Aflatoxin B1 degradation by Bacillus subtilis UTBSP1 isolated from pistachio nuts of Iran

Pistachio nuts are among the commodities with the highest risk of aflatoxin contamination in Iran. Aflatoxin B1 (AFB1) is one of the most hazardous mycotoxins for humans and livestock. In nature, there are microorganisms which are capable of reducing aflatoxins contamination in food and feed products. In this study, Bacillus subtilis strain UTBSP1 was isolated from pistachio nuts and studied for the degradation of AFB1. The AFB1 contents were determined by the use of HPTLC and HPLC as well as multiple reactions monitoring (MRM) method in LC-MS/MS. The results indicated B. subtilis UTBSP1 could considerably remediate AFB1 from nutrient broth culture and pistachio nut by 85.66% and 95%, respectively. Cell free supernatant fluid caused an apparent 78.39% decrease in AFB1 content. The optimal conditions for AFB1 degradation by cell free supernatant appeared at 35-40 °C, during 24 h. Furthermore, the results indicated that AFB1 degradation is enzymatic and responsible enzymes are extracellular and constitutively produced. The destructive AFB1 differed from standard AFB1 chemically, and lost a fluorescence property.     

Measurement of food safety culture using survey and maturity profiling tools

Organizational culture is defined by dimensions and characteristics that can be used to measure food safety culture in food manufacturing through a food safety maturity model. Maturity models from quality, health care, and information technology have been used since early 1970 and this work presents a novel food safety culture maturity model with five capability areas and food safety pinpointed behaviours specific to functions and levels in a food manufacturing company. A survey tool linked to the model is used to measure a company's position within the maturity model framework. The method was tested with a Canadian food manufacturer and proved valuable to measure food safety culture across the five capability areas, which provides the manufacturer with a map for prioritizing future efforts to strengthen food safety culture.     

Isolation and characterization of a Bacillus subtilis strain with aflatoxin B1 biodegradation capability

Aflatoxins are type of mycotoxins mainly produced by Aspergillus flavus and a common contaminant of food and grain, posing a serious economic and health problem worldwide. In order to find efficient bacteria to remove or detoxify these mycotoxins, a bacterial strain capable of degrading aflatoxin B₁ (AFB₁) was isolated from soil samples using a culture medium containing coumarin as the sole carbon source. Based on 16S rRNA gene sequence analysis, this isolate was identified as Bacillus subtilis JSW-1; its further characterization showed that it could inhibit the growth of A. flavus with an inhibition ratio of 58.3% and could degrade AFB₁ by 67.2% after incubation at 30 °C for 72 h. The aflatoxin B₁-degrading activity of isolate JSW-1 was predominantly attributed to the cell-free supernatant and this activity was found to be heat stable but sensitive to proteinase K treatment, indicating that the extracellular proteins or enzymes are responsible for the AFB₁ degradation. In addition, no degradation products of AFB₁ could be detected by liquid chromatography-mass spectrometry (LC-MS) analysis, indicating that the parent AFB₁ might be biotransformed to compounds with chemical properties different from that of AFB₁.     

