The objective of this study was to investigate the effect of dielectric-barrier discharges plasma (DBDP) treatment against Escherichia coli O157:H7 and Staphylococcus aureus in different types of food matrix. Dried julienned squid (DS), squid powder (SP), beef jerky (BJ), and beef powder (BP) were inoculated with E. coli O157:H7 or S. aureus and treated with DBDP. The treatment voltage varied at 6.11, 9.25, and 11.86 kV. Treatment time at each voltage was controlled at 5, 10, 15, and 20 min. The most significant inhibition for E. coli O157:H7 and S. aureus was observed in SP, followed by BP, DS, and BJ. The highest log reduction (2.67 log CFU/g) and injury (47.95%) were observed for E. coli O157:H7 in SP at 11.86 kV for 15 min. Overall, DBDP treatment was more effective in inactivating pathogens in powder type than in the solid type, regardless of pathogens. The DBDP treatment more effectively inactivated E. coli O157:H7 than S. aureus. Most E. coli O157:H7 and S. aureus cells died with 20 min treatment. These results suggest that DBDP treatment is more effective against a gram-negative pathogen in powder types of food such as spices and seasoning powder.