Quinoa (Chenopodium quinoa)

Description

Quinoa is an annual herbaceous plant belonging to the family Amaranthaceae, traditionally cultivated in the Andean region (notably Peru, Bolivia and Ecuador). It has been grown for thousands of years by indigenous populations as a staple crop and has more recently spread worldwide thanks to its remarkable nutritional profile and agronomic adaptability (tolerance to altitude, cold and poor soils).

The edible part is the seed, a small, usually round or slightly oval grain, only a few millimetres in diameter. Seed colour varies with the variety: white (or ivory), red, purple, black and intermediate shades are all possible. Each seed is covered by a thin outer layer that contains saponins, natural bitter-tasting compounds that protect the plant against pests and birds. These saponins must be washed off (or mechanically removed) before consumption.

From a culinary standpoint, quinoa is often classed as a pseudo-cereal: it is not a true cereal botanically (not a grass) but is used like grains such as rice or wheat. Once cooked, the seeds become tender yet slightly al dente, with a light, mildly nutty flavour and the characteristic “halo” of the germ that curls away from the seed.

Botanical classification

• Common name: Quinoa

• Clade: Angiospermae

• Order: Caryophyllales

• Family: Amaranthaceae

• Genus: Chenopodium

• Species: Chenopodium quinoa Willd.

Climate
Quinoa is a species native to the Andean regions and adapts well to temperate, semi–arid and even cool climates, with a remarkable ability to tolerate wide temperature ranges and high altitudes. It withstands drought and moderately cold conditions relatively well, but it is sensitive to frost during flowering and seed ripening, which can compromise yield. Excess moisture and prolonged rainfall, especially close to maturity, increase the risk of lodging and disease on the panicles.

Exposure
The ideal exposure is full sun, which promotes good photosynthesis, balanced vegetative growth and regular flowering. In warmer environments, quinoa benefits from good air circulation, which helps to limit humidity on foliage and reduce the incidence of fungal diseases. Positions that are too shaded lead to weaker, elongated plants with lower seed production.

Soil
Quinoa is a fairly rustic crop and adapts to different soil types, from light, sandy soils to medium–textured ones, as long as they are well drained. It grows best in moderately fertile soils with a pH from slightly acidic to neutral, but it can also tolerate some salinity and poor soils where many other crops would struggle. Waterlogging should be avoided, as it favours root rot and collar diseases.

Irrigation
Under extensive cultivation conditions, quinoa can be grown with limited water inputs, relying largely on natural rainfall, especially in semi–arid areas. However, in critical stages such as emergence, early growth and flowering, supplemental irrigation can improve crop uniformity and final yield. It is important not to over–irrigate, keeping the soil only moderately moist and always ensuring good drainage.

Temperature
The optimal temperature range for germination and early development is generally between 10 and 20 °C. Quinoa also tolerates higher temperatures during vegetative growth, provided there is no severe water stress. During flowering and seed ripening, late frosts or sudden temperature drops can cause flower abortion or reduce harvest quality, while extreme heat combined with drought can decrease seed size.

Fertilization
Quinoa has moderate nutrient requirements compared to many other crops and makes good use of residual soil fertility. The application of well–matured organic matter before sowing improves soil structure and nutrient availability, while light, balanced mineral fertilization (nitrogen, phosphorus, potassium) may be advisable on very poor soils. Excessive nitrogen favours overly lush vegetative growth at the expense of seed production and increases the risk of lodging.

Crop care
Crop care focuses mainly on the early growth stages, when it is important to control weeds by light hoeing or, on smaller surfaces, by mulching. Once plants have reached a certain height, quinoa competes better with weeds. It is useful to monitor for possible pests and fungal diseases and to intervene only when necessary, giving priority to agronomic practices such as crop rotation and the choice of well–drained fields.

Harvest
Harvesting takes place when panicles are fully mature and seeds are well formed, dry and easily detachable. Seed moisture must be sufficiently low to minimise the risk of mould during storage; often, after harvesting, quinoa is further dried in a ventilated environment. The seeds are then cleaned and de–saponified to remove the saponins on the outer coat, which are responsible for the bitter taste.

Propagation
Propagation is by seed. Sowing is usually done directly in the field, in rows, on well–prepared and finely worked soil, adjusting sowing depth according to soil texture (shallower in heavy soils, slightly deeper in lighter ones). It is important to ensure even seed distribution and, after emergence, thinning may be carried out to give each plant enough space to develop and produce a well–formed panicle.

