Microgreens, the young seedlings of vegetables and herbs, have become a popular choice for health-conscious consumers and chefs alike. Known for their vibrant colors, intense flavors, and high nutrient content, these tiny greens are often called “superfoods.”
However, their success in the market depends not just on their nutritional value but also on how much people enjoy their taste, texture, and appearance. A recent study published in the journal Agronomy explored these factors in detail, testing 12 different microgreens species to understand what makes them appealing—or unappealing—to consumers.
Understanding Microgreens and Their Importance
Microgreens are young, edible greens harvested 7–14 days after germination, when the first pair of true leaves develop. They are larger than sprouts (which are eaten with roots) but smaller than baby greens.
Microgreens are grown in soil or nutrient-rich substrates and require light, distinguishing them from sprouts, which germinate in water and darkness. Examples include radish, beet, Swiss chard, and basil microgreens.
Their importance lies in their dense nutrient profile: they contain higher concentrations of vitamins (C, E, K), minerals (iron, magnesium), and antioxidants compared to mature plants. For instance, red cabbage microgreens have six times more vitamin C than mature red cabbage.
Phytonutrients, such as polyphenols and carotenoids, are bioactive compounds in microgreens that protect against chronic diseases. These compounds give microgreens their vibrant colors and distinct flavors.
For example, purple basil’s deep hue comes from anthocyanins (a type of polyphenol), while the peppery taste of radish microgreens is due to glucosinolates (sulfur-containing compounds). However, some phytonutrients, like glucosinolates, contribute to bitterness, which can deter consumers.
Research Methods in Microgreens Study
Researchers from the University of Naples Federico II in Italy grew 12 microgreens species in a controlled climate chamber—a sealed environment where temperature, humidity, and light are precisely regulated. This ensured consistent growing conditions, eliminating variables like weather or soil quality that could affect flavor. The researchers selected 12 species from 7 botanical families
- Amaranth (Amaranthus tricolor)
- Coriander (Coriandrum sativum)
- Cress (Lepidium sativum)
- Green Basil (Ocimum basilicum)
- Komatsuna (Brassica rapa var. perviridis)
- Mibuna (Brassica rapa var. japonica)
- Mizuna (Brassica juncea var. japonica)
- Pak Choi (Brassica rapa var. chinensis)
- Purple Basil (Ocimum basilicum)
- Purslane (Portulaca oleracea)
- Swiss Chard (Beta vulgaris subsp. vulgaris)
- Tatsoi (Brassica rapa var. rosularis)
The microgreens were grown under a 12-hour photoperiod (light/dark cycle) with high-pressure sodium lamps providing optimal light intensity. They were irrigated with a Hoagland nutrient solution—a standardized mix of minerals essential for plant growth, including nitrogen, phosphorus, and potassium.
After harvesting, the greens were washed and presented to 54 volunteers, mostly Italian students aged 20–23, who participated in structured tasting sessions. During these sessions, participants rated each microgreen on a 15-point scale for sensory attributes:
- Sweetness: Perception of sugary taste.
- Bitterness: Sharp, unpleasant taste often linked to alkaloids or phenolics.
- Astringency: Dry, puckering sensation caused by tannins.
- Heat: Spicy or peppery sensation from compounds like glucosinolates.
- Texture: Crispness, tenderness, or crunchiness.
They also rated acceptability factors like appearance, flavor, and overall liking. The researchers used ANOVA (Analysis of Variance) and Tukey’s HSD (Honestly Significant Difference) test to determine if differences in scores between species were statistically significant.
These statistical tools help identify whether variations (e.g., Swiss chard’s sweetness vs. mibuna’s bitterness) are meaningful or due to random chance.
Key Findings from the Study
The results revealed significant differences in how the 12 microgreens species were perceived. Swiss chard and coriander emerged as clear favorites, while mibuna and cress scored the lowest.
Swiss chard received the highest overall acceptability score (8.5/15) due to its mild sweetness (5.9/15) and low bitterness (3.8/15). Its soft, tender texture (4.8/15) was less preferred than crunchier varieties but did not outweigh its pleasant flavor.
Coriander, known for its fresh aroma (13.0/15), scored well in flavor (7.9/15) despite moderate bitterness (6.3/15).
In contrast, mibuna and cress were disliked for their intense bitterness and heat. Mibuna scored 10.0/15 for bitterness—the highest in the study—and 10.6/15 for heat.
