## 2 Results and Discussion
### Ethanol Contents and Acidity  
The analysis of ethanol and total volatile acidity is crucial for assessing the quality and legal compliance of fermented beverages. Dates and their derivatives, such as date vinegar, exhibit variable acidity levels depending on production methods and the maturity of the fruit used. Compared with other fermented beverages, it emerges that production methods, regional specifications, and the management of additives play a significant role in determining the final acidity of the product. The samples underwent submerged fermentation, an aerobic fermentation process that uses a powerful aeration system to supply the system's oxygen requirement while suspending acetic acid bacteria in the acetifying culture [21]. Strong acetic acid bacteria cultures that can convert ethanol into acetic acid are necessary for this aerobic fermentation; successful fermentation also depends on the right temperature and oxygen availability. The amount of ethanol found in the alcoholic date derivative was 5.82%. The values recorded in our study are consistent with those reported for date palm matrices, where ethanol content typically ranges from 4.26% to 6.78% \(v/v\) after 96 h of fermentation [28]. Due to the fermentation process, vinegar samples have very low alcohol content; in fact, ethanol oxidizes to produce molecules of acetic acid. Residual ethanol and acidity are two main parameters evaluated to classify vinegar that has different definitions and characteristics depending on the specific country's regulation. FAO/WHO defines vinegar as \"...a food derived from a source rich in sugar and starch that underwent to a double fermentation alcoholic and acetous with an ethanol content less than 0.5% in wine vinegar and less than 1% in other vinegas....\" [29]. In the USA, there are no official standards of identity for labeling various types of vinegar, including cider, wine, malt, sugar, spirit, and blends; the only requirement from the FDA is that vinegar products have a minimum acidity of 4% to ensure retail strength. In China, vinegar has only recently been classified as natural fermented product or as artificial, i.e., acetic acid mixed with other ingredients; previously the term \"vinegar\" included both with a different set of acetic acid from 3.5% to > 6%. European countries follow regional standards for vinegar that is produced or marketed within their territories [30]. In contrast to other countries, the European Union has set specific limits for both acidity and ethanol content. The term 'Vinegar of X' broadly refers to products containing at least 5% (\(w/v\)) acidity and no more than 0.5% (\(v/v\)) ethanol. Wine vinegar, which must be derived exclusively from the acetous fermentation of wine, is required to have a minimum acidity of 6% (\(w/v\)) and may contain up to 1.5% (\(v/v\)) ethanol, in accordance with law [31]. In Europe, vinegar is mainly used as a sharp, sour flavoring or preservative. In contrast, in Asia and Africa, it is also consumed as a milder-tasting drink, with sweetened, low-acidity fruit vinegas especially popular in China and Southeast Asia. In Europe's  
Figure 4: The evolution of the date’s aroma throughout fermentation process to vinegar (see Table 1). wine-producing regions, clear distinctions exist between wine and vinegar, with well-established terminology. However, in Africa, some fermented beverages naturally acidify into alcoholic-acetous products, though they are difficult to classify. In Japan, black rice vinegar is often diluted with fruit juice and consumed as a health tonic. However, under EU and FAO/WHO definitions, many fruit vinegars do not qualify as true vinegar due to low acetic acid and residual ethanol. The ethanol level in the vinegar date samples, measured at 0.39% \(v/v\), is also within the acceptable limit (<0.5% \(v/v\)) defined for commercial vinegar in EU [25].