Biological detoxification of Aflatoxin B1 by Bacillus licheniformis CFR1

Aflatoxin B₁ is the most harmful among the mycotoxins commonly present in food and feed, and it may lead to hepatocellular carcinoma in humans and animals. Therefore, limiting its exposure to humans and livestock is very much essential. The present study aims to isolate and characterize Aflatoxin B₁ detoxifying bacteria from various sources, to develop a safe and environment-friendly strategy for Aflatoxin B₁ management. Fifty-six bacteria were isolated using a media amended with coumarin as a sole carbon source. Seven strains showed more than 70% reduction of AFB₁ in liquid culture media. Among them, isolate CFR1 reduced Aflatoxin B₁ by 94.7%, and it was selected for further studies. CFR1 was identified as Bacillus licheniformis CFR1, by biochemical characterization and 16S rRNA gene sequencing. The cell-free supernatant of B. licheniformis CFR1 was able to degrade AFB₁ efficiently than the cell lysate. The degradation of AFB₁ was examined using High-Performance Thin Layer Chromatography (HPTLC), High-Performance Liquid Chromatography (HPLC) and Electron spray ionization-Mass Spectrometry (ESI-MS). The optimal temperature, time, and pH of the medium for the maximum degradation of Aflatoxin B₁ were found to be 37 °C, 24 h and 7, respectively. Furthermore, Ames test for mutagenicity showed that when treated with B. licheniformis CFR1 extracellular fraction coincided with the loss of Aflatoxin B₁ mutagenicity. To the best of our knowledge, this is the first study that shows more than 90% degradation of AFB₁ by B. licheniformis. Thus, B. licheniformis CFR1 might be an excellent candidate for bioremediation and detoxification of Aflatoxin B₁ from both field and food matrices.     

Isolation and characterization of Bacillus amyloliquefaciens ZDS-1: Exploring the degradation of Zearalenone by Bacillus spp.

Zearalenone (ZEN) is a mycotoxin produced mainly by various Fusarium species which occur naturally in many crops worldwide. ZEN causes reproductive disorders and hyperestrogenic syndromes in animals and humans. This study aimed to isolate ZEN-degrading bacteria to develop strategies for detoxifying ZEN contamination in cereal crops. We screened approximately 1000 colonies for degrading ability and found four strains were capable of degrading ZEN. We selected one strain ZDS-1 for further study because it showed the high ZEN-degrading ability. On the basis of morphological, physiological and phylogenetic analysis of its 16SrRNA, gyrA gene sequences, strain ZDS-1 was identified as Bacillus amyloliquefaciens. The optimal conditions for the biodegradation of ZEN by ZDS-1 were temperature; 30 °C, pH; 6.0–7.0, and cell concentration; 5 × 10⁸ cfu/mL. ZDS-1 could degrade ZEN efficiently with the concentration from 1 mg/L to 100 mg/L. ZDS-1 not only could remove ZEN in the culture medium, but also could degrade ZEN in wheat. The ZEN removal by ZDS-1 was not due to binding or absorption, and during the process of ZEN degradation, no ZEN derivatives of ZEN were produced. These results suggested that Bacillus amyloliquefaciens ZDS-1 would be explored further for its ability to degrade ZEN in field trials.     

Development and validation of a scale to capture social desirability in food safety culture

The evaluation of food safety culture in a food company is influenced by human factors such as employees' tendency to respond to social desirability – a reflection of respondents' tendency to answer questions in a manner that will be viewed favorably by others. Building on previous research a self-assessment scale consisting of 18-statements (FSDRS) was developed to capture desirable responding in food safety. Statistical analyses of data collected from 816 North-American food manufacturing professionals revealed that a shortened 14-item version of the FSDRS scale provides a reliable and valid measurement of the extent to which employees deceive themselves. It is concluded that the proposed FSDRS will enrich food safety culture measurement and food safety performance.     

Aflatoxin B1 decontamination by UV-mutated live and immobilized Aspergillus niger

The decontamination of Aflatoxin B₁ (AFB₁) by immobilized cells of a new mutant strain, prepared on a base of HSCAS (hydrated sodium calcium aluminosilicate), was studied. Novel strains were induced by UV irradiation, from which 50 were screened according to their degradation efficacy on AFB_1, compared with the wild strain (FS-Z1). The FS-UV1 strain exhibited highest degradation efficacy, which was confirmed by 18SrDNA to be Aspergillus niger. The results indicate that both immobilized cells and this mutant strain which are incubated for 48 h at 30 °C, would considerably remediate AFB₁ in nutrient broth culture, by 95.32% and 82.43%, respectively. By the application of samples of contaminated cottonseed meal, with results of 93.46%∼96.82%, the degradation rate was also validated. The results of Ames test indicate the mutagenic activity of treated AFB₁ is greatly abated, with treated controls. The Application of LC-q-TOFMS (liquid-chromatography, quadrupole, time-of-flight mass spectrometry) deduces the structure and molecular formulas of the degradation products. In the vivo study, the damages of photomicrographic evidence are decreased in kidney and liver and the serum biochemical parameters is improved, in response to preventative treatment with immobilized cells. This is the application of HSCAS-prepared, immobilized A. niger cells to degrade AFB₁ of contaminated samples. The investigation in this paper offers a novel path for economical, time-saving biodegradation of AFB₁ in foods and feeds.     

