Inactivation activity and mechanism of pulsed light against Alicyclobacillus acidoterrestris vegetative cells and spores in concentrated apple juice.
Int J Food Microbiol
; 413: 110576, 2024 Mar 02.
Article
em En
| MEDLINE
| ID: mdl-38246025
ABSTRACT
Alicyclobacillus acidoterrestris has received much attention due to its unique thermo-acidophilic property and implication in the spoilage of pasteurized juices. The objective of this study was to evaluate the sterilization characteristics and mechanisms of pulsed light (PL) against A. acidoterrestris vegetative cells and spores in apple juice. The results indicated that bacteria cells in apple juice (8-20°Brix) can be completely inactivated within the fluence range of 20.25-47.25 J/cm2, which mainly depended on the soluble solids content (SSC) of juice, and the spores in apple juice (12°Brix) can be completely inactivated by PL with the fluence of 54.00 J/cm2. The PL treatment can significantly increase the leakage of reactive oxygen species (ROS) and proteins from cells and spores. Fluorescence studies of bacterial adenosine triphosphate (ATP) indicated that the loss of ATP was evident. Scanning electron microscopy and confocal laser scanning microscope presented that PL-treated cells or spores had serious morphological damage, which reduced the integrity of cell membrane and led to intracellular electrolyte leakage. In addition, there were no significant negative effects on total sugars, total acids, total phenols, pH value, SSC and soluble sugars, and organic acid content decreased slightly during the PL treatment. The contents of esters and acids in aroma components had a certain loss, while that of alcohols, aldehydes and ketones were increased. These results demonstrated that PL treatment can effectively inactivate the bacteria cells and spores in apple juice with little effect on its quality. This study provides an efficient method for the inactivation of A. acidoterrestris in fruit juice.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Malus
/
Alicyclobacillus
Idioma:
En
Revista:
Int J Food Microbiol
Assunto da revista:
CIENCIAS DA NUTRICAO
/
MICROBIOLOGIA
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
China