88C-29 |
Determination of powder characteristics important for powder coating of foods |
N. P. RICKS and S. A. Barringer. Dept. of Food Science & Technology, The Ohio State Univ., 2015 Fyffe Ct., Columbus, OH 43210 Many snack foods and cereals are powder coated to add flavor. Most coating methods are inconsistent and waste seasoning. Electrostatic coating has been used in painting and snack companies to improve efficiency. Electrostatic painting produces little powder waste, reduces dust, and coats evenly. Electrostatic coating has been used on meat and snack foods but little data exists on which seasonings work best for electrostatic coating. The objective was to determine powder characteristics that result in higher coating efficiency, for electrostatic and non-electrostatic coating. Popcorn was oiled and coated in a tumble drum or on a conveyor belt using an electrostatic or non-electrostatic coater. Nine varieties of salt, salt and vinegar, cheese, barbecue, sugar, and sour cream and onion seasoning powders were applied electrostatically and non-electrostatically at three coating levels. Popcorn was analyzed for total powder content and transfer efficiency. Dust produced during coating was measured. Powder composition, size, angle of repose and induced charge to mass at 20.7 kV were determined for each powder. Analysis of variance was used to find significant differences between coating methods. When a tumble drum was used, composition and angle of repose had no effect on the transfer efficiency of the powder. Powders ranging from very free flowing salt to very cohesive cheese powders result in no significant difference in the final coating efficiency, despite differences in effective particle size due to clumping. On the conveyer belt, electrostatics increased transfer efficiency and was affected by composition as it affected the powder's ability to pick up a charge. Use of electrostatics significantly reduced the amount of dust produced in both systems, for powders that are dusty. Understanding when and to what extent powder properties effect transfer efficiency and dustiness will allow processors to optimize their coating systems.
Session 88C, Food Engineering: Physical and Chemical Properties
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