Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Food Microbiol ; 25(5): 714-21, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18541171

RESUMEN

The growth kinetic parameters of germinated cells from heat-activated spores of the psychrotrophic Bacillus cereus EPSO-35AS strain in nutrient broth (NB) and in tyndallized carrot broth (TCB) were evaluated at different temperatures (8, 12, and 16 degrees C) for control samples and for samples acidified with citric acid or lemon juice at pH values between 4.7 and 5.5. Lowering the pH from 7.4 or 6.2 to 5.2 inhibited bacterial growth in both tested media after 60 days at 12 degrees C and lower temperatures, confirming the effectiveness of acidification in association with refrigeration to control B. cereus proliferation in minimally processed foods (MPFs) based on carrot. The activities of selected concentrations of cinnamon essential oil, cinnamaldehyde, carvacrol, and eugenol against B. cereus EPSO-35AS and INRA TZ415 strains in both media over the same temperature range were also studied. Addition of either cinnamon essential oil or cinnamaldehyde at concentrations of 5 and 2 microL 100mL(-1), respectively, caused complete inhibition of the growth of both psychrotrophic strains even if mild temperature abuse occurred (12 degrees C). Hence, a combination of one of these compounds and refrigerated storage may be useful for preservation of MPFs in which major ingredient was carrot. On the contrary, carvacrol and eugenol were not able to prevent B. cereus growth in TCB during storage at 8 degrees C. Their effects on the organoleptic characteristics of TCB are discussed.


Asunto(s)
Bacillus cereus/efectos de los fármacos , Daucus carota/microbiología , Manipulación de Alimentos/métodos , Conservación de Alimentos/métodos , Concentración de Iones de Hidrógeno , Esporas Bacterianas/crecimiento & desarrollo , Acroleína/análogos & derivados , Bacillus cereus/fisiología , Seguridad de Productos para el Consumidor , Sinergismo Farmacológico , Germinación , Humanos , Cinética , Aceites Volátiles/farmacología , Refrigeración , Temperatura , Factores de Tiempo
2.
Food Microbiol ; 24(7-8): 671-7, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17613363

RESUMEN

Incidence and population levels of Bacillus cereus in American salad, an industrially manufactured, packaged and refrigerated deli salad containing vegetables and mustard, were determined. Of 12 ready-to-eat samples examined, one (8.3%) was positive for B. cereus at less than 5 x 10(3)cfu g(-1). According to the ISO confirmation procedure, a strain was isolated and further characterized and identified as B. cereus EPSO-35AS by API 50CH/20E phenotypic system, combined with additional tests of motility, oxidase activity and anaerobic growth. This strain produced diarrhoeal enterotoxin in tryptic soy broth culture as detected by BCET-RPLA test, hydrolysed starch and had a low D(90)-value (2.1 min), with an estimated z-value of 6.79 degrees C. After a lengthy lag phase (9-12 days of incubation), the strain was able to grow at 8 degrees C in both nutrient broth and tyndallized carrot broth with specific growth rates from 0.009 to 0.037 h(-1), respectively. In the vegetable substrate, lag time was approximately 3 days (66 h) shorter than in laboratory medium. The effect of temperature abuses on the safety of the product during the time of use or consumption is discussed.


Asunto(s)
Bacillus cereus/aislamiento & purificación , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Verduras/microbiología , Bacillus cereus/clasificación , Bacillus cereus/metabolismo , Técnicas de Tipificación Bacteriana , Recuento de Colonia Microbiana , Seguridad de Productos para el Consumidor , Enterotoxinas/biosíntesis , Manipulación de Alimentos/métodos , Humanos , Cinética , Temperatura , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...