Please use this identifier to cite or link to this item: https://hdl.handle.net/10953/2219
Title: Impact of High-Hydrostatic Pressure Treatments Applied Singly or in Combination with Moderate Heat on the Microbial Load, Antimicrobial Resistance, and Bacterial Diversity of Guacamole
Authors: Javier Rodríguez López
Mª. José Grande
Rubén Pérez-Pulido
Antonio Galvez
Rosario Lucas
Abstract: Guacamole is an avocado sauce highly appreciated for its pleasant taste and nutritional value. The present study addressed the impact of high-hydrostatic pressure (HP) treatments on the product safety and bacterial diversity. Four HP treatments, 5 min each, were applied: (A) 450 megapascals (MPa) at 22 C; (B) 450 MPa at 50 C; (C) 600 MPa at 22 C; (D) 600 MPa at 50 C. Controls and treated samples were refrigerated stored for 50 days. The residual surviving fraction was lowest for the 600 MPa treatment at 50 C. Bacterial growth on media supplemented with antibiotics (cefotaxime and imipenem) or the biocide benzalkonium chloride was detected only from control samples but not from HP-treated samples. High throughput sequencing analysis indicated that the bacterial diversity of control samples was dominated by members of Fam. Enterobacteriaceae, but it changed to a lactic acid microbiota during storage. HP-treated samples showed reduced relative abundances of Enterobacteriaceae and lactic acid bacteria and higher abundances of Pantoea, Ralstonia and Methylobacterium. Results from the study indicate that HP treatments of guacamole at 50 C show higher microbial inactivation compared to 22 C. However, all treatments reduced the levels of Enterobacteriaceae and penem-tolerant bacteria and provided product stability against acidification by lactic acid bacteria.
Keywords: guacamole; antimicrobial resistance; high pressure processing; bacterial diversity
Issue Date: 16-Jun-2020
metadata.dc.description.sponsorship: This research was funded by MINECO, grant number AGL2016-77374-R. J.R.L. was beneficiary of a research grant from the University of Jaen’s Plan de Apoyo a la Investigación. The APC was funded by University of Jaen
Publisher: MDPI
Appears in Collections:DCS-Artículos

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