Instead of going to bed I decided to ask ChatGPT, here's what it said to the question "what chemical reactions happen in tobacco leaf fermentation":
- Hydrolysis: The breakdown of complex organic compounds into simpler ones by adding water molecules. During fermentation, hydrolysis of the tobacco leaves results in the breakdown of starches and other complex carbohydrates into simple sugars.
- Oxidation: The process by which oxygen molecules are added to organic compounds. In tobacco fermentation, oxidation occurs due to the exposure of tobacco leaves to air. This process results in the development of the characteristic aroma and flavor of tobacco.
- Reduction: The process by which electrons are added to organic compounds. Reduction occurs during fermentation when bacteria and other microorganisms consume oxygen and produce carbon dioxide and other byproducts.
- Esterification: The reaction between an alcohol and a carboxylic acid to produce an ester. During tobacco fermentation, esterification occurs as a result of the interaction between alcohols and carboxylic acids present in the tobacco leaves.
- Pyrolysis: The breakdown of organic compounds by heat. During tobacco fermentation, pyrolysis occurs due to the high temperatures generated by the bacterial activity, which results in the breakdown of organic compounds and the release of volatile compounds responsible for the characteristic aroma and flavor of tobacco.
And this is what it said about chemical reactions occurring in wine aging:
- Oxidation: Oxygen reacts with various organic compounds in wine, such as ethanol and phenolic compounds, resulting in the development of new aroma and flavor compounds. Controlled levels of oxidation are important to the aging process and can be influenced by factors such as oxygen permeability of the wine bottle closure and the storage temperature.
- Reduction: The opposite of oxidation, reduction is the removal of oxygen atoms from organic compounds. This process can contribute to the development of desirable aroma and flavor compounds, such as those associated with aging in oak barrels.
- Hydrolysis: The breakdown of chemical compounds in the presence of water. During wine aging, hydrolysis of the glycosides that are present in grape juice or wine can release aroma and flavor compounds, including terpenes and other aromatic compounds.
- Esterification: The reaction between an alcohol and a carboxylic acid to produce an ester. During wine aging, esterification occurs as a result of the interaction between alcohols and acids present in the wine, producing compounds such as ethyl acetate and isoamyl acetate.
- Polymerization: The combination of small molecules into larger ones. During wine aging, tannins can undergo polymerization, resulting in the development of a smoother texture and more complex aroma and flavor profiles.
- Maillard reaction: The reaction between amino acids and reducing sugars, which can lead to the development of brown color and flavor compounds. This reaction is more common in fortified wines, such as sherry, where it contributes to the development of nutty and caramelized flavors.
And this is what it said about pipe tobacco aging:
When pipe tobacco ages, a variety of chemical and physical changes occur that can alter its aroma, flavor, and smoking characteristics. The aging process can also help to reduce harshness and bitterness in the tobacco, resulting in a smoother smoking experience. Some of the key changes that occur during pipe tobacco aging include:
- Oxidation: Over time, the organic compounds in the tobacco are exposed to oxygen, which can lead to the development of new flavor and aroma compounds. Controlled levels of oxidation can help to enhance the tobacco's flavor, while excessive oxidation can cause the tobacco to become stale.
- Fermentation: Like tobacco used for cigars, pipe tobacco is often fermented during the aging process. This process helps to break down complex organic compounds and create new flavor and aroma compounds. Controlled levels of fermentation can help to enhance the tobacco's flavor and aroma, while excessive fermentation can lead to the development of off-flavors.
- Maillard reaction: This is a chemical reaction between amino acids and reducing sugars, which can create new flavor and aroma compounds. This reaction is more common in darker, sweeter tobacco blends and can lead to the development of notes of caramel, chocolate, or coffee.
- Evaporation: Over time, some of the volatile compounds in the tobacco can evaporate, which can lead to a more concentrated flavor and aroma. However, excessive evaporation can cause the tobacco to become dry and harsh.
- Polymerization: The combination of small molecules into larger ones. During aging, tobacco leaves can undergo polymerization, resulting in a smoother smoking experience and more complex flavor and aroma profiles.
Overall, the aging process for pipe tobacco is influenced by a range of factors, including the type of tobacco used, the storage conditions, and the length of time the tobacco is aged. By taking care to properly store and age their pipe tobacco, smokers can enhance its flavor and aroma and enjoy a smoother smoking experience.
What I bolded are the mentions of the Maillard reaction, a term very well-known to foodies and beloved the world over by its impact on fried/grilled food!