resumo
This study tested hyperbaric storage (25-150 MPa, for 30 days) at room-temperature (HS/RT, 18-23 degrees C) in order to control the development of Byssochlamys nivea ascospores in apple juice. In order to mimic commercially pasteurized juice contaminated with ascospores, thermal pasteurization (70 and 80 degrees C for 30 s) and nonthermal high pressure pasteurization (600 MPa for 3 min at 17 degrees C, HPP) took place, and the juice was afterwards placed under HS/RT conditions. Control samples were also placed in atmospheric pressure (AP) conditions at RT and were refrigerated (4 degrees C). The results showed that HS/RT, in samples without a pasteurization step and those pasteurized at 70 degrees C/30 s, was able to inhibit ascospore development, contrarily to samples at AP/RT and refrigeration. HS/RT for samples pasteurized at 80 degrees C/30 s evidenced ascospore inactivation, especially at 150 MPa, wherein an overall reduction of at least 4.73 log units of ascospores was observed to below detection limits (1.00 Log CFU/mL); meanwhile, for HPP samples, especially at 75 and 150 MPa, an overall reduction of 3 log units (to below quantification limits, 2.00 Log CFU/mL) was observed. Phase-contrast microscopy revealed that the ascospores do not complete the germination process under HS/RT, hence avoiding hyphae formation, which is important for food safety since mycotoxin development occurs only after hyphae formation. These findings suggest that HS/RT is a safe food preservation methodology, as it prevents ascospore development and inactivates them following commercial-like thermal or nonthermal HPP pasteurization, preventing mycotoxin production and enhancing ascospore inactivation.
palavras-chave
GERMINATION; ACTIVATION; FUNGI; JUICE; TIME
categoria
Food Science & Technology
autores
Pinto, CA; Galante, D; Espinoza-Suarez, E; Gaspar, VM; Mano, JF; Barba, FJ; Saraiva, JA
nossos autores
agradecimentos
This work received financial support from PT national funds (FCT/MCTES, Fundacao para a Ciencia e Tecnologia and Ministerio da Ciencia, Tecnologia e Ensino Superior) through the projects UIDB/50006/2020 and UIDP/50006/2020.