No abstract

Strawberries are an important fruit in Belgium in both production and consumption, but little information is available about the presence of Salmonella and Shiga toxin-producing Escherichia coli (STEC) in these berries, the risk factors in agricultural production, and possible specific mitigation options. In 2012, a survey was undertaken of three soil and three soilless cultivation systems in Belgium. No Salmonella spp. were isolated. No STEC was detected in the strawberry samples (0 of 72), but STEC was detected by PCR in 11 of 78 irrigation water and 2 of 24 substrate samples. Culture isolates were obtained for 2 of 11 PCR-positive irrigation water samples and 2 of 2 substrate samples. Multivariable logistic regression analysis revealed elevated generic E. coli numbers (the odds ratio [OR] for a 1 log increase being 4.6) as the most important risk factor for STEC, together with the berry-picking season (elevated risk in summer). The presence of generic E. coli in the irrigation water (>1 CFU per 100 ml) was mainly influenced by the type of irrigation water (collected rainfall water stored in ponds was more often contaminated than groundwater pumped from boreholes [OR ‫؍‬ 5.8]) and the lack of prior treatment (untreated water versus water subjected to sand filtration prior to use [OR ‫؍‬ 19.2]). The follow-up study in 2013 at one of the producer locations indicated cattle to be the most likely source of STEC contamination of the irrigation water.

No abstract

Irrigation water has been recognized as an important microbial risk factor for fruits and vegetables in many production areas, but there is still a lack of information about how the microbiological quality of different irrigation water sources and climatic conditions influence the safety of vegetables produced in Brazil. This study evaluated the distribution of generic E. coli and the prevalence of E. coli O157:H7 in two different water sources (ponds and streams bordering farmlands and urban areas) used for irrigation and on commercially produced lettuces in Southern Brazil. We also evaluated the effect of agricultural factors and meteorological conditions in the potential contamination of water and produce samples. A longitudinal study was conducted on four farms during a year (July 2014 to August 2015). The results showed generic E. coli prevalence of 84.8% and 38.3% in irrigation water samples and on lettuces, respectively, indicating irrigation water as an important source of contamination of lettuces. No significant differences were detected in the counts of E. coli between the two different surface water sources. The climatic conditions, particularly rainfall and environmental temperature, have influenced the high concentration of E. coli. The highest loads of E. coli in irrigation water and on lettuces were found during the warmest time of the year. E. coli O157:H7 was detected by qualitative polymerase chain reaction (qPCR) in 13 water samples but only 4 were confirmed by isolation in culture media.

An antimicrobial and antioxidant film based on cassava starch incorporated with oregano essential oil (2% w/v) and pumpkin residue extract (3% w/v) was developed for application onto ground beef. A control film (without additives) was used for comparison. The film's physical, barrier, antioxidant (DPPH), and antimicrobial properties were analyzed. The addition of oil does not contribute to reducing the film's water vapor permeability or impact solubility values. Regarding the application of the film on ground beef, the addition of oregano oil demonstrated antimicrobial activity against mesophilic bacteria, coliforms, and Salmonella. The film also showed significant antioxidant activity. Meat color and pH were assessed and it was found that the film contributed to keeping the pH at low values until the sixth day of storage, but had no influence in maintaining color in the samples. Based on the results, the film may be used as an alternative to packaging because it can contribute to ground beef quality and safety. Practical application Developed films have antioxidant and antimicrobial activity, and the latter was proven when applied in ground beef. The film characteristics show that it may be applied in other foods such as cheeses and other meat cuts to avoid the multiplication of microorganisms. These films can be used as extra conventional packaging protection and its implementation would improve the microbiological quality and contribute to the safety and quality of packaged food.

No abstract

Introduction: Washing and disinfection methods used by minimally processed vegetable industries of Southern Brazil were reproduced in laboratory in order to verify their effectiveness to reduce Salmonella Enteritidis SE86 (SE86) on lettuce. Methodology: Among the five industries investigated, four carried out washing with potable water followed by disinfection with 200 ppm sodium hypochlorite during different immersion times. Results: The washing procedure alone decreased approximately 1 log CFU/g of SE86 population and immersion times of 1, 2, 5, and 15 minutes in disinfectant solution demonstrated reduction rates ranging from 2.06±0.10 log CFU/g to 3.01±0.21 log CFU/g. Rinsing alone was able to reduce counts from 0.12±0.63 log CFU/g to 1.90±1.07 log CFU/g. The most effective method was washing followed by disinfection with 200 ppm sodium hypochlorite for 15 minutes and final rinse with potable water, reaching 5.83 log CFU/g of reduction. However, no statistical differences were observed on the reduction rates after different immersion times. Conclusion: A time interval of 1 to 2 minutes may be an advantage to the minimally vegetable processed industries in order to optimize the process without putting at risk food safety.

Background: Three conventional lettuce farms were evaluated in Southern Brazil using a standardized selfassessment questionnaire with 69 indicators and a microbiological sampling plan in order to assess the status of current agricultural practices and management systems. The use of both tools aimed to identify the foremost contamination sources and control measures during the crop production. A total of 128 samples were taken (manure, soil, water, workers' hands and equipment, lettuce seedlings and lettuce heads) in four visits during the growth cycle of lettuces. Samples were analysed for hygiene indicators (E. coli) and presence of pathogens (Salmonella spp. and E. coli O157). Results: Microbiological results indicated that E. coli counts were very low in all analysed samples and no pathogens were detected. These results could be explained partially because all farms had toilets near to the fields, they did not raise animals near the crops, fields were located in areas where flooding was not possible, they used organic fertilizers adequately composted, and irrigation water demonstrated good microbiological quality. The microbial results for manure and soil indicated that the composting time was of utmost importance to maintain minimal contamination levels for the duration of the cultivation period, as long as the quality of irrigation water was very important to prevent further contamination of the crop. On the other hand, the self-assessment questionnaire identified a moderate to high risk level concerning microbiological contamination in all evaluated farms, because they had no formal good agricultural practices implemented, technical support, water control, inspections, food safety registers or sampling plan for microbiological or chemical analyses.Conclusion: These different results are important in order to provide information about the actual status of contamination (microbial sampling plan) and possible food safety problems in the future based on the results given by the questionnaire. Furthermore, the results of this study also highlighted the necessity to provide more safety during the fresh produce cultivation, being formal good agricultural practices implementation an important start to the fresh produce farms in Brazil, as well as to adopt a higher level of control activities in order to achieve lower risk levels.