Inactivation of Alicyclobacillus acidoterrestris vegetative cells and spores induced by atmospheric cold plasma

Abstract

This study aimed to inactivate Alicyclobacillus acidoterrestris vegetative cells and spores (107–108 CFU/mL) using atmospheric cold plasma (ACP). Alicyclobacillus acidoterrestris vegetative cells decreased by 6.63 and 6.47 log under only ACP treatment of 30 kV for 6 min in saline solution and apple juice, respectively. ACP was less effective against spores, resulting in 2.64 and 2.43 log reductions at the same treatment parameter. However, better inactivation (4.03 log and 3.95 log) was achieved in apple juice and saline solution using ACP at 30 kV combined with mild heat (85 °C) for 6 min. Morphological observation and intracellular substance release revealed severe structural damage to spores induced by ACP. The application of ACP resulted in improved color, reduced pH, and increased levels of total phenolic content and total soluble solids in apple juice. This study offers an effective method for inactivating Alicyclobacillus acidoterrestris in apple juice. Industrial relevanceThe application of atmospheric cold plasma in combination with mild heat to effectively inactivate Alicyclobacillus acidoterrestris in apple juice offers a promising method for ensuring juice product quality. The enhancement of color, reduction in pH, and increase in total phenolic content and total soluble solids further underscore the potential benefits of this technique for enhancing the sensory attributes of apple juice. This study offers a potential approach that may directly contribute to enhancing production practices and product value.