The Changes in Food Coating Characteristics during Coating a Powder Mixture and Salting Potato Chips Nonelectrostatically and Electrostatically

摘要

Changes in coating characteristics, when powder mixtures and extra fine NaCl were coated nonelectrostatically and electrostatically, were determined in this study. Mixtures contained powders of two different compositions or two different sizes of one composition, of common food ingredients such as salts, sugar, starch, proteins, and maltodextrin were coated at 0 and -25 kV on aluminum targets. The separation and dustiness after coating the mixtures were determined. Extra fine NaCl was also coated individually at 0-95 kV onto potato chips by different coating systems to investigate which system provides better transfer efficiency, more even distribution and lower amount of dust. When the mixtures were coated, separation occurred in most mixtures. In the mixtures containing the same size powders but different composition, differences in individual transfer efficiency of powders was the greatest cause of separation. Moreover, interactions between the powders during coating generally decreased the separation. In the mixtures of the powders containing the same composition but different size powders, the differences in individual transfer efficiency was also a cause of separation. Interactions between the powders generally increased the separation. In mixtures with salt either mixed with other powders or salt itself of a different size, the magnitude of separation was higher than other mixtures. Electrostatic coating decreased separation in the mixtures of non-salt powders when the same size but different composition powders were mixed. Being in a mixture generally had no effect on dustiness during either nonelectrostatic or electrostatic coating. For potato chip salting, there was no significant difference in the percent of NaCl on the chips when nonelectrostatic or electrostatic salting was performed by spray gun or scarf plate. During nonelectrostatic salting, the spray gun produced more dust than the scarf plate. However, when electrostatics (≥50 kV) was applied, the amount of dust produced by the spray gun decreased up to 88%. NaCl distribution across the bed of chips was more even when using the spray gun than the scarf plate. With the spray gun the evenness of the distribution decreased at high voltage (≥75 kV).