Effects of Organic Acid Vapors on Salmonella Inactivation and Quality Characteristics of Blueberries

Abstract

The aim of this study was to control Salmonella Newport contamination in blueberries using organic acid vapors while monitoring changes in the quality of the blueberries. Blueberries inoculated with S. Newport were subjected to organic acid vapors for 4 h at either 12 °C or 25 °C (with 85% relative humidity). Within just 1 h, the population of S. Newport on blueberries exposed to formic acid vapor at 12 °C dropped below the detection limit (1.70 log cfu/sample). Irrespective of the type of organic acid used, the S. Newport population on blueberries decreased to below the detection limit within 30 min at 25 °C. Furthermore, S. Newport was not detected when blueberries were treated with formic acid vapor for 2 h at 12 °C and for 30 min at 25 °C. Upon storage of blueberries at 25 °C, mold growth appeared on their surface after 2 days. However, blueberries treated with acetic acid, formic acid, or propionic acid vapor showed no signs of mold growth for up to 7 days of storage. The hardness of blueberries decreased after 2 h of treatment with propionic acid or formic acid vapor at 25 °C. Blueberries were treated with organic acid vapors for 30 min at 25 °C and then stored at 4 ± 2 °C for 24 h. Sensory evaluation afterward showed no differences in color, odor, or texture compared to untreated blueberries. In summary, S. Newport contamination of blueberries was effectively controlled by organic acid vapors at 25 °C for 30 min, with no critical changes observed in the quality of the blueberries.