Food safety knowledge of foodservice workers at a university campus by education level,experience, and food safety training

Food safety knowledge of university foodservice workers was evaluated and the relationship between food safety knowledge and education level, length of employment, and food safety training was assessed using a 40-item food safety questionnaire. Each knowledge question was scored as “1” for a correct answer and as “0” for an incorrect answer. The relationships between the level of education and food safety knowledge scores and length of employment in the foodservice industry and food safety knowledge scores were determined using bivariate correlation analysis. A total of 63.5% of the respondents had limited knowledge, 79% were well-informed about hygiene practices, while 33.9% of persons knew of correct time-temperature control measures. Kendall's tau = 0.067; p = 0.294 revealed a lack of strength of the relationship between education level and food safety knowledge. The relationship between length of employment and food safety knowledge was Kendall's tau = −0.133; p = 0.121. No mean differences (p = 0.426) were observed for mean knowledge scores between groups of food safety trained and untrained persons. Neither education level, nor the length of employment in the foodservice industry had a significant impact on food safety knowledge. The authors recommend that in order to improve food safety knowledge, attention should be given to the planning, implementation, monitoring, and evaluating food safety education programs.     

Establishment of a method to detect sulfonamide residues in chicken meat and eggs by high-performance liquid chromatography

Sulfonamides are a group of antimicrobials used for treatment and prevention of infectious diseases in humans and animals. In veterinary practice, sulfonamides are extensively used due to its broad spectrum of activity and low cost. A multi-residue analysis of seven sulfonamides (sulfadiazine, sulfathiazole, sulfapyridine, sulfamerazine, sulfamethazine, sulfamethizole, and sulfamethoxypyridazine) in chicken and eggs using HPLC- DAD detection method has been proposed. Chicken and egg samples were homogenized and extracted with distilled water:ethyl acetate (1:3, v/v) liquid-liquid extraction. The extracts were defatted with n-heptane and dried under nitrogen flow at 55 °C. The dry residue was dissolved in 500 μL methanol:acetic acid:water mixture with a ratio of 10:4:36 (v/v/v) and 10 μL of the sample was subjected to HPLC determination under the following conditions: column, Luna 5 μ C18; particle size, 5 μm; mobile phase, 17 mM acetic acid: methanol: acetonitrile (83:10:7, v/v/v); flow rate, 1.0 mL/min; and detection, 270 nm. The specificity was evaluated by analyzing 30 different blank samples of chicken and eggs in order to verify the absence of potential interfering compounds. No interfering peaks were found around the retention time of analytes in the matrices under investigation. The linear correlation coefficients (r²) for 50–250 ppb range were above 0.99 for all sulfonamides tested. The mean recoveries for chicken and eggs spiked at 50, 100, and 150 ppb were in the range of 86–108% for all analytes. Repeatability and within laboratory reproducibility of the developed method was determined at 100 ppb and quantified as the relative standard deviation was lower than 15%. The decision limits were between 108 and 116 ppb for all analytes whilst the detection capability of all analytes ranged from 129 to 140 ppb. An inexpensive and simple liquid-liquid extraction with isocratic elution mode for rapid analysis of residues of seven sulfonamides in chicken and egg samples using HPLC-DAD detection was established in this study.     

