1. BY, R.KEERTHANA PRIYA, BTM 11008.

2. Coating in the food industry is the application of a layer of liquid and/or solids onto a product. The operation essentially relies on mechanical energy and physical principles. It consists mostly in setting the product particles in motion and simultaneously applying the coating ingredient in a certain pattern to expose one to the other. 3. The snack food industry includes everything from chips to confections ,from salty to sweet. Most of the success of snack food industry is due to the coating that are applied. 4. Adhesion is the tendency of certain dissimilar substance to cling together. For fried snacks ,seasonings are typically powder, no tack agent is needed for adhesion. The dry products are sprayed with oil, then the seasonings are applied and adheres to the oil. Other tack agents includes water ,sugar water and hydrocolloids, for these solutions drying is required. Exception-fried corn chips, they require secondary spraying. 5. Coating ingredients generally used are Salt Other Flavors 6. The most common snack food seasoning is salt, but even with other seasonings ,salt is added to accentuate the flavor. The snack food association recommends a salt level of 1.75% plus or minus 0.25% for salted potato chips. Cube , dendritic and grainer salt are used. 7. Cube saltDendritic saltGrainer salt 8. The most popular flavors for salty snacks are cheese, BBQ,sour cream and onion. Typical seasoning levels are 8-10%,depending on the seasoning and snacks base. The flavor base frequently combines cheese ,tomato, onion and garlic. Monosodium glutamate, yeast extracts, disodium inosinate and disodium guanylate can be added to accentuate savory , salty flavors. Botanical extracts Maltol Fillers Anticaking agent 9. Size , shape , taste ,adherence and flow ability of powder seasoning decides the quality of the coating. If the powder is cohesive or ambient humidity gets too high , spices clump, and uniformity in application suffers. Many flavor powders are highly hygroscopic and agglomerate easily, thus anti-caking agent is important to keep the powders free flowing. Small powders are more cohesive, thus more anticaking agent required. Larger powders are more unlikely distributed than small powders. 10. Conveyor belt Tumble drumCoating pans and Enrobing 11. Powder coating Liquid coating and Electrostatic coating 12. The seasoning are dispensed over the belt , one side of the snack only get coated, unless there is a device to flip the pieces over. In some foods such as potato chips, the chips are layered two or three layers deep, so that more seasonings lands on the top layers. One study found that adherence dropped from 60% on the top layers to 30% on the middle layer and 10% on the bottom layer. Thus, a conveyor belt system may not produce snacks that are as evenly coated as other methods, but requires much less space. 13. Even coating on both the sides. Thumble drums are horizontal cylinders with one side raised so that product flows from one end to the other. Flights are provided. Spray nozzles and dispensing tubes can be installed inside the drum, so that the snack may be sprayed with oil in one section , then coated with powder in other section. 14. THUMBLE DRUM 15. It is a slow batch process. Coating mainly with sugar or chocolate. There are three types of coating pans, they are 1. 2.3.The round or apple shape The doughnut shape Pear shaped 16. COATING PANS 17. Enrobers works by dipping, Pouring or spraying a liquid coating onto a core material. Over thickening of enrobing material is prevented or controlled by air knives, this is followed by shaker to remove further excess coating.Pre-bottomer for cooling. For smoother coating ,they are coated with hydrocolloidal solution i.e., when dried it gives glossy and smoothie flavourEg: Gumarabic 18. Enrobing 19. Powder coating is usually by three methods 1. Gravity feed 2. Pneumatically conveyed by forced air and 3. Centrifugally applied 20. Oil are aplied to the surface of the products,alongwith other flavors substance can also be added Usually 80% sugar solution are sprayed. It is mainly meant for its adhesion ability. Powder is suspended in the oil in the ratio of 80:20 21. The basic of electrostatic coating is that by charging the seasoning powder as it is dispensed,it is attracted to the product,which grounded through contact with the conveyor belt. It reduces the seasoning fall off ,eventual coating and reduce the oil content by 20%. Eg: Seasoning of corn and tortilla chips. 22. Give an attractive appearance. Define product shape. Improve taste. Increases the shelf life. Protect ingredients. Prevent migration of core constituents & Create texture or maintain structural integrity. 23. Hand book of food science ,Technology andEngineering-WH yuhi 169 chapter coating snack foods -Sheryl Barringer Deparment of food science and technology,The Ohio State University.