeeding, or before changing to an exclusively plant-based diet.

References:

• Lemon, P. W. (2000). Beyond the zone: Protein needs of active individuals. Journal of the American College of Nutrition, 19(suppl 5), 513S–521S.
• Helms, E. R., et al. (2014). A Systematic Review of Dietary Protein During Caloric Restriction in Resistance Trained Lean Athletes: A Case for Higher Intakes. International Journal of Sport Nutrition and Exercise Metabolism, 24(2), 127–138.
• Gorissen, S. H. M., et al. (2018). Protein content and amino acid composition of commercially available plant-based protein isolates. Amino Acids, 50(12), 1685–1695.
• German Nutrition Society (DGE): D-A-CH reference values for nutrient intake. www.dge.de
• Mariotti, F. & Gardner, C. D. (2019). Dietary Protein and Amino Acids in Vegetarian Diets – A Review. Nutrients, 11(11), 2661.

Author: Uwe | Vida Vertical – Health