Promoting a culture of food safety to improve hygiene in small restaurants in Madagascar

In this study, we combined microbiological analyses; spot-check observations and in-depth interviews to study food safety in small restaurants in Antananarivo (Madagascar). We showed that faecal contaminations (Escherichia coli, Salmonella spp.) occur at high rate in mixed salad sold in these restaurants. This is resulting from vendors’ unhygienic behaviours. We studied vendors’ motivations and priorities as well as their material and social context of activity. Based on our findings, we propose key elements to build intervention programmes to promote an appropriate culture of food safety: (i) using disgust associated with the contact with stools to explain contamination chains of food and water; (ii) emphasizing on vendors’ representation of the link between cleanliness and health together with changing norms about what is seen as “clean”; and (iii) emphasizing on vendors’ responsibility towards customers’ health using the Malagasy traditional ideology of “tody”.     

Improvement of food safety in school meal service during a long-term intervention period: a strategy based on the knowledge,attitude and practice triad

The objective of the present study was to evaluate the development of food safety scores in school meal services during the application of a systematic intervention based on the knowledge, attitude and practice triad. A total of 68 public schools were included in the study. School meal services were assessed every three months with a checklist, which resulted in eight evaluations over two years. A program was developed and implemented in all the schools during this period that was comprised of three steps: 1) theoretical training, 2) implementation of action plans in situ and 3) weekly visits to motivate food handlers and monitor good practices. These steps were designed to promote changes in the attitudes and practices of food handlers. An ascending linear function was observed for the school meal services' general adequacy percentage over time. Positive developments were also observed regarding buildings and facilities, processes and procedures, distribution of meals, integrated pest management, water control, controls and records, health and safety of employees and equipment and utensils. Our results suggest that the proposed intervention strategy performs well in making school meal services conform to good practices and that strategies in this context should be permanent and continuous.     

A longitudinal evaluation of food safety knowledge and attitudes among Ontario high school students following a food handler training program

Youth are a unique audience for food safety education, in part due to low food safety knowledge. Although the effectiveness of such education has been explored for primary school and college students, no studies have assessed effectiveness among high school students specifically. We conducted a longitudinal intervention study in Ontario, Canada, between February and May 2015, to measure the baseline food safety knowledge and attitudes of high school students (n = 119; from 8 classes in 4 high schools), and determine whether these factors improved following in-class delivery of a provincial standardized food handler training program. Linear mixed effects regression models were used to model within-student changes in knowledge scores and attitudes over time (i.e., circa 2 and 12 weeks post-intervention), and to investigate associations with student characteristics. At baseline, knowledge and attitudes were poor. Following training, overall knowledge was significantly greater than at baseline, although at three months post-intervention only knowledge of safe times and temperatures for cooking and storing food remained significantly higher than baseline. Following training, students were significantly less interested in learning about how to avoid foodborne disease. Other attitudes, as well as knowledge of cross-contamination prevention and disinfection procedures, remained unchanged. These findings suggest that delivering existing food handler training programs within high schools may be a feasible mechanism for food safety educators to improve students' food safety knowledge, both overall and specific to safe times and temperatures, albeit potentially for short timeframes. Whether knowledge continues to decline beyond three months after training bears further investigation. As well, future research to investigate how students' actual food safety practices may change following such training, and whether improvements in knowledge translate into reduced foodborne disease risk, is warranted.     

Aflatoxin B1 production by Aspergillus parasiticus and strains of Aspergillus section Nigri in currants of Greek origin

Aflatoxin B₁ (AFB₁) mostly produced by Aspergillus flavus and Aspergillus parasiticus, is an extremely toxic and carcinogenic metabolite. Currants are used in the Mediterranean diet as a food with antioxidant properties. Four strains of Aspergillus section Nigri have been isolated from currants originated from Crete and Corinth. In this study AFB₁ production by A. parasiticus and the four strains of Aspergillus section Nigri in Cretan and Corinthian currants (Vitis vinifera L.) is investigated. AFB₁ determination was performed by HPLC–FID. Results revealed that the four strains Aspergillus section Nigri, as well as the aflatoxigenic strain A. parasiticus produced AFB₁ (0.0052–1.31 μg AFB₁ 15 g⁻¹, corresponding to 0.0003–0.087 μg AFB₁ g⁻¹) in both type of currants (Cretan and Corinthian) on the 12th day of observation. Moreover, AFB₁ production, by A. parasiticus in the synthetic Yeast Extract Sucrose (YES) medium was also studied. The ability of AFB₁ production has been affected by the special characteristics of each isolate and the currants substrate.     

