Evaluation of electrostatic powder coating method to prolong the shelf life of cheese slices

Electrostatic coating is being developed as an attractive alternative to overcome the problems encountered during conventional coating which includes non-uniform coating, dust generation, high energy and time consuming, equipment cleaning, and operating expenses. In this method, powder particles are charged by passing through an ion-rich region, which repel each other to produce an evenly distributed coating. This results in a uniform distribution of powder on target surface. In this study, the electrostatic coating of black pepper powder was applied by varying the applied voltage (0-20 kV), at a conveyor belt speed of 10 m/s and compared with manually coated cheese slices. The values of transfer efficiency (52.7%-87.0%), dust reduction (76.2%-85.8%), and adhesion (20.8%-85.3%) were higher for electrostatic coatings. The weight losses were lower (0.19%) at 15 kV as compared to 20 kV (0.67%). The total plate count of cheese slice coated at 20 kV was significantly higher (p < 0.05), whereas at 15 kV it was lower than all other treatments. The shelf life of coated cheese slices at 15 kV lasted up to 1 month due to better coating compared to other treatments. From the results, it can be concluded that electrostatic coating of cheese slice with black pepper is best at 15 kV along with higher transfer efficiency and dust reduction. PRACTICAL APPLICATION: Electrostatic powder coating of cheese resulted in higher transfer efficiency and reduction in dust production. later one has reduce the coating material requirement, thereby, reducing the processing cost. Moreover, dust reduction will reduce the burden of cleaning cost of environment and enhance worker health.