Where is Trigonelline Found?

December 27, 2025 •

3 min read

As a natural plant compound, trigonelline is present in a surprisingly wide array of foods. First isolated from fenugreek seeds in 1885, this bioactive pyridine alkaloid is now known to be abundantly present in coffee beans and various other plants. Its ubiquity across different plant species highlights its significant role in botanical systems and makes it a subject of increasing nutritional interest.

Quick Summary

This article details the primary and secondary food sources of the plant alkaloid trigonelline, including its high concentration in green coffee beans and fenugreek seeds, along with how its content changes during processing, especially roasting. It also examines lesser-known sources, discusses its biochemical significance, and covers common supplement forms.

Key Points

Coffee and Fenugreek: The most concentrated sources of trigonelline are green coffee beans and fenugreek seeds.
Heat Sensitivity: Roasting and brewing coffee significantly reduce trigonelline content, converting some into niacin.
Widespread Presence: Trigonelline is found in a variety of other plant foods, including some legumes (peas, chickpeas), grains (oats), and vegetables (potatoes, certain radishes).
Coffee By-products: Different parts of the coffee plant, such as the leaves and cherry husks, also contain trigonelline and are used in some products.
Forms of Intake: Besides whole foods, trigonelline can be consumed through supplements, most commonly fenugreek extracts.
Processing Matters: To maximize trigonelline content from coffee, cold brewing is a more effective method than hot brewing due to its thermal instability.

Top Sources of Trigonelline in the Diet

Trigonelline is most famously and abundantly found in certain plant-based foods, with green coffee beans and fenugreek seeds containing the highest concentrations. However, the level of trigonelline can vary significantly based on the plant species, processing methods, and even the maturity of the plant part.

Coffee Beans: The Leading Source

Green (unroasted) coffee beans are one of the richest dietary sources of trigonelline. The concentration differs between coffee species, with Arabica coffee typically containing higher levels than Robusta beans. However, the roasting process, which applies high heat, causes a substantial portion of the trigonelline to decompose. This thermal degradation is responsible for a significant change in the coffee's chemical composition and plays a role in the development of its aroma and flavor profile. Part of the degraded trigonelline is converted into niacin (vitamin B3), making roasted coffee a source of this essential vitamin as well. The concentration is even lower in coffee beverages and spent coffee grounds, due to both thermal decomposition during brewing and its high water solubility. Interestingly, cold-brewed coffee retains more trigonelline than its hot-brewed counterparts because it is not exposed to the same high temperatures.

Fenugreek Seeds and Leaves

The name Trigonelline is derived from the fenugreek plant's botanical name, Trigonella foenum-graecum, from which the compound was first isolated. Fenugreek seeds are a concentrated source of this alkaloid and are widely used in traditional medicine and culinary applications. The leaves of the plant also contain trigonelline, though the concentration can vary with the plant's age. Many dietary supplements also utilize fenugreek extract standardized to contain a specific concentration of trigonelline.

Lesser-Known Plant Sources

Beyond coffee and fenugreek, trigonelline is present in a variety of other plants, though usually in lower concentrations. These sources can still contribute to overall dietary intake.

Legumes: Several common legumes are known to contain trigonelline, including chickpeas, alfalfa, and garden peas. The compound may play a role in the plant's symbiotic relationship with nitrogen-fixing bacteria.
Cereals and Grains: Cereals like oats and barley contain detectable amounts of trigonelline.
Vegetables: Vegetables such as potatoes and certain radishes, including the Japanese radish (Raphanus sativus cv. Sakurajima Daikon), are also sources.
Fruit: Bananas are another fruit source of trigonelline.
Other Herbs and Spices: Besides fenugreek, other herbs and spices may contain this compound.

The Fate of Trigonelline During Processing

Heat processing is the most significant factor affecting trigonelline content. As a thermolabile compound, it is highly susceptible to breakdown when exposed to high temperatures. The roasting of coffee is a prime example, but other forms of food preparation also have an impact. The method of extraction can also determine the final concentration in a product, as seen with different preparations of fenugreek extracts.

Comparison of Trigonelline Content in Selected Sources


Source	Processing	Example Concentration (g/kg dry weight)	Change in Content
Green Coffee Beans (Arabica)	Unroasted	8.8–29.0 g/kg	Highest raw concentration
Roasted Coffee Beans (Arabica)	Roasted	3.7–7.5 g/kg	Significantly reduced via heat
Fenugreek Seeds	Raw	Varies, high concentration	Depends on preparation; less affected by light cooking
Coffee Leaves	Processed for tea	1.1–11.7 g/kg	Heat-sensitive, varies with leaf maturity
Coffee Cherry Husks/Pulp	Processed for cascara	0.6–5.4 g/kg	Content varies based on processing

Conclusion

Trigonelline is a widely distributed plant alkaloid, with coffee and fenugreek seeds being the most well-documented and abundant sources. Its concentration is highly dependent on processing, particularly the thermal effects of roasting and brewing, which cause a significant portion to break down into niacin. While coffee offers the most readily available dietary source, other plants like legumes, grains, and some vegetables also contribute smaller amounts. For those interested in maximizing their trigonelline intake, focusing on raw or lightly processed versions of these foods is key, as is opting for cold brew coffee over hot. As research into this phytochemical continues, its role in human health and its presence across the plant kingdom will likely become even more understood. For a deeper dive into the health implications of trigonelline, consult peer-reviewed journals on the subject.

Frequently Asked Questions

During coffee roasting, trigonelline decomposes due to high temperatures. This process contributes to the development of the coffee's flavor and aroma, and a portion of the trigonelline is converted into niacin (vitamin B3).

Yes, trigonelline is present in both green and roasted coffee beans, but in significantly different concentrations. Green coffee beans have a much higher content of trigonelline, which is substantially reduced during the roasting process.

While green coffee beans are a top source, fenugreek seeds and their extracts are also known for their high trigonelline content. The name trigonelline is derived from the fenugreek plant (Trigonella foenum-graecum).

Yes, the preparation method affects the amount of trigonelline. Because it is heat-sensitive and highly water-soluble, hot brewing extracts it from the grounds and also causes some to degrade. Cold brewing, which uses no heat, preserves a higher concentration of trigonelline.

In plants, trigonelline serves several functions, including involvement in cell cycle regulation, signal transduction, and acting as an osmoregulator in response to environmental stresses like drought and salt.

Yes, trigonelline can also be obtained from dietary supplements, which often contain extracts from fenugreek seeds standardized to a specific trigonelline concentration.

Other dietary sources of trigonelline include legumes like peas and chickpeas, certain grains like oats, and vegetables such as potatoes and Japanese radish.