Talking About Fragrance, Flavor and Color: Terpenes and Flavonoids


Talking About Fragrance, Flavor and Color: Terpenes and Flavonoids

Hi and welcome to our webcast. My name is Patricia Atkins, the Senior Application Scientist at SPEX CertiPrep. Today we’re going to take a deeper look at fragrance, flavor and color. These are mostly terpenes and flavonoids. So why should we care about terpenes and flavonoids? Well, they produce color, fragrance, flavor for a lot of botanical products. So, if you see that beautiful rose, those are terpenes and flavonoids. That beautiful smell, are terpenes and flavonoids. That color is definitely a flavonoid. They create a unique fingerprint in plants and they can be used to identify different botanical products. So, different manufacturers of botanical products like cannabis and tea and spices, they can use these unique fingerprints to identify true products instead of adulterated or fraudulent products. And over the years we know that they have great health benefits. We all know about antioxidants, about the antioxidants in wine and chocolate and all of those great compounds, they are usually terpenes and flavonoids.

What’s a terpene? At its base, it’s an isoprene unit and people are saying ok, isoprene that sounds like it is kind of part of the rubber family and it is. Isoprene is part of the what you think of as part of the rubber family. But these terpenes, they contain compounds that are fragrance, flavor and smell. So, these are botanical products. Yes, they’re composed of the isoprene but they’re really not part of natural rubber. So, natural rubber isn’t part of terpenes perse. There are two categories of terpenes; essential terpenes. These are necessary for health and growth and they have more than 15 carbons. If you don’t have an essential terpene, you will die; you will not have good health, you will not grow, so, if you are a plant or an animal, these are necessary terpenes. Then there are non-essential terpenes. These are part of the defense and the biological processes of the plant or the animal and they usually have less than 15 carbons.

So, how are terpenes created? They are synthesized along two pathways. There is the mevalonic acid pathway, the MVA pathway, and this was discovered around 1950. This is also the pathway that produces cholesterol. And it takes places in the cytosol of the cell and this happens in humans, fungi, plants. So, this is a common pathway to produce terpenes. And then there is the MEP/DOXP pathway that was found in the 1980s. And, this is the pathway for green algae, plants, some protozoans, and bacteria. Plants can use both pathways, so, they can use both the mevalonic (the MVA) or the MEP pathways.

So, what are terpenoids? We talked about terpenes, but what is a terpenoid? It’s sort of an interchangeable term for terpenes, but they are actually modified terpenes. They have a functional group with an oxygen, things like alcohols, aldehydes, ketones, things like that. So, if you think of a particular terpene and it has an OH group on it, a hydroxyl group on, then its an alcohol. If it has an aldehyde group on it, then it’s an aldehyde. If you group terpenes, they are categorized by the number of isoprene units, that’s the small functional group that we were talking about. So, the smallest is the hemiterpene and there is only one isoprene. An example would be isovaleric acid. Isoprene is the only hemiterpene. Then you could have ten carbons, they go up in units of five, those are monoterpenes. So, they hemiterpene and the monoterpene, we said that anything less than fifteen is non-essential, so those tend to be non-essential. Then you get into the over C15 and you have the sesquiterpenoids, the diterpenes and so on. These are a lot of things that we’ve heard of. We’ve heard of like some of the different fragrance compounds and flavor compounds, linalool and things like that. 

So, these are some very common terpenes, ones that most people will at least know their smell. So, that Linalool, like I said before, that’s a lavender/mint smell. You have pinenes, those are from pine; the caryophyllene, those give the floral notes to peppercorns; carene, that’s like a cedar smells; limonene, that’s the citrus or the lemony smells. Something that, if you drink beer, you will know that humulene, that’s mostly in hops, it’s also in cannabis; and myrcene, again, found in cannabis, myrtles and things like that; and then the roses and wine grapes have that kind of floral fragrance, that’s the geraniol.

