Wine grapes transforming into aroma molecules

Unlock the Secret to Wine Aroma: How Amino Acids Shape Your Favorite Glass

Mira Elwood in Science & Nature September 2025 • 4 min read.

"Dive into the fascinating world of wine and discover how varying amino acid profiles can dramatically alter the aroma of your favorite vintage."

Wine lovers know that each bottle offers a unique sensory experience. From the subtle hints of fruit to the deeper notes of earthiness, the aroma of wine is a complex tapestry woven from various compounds. What many don't realize is that the secret to a wine's distinctive scent might lie in its amino acid composition.

New research sheds light on the profound influence of amino acid profiles on the development of key aroma compounds known as polyfunctional mercaptans. These compounds, present in trace amounts, contribute significantly to a wine's varietal aroma, impacting notes of grapefruit, passion fruit, and even the savory scent of boxwood.

This article explores how different amino acid compositions, akin to those found in various grape varieties, affect the release and transformation of these crucial aroma precursors during fermentation. Understanding this intricate relationship could revolutionize winemaking, allowing for more precise control over the final aromatic profile.

Amino Acids: The Unsung Heroes of Wine Aroma

Wine grapes transforming into aroma molecules

The study, conducted by researchers at the Universidad de Zaragoza, investigated the impact of nine different amino acid profiles on the release of polyfunctional mercaptans. These profiles mimicked those of popular grape varieties, including Sauvignon Blanc, Chardonnay, and Cabernet Sauvignon. By fermenting synthetic musts (a grape juice substitute) with these varying amino acid compositions, scientists were able to isolate the effect of amino acids on aroma development.

Researchers introduced known amounts of polyfunctional mercaptan precursors into the synthetic musts. These precursors are odorless compounds that, during fermentation, are converted into the volatile thiols we perceive as aroma. The team then meticulously tracked the consumption of these precursors and the release of the target aroma compounds.

Significant Variations: The research revealed significant differences in the release of polyfunctional mercaptans based on the amino acid profile.
Precursor Preferences: The yeast strain used in the fermentation exhibited distinct preferences for certain aroma precursors depending on the amino acid environment.
Cysteine's Crucial Role: The study highlighted the importance of cysteine-linked precursors for the formation of 4-mercapto-4-methyl-2-pentanone (4MMP), a key aroma compound.

The results indicated that the amino acid profile not only affects the amount of polyfunctional mercaptans released but also influences which precursors are preferentially used by the yeast. This suggests that winemakers could potentially manipulate the aromatic profile of their wines by carefully managing the amino acid composition of their must.

Crafting the Perfect Bouquet: The Future of Wine Aroma Control

This research opens exciting new avenues for winemakers seeking to fine-tune the aromatic profiles of their wines. By understanding the interplay between amino acids, aroma precursors, and yeast metabolism, vintners can potentially influence the development of desired aroma compounds.

The study underscores the complexity of wine fermentation, highlighting the far-reaching impact of seemingly subtle variations in must composition. Manipulating the amino acid composition in grape juice could lead to a wine having the aromas wanted in its profile.

Future research could focus on identifying specific amino acid combinations that promote the formation of particular aroma compounds. Ultimately, this knowledge could empower winemakers to craft wines with greater precision and consistency, catering to evolving consumer preferences and achieving new levels of aromatic complexity.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.foodres.2017.07.081, Alternate LINK

Title: Study Of The Influence Of Varietal Amino Acid Profiles On The Polyfunctional Mercaptans Released From Their Precursors

Subject: Food Science

Journal: Food Research International

Publisher: Elsevier BV

Authors: Yohanna Alegre, Laura Culleré, Vicente Ferreira, Purificación Hernández-Orte

Published: 2017-10-01

Everything You Need To Know

What exactly are amino acids, and why are they important for wine aroma?

Amino acids are organic compounds that serve as the building blocks of proteins. In the context of wine, they are crucial because they influence the creation of aroma compounds. The amino acid profile, which is the specific composition of different amino acids present, can dramatically alter the aromatic profile of a wine, impacting the sensory experience of each sip.

Why are amino acid profiles important to understand when it comes to wine?

The significance lies in how they affect the development of key aroma compounds known as polyfunctional mercaptans. These compounds are responsible for the distinctive scents in wine, such as grapefruit or passion fruit. The research showed that the specific amino acid profile influences both the quantity and the type of polyfunctional mercaptans released during fermentation. The implications for winemaking are considerable, allowing for the potential to control and enhance the wine's aroma.

What are polyfunctional mercaptans and why do they matter in wine?

Polyfunctional mercaptans are a type of aroma compound present in trace amounts in wine. They are critical contributors to the varietal aroma, giving wines their characteristic scents of fruits like grapefruit and passion fruit, and even savory aromas like boxwood. The research indicates that the presence and concentration of these compounds are highly influenced by the amino acid profile.

How can amino acid profiles impact the aroma of wines?

The research focused on how different amino acid compositions, like those found in grape varieties such as Sauvignon Blanc, Chardonnay, and Cabernet Sauvignon, affect the release and transformation of aroma precursors. These precursors are odorless compounds that yeast converts into volatile thiols during fermentation. By manipulating the amino acid profile, winemakers can potentially influence which precursors are used and the resulting aroma compounds formed. This could lead to precise control over the final aromatic profile of a wine.

What role does cysteine play in the aroma of wine?

Cysteine plays a crucial role in the formation of 4-mercapto-4-methyl-2-pentanone (4MMP), a key aroma compound. The study highlighted the importance of cysteine-linked precursors for the formation of 4MMP. This means the presence of cysteine in the amino acid profile is directly linked to the production of a significant aroma compound, further emphasizing the importance of amino acids in shaping a wine's aromatic qualities. Understanding this can help winemakers manage and control specific aromatic notes.