Food flavorings are essential food additives in the food industry. They form a category of their own among food additives, with over a thousand varieties. Food flavorings can be classified as follows:

(1) Natural flavorings. These are completely natural substances extracted from natural plants and animals (spices) through physical methods. Common sources from which natural flavor substances can be obtained include fruits, animal organs, leaves, tea, and seeds. The extraction methods include extraction, distillation, and concentration. Extraction can yield vanilla extract, cocoa extract, strawberry extract, etc.; distillation can produce peppermint oil, aniseed oil, cinnamon (osmanthus) oil, eucalyptus oil, etc.; rectification can obtain orange oil, lemon oil, citrus oil, etc.; and concentration can result in apple juice concentrate, mango concentrate, orange juice concentrate, etc. There are over 5,000 raw materials worldwide that can be used to extract food flavorings, with more than 1,500 commonly used.

(2) Nature-identical flavorings. These are chemical substances that are either obtained by chemically processing natural raw materials or artificially synthesized, and are completely identical to natural flavor substances.

(3) Artificial flavorings. These are substances obtained through chemical methods such as artificial synthesis, whose chemical molecules have not been confirmed to exist in nature. If the same chemical molecules are found to exist in nature, they are classified as nature-identical flavorings. As long as one raw material in the flavoring is artificially synthesized, it is classified as an artificial flavoring.

(4) Flavorings prepared by microbial methods. These are flavorings obtained through microbial fermentation or enzymatic reactions.

(5) Reaction flavorings. These are obtained by heating proteins and reducing sugars to undergo the Maillard reaction, and are commonly used in meat, chocolate, coffee, and malt flavors.

Classified by state, food flavorings include: liquid flavorings (water-soluble, oil-soluble, emulsifiable), in which flavor substances account for 10%-20% and solvents (water, propylene glycol, etc.) account for 80%-90%; emulsifiable flavorings, in which solvents, emulsifiers, gums, stabilizers, pigments, acids, antioxidants, etc., together account for 80%-90%; and powder flavorings, in which flavor substances account for 10%-20% and carriers account for 80%-90%.

Powder flavorings are developing rapidly and are widely used in beverages, snacks, baked goods, etc. There are three common types of powder flavorings:

(1) Blended powder flavorings: Obtained by mixing several powdery flavor substances, such as five-spice powder and curry powder. Most of these flavors come from natural plant spices and are used in formulating meat flavors; vanilla powder, vanillin, etc., are also blended powder flavorings.

(2) Adsorbed powder flavorings: Flavor components are adsorbed on the surface of carriers, and the composition of such flavorings must have low volatility. Various meat flavorings are mostly adsorbed powder flavorings.

(3) Encapsulated microcapsule powder flavorings: These are currently the most widely used powder flavorings in the food industry.

Microencapsulation of flavorings is a special method that functions to package, isolate, preserve, slowly release, and solidify liquid flavorings. Its main purpose is to maintain the original flavor of the flavorings for a longer period, while preserving the flavorings well and preventing them from deteriorating due to oxidation and other factors.

This effect endows microcapsule powder flavorings with special significance and wide practicality in applications in the food industry. Briefly as follows: Traditional solid beverage production mostly uses spray drying, vacuum drying, and fluidized bed drying. In the production process, liquid flavorings are used, which require heating to remove solvents, thus affecting the flavor of the products.

Solid beverage production mostly uses dry powder mixing. In the production process, various powder ingredients are directly mixed with microcapsule powder flavorings without heating, so the product flavor remains unchanged. Using microcapsule powder flavorings to flavor solid beverages is convenient to operate, easy to mix evenly, does not increase the temperature of the flavored products, keeps the products in their original powder state, and does not cause discoloration in white sugar-containing products.

Because flavor components are encapsulated in capsules, volatile loss is inhibited, thereby extending the flavor retention time. Flavor components are isolated from the surrounding space, preventing the possibility of flavor deterioration due to oxidation and other factors, thus greatly extending the product shelf life.

Using liquid flavorings for flavoring is inconvenient to operate, not easy to mix evenly, increases the water content of the flavored products, making them prone to caking. In white sugar-containing products, they will gradually turn yellow. Liquid flavorings can only be added to the surface, exposed to space, leading to rapid volatilization and short flavor retention time. Large areas of liquid flavorings come into contact with air, are easily oxidized, causing flavor deterioration and short shelf life.