So, if we look at another close relative of the beer hops, we are talking about cannabis. They come from the same family and they have well over 200 terpenes and terpenoids in common. And so, they have a lot of the same odors, a lot of the same flavors, that myrcene that is in both the hops and the cannabis. Here is a very long list of terpenes for cannabis and terpenes for hops. As we said before, the myrcene is a monoterpene and is like the most common of the cannabis terpenes. Then you have things like the caryophyllenes, we said that’s like the black pepper, that’s where you get that kind of black peppery smell in varieties of cannabis like Skywalker of Gorilla Glue. If you are looking for more of piney kind of, then it’s a monoterpene that’s the pine scents and aroma, that’s where you will find it in something like a Bubba Hash or a Strawberry Cough. If you are looking for a limonene, well of course you are going to find that lemon in something like a Lemon Haze. So, these terpenes have their different flavor and scent characteristics that then, in the cannabis world, turn into different names.

And just like with wine and hops, cannabis has a lot of terpenes in common with the wine and hops. You have the myrcene, you have the limonene, so you have the lemons, you have the kind of earthy smells, you have the humulenes and things like that. So, they really do overlap with each other quite a bit.
So, we talked about, what are flavonoids? They are secondary or non-essential metabolites. So, they are kind of like the non-essential terpenes, these are non-essential metabolites. And, they’re based on the phenol group structure. They usually have a very specific structure, a fifteen-carbon structure with two phenol rings and one heterocyclic pyran ring.

There are three classes and they’re divided up by structure. The bioflavonoids, they attach at the C2, so that’s where that benzopyrene ring attaches to. Isoflavonoids attach at the C3 and neoflavonoids attach at the C4. And then there’s dozens and dozens of other sub-groups. And here you have a little bit of the different important functional sub-groups. The flavones, the flavanols, the neoflavenes, the neoflavones.  So, there is a very large distinction between all the different sub-groups for different flavonoids. Some of the important ones are the 1-flavonols. These are things that make tea and berries and apples have that kind of color, scent, those antioxidant properties. You have the dimers, the polymers, some of them that you might have heard of. Proanthocyanidins, those are the ones that say for heart health and things like that, you want those Proanthocyanidins from wine, grapes, berries, things like that. You have your 2-flavonols, again you probably heard of quercetin, that’s one of those wine compounds everybody is hot for, they take supplements sometimes. The myrcene which gives onion, kale, broccoli those characteristic defensive odors. The anthocyanidins are those blue, red, purple compounds, so that’s where you get all those colors and compounds from.
Some of the major flavonoids for cannabis are the Cannaflavins, they’re very unique to the cannabis family. So, there are three as of right now that have been discovered; cannaflavin A, B and C. There’s also a host of other, different flavonoids that are associated with cannabis. The quercetin is there, the catechins which are also known to be in teas and things like that. So, there’s a wide range of flavonoids associated with cannabis. And those different flavonoids produce a whole range and spectrum of color, from reds to oranges to yellows to black. So, these are all different possible colors of cannabis associated with the different flavonoid. The anthocyanins giving you the yellow/orange, blue to black. The carotenoids, giving you the orange, yellows and reds.

Now, everything from fragrance to colors are usually die to the components of the terpenes and flavonoids in a particular botanical and they’re found in almost all agricultural products. Think of any agriculture product, grape juice, apple juice, tea, wine, spices, berries. These all benefit from the fingerprint chemicals of the terpenes and flavonoids in those particular botanical products. And they’re known to have a lot of healthy benefits. We have all hears of the benefits of the berries, the antioxidants. So, these are very important compounds that tend to get overlooked for some of the more dramatic compounds.

SPEX has been involved in terpene and flavonoid standards for quite a few years, terpenes especially. And, we have just started to produce flavonoid standards for the cannabis and for the other food markets. If you need more information on terpenes or flavonoids, please contact us.

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Thanks a lot!


Terpenes are the common term for a large group of compounds that contribute to the flavor and smell of botanical products. Flavonoids are botanical compounds, similar to terpenes, responsible for different processes for defense and metabolic processes in plants. These compounds are responsible for many colors observed in botanical materials and plants.