Indicative nutritional values per 100 g

(Raw quinoa, dry seeds, average values)

• Energy: ~ 370–380 kcal

• Water: ~ 10–12 g

• Total carbohydrates: ~ 64–66 g

• Dietary fiber: ~ 7–8 g

• Proteins: ~ 13–14 g

• Total fats: ~ 5–7 g

  • of which SFA (saturated fatty acids): ~ 0.7–1 g

  • of which MUFA (monounsaturated fatty acids): ~ 1–2 g

  • of which PUFA (polyunsaturated fatty acids): ~ 3–4 g (mainly n-6 linoleic acid with small amounts of n-3)

• Minerals: significant amounts of magnesium, phosphorus, potassium, iron, zinc

• Vitamins: B-group vitamins, vitamin E (tocopherols) and other micronutrients in smaller quantities

Values vary slightly depending on cultivar, growing conditions and analytical reference.

Key constituents

• Complex carbohydrates with a meaningful dietary fiber fraction

• High-quality plant proteins, with a relatively complete amino acid profile (including essential amino acids such as lysine, often low in cereals)

• A modest but nutritionally relevant fraction of unsaturated fats (MUFA and PUFA)

• Minerals: magnesium, phosphorus, potassium, iron, zinc and trace elements

• Vitamins: B-group vitamins (e.g. folate, riboflavin, thiamine) and vitamin E

• Bioactive compounds: saponins (in the outer layer), phytosterols, phenolic compounds and other antioxidants

Production process

• Cultivation

  • adapted to high altitudes and cool climates

  • grows best in well-drained soils; tolerant of relatively poor, marginal soils

• Harvest

  • plants are cut when seeds have fully matured and dried on the plant

• Threshing and cleaning

  • seeds are separated from the panicles and plant residues

  • impurities (dust, fragments, stones) are removed

• De-saponification (cleaning of saponins)

  • industrially: mechanical abrasion and/or wet washing

  • domestically: careful rinsing under running water before cooking

• Drying and packaging

  • seeds are dried back to a safe moisture level and then packed (bags, boxes, etc.) for long-term storage

Physical properties

• small, round to slightly oval seeds (a few millimetres in diameter)

• colour varieties: white/ivory, red, purple, brown, black

• raw seeds: dry, hard, with a thin outer layer rich in saponins

• cooked seeds: tender but defined, with visible germ ring, slightly translucent endosperm and a light, fluffy structure

Sensory and technological properties

• taste: mild, slightly nutty and earthy; if saponins are not properly removed, a noticeable bitter taste may be present

• aroma: delicate, cereal-like, not overpowering

• texture after cooking: soft but not mushy, with grains remaining distinct and slightly al dente

• high versatility:

  • works well in boiled, steamed or pilaf-style preparations

  • can absorb flavours from broths, spices and sauces

  • forms a good base for salads, side dishes, grain bowls and patties

Food applications

• grain alternative: replacement for rice, couscous, bulgur or pasta in many dishes

• salads and cold dishes: quinoa salads with vegetables, legumes, cheese, seeds, dressings

• soups and stews: added to increase protein and fiber content

• breakfast and energy dishes: warm cereals, porridge, granola mixes

• vegetarian and vegan products: burgers, patties, stuffings in combination with legumes and vegetables

• bakery and pastry: quinoa flour as a gluten-free ingredient in breads, cakes, biscuits and pancakes (often blended with other flours)

Nutrition and health

Quinoa is often highlighted for its nutritional density and is particularly interesting in modern dietary patterns:

• provides complete plant protein, important in vegetarian and vegan diets

• offers dietary fiber which contributes to intestinal regularity, satiety and glycaemic control when part of a balanced meal

• contains unsaturated fats (mainly PUFA and MUFA), favourable in the context of a varied diet and healthy fat profile

• supplies minerals (magnesium, phosphorus, iron, zinc) important for energy metabolism, bone health and muscle function

• is naturally gluten-free, making it suitable for individuals with coeliac disease or gluten sensitivity

• its relatively low glycaemic index (when properly cooked and eaten with other fibre-rich foods) can be beneficial for metabolic balance

As with any energy-dense food, very large portions may add a substantial calorie load; it is therefore best combined with plenty of vegetables and other nutrient-dense ingredients.

Portion note

A typical serving of cooked quinoa is about 60–80 g (cooked weight), corresponding roughly to 20–25 g of dry seeds per person as a side dish. In a main dish or “grain bowl”, the portion can be slightly higher, depending on overall meal composition and energy needs.