Bitterness in microgreens is often linked to glucosinolates, sulfur-containing compounds with anti-cancer properties, but these flavors clash with Western palates. Cress, while slightly less bitter (9.0/15), was the spiciest microgreen (12.6/15 for heat), a trait attributed to phenethyl isothiocyanate, a compound also found in wasabi.
Astringency, a dry sensation caused by tannins binding to saliva proteins, also influenced preferences. Amaranth scored high in sourness (7.3/15) and astringency (6.4/15), contributing to its low overall acceptability (3.0/15).
Impact of Bitterness And Texture On Microgreens
The study found that bitterness and sourness were the biggest barriers to consumer acceptance. This is partly due to human evolution: bitterness is often a warning sign for toxins, while sourness can indicate spoilage. Though microgreens are safe, these innate aversions persist.
For example, glucosinolates in mibuna trigger a bitter taste as a natural defense against pests, but humans perceive this as unpleasant.
Cultural preferences further shape these reactions. In Western diets, sweet and salty flavors dominate, whereas Asian cuisines embrace bitterness (e.g., bitter melon, mustard greens). The study’s Italian participants favored mild, sweet flavors like Swiss chard, while rejecting bold varieties like mibuna.
However, bitterness and astringency are not inherently bad. Polyphenols, the antioxidants responsible for these traits, reduce inflammation and oxidative stress.
For instance, Swiss chard’s lower polyphenol content (3.7 mg/g) makes it milder, while mibuna’s high levels (9.2 mg/g) explain its bitterness. Educating consumers about these health benefits could shift perceptions.
Texture significantly impacts acceptability. Participants preferred crisp, juicy textures like coriander (9.1/15) and mibuna (9.5/15) over softer varieties like Swiss chard (4.8/15). Crunchiness is often associated with freshness, while chewiness can signal age or poor quality.
Appearance, though less critical than flavor, still plays a role. Purple basil’s vivid color scored high in visual appeal (9.1/15), but its bland flavor (5.0/15) reduced overall liking. This highlights that while aesthetics attract initial interest, taste determines long-term acceptance.
Microgreens Farming and Retail Strategies
For farmers, the study highlights the importance of selecting the right species to grow. Swiss chard, coriander, and komatsuna are safe choices for Western markets due to their mild flavors. However, there is also room for niche products.
Chefs and health-focused consumers might seek out bold flavors like mibuna for specialty dishes or juices. Farmers could experiment with growing conditions to reduce bitterness—for example, adjusting light intensity or nutrient levels during growth.
Retailers, meanwhile, should consider how they present microgreens to consumers. Clear labeling about flavor profiles (e.g., “mild and sweet” for Swiss chard or “spicy and bold” for cress) can help customers make informed choices. Sampling stations in stores or partnerships with restaurants could also introduce people to less familiar varieties.
While the study provides valuable insights, it has some limitations. The participants were mostly young students from Italy, which means the results might not apply to older adults or other cultures.
For example, older individuals might have different taste preferences, and consumers in countries like India or Japan might enjoy stronger flavors. Future research could explore these differences to create a more global understanding of microgreens acceptance.
Another area for exploration is the impact of cooking on flavor. The study tested raw microgreens, but cooking methods like sautéing or blending into smoothies might reduce bitterness and improve acceptability.
Additionally, pairing microgreens with other ingredients—such as sweet fruits or creamy cheeses—could make bitter varieties more enjoyable.
Conclusion
Microgreens have the potential to revolutionize diets by combining nutrition, sustainability, and flavor. While Swiss chard and coriander lead in acceptability, the study highlights the need for consumer education and culinary creativity.
By pairing bitter varieties with sweet or creamy ingredients (e.g., mango, avocado), chefs can make them more palatable. Farmers and retailers, meanwhile, must balance aesthetics with taste to ensure these nutrient-packed greens transition from garnishes to kitchen staples.
As urban farming and vertical agriculture expand, microgreens offer a scalable solution for fresh, local produce. With continued research and innovation, these tiny greens could become a cornerstone of global food systems, proving that health and flavor can coexist in every bite.
Power Terms
Phytonutrients: These are natural compounds in plants that promote health. Phytonutrients like polyphenols and carotenoids protect against diseases by acting as antioxidants or anti-inflammatory agents. For example, anthocyanins in purple basil give it color and combat oxidative stress. They are crucial for preventing chronic illnesses like heart disease.
