This study was conducted to investigate the growth of microorganisms, including pathogenic bacteria such as Cronobacter sakazakii and Bacillus cereus, in Sunsik beverages made of water, milk, soymilk, or honey-water during storage at room temperature. Prepared Sunsik beverages were stored at room temperature and the growth of total aerobic counts, Escherichia coli/coliforms, and yeast and mold were measured. Also, samples inoculated with a cocktail of C. sakazakii or B. cereus spores were stored at room temperature and their growths were determined during storage. Populations of total aerobic counts and coliforms significantly increased with increasing storage time at room temperature, which resulted in higher than 8 log and 7 log after 24 h in all samples except for the honey-water sample, respectively. Levels of total aerobic counts and coliforms were significantly lower in the honey-water sample than in the other samples after 6 and 9 h of storage, respectively. Initial populations of C. sakazakii and B. cereus ranged from 0 to 1 log CFU/mL, respectively, and these populations significantly increased with increasing storage time at room temperature. Therefore, populations of C. sakazakii and B. cereus were approximately 7 to 8 log CFU/mL after 24 h of storage. However, after 12 and 9 h of storage, there were significant differences in levels of C. sakazakii and B. cereus between the honey-water sample and the other samples, respectively. Based on these results, the addition of honey can inhibit microbial growth in Sunsik beverages; however, the best way to avoid pathogen infection would be to consume Sunsik beverages as soon as possible after preparation.

In the present study, silver nanoparticles (AgNPs) synthesized from aqueous leaves extract of Malva crispa and their mode of interaction with food- and water-borne microbes were investigated. Formation of AgNPs was conformed through UV–Vis, FE-SEM, EDS, AFM, and HR-TEM analyses. Further the concentration of silver (Ag) in the reaction mixture was conformed through ICP-MS analysis. Different concentration of nanoparticles (1–3 mM) tested to know the inhibitory effect of bacterial pathogens such as Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhi, Salmonella enterica and the fungal pathogens of Penicillium expansum, Penicillium citrinum, Aspergillus oryzae, Aspergillus sojae and Aspergillus niger. Interestingly, nanoparticles synthesized from 2 to 3 mM concentration of AgNO₃ showed excellent inhibitory activities against both bacterial and fungal pathogens which are well demonstrated through well diffusion, poison food technique, minimum inhibitory concentration (MIC), and minimum fungicidal concentration (MFC). In addition, mode of interaction of nanoparticles into both bacterial and fungal pathogens was documented through Bio-TEM analysis. Further the genomic DNA isolated from test bacterial strains and their interaction with nanoparticles was carried out to elucidate the possible mode of action of nanoparticles against bacteria. Interestingly, AgNPs did not show any genotoxic effect against all the tested bacterial strains which are pronounced well in agarose gel electrophoresis and for supporting this study, UV–Vis and Bio-TEM analyses were carried out in which no significant changes observed compared with control. Hence, the overall results concluded that the antimicrobial activity of biogenic AgNPs occurred without any DNA damage.

This is a retrospective study describing data on the microbiological conditions of food and water obtained from analysis reports issued by the Central Laboratory of the Federal District (LACEN-DF), and information on foodborne disease outbreaks investigated by the Office of Water and Food Borne Diseases of the Federal District (NATHA), Brazil, between 2000 and 2010. A total of 4576 analysis reports were evaluated, from which 92.9% of monitoring samples and 7.1% of samples suspected to be involved in outbreaks. Of the total number of samples, 630 did not comply with Brazilian legislation (rejected). Ready-to-eat food, milk/dairy products, water, spices/seasonings, and ice cream/sorbets had the highest rejection rates among the monitoring samples (18.9–11%), with the first two groups having the highest rates among the outbreak samples (23.5 and 21.7%). Minas cheese showed to be the food with the highest rejection rate among the samples analyzed by the LACEN-DF. About 9% of the food samples were rejected due to thermotolerant coliforms and/or coagulase-positive staphylococci, and 10.5% of the water samples were rejected due to Pseudomona aeruginosa. Ready-to-eat food were the main foods involved in the foodborne disease outbreaks investigated by NATHA (51.3% of the 117 outbreaks with the food identified) and Bacillus cereus the most identified etiologic agent (41.2% of the 80 outbreaks with the agent identified). This study indicated that microbiological surveillance programs should focus on ready-to-eat food to prevent the occurrence of foodborne disease outbreaks in the region.

The resistance pattern and mechanisms of bacterial isolates obtained from clinical origin, soil, industrial effluent, orange juice products and drinking water were studied using commonly used antibiotics. The microbial load of the water samples, industrial effluent and orange juice products were 1.0 × 10¹−2.25 × 10⁶, 2.15 × 10⁵, and 3.5 × 10⁴−2.15 × 10⁵ cfu mL⁻¹, respectively. The faecal coliform test revealed that only two out of twenty orange juice products had MPN of 2 and 20, the MPN of water ranged from 1−≥1800, while the effluent had MPN of ≥1800. The bacterial isolates that were isolated include E. coli, S. aureus, P. vulgaris, S. marcescens, S. pyogenes, B. cereus, B. subtilis, Micrococcus sp., Klebsiella sp., P. aeruginosa, and Enterobacter sp. Also, clinical and soil isolates of P. aeruginosa were used in the study. Among the eight antibiotics tested for resistance on five strains of each bacterium, seven different resistance patterns were observed among the bacterial isolates obtained from water, effluent and orange juice products. Among the clinical and soil isolates of P. aeruginosa, four multiple-drug resistance patterns were obtained. Thirty strains of E. coli and S. aureus were tested for β-lactamase production and fourteen strains, seven each of E. coli and S. aureus that had high Minimum Inhibitory Concentration values (MIC) for both Amoxycillin and Cloxacillin were positive.

