Methyl cyclopentenolone (FEMA# 2700, CAS# 765-70-8) must have more aliases than almost any other flavor chemical. It exists, like many other chemicals with similar structures, as a keto-enol tautomer, and 3-methyl cyclopentan-1,2-dione as the name of the keto form. This is one frequently used name. Other widely used names include maple lactone, cyclotene and corylone. Methyl cyclopentenolone is found very widely in nature, especially in foods containing sugars that have been subjected to heat. The profile is distinctly cooked sugar and quite specifically reminiscent of maple syrup. It can be used at high levels in many obviously brown flavors, but its attractive profile can also find a home in many other areas.
Note that the dose rates given throughout this article are the levels suggested for use in flavors intended to be dosed at 0.05% in ready-to-drink beverages or in a simple bouillon.
Caramel: The ideal level of use of methyl cyclopentolone in caramel flavors does vary with the level of burnt sugar note that is required but 10,000 ppm makes a good starting point.
Chocolate and Cocoa: Much more modest levels are effective in dark chocolate and cocoa flavors, nearer to 500 ppm.
Coffee: The level in coffee flavors depends to some extent on the degree of roast but, as with caramel, 10,000 ppm is a reasonable compromise.
Licorice: Methyl cyclopentenolone is not a dominant aspect of licorice flavors but as little as 200 ppm still has a sweetening and deepening effect on the profile.
Malt: At a high level, around 3,000 ppm, methyl cyclopentenolone provides a very useful cooked aspect to malt flavors. Much lower levels are better with malted milk flavors.
Maple: Maple flavors are, unsurprisingly, the perfect home for this ingredient and high levels work very well, balancing out the fenugreek character which is all too dominant in some profiles. An ideal level of addition is 25,000 ppm.
Molasses and Brown Sugar: Molasses varies considerably in character from blackstrap at the burnt extreme to Barbados at the softer end of the scale. A lesser example of the same variations applies to brown sugars. Similar variations in the ideal level of methyl cyclopentenolone work best in these different profiles, ranging from 20,000 ppm down to 4,000 ppm.
Vanilla: True vanilla bean flavors only need a modest addition of this ingredient, around 50 ppm. French style flavors can happily accommodate ten times as much.
Bacon: Bacon flavors vary considerably in profile, but methyl cyclopentenolone can be used across the board. In most bacon flavors, 1,000 ppm is an attractive level but that can be increased to 1,500 ppm in particularly smoky types.
Beef: In beef flavors, 1,000 ppm of this ingredient is also a good level, working equally well in roast, BBQ and boiled beef profiles.
Fish: Fried methyl cyclopentenolone would seem to be completely incompatible with fish and seafood flavors but it does have one useful niche that it fits surprisingly well. High levels, around 2,000 ppm, have a spectacular effect in fried fish flavors, especially shrimp and scampi.
Ham: As with bacon, the best level in ham flavors depends on the level of smoke character. A sensible starting point is 1,000 ppm, but higher levels can be used.
HVP: Hydrolysed vegetable protein and yeast flavors can accommodate levels up to 2,000 ppm without any problem.
Smoke: This ingredient is pretty much essential for smoke flavors and helps to soften the inevitable phenolic notes. An ideal level of use is 500 ppm.
Soy Sauce: Some soy sauce flavors are quite smoky, but this is not typical of the best commercial soy sauces. A moderate level of methyl cyclopentenolone, in the region of 300 ppm, works best for authentic style flavors.
Almond, Toasted and Pistachio: For toasted almond and pistachio flavors, 4,000 ppm of methyl cyclopentenolone works very well, adding depth and realism.
Hazelnut and Praline: Methyl cyclopentenolone is highly compatible with all nut flavors but especially hazelnut. Very high levels, up to 10,000 ppm, can be used successfully in hazelnut and praline flavors.
Peanut: For peanut flavors, 10,000 ppm would threaten to overwhelm, but the best level is not far below that. At 6,000 ppm, it can easily be added to good effect.
Walnut: A good level for walnut flavors is also 6,000 ppm, adding depth and a degree of sweetness to the profile.
Beer Dark: Most beer flavors would not be improved by the addition of methyl cyclopentenolone. Dark beers, such as Guinness, are the exception and modest levels, around 50 ppm, can be quite effective.
Bread: Methyl cyclopentenolone does work well in all bread flavors. A reasonable starting level is 100 ppm, but higher levels can be effective in more toasted bread flavors, especially pizza base flavors.
Butter, Toasted: This ingredient is only useful in cooked butter and ghee flavors but, within that context, it delivers authenticity when added at around 200 ppm.
Coconut, Toasted: In the same way, methyl cyclopentenolone is very attractive in toasted coconut flavors at levels in the region of 1,000 ppm. It is not helpful in coconut milk or dried coconut flavors.
Honey: Honey flavors cover a multitude of different characters. Methyl cyclopentenolone should only be used at trace levels, around 50 ppm, in the popular floral honey flavors. In clover honey flavors, higher levels are very attractive.
Plum: A good level for this ingredient is 100 ppm in plum flavors, giving depth without imparting a dried character.
Root Beer: Root beer flavors tend to be completely dominated by their wintergreen note and any distraction from this juggernaut is welcome. At 200 ppm of methyl cyclopentenolone, it provides a very effective distraction and softens the flavor profile nicely.
Rum: The level of smoky character resurfaces in rum flavors, and more smoky flavors can use higher levels of methyl cyclopentenolone. A good starting point is 1,000 ppm.
Strawberry, Cooked: Very low, trace levels of methyl cyclopentenolone can provide an interesting diversion from the candy notes of maltol, ethyl maltol or furaneol but the chemical really come into its own in cooked strawberry flavors. With this profile, 300 ppm is a good level.