The effect of watering frequency on the welfare quality of dairy cow

Abstract

Wine aroma is an important index for wine quality evaluation. There are also many flavor substances, including esters, alcohols, acids, aldehydes, ketones, glycerin, sugars, amino acids, organic acids, phenolic compounds, and so on. They play important roles in wine sensory quality and flavor, characteristics such as acidity, color, bitter taste, convergence, clarifying degree, and so on. The existence of complex aroma compounds in wines, together with their concentration, their proportion, and the balance among them, leads to unique styles and characteristics of wines. In these compounds, each kind of aroma compound contributes to the wine flavor at a different grade, and additive effects, synergistic interaction, and separation and inhibition effects among them endow wine with complex and unique flavors. In this chapter, the types, extraction, isolation, and identification of flavor compounds in wine are introduced. Regarding beer, as a kind of food, flavor is a significant attribute. Beer flavor is studied to figure out consumption tendency and launch products catering to consumers' demands and desires. In the meantime, because of the complex mechanism of the fermentation process, flavor is used as an indicator to monitor beer fermentation and ensure the stability and quality of products. Among the various flavor components that exist in beer, more than 600 kinds are known and the thresholds of over 200 kinds have been determined. Furthermore, new flavor compounds will be generated during processing and subsequent storing, which have impacts on beer flavor. To some extent, the beer brewing process is the process of the synthesis, decomposition, and transformation of these flavor compounds. From the perspective of flavor, the properties, sources, and metabolic processes of alcohols, esters, carbonyl compounds, sulfides, diketones, and acids are introduced in this section.