INTRODUCTION
Definition
In chemistry, an alcohol is defined as an organic compound featuring a hydroxyl functional group (–OH) attached to a saturated carbon atom Initially, the term "alcohol" specifically referred to ethanol (ethyl alcohol), which is the main type of alcohol found in alcoholic beverages.
Figure 1.1: Chemical structure of alcohol [19]
In IUPAC chemical nomenclature, the suffix "-ol" signifies that the hydroxyl group is the highest priority functional group in a compound When a higher priority group is present, the prefix "hydroxyl-" is used instead Non-systematic names also often use the suffix "-ol" to indicate the presence of a hydroxyl group, categorizing these substances as alcohols However, certain compounds, particularly sugars like glucose and sucrose, contain hydroxyl groups without adopting the "-ol" suffix A notable category of alcohols is the saturated straight-chain alcohols, with methanol and ethanol as the simplest examples, which follow the general formula CnH2n+1OH.
Aging wine can enhance its quality, setting it apart from most other perishable goods Although wine can deteriorate, intricate chemical reactions among its sugars, acids, and phenolic compounds, like tannins, can transform its aroma, color, mouthfeel, and taste, potentially making it more enjoyable for the taster.
Before the French colonial invasion, Vietnam had a rich history of liquor production dating back to feudal times The Vietnamese recognized the significance of aging wine to reduce its toxicity Each region had its unique names for their local wines, with rice, sticky rice, corn, and cassava being the most common ingredients used in the brewing process.
The Ancient Greeks and Romans recognized the potential of aged wines, with early Greek "straw wines" noted for their high sugar content that allowed for long aging These wines were preserved in sealed earthenware amphorae for many years In Rome, wines like Falernian and Surrentin were especially valued for their remarkable aging capabilities, often lasting for decades.
Figure 1.2: The Ancient Greeks and Romans were aware of potential of aging [20]
By the 16th century, the production of sweeter and more alcoholic wines in the Mediterranean was on the rise, capturing attention for their aging potential In parallel, German Riesling showcased its remarkable aging capabilities, thanks to its unique balance of acidity and sugar.
In the 17th century, two significant innovations transformed the wine industry's approach to aging The introduction of the cork and bottle enabled producers to package and store wine in a nearly air-tight environment, enhancing preservation Additionally, the rising popularity of fortified wines like Port and Madeira further influenced the perception of wine aging, leading to new practices in the industry.
Sherries, fortified with added alcohol, served as a preservative that enabled wines to endure lengthy sea voyages to destinations such as England, the Americas, and the East Indies This preservation method significantly influenced the wine trade by increasing the demand for matured wines.
1.1.4 Safe alcohol and unsafe alcohol
Safe alcohol: The Concentration of poisons like Methanol, Aldehyde, Furfural… satisfy the Vietnamese’s standard about using alcohol and after drinking without dizzy, spinning, headache…
Unsafe alcohol: The Concentration of poisons like Methanol, Aldehyde, furfural… too high to compare with the Vietnamese’s standard about using alcohol and after drinking with dizzy, spinning, headache…
The role of Alcohol Treatment
Alcohol treatment methods have been studied and applied over the centuries for the purpose of protecting public health against harmful chemicals Some harmful chemicals in alcohol:
Methanol, unlike ethanol, is a toxic alcohol that the human body metabolizes into harmful substances like formaldehyde and formic acid, which can severely damage the brain, eyes, kidneys, and liver While pure methanol is not used in winemaking, it is sometimes incorporated for profit, posing serious health risks Additionally, aldehydes, which can result from alcohol metabolism, may lead to shock, disrupt circulation and digestion, and cause symptoms such as high blood pressure and headaches.
+ Furfural: Is a poison that can cause cancer, disabilities in the fetus [13]
Rice wine is one of the most popular alcohol drinking in Vietnam and here is the fermentation processes:
+ The first part of the distillation process is called alcohols consisting of a portion of ethanol and low molecular impurities such as methanol, aldehydes and low boiling esters [2]
+ Final alcohol containing furfural, esters and higher alcohols of 3C and above have a higher boiling point than ethanol [2]
About the harm, we glide through some of the most harmful toxins: Even alcohol containing pure ethanol alone is a dangerous poison to the human body,
Alcohol consumption can lead to varying levels of toxicity, with a blood alcohol concentration (BAC) of 0.1% causing mild effects, while levels between 0.2% and 0.4% result in severe toxicity A BAC exceeding 0.5% can be fatal, with a significant percentage of drinkers succumbing to acute poisoning Long-term alcohol use is associated with serious health issues, including inflammation, peptic ulcers, gastrointestinal hemorrhage, hepatitis, cirrhosis, and reproductive problems such as impotence in men and complications during pregnancy in women, including miscarriage and fetal abnormalities.
Some current methods for treating alcohol
For over a thousand years, Vietnam and the world have recognized that aging wine in oak barrels under optimal conditions—such as ideal temperature, humidity, and light—effectively reduces impurities and enhances flavor However, contemporary methods have emerged that also contribute to improving wine quality.
To effectively reduce methanol during the distillation process, it's crucial to understand that methanol is a volatile compound that evaporates at low temperatures As the wine pot heats up, impurities begin to evaporate around 60 degrees Celsius To minimize toxins, it's recommended to discard 5-10% of the initial distillate, as this portion contains a significantly higher concentration of harmful substances.
1000 times higher than the amount reached after reaching the stable temperature [5]
+ When used to remove aldehyde, people can use filtration through clean activated carbon Because this coal has the effect of absorbing toxins, when alcohol containing aldehyde is also filtered [6]
To minimize aldehyde levels in wine, one effective method is to utilize the low boiling point of aldehydes By heating the alcohol, significant quantities of aldehyde can evaporate, thereby decreasing its potential harm to the body Additionally, allowing the wine to soak and burying it underground for an extended period can further enhance this process.
Sonic Technology has enabled the development of machines in Vietnam and globally that address various challenges; however, certain drawbacks remain, such as the aldehyde index exceeding 5 mg/l in alcohol per 1000.
+ No methanol index of