Allergens and intolerances

• quinoa is naturally gluten-free, so it is usually suitable for people with coeliac disease or gluten intolerance (as long as there is no cross-contamination with gluten-containing grains)

• most people tolerate quinoa well; however, residual saponins may cause digestive discomfort or bitterness if the seeds are not washed adequately

• rare individual sensitivities to specific plant proteins or pseudo-cereals are possible; in such cases, gradual introduction and monitoring is advisable

Storage and shelf-life

• dry seeds

  • store in a cool, dry place, away from direct light and strong odours

  • keep in airtight containers after opening the package

  • shelf-life is typically many months if protected from moisture and heat

• cooked quinoa

  • store in the refrigerator in a closed container

  • ideally consume within 1–2 days

  • not recommended for extended storage due to risk of microbial growth and texture loss

Safety and regulatory

Quinoa, as a food grain, is generally regarded as safe. Key safety considerations include:

• adequate removal of saponins, which are bitter and may irritate the digestive tract in large amounts

• hygienic cultivation, harvesting and processing practices (as for other cereal and pseudo-cereal products)

• appropriate controls for contaminants, moisture content and storage conditions to prevent mould growth or infestation

Regulatory frameworks typically treat quinoa similarly to other grains and pseudo-cereals, with attention to gluten-free labelling where applicable.

Labeling

On packaged quinoa, labels typically include:

• product name: “quinoa” (sometimes specifying colour: white, red, black, tricolour)

• net weight

• country of origin or production region, where required

• storage instructions (cool, dry place; once opened, close tightly)

• cooking instructions (water-to-grain ratio, cooking time, rinsing recommendation)

• gluten-free indication if certified according to local regulations

• any claims (organic, fair trade, wholegrain) supported by documentation

Troubleshooting

• bitter taste after cooking

  • likely due to residual saponins

  • solution: rinse thoroughly under running water, rubbing the seeds gently before cooking

• mushy or overly soft texture

  • water-to-grain ratio may be too high, or cooking time too long

  • solution: reduce cooking water, shorten cooking time, let the quinoa rest covered to finish steaming

• hard or undercooked centre

  • insufficient cooking time or too little water

  • solution: add a small amount of water and continue gentle cooking until the germ ring separates and the texture is tender

• off or rancid flavour

  • possible poor storage conditions or prolonged shelf-life

  • solution: check best-before date and storage; discard if clearly rancid or stale

Main INCI functions (cosmetics)

Quinoa is not among the most common cosmetic plants, but quinoa-derived ingredients (e.g. hydrolyzed quinoa protein, quinoa seed extract) may be used for:

• skin conditioning: helping to keep skin in good condition, offering a soft, smooth feel

• hair conditioning: quinoa protein hydrolysates can support hair strength, shine and manageability in shampoos and conditioners

• film-forming and texturizing roles in lotions and creams, improving sensorial profile

• positioning in natural and plant-based formulations, contributing to the marketing value of “superfood-inspired” cosmetics

These uses are still more niche compared with classic plant oils and extracts, but they are increasingly present in modern formulations.

Conclusion

Quinoa (Chenopodium quinoa) is an ancient Andean seed that today plays a central role in modern, health-oriented diets. It offers a rare combination of complete plant protein, dietary fiber, unsaturated fats, minerals and vitamins, all in a versatile grain-like format that fits savoury and sweet preparations alike. Its gluten-free nature makes it especially valuable for people with coeliac disease or gluten sensitivity, while its neutral, mildly nutty flavour allows it to adapt to countless culinary traditions.

From a nutritional standpoint, quinoa acts as a bridge between cereals and legumes, helping diversify carbohydrate and protein sources and enriching meals with micronutrients and bioactive compounds. Provided that saponins are adequately removed and portions are balanced within the overall diet, quinoa can be considered a nutrient-dense, multifunctional staple suited to contemporary nutritional needs. Its emerging role in cosmetic formulations through quinoa-derived proteins and extracts further extends its relevance beyond the kitchen, although its primary importance remains firmly anchored in the food domain.

Studies

The total amount of phenolic acids varies from 16.8 to 59.7 mg/100 g and the proportion of soluble phenolic acids varies from 7% to 61%. The phenolic acid content in Andean crops is low compared with common cereals like wheat and rye, but is similar to levels found in oat, barley, corn and rice. The flavonoid content of quinoa and kañiwa is exceptionally high, varying from 36.2 to 144.3 mg/100 g (2).

Potential health benefits

Quinoa protein has a balanced amino acid composition being rich in essential amino acids such as lysine (5.1–6.4%) and methionine (0.4–3.1%). The total dietary fiber content of quinoa grains (average of 4.1%) compares favorably with those of wheat (2.7%) and corn (1.7%). Moreover, the amounts of calcium, magnesium, iron, and phosphorus (especially calcium and iron) are significantly higher than in most other cereals. Quinoa oil is rich in polyunsaturated fatty acids such as linoleic and linolenic acid, which have the potential to help in degenerative diseases such as cardiovascular diseases, cancer, inflammatory and autoimmune diseases. Quinoa grains have high concentrations of polyphenols and antioxidants such as α‐ and γ‐tocopherol—compounds suggested to have anticarcinogenic and anti‐inflammatory activities. They are also a good source of vitamin C, E, and folic acid (3).

