title: Atmospheric cold plasma inactivation of aerobic microorganisms on blueberries and effects on quality attributes.
abstract: Cold plasma (CP) is a novel nonthermal technology, potentially useful in food processing settings. Berries were treated with atmospheric CP for 0, 15, 30, 45, 60, 90, or 120 s at a working distance of 7.5 cm with a mixture of 4 cubic feet/minute (cfm) of CP jet and 7 cfm of ambient air. Blueberries were sampled for total aerobic plate count (APC) and yeast/molds immediately after treatment and at 1, 2, and 7 days. Blueberries were also analyzed for compression firmness, surface color, and total anthocyanins immediately after each treatment. All treatments with CP significantly (P < 0.05) reduced APC after exposure, with reductions ranging from 0.8 to 1.6 log CFU/g and 1.5 to 2.0 log CFU/g compared to the control after 1 and 7 days, respectively. Treatments longer than 60s resulted in significant reductions in firmness, although it was demonstrated that collisions between the berries and the container contributed significantly to softening. A significant reduction in anthocyanins was observed after 90 s. The surface color measurements were significantly impacted after 120 s for the L* and a* values and 45 s for the b* values. CP can inactivate microorganisms on blueberries and could be optimized to improve the safety and quality of produce.
authors.affiliation: Food Safety and Intervention Technology Research Unit, United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Alison
authors.initials: A
authors.lastname: Lacombe
authors.affiliation: Food Safety and Intervention Technology Research Unit, United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA. Electronic address: Brendan.Niemira@ars.usda.gov.
authors.forename: Brendan A
authors.initials: BA
authors.lastname: Niemira
authors.affiliation: Food Safety and Intervention Technology Research Unit, United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Joshua B
authors.initials: JB
authors.lastname: Gurtler
authors.affiliation: Residue Chemistry and Predicative Microbiology Research Unit, United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Ln, Wyndmoor, PA 19038, USA.
authors.forename: Xuetong
authors.initials: X
authors.lastname: Fan
authors.affiliation: Food Safety and Intervention Technology Research Unit, United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Sites
authors.affiliation: Food Safety and Intervention Technology Research Unit, United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Glenn
authors.initials: G
authors.lastname: Boyd
authors.affiliation: Department of Food and Animal Sciences, University of Delaware, 20 Townsend Hall, Newark, DE 19716, USA.
authors.forename: Haiqiang
authors.initials: H
authors.lastname: Chen
mesh_terms: D029798:Blueberry Plants / Q000737:chemistry / Q000187:drug effects / Q000382:microbiology*; D005519:Food Preservation / Q000295:instrumentation / Q000379:methods*; D005638:Fruit / Q000737:chemistry / Q000382:microbiology; D005658:Fungi / Q000187:drug effects* / Q000254:growth & development; D058626:Plasma Gases / Q000494:pharmacology*; D011786:Quality Control
chemical_list: D058626:Plasma Gases
keywords: Blueberry; Cold plasma; Microflora; Quality; Sensory attributes; Storage