Glucosinolates: Sulfur-containing compounds found in cruciferous plants like broccoli and mibuna. When plants are damaged, glucosinolates break down into isothiocyanates, which have anti-cancer properties. Their bitter taste, however, can deter consumption. These compounds are vital for plant defense and human health.
Polyphenols: A type of antioxidant found in plants. Polyphenols neutralize harmful free radicals, reducing cell damage and inflammation. Examples include flavonoids in berries and tannins in tea. They improve heart health and may lower cancer risk, making them essential in functional foods.
Carotenoids: Pigments responsible for red, orange, and yellow hues in plants. Beta-carotene (found in carrots) converts to vitamin A in the body, supporting vision and immunity. Carotenoids like lutein in Swiss chard protect eyes from age-related damage.
Antioxidants: Molecules that prevent cell damage caused by free radicals. Vitamins C and E, found in microgreens, are antioxidants that reduce oxidative stress, lowering the risk of chronic diseases like diabetes. They are added to supplements and health foods.
ANOVA (Analysis of Variance): A statistical test comparing means across multiple groups. In the study, ANOVA determined if differences in microgreens’ sensory scores were significant. The formula F = variance between groups / variance within groups helps identify meaningful patterns.
Tukey’s HSD Test: A post-hoc test used after ANOVA to pinpoint which groups differ. For example, it showed mibuna’s bitterness was significantly higher than Swiss chard’s. This test ensures accurate comparisons in experiments.
Controlled Climate Chamber: A sealed environment regulating temperature, light, and humidity. Used to grow microgreens uniformly, it eliminates external variables, ensuring consistent quality for research.
Photoperiod: The duration of light exposure a plant receives daily. A 12-hour photoperiod optimizes growth for microgreens, influencing photosynthesis and nutrient production.
Hoagland Nutrient Solution: A mix of minerals (nitrogen, potassium) dissolved in water to feed plants in hydroponic systems. It ensures microgreens receive essential nutrients for robust growth.
Sensory Attributes: Characteristics perceived by taste, smell, or touch. Bitterness, texture, and aroma are sensory attributes affecting consumer preference. For instance, crunchy textures are often preferred.
Bitterness: A sharp taste linked to compounds like glucosinolates. While bitterness in mibuna deters some consumers, it signals health benefits, such as detoxification support.
Astringency: A dry, puckering sensation caused by tannins binding to saliva proteins. High astringency in amaranth reduces its acceptability, though tannins have antioxidant properties.
Texture: The physical feel of food, like crispness or tenderness. Crunchy textures (e.g., coriander) are associated with freshness, influencing consumer choices.
Acceptability: How much consumers like a product. Swiss chard’s high acceptability stems from mild flavor, guiding farmers to prioritize such varieties.
Cultural Preferences: Regional differences in taste. Western cultures often reject bitter foods like mibuna, while Asian cuisines embrace them, affecting market strategies.
Human Evolution: Biological adaptations shaping taste. Bitterness aversion evolved to avoid toxins, explaining why some microgreens are less popular despite health benefits.
Phenethyl Isothiocyanate: A spicy compound in cress, contributing to its heat. It acts as a natural pesticide and has anti-cancer properties.
Urban Farming: Growing food in cities using rooftops or vertical setups. Microgreens thrive here due to quick growth and minimal space needs, enhancing local food security.
Vertical Agriculture: Stacking crops in layers to save space. Used for microgreens in indoor farms, it maximizes yield and reduces transportation costs.
Nutrient Profile: The nutritional content of food. Microgreens have superior profiles, like red cabbage’s high vitamin C, making them functional foods.
Functional Foods: Items offering health benefits beyond basic nutrition. Antioxidant-rich microgreens help prevent diseases, aligning with this category.
Oxidative Stress: An imbalance between free radicals and antioxidants, damaging cells. Chronic oxidative stress leads to diseases like Alzheimer’s, mitigated by microgreens’ antioxidants.
Chronic Diseases: Long-term illnesses like diabetes or cancer. Phytonutrients in microgreens reduce risks, emphasizing their role in preventive healthcare.
Statistical Significance: A measure indicating results are not random. A p-value < 0.05 in the study confirmed mibuna’s bitterness was truly higher, not due to chance.
Reference:
Caracciolo, F., El-Nakhel, C., Raimondo, M., Kyriacou, M. C., Cembalo, L., De Pascale, S., & Rouphael, Y. (2020). Sensory attributes and consumer acceptability of 12 microgreens species. Agronomy, 10(7), 1043.
