© 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.A new device that can generate cold plasma using air or helium at atmospheric pressure was designed. The whole sea bass was treated with atmospheric pressure air-plasma or atmospheric pressure helium-plasma (He-plasma) for 0.5, 1, 3, 5, 7, and 10 min. Immediate and potential residual effects of plasma treatments on sensory acceptability and quality were evaluated. The immediate effects were studied to reveal the effect of treatment on the freshness properties. The residual effects of cold plasma after 5 days of cold storage were examined to determine the changes during marketing. Sensory scores were above 7 (good) immediately after 0.5–7 min of air- or He-plasma treatments and did not change consumer purchase intention. The samples treated for 10 min scored lower and were found less preferable to purchase than the others. Sensory tests showed that the samples treated for 10 min were harder and dryer. The air-plasma treatment, especially for 7 and 10 min, significantly reduced mesophilic aerobic bacterial counts immediately after treatment. On the other hand, the increase in psychrophilic bacteria growth was better suppressed in He-plasma-treated samples after 5 days of storage, indicating He-plasma may be beneficial for delaying psychrophilic aerobic bacteria growth during cold storage. Generally, higher total color changes (ΔE) were detected when He-plasma was applied or treatment times increased. The thiobarbituric acid reactive substance (TBARS) values did not exceed the acceptable limits. The findings show the promising potential of cold plasma in the fresh fish industry.