The Influence of Food Physical Properties on Transfer Efficiency and Adhesion in a Tumble Drum Process

The purpose of this study was to investigate the influence of the food properties moisture content, resistivity, surface oil content, and surface roughness on the adhesion and transfer efficiency of different food products.Food items were coated using a tumbling system equipped with electrostatic coating equipment (Spray Dynamics, St. Clair, MO). Surface oil content was determined by dipping each food item in previously weighed petri dishes containing petroleum ether and measuring the amount of weight gain after the petroleum ether evaporated. Moisture content was determined by drying each food sample in a vacuum oven for 24 hr. and calculating the amount of weight lost.Surface roughness was determined by scanning the surface of each food item using an optical profilometer. Resistivity was measured by applying voltage to a powder resistivity test cell (Electrostatics Solutions, Bassett, Southampton, Hampshire, U.K.) containing 5 cm3 of ground food item. The actual amount of current exiting the test cell was measured using an electrometer (Model 614, Keithley Instruments, Inc., Cleveland, OH) and theresistivity was determined by the following equation: ¿ = (KV)/I, where ¿= resistivity, K is the cell constant which is equal to 0.014, V= the voltage applied to the test cell, and I = the current exiting the test cell. Three maltodextrin powders, four salt powders, and one sucrose powder was used to coat the food items.Transfer efficiency increased with increasing surface oil content for both nonelectrostatic and electrostatic coating. The higher the surface oil content of the food being coated, the more efficient the coating will be. Transfer efficiency also increased with decreasing moisture content for both nonelectrostatic and electrostatic coating. Highmoisture present in the food made the target more conductive, resulting in the loss of the electrostatic image charge faster. As a result, lower transfer efficiency was achieved. At high surface roughness values, transfer efficiency of the food powders to the food targets was high and fairly constant but at low surface roughness the transfer efficiency values varied. No trend was established for food resistivity value with transfer efficiency forboth nonelectrostatic and electrostatic coating. Carbohydrates (maltodextrin and powdered sugar) were shown to produce higher transfer efficiency values than salt.Moisture content, resistivity value, surface oil content, and surface roughness had no influence on the adhesion of the food products coated nonelectrostatically and electrostatically.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Food Science and Nutrition

Grantor dc:publisher

The Ohio State University

Year dc:date

2006

Author dc:creator

• Johnson, Deirdra Renee

Contributors dc:contributor

• Barringer, Sheryl

• Food Science
• Nutrition

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=osu1364294317

OAI identifier oai:identifier

oai:etd.ohiolink.edu:osu1364294317