The Chemistry of Grape

The chemistry of
Written By Fulvio Ciccolo

Grape

The Chemistry of Grape

Grapes (or Vinis Vinifera if we are referring to the generic and most common Genus) although not widely DIFFUSE in the context of perfumery, present one of the most interesting, complex, and kaleidoscopic facets to the point of becoming a conflicting addition to each perfume to which its added. However, even if its peculiar aromatic flexibility may appear as a flaw, in the sapient hands of a master perfumer grapes may well become a formidable asset for selected fragrances, thus making grapes a proper underdog of perfumery.

Grapes: A Brief History

The first reported use of grapes in perfumery dates back to the Egyptian civilization, during which perfumes could be differentiated into two distinct categories: oily vegetable and animal-derived perfumes, and physical, pastille-like concoctions. While the former was mainly used in curative and funeral ceremonies, the latter was burned as a tribute to their deities; said tribute was known as fumum. One of the most renowned pastille-like fragrances was Kyphi, a peculiar mix of around 16 -if not more- ingredients: enumerated honey, myrrh, wine, cyperus longus, and mashed grapes.

Another civilization that adopted grapes in their fragrances was the Romans who, thanks to the territorial extension of their empire, had access to numerous raw materials imported from their dominations. Rose, pomegranate, quince, rosemary, basil, lavender, and grapes were only a few of the raw materials that the Romans employed in/for their bitter almond oil and olive oil-based perfumes. Later, the aforementioned bases were substituted by olive oil and by the green, unripe grape juice.

Components and Formulations

It is not easy to identify the various components that define the peculiarly phenolic, sweet, sharp, sulphuric, and occasionally pungent aspects of grapes. More than 2,000 volatile compounds, ranging from esters, alcohols, aldehydes, ketones, and volatile terpenes have been identified in grapes. Albeit the above-mentioned elements have been identified as the principal responsible for their characteristic odor and aroma, many more elements may vary according to the Genus, ripening stage, soil, and geographical origin, actively altering their perception. It is then relevant to specify that everything listed and discussed in the following article will directly refer, unless previously specified, to the description and composition of the generic grape aroma/perfume.

Esters:

  • Methyl Anthranilate

Aldehydes:

  • Hexanal

Terpenes:

  • β-myrcene

Alcohols:

  • Cis-3-hexen-1-ol

Ketones:

  • Alpha-Ionone

Description and Function

Methyl Anthranilate, also known as Methyl 2-aminobenzoate, represents the quintessential molecule used to recreate the typical grape-like scent. The clear to pale yellow liquid, which appears to be partially soluble in water and completely soluble in ethanol and propylene glycol, acquires different nuances dependently on its grade of dilution, presenting a fruity, grape smell at full concentration; while developing a sweet, fruity, concord grape-like smell with a musty and berry nuance at 25 ppm. This molecule can be used both in perfumery to impart a strong, sweet grape-like accord to a fragrance, or as a flavor additive employed in vintage American beverages or candies such as NuGrape and Jolly Ranchers. It is also not uncommon to detect a familiar orange-like odor, that might be reminiscent of Neroli, considering that Methyl Anthranilate is one of the most important constituents of said oil. In the twentieth century, the presence of the molecule was also observed in other natural essences like jasmine, gardenia, bergamot, and ylang-ylang. If you’d like to expand your knowledge concerning this molecule feel free to click on our article dedicated to Methyl Anthranilate.

Cis-3-hexen-1-ol, also known as “leaf oil” due to its characteristic olfactory properties, is an alcohol whose natural presence has been ascertained in a plethora of both plants and leaves. Its peculiar nickname originated from its potent green, and grass-like odour, also being reminiscent of freshly cut grass. Cis-3-hexen-1-ol presence has been detected in many fruits and vegetables such as grapes, kiwis, corn, tea, and tomatoes, and it has also been confirmed as the primary contributor to the aroma of freshly cut pumpkins. Although said molecule can easily be found in nature, the manufacture of Cis-3-hexen-1-ol appears to be more cost-efficient than the extraction process from natural sources. The odor is often associated with grapevines.

As per the already discussed Cis-3-hexen-1-ol, hexanal possesses a freshly cut grass odor, thus fulfilling a similar role to the previously mentioned molecule. Additionally, Hexanal has been found responsible for an atypical hay-like note present in green peas, and it is also used in the flavor industry as a fruit flavoring.

β-myrcene is a terpene, specifically a monoterpene, which may vary from a colorless aspect to a pale, straw-colored liquid depending on its exposure to light. β-myrcene contributes to the odor with its peculiar sweet, balsamic, and resinous facets that, although significant in intensity, HOLDS little tenacity; while, if purified, myrcene acquires refreshing, citrusy-like, ethereal-sweet, and warm-balsamic aspects. If you might find yourself interested in this molecule, here you can find the link for our β-myrcene profile.

Alpha-ionone is a widely renowned ketone for its characteristic violet-like scent. The molecule can be naturally produced in plants such as Chromoleana Odorata, and Swertia Japonica and has also been detected in grapes, sour cherries, common wheats, garden tomatoes, wakame, corn, tea, carrots, and many more. Alpha-ionone can impart a warm, woody, balsamic, and floral aroma while also imparting a deeply sweet and moderately tenacious facet to the fragrance. For a more in-depth look regarding the use, history, extraction method, description, and application of the molecule in perfumery feel free to click on the following link to our deep-dive article concerning Alpha-Ionone.

A variety of other molecules among which we can find linalool, geraniol, nerol, benzaldehyde, and many others can be used to balance or modify the fragrance, fashioning it according to the taste of the master perfumer.

Formulation

When it comes to the generic formulation of grapes, in addition to what has been already said, we from Scentspiracy are going to propose two formulae. The first is a vintage approach illustrated by Professor Giovanni Fenaroli in his Aromatizzazione (1969) in which he offers what may result as a satisfactory basis to be later adapted, to his or her necessities, by the perfumer.

  • Methyl Anthranilate

  • Ethyl Capronate

  • Benzyl propionate

  • Benzyldenacetone / DiMethyl anthranilate

  • Ethyl acetate

  • Ethyl Anthranilate

  • Methyl naphthyl ketone

  • Rhum ether

  • Cinnamic Alcohol

  • Aldehyde c16 and c14

  • Ethyl oenanthate

  • Ionone alpha

  • Terpeneless lemon oil

  • Terpeneless lime

While the second formulation represents a more modern take by Louis Appel (Cosmetic. Fragrances and Flavors. Louis Appel. 1982. Novox. Inc. Da. 340)

  • 4% Ethyl Acetate

  • 4% Ethyl propionate

  • 8% Ethyl Butyrate

  • 2% isoamyl valerate

  • 0,5% butyric acid (dilution at 10%)

  • 3% Orange oil

  • 1,5% Ethyl Oenanthate (Ethyl Heptanoate)

  • 2% Lemon Oil

  • 4,5% Benzyl Propionate

  • 1% Citral

  • 34% Methyl Anthranilate

  • 3% Ethyl Cinnamate

  • 0,3% Aldehyde c16

  • 3,5% Beta Methyl Naphtyl Ketone

  • 0,7% Aldehyde c14

  • 28% Propylene glycol

 

Sources:

Fulvio Ciccolo
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