Increasing the utilisation of plant proteins is needed to support the production of protein-rich foods that could replace animal proteins in the human diet so as to reduce the strain that intensive animal husbandry poses to the environment. Lupins, quinoa and hempseed are significant sources of energy, high quality proteins, fibre, vitamins and minerals. In addition, they contain compounds such as polyphenols and bioactive peptides that can increase the nutritional value of these plants. From the nutritional standpoint, the right combination of plant proteins can supply sufficient amounts of essential amino acids for human requirements. This review aims at providing an overview of the current knowledge of the nutritional properties, beneficial and non-nutritive compounds, storage proteins, and potential health benefits of lupins, quinoa and hempseed (4).

Quinoa (Chenopodium quinoa Willd.) and amaranth (Amaranthus cruentus L.) are pseudocereal grains rich in both macronutrients and micronutrients including vitamins and minerals. The proteins are particularly of high nutritional quality due to the outstanding balance of essential amino acids. However, recent research strongly suggests that nonessential nutrients such as phytochemicals of quinoa and amaranth may also have potential health beneficial effects. This review focuses on the phytochemical composition of quinoa and amaranth seeds, the antioxidant and anti-inflammatory activities of hydrophilic (e.g. phenolics, betacyanins) and lipophilic (e.g. fatty acids, tocopherols, and carotenoids) nutrients, and how these contribute to the potential health benefits, especially in lowering the risk of the oxidative stress related diseases e.g. cancer, cardiovascular disease, diabetes, and obesity (5).

The good amount of essential fatty acids present in Quinoa have been shown to mitigate degradation, dehydration and inflammation of epidermal tissues by virtue of their antioxidant properties (6). Quinoa oil and extract are often included in sunscreen products as the polyphenols contained in Quinoa are able to absorb UV radiation (7).

Quinoa studies

Mini-glossary

• Pseudo-cereal: a non-grass plant whose seeds are used like cereals (e.g. quinoa, amaranth, buckwheat)

• Saponins: natural surfactant compounds with a bitter taste found in the outer layer of quinoa seeds; they must be removed by washing before consumption

• SFA (saturated fatty acids): type of fat that, in excess, is generally considered less favourable for cardiovascular health

• MUFA (monounsaturated fatty acids): fats linked to beneficial effects on blood lipids when they replace saturated fats in a balanced diet

• PUFA (polyunsaturated fatty acids): include omega-6 (e.g. linoleic acid) and omega-3 (e.g. alpha-linolenic acid), essential in small amounts for human health

References________________________________________________________________________

(1) Jacobson S. The worldwide potential for quinoa (Chenopodium quinoa Willd.) Food Rev Int. 2003;19:167–177. doi: 10.1081/FRI-120018883.

(2) Repo-Carrasco-Valencia R, Hellström JK, Pihlava JM, Mattila PH. Flavonoids and other phenolic compounds in Andean indigenous grains: quinoa (Chenopodium quinoa), kaniwa (Chenopodium pallidicaule) and kiwicha (Amaranthus caudatus)  Food Chem. 2010;120:128–133. doi: 10.1016/j.foodchem.2009.09.087.

(3) Ludena Urquizo FE, García Torres SM, Tolonen T, Jaakkola M, Pena-Niebuhr MG, von Wright A, Repo-Carrasco-Valencia R, Korhonen H, Plumed-Ferrer C. Development of a fermented quinoa-based beverage. Food Sci Nutr. 2016 Oct 28;5(3):602-608. doi: 10.1002/fsn3.436. 

(4) Pihlanto A, Mattila P, Mäkinen S, Pajari AM. Bioactivities of alternative protein sources and their potential health benefits. Food Funct. 2017 Oct 18;8(10):3443-3458. doi: 10.1039/c7fo00302a. Review.

(5) Tang Y, Tsao R. Phytochemicals in quinoa and amaranth grains and their antioxidant, anti-inflammatory, and potential health beneficial effects: a review. Mol Nutr Food Res. 2017 Jul;61(7). doi: 10.1002/mnfr.201600767. 

(6) McCusker MM, Grant-Kels JM. Healing fats of the skin: the structural and immunologic roles of the omega-6 and omega-3 fatty acids. Clin Dermatol. 2010 Jul-Aug;28(4):440-51. doi: 10.1016/j.clindermatol.2010.03.020.

(7) Nichols JA, Katiyar SK. Skin photoprotection by natural polyphenols: anti-inflammatory, antioxidant and DNA repair mechanisms. Arch Dermatol Res. 2010 Mar;302(2):71-83. doi: 10.1007/s00403-009-1001-3.