Alicyclobacillus spp. in fruit-based products: Isolation, identification, quantitative assessment (SPME/GC-MS) of spoilage compounds and spore's resistance to thermal shocks.

Autor: do Prado-Silva L; Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil., Godoy AT; Department of Analytical Chemistry, Institute of Chemistry, University of Campinas, 13083-970 Campinas, SP, Brazil., Câmara AA Jr; Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil., Oteiza JM; Centro de Investigación y Asistencia Técnica a la Industria Agroalimentaria (CIATI), Neuquén, Argentina., Brusa V; IGEVET - Instituto de Genética Veterinaria 'Ing. Fernando N. Dulout' (UNLP-CONICET LA PLATA), Facultad de Ciencias Veterinarias UNLP, Buenos Aires, Argentina., Maffei DF; Department of Food Science and Technology, 'Luiz de Queiroz' College of Agriculture, University of Sao Paulo, Piracicaba, Brazil; Food Research Center (FoRC-CEPID), Sao Paulo, Brazil., Eberlin MN; Mackenzie Presbyterian University, MackMass Laboratory, School of Engineering, 01302-907 São Paulo, SP, Brazil., Sant'Ana AS; Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Campinas, SP, Brazil. Electronic address: and@unicamp.br., Franco BDGM; Food Research Center (FoRC-CEPID), Sao Paulo, Brazil; Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
Jazyk: angličtina
Zdroj: International journal of food microbiology [Int J Food Microbiol] 2024 Jun 16; Vol. 418, pp. 110731. Date of Electronic Publication: 2024 May 03.
DOI: 10.1016/j.ijfoodmicro.2024.110731
Abstrakt: Alicyclobacillus spp. is the cause of great concern for the food industry due to their spores' resistance (thermal and chemical) and the spoilage potential of some species. Despite this, not all Alicyclobacillus strains can spoil fruit juices. Thus, this study aimed to identify Alicyclobacillus spp. strains isolated from fruit-based products produced in Argentina, Brazil, and Italy by DNA sequencing. All Alicyclobacillus isolates were tested for guaiacol production by the peroxidase method. Positive strains for guaiacol production were individually inoculated at concentration of 10 3  CFU/mL in 10 mL of orange (pH 3.90) and apple (pH 3.50) juices adjusted to 11°Brix, following incubation at 45 °C for at least 5 days to induce the production of the following spoilage compounds: Guaiacol, 2,6-dichlorophenol (2,6-DCP) and 2,6-dibromophenol (2,6-DBP). The techniques of micro-solid phase extraction by headspace (HS-SPME) and gas-chromatography with mass spectrometry (GC-MS) were used to identify and quantify the spoilage compounds. All GC-MS data was analyzed by principal component analysis (PCA). The effects of different thermal shock conditions on the recovery of Alicyclobacillus spores inoculated in orange and apple juice (11°Brix) were also tested. A total of 484 strains were isolated from 48 brands, and the species A. acidocaldarius and A. acidoterrestris were the most found among all samples analyzed. In some samples from Argentina, the species A. vulcanalis and A. mali were also identified. The incidence of these two main species of Alicyclobacillus in this study was mainly in products from pear (n = 108; 22.3 %), peach (n = 99; 20.5 %), apple (n = 86; 17.8 %), and tomato (n = 63; 13 %). The results indicated that from the total isolates from Argentina (n = 414), Brazil (n = 54) and Italy (n = 16) were able to produce guaiacol: 107 (25.8 %), 33 (61.1 %) and 13 (81.2 %) isolates from each country, respectively. The PCA score plot indicated that the Argentina and Brazil isolates correlate with higher production of guaiacol and 2,6-DCP/2,6-DBP, respectively. Heatmaps of cell survival after heat shock demonstrated that strains with different levels of guaiacol production present different resistances according to spoilage ability. None of the Alicyclobacillus isolates survived heat shocks at 120 °C for 3 min. This work provides insights into the incidence, spoilage potential, and thermal shock resistance of Alicyclobacillus strains isolated from fruit-based products.
Competing Interests: Declaration of competing interest The authors declare no conflicts of interest.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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