The fate of Bacillus cereus and Geobacillus stearothermophilus during alkalization of cocoa as affected by alkali concentration and use of pre-roasted nibs

Autor(es)

Pia, Arthur K. R. ^[1] ; Pereira, Ana P. M. ^[1] ; Costa, Ramon A. ^[1] ; Alvarenga, Veronica O. ^[1] ; Freire, Luisa ^[1] ; Carlin, Frederic ^[2] ; Sant'Ana, Anderson S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Fac Food Engn, Dept Food Sci, Campinas, SP - Brazil

^[2] INRA Avignon Univ, SQPOV, UMR408, F-84000 Avignon - France

• Tipo de documento: Artigo Científico
• Fonte: FOOD MICROBIOLOGY; v. 82, p. 99-106, SEP 2019.
• Citações Web of Science: 2

Resumo

Alkalization is a step of cocoa processing and consists of the use of alkali and high temperature to improve the sensorial and technological qualities of cocoa. Intense food processing can select spores, which can compromise safety and quality of the final product. Thus, the aim of this study was to evaluate the fate of B. cereus and G. stearothermophilus spores during the alkalization of pre-roasted (Pr) nibs (held at 120 degrees C) and unroasted (Ur) nibs (held at 90 degrees C) using potassium carbonate (0, 2, 4 and 6% w/w). In all conditions, log-linear inactivation kinetics with a tail was observed. The inactivation rate (k(max)) for B. cereus varied from 0.065 to 1.67 min(-1), whereas the k(max) for G. stearothermophilus varied from 0.012 to 0.063 min(-1). For both microorganisms, the lowest k(max) values were observed during Ur nibs alkalization. The carbonate concentration increase promoted k(max) values reduction. The highest tail values were observed for G. stearothermophilus in Ur nibs alkalization, reaching 3.04 log spores/g. Tail formation and low k(max) values indicated that cocoa alkalization does not cause significant reductions on bacterial spore population. Therefore, the microbiological control should be primarily ensured by the raw material quality and by avoiding recontamination in the cocoa chain. (AU)

• Processo FAPESP: 14/12313-6 - Impacto de diferentes operações unitárias do processamento do cacau sobre os micro-organismos esporulados
• Beneficiário: Henrique Antonio Stelari
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 16/21041-5 - Fungos e micotoxinas modificadas em uvas e vinhos: modelagem da variabilidade de formação, estabilidade ao longo do processamento e efeitos à saúde
• Beneficiário: Luisa Freire Colombo
• Modalidade de apoio: Bolsas no Brasil - Doutorado