RESUMO
ABSTRACT: Experiments were performed to assess the survival of Salmonella on whole Brazil nut kernels and pumpkin seeds stored at 8, 23, and 37°C. Brazil nut kernels and pumpkin seeds were inoculated with bacterial inoculum containing 10.4 log CFU/mL Salmonella Enteritidis phage type 30 and aseptically dried at room temperature for 24 h. After the drying step, levels of Salmonella recovered from Brazil nut kernels and pumpkin seeds were 8.67 ± 0.01 and 9.27 ± 0.03 log CFU/g, respectively. The survival of Salmonella and change in water activity was assessed over 413 days. Although Salmonella survived throughout the storage period, significant differences were recorded between the storage temperatures. Results showed that the survival of Salmonella Enteritidis phage type 30 was more enhanced at 8°C compared with storage at 23 and 37°C. Comparing the survival of Salmonella on the two products at different storage temperatures, there was no significant difference between the means of Salmonella counts for the two products. Results show that Salmonella survived longer on pumpkin seeds stored at 8°C (P = 0.53, compared with Brazil nut kernels), and at 23 and 37°C, Salmonella survived longer on Brazil nut kernels (P = 0.12, compared with pumpkin seeds). The highest and lowest survival of Salmonella was observed on pumpkin seeds with decay rates of -0.003 ± 0.001 and -0.015 ± 0.001 log CFU/g/day for pumpkin seeds stored at 8 and 37°C, respectively. The water activity values recorded on days 2 and 413 for Brazil nut kernels stored at 8, 23, and 37°C were 0.424 and 0.434, 0.383 and 0.385, and 0.372 and 0.256, respectively. For pumpkin seeds stored at 8, 23, and 37°C, water activity values recorded on days 2 and 413 were 0.754 and 0.412, 0.627 and 0.350, and 0.787 and 0.205, respectively. The data obtained in this study provide useful insight on the influence of temperature on the survival of Salmonella on the surface of Brazil nut kernels and pumpkin seeds.
Assuntos
Bacteriófagos , Bertholletia , Cucurbita , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Salmonella enteritidis , TemperaturaRESUMO
A total of thirteen genera of bacteria and two genera of yeasts were detected in surface sterilized and unsterilized Brazilian commodities and spices such as cashew kernels, Brazil nut kernels, black and white pepper. The genus Bacillus with eight species was by far the most common. The yeasts isolated were Pichia sp., P. guillermondii and Rhodotorula sp. Bacillus cereus, Salmonella typhimurium and Staphylococcus aureus were detected in cashew and Brazil nut kernels.
Um total de 13 gêneros de bactérias e 2 de leveduras foi detectado a partir de amêndoas de castanha de cajueiro, de amêndoas de castanha-do-Brasil e de pimenta-do-reino preta e branca produzidas no Brasil. O gênero bacteriano mais freqüentemente encontrado foi o Bacillus, com 8 espécies. As leveduras Pichia sp., P. guillermondii e Rhodotorula sp., isoladas somente a partir de amêndoas de cajueiro, apresentaram populações mais elevadas que as de bactérias. Bacillus cereus, Salmonella typhimurium e Staphylococcus aureus foram também detectadas em amêndoas de cajueiro e de castanha-do-Brasil.