How to distinguish flavour quality

Flavour is a necessary ingredient in many products, such as perfume, body wash, shampoo and so on. For manufacturers who need to use flavors, how to distinguish the quality of flavors when choosing and purchasing flavors? Here are two simple ways to distinguish between good and bad flavors. 

High-quality Flavour from the appearance of transparent and bright, no turbidity, and those inferior Flavour at the bottom often have sediment, gently shake the liquid will be turbid liquid state. 

This is in the selection and purchase of flavors when the more common way to identify whether the Flavour is of high quality. The high-quality Flavour opens the lid fragrance will overflow, the fragrance level is clear, has the front in the back key, the general Flavour will have a main fragrance, and the high-quality Flavour stays fragrant for a long time, after the lid fragrance will also surround in the space; And inferior Flavour fragrance will have "mixed" phenomenon, that is, between the taste is not clear, there is no main fragrance, stay fragrance time is also short, fragrance in the air spread for a short time may disappear.