A continuous pasteurization system was designed based on a domestic microwave oven. Broth was pumped through helical coils of glass tubing placed in the center of the oven cavity. Inactivation of two selected spoilage microorganisms, Bacillus cereus and Saccharomyces cerevisiae in broth were evaluated under continuous flow microwave heating conditions and compared with conventional batch heating in a well stirred hot water bath. Inoculated broth was heated in a microwave oven (700 W, 2450 MHz) under continuous flow conditions to selected exit temperatures of 90°C for B. cereus and 60°C for S. cerevisiae at five power levels (210, 280, 350, 420, 490 W) and five time intervals (1, 2, 3, 4, 5 minute). Broth treated in hot water bath at 90˚C for B. cereus and 60˚C for S. cerevisiae was taken as control. There was a decrease in B. cereus and S. cerevisiae count after microwave and hot water bath treatment (control) with increasing treatment time. Higher microbial inactivation was observed at lower power levels. For all the microwave power levels, higher inactivation of B. cereus and S. cerevisiae was observed in comparison to control, this may be due to some non thermal effects associated with microwave. Heating rate and flow rate also increased with the increasing power level with decrease residence time to kill the contaminants. In future, this system may be useful for effective pasteurization of liquid foods e.g. sugarcane juice and soymilk without affecting the taste of processed juices.

Seaweeds are rich in bioactive compounds which have well-documented antioxidant properties. They also have antimicrobial activities against food pathogenic microorganisms. This study uses an extract of the brown seaweed, Saccharina (Laminaria) japonica, produced by subcritical water hydrolysis (SWH) for investigating its potential to inhibit bacteria. De-oiled S. japonica was obtained by supercritical carbon dioxide extraction. The reaction temperatures for hydrolysis of raw and de-oiled S. japonica were maintained from 200 to 280 °C. The experiment was done with condition 1.3–6.0 MPa for the reaction pressure and 1:10 (w/v) for the ratio of material to water. The antibacterial activities of raw and de-oiled S. japonica produced by SWH were determined by using the agar diffusion method. Antibacterial activity was tested against two Gram-negative (Escherichia coli and Salmonella typhimurium) and two Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus). The antibacterial activities of hydrolysate water with catalyst at 240 °C showed better bacterial inhibition than the others. Strong antibacterial activity was found using de-oiled material with acetic acid added, with a zone of inhibition of S. typhimurium (14.33 ± 0.06 mm) and E. coli (13.00 ± 0.09 mm). On the other hand, the weakest antibacterial inhibition was found for S. aureus (12.83 ± 0.10 mm) and B. cereus (12.50 ± 0.09 mm).

The objective of the study was to evaluate the combined effects of pasteurization intensity (no heat treatment and 10min at 70, 80 and 90°C), water activity (aw) (0.960–0.990), pH (5.5–7.0) and storage temperature (7 and 10°C) on the survival and outgrowth of psychrotolerant spores of Bacillus cereus FF119b and Bacillus pumilus FF128a. The experiments were performed in both artificial media and a validation was performed on real food products (cream, béchamel sauce and mixed vegetable soup). It was determined that in general, heat treatments of 10min at 70°C or 80°C activated the spores of both B. cereus FF119b and B. pumilus FF128a, resulting in faster outgrowth compared to native (non-heat treated) spores. A pasteurization treatment of 10min at 90°C generally resulted in the longest lag periods before outgrowth of both isolates. Some of the spores were inactivated by this heat treatment, with more inactivation being observed the lower the pH value of the heating medium. Despite this, it was also observed that under some conditions the remaining (surviving) spores were actually activated as their outgrowth took place after a shorter period of time compared to native non-heated spores. While the response of B. cereus FF119b to the pasteurization intensity in cream and béchamel sauce was similar to the trends observed in the artificial media at 10°C, in difference, outgrowth was only observed at 7°C in both products when the spores had been heated for 10min at 80°C. Moreover, no inactivation was observed in cream or béchamel sauce when the spores were heated for 10min at 90°C in these two products. This was attributed to the protective effect of fat in the cream and the ingredients in the béchamel sauce. The study provides some insight into the potential microbial (stability and safety) consequences of the current trend towards milder heat treatments which is being pursued in the food industry.

L'analyse de 250 echantillons du commerce (galettes de sarrasin, crepes, pates alimentaires fraiches, pates a patisserie a cuire, pates a pizza, gnocchis) a mis en evidence une contamination importante des galettes. Les facteurs de la contamination sont etudies: contamination de la farine de sarrasin, croissance de Bacillus cereus et de la microflore aerobie dans la pate a galettes et dans les galettes, analyse d'echantillons a la date limite d'utilisation optimale, synthese de toxine diarrheique par Bacillus cereus. Des mesures preventives sont proposees, en particulier un stockage court de la pate avant cuisson, l'entreposage des galettes a une temperature inferieure ou egale a 4 degres C et le raccourcissement de leur duree de vie