Comparative analysis of existing food safety culture evaluation systems

The purpose of the research was firstly, to analyze existing culture evaluation systems for commonalities and differences in research quality, applied validation strategies, and content. Secondly, to suggest a simple structure of food safety cultural dimensions to help unify the culture evaluation field. To achieve these goals, a comparison of eight culture evaluation models applied to varing degrees in the food industry was conducted. The systems were found to vary significantly in applied validation strategies but through deductive, textual data analysis, five dimensions were identified that cover elements present in all the models. Transparency is needed when using applied research methodologies to continually increase quality and trustworthiness of culture research in the food safety domain and this field would benefit from both further commonality of approach to validation strategy and structure and adoption of an overarching structural framework.     

Barriers and benefits to the adoption of a third party certified food safety management system in the food processing sector in Shanghai,China

Despite the recent passing of legislation by the National People's Congress of China in 2009, many food businesses in China have yet to implement a third party certified food safety management system (FSMS). While the extent literature identifies a number of internal and external barriers and benefits, the extent to which these impact on the business is thought to be dependent upon how much progress the firm has made on its journey towards quality assurance and the environment within which the firm operates. To test this proposition, the barriers and the benefits accrued from the implementation of a third party certified FSMS were explored by segregating the participating firms into three distinct groups; (i) those that have yet to implement a third party certified FSMS; (ii) those that were in the process of adopting a third party certified FSMS; and (iii) those that were already operating under a third party certified FSMS. Contrary to expectations, in what is a highly competitive market, those firms which were operating under a third party certified FSMS were more likely to question the benefits they had derived than those firms that were either in the process of adoption or had chosen not to adopt a third party certified FSMS. Irrespective of the stage of adoption, the major constraint to the implementation of a third party certified FSMS was the need for the organisation to focus on more immediate issues and the lack of any strategic long-term planning.     

开展安全文化建设,强化岗位技能练兵,不断提高安全管理水平

介绍了中国石化山西石油分公司在开展安全文化建设和强化岗位技能练兵，不断提高安全管理水平的经验，其做法是：开展安全文化建设，培植安全理念，规范安全行为，实现“要我安全”向“我要安全”转变；从强化岗位练兵入手，开展技术比武，提高员工技术素质。     

Food safety knowledge and attitudes: culture and environment impact on hawkers in Malaysia.: Knowledge and attitudes are key attributes of concern in hawker foodhandling practices and outbreaks of food poisoning and their prevention

This study determined the impact of culture and environment on knowledge and attitudes of hawkers towards food safety, foodborne illnesses and their prevention. One hundred hawkers in Kuala Lumpur (KL) were interviewed, using a structured interview schedule. Environment did not effect hawkers’ knowledge and attitudes. Education influenced knowledge and attitudes scores of the interviewees. Differences in knowledge of the ethnic groups were in cross-contamination, equipment, utensils and premises, personal hygiene, hazard analysis critical control point (HACCP) and food regulations and control. Malay and Indian hawkers had better educational background, hence better knowledge and attitude scores than Chinese. The findings highlight the importance of education to bridge cultural gaps in food safety knowledge and attitudes. A strong relationship exists between the knowledge and attitudes of hawkers.     

Understanding and attitude regarding the shelf life labels and dates on pre-packed food products by Belgian consumers

Based on an on-line survey using questionnaires, information on Belgian consumers (n = 907) regarding their understanding and attitude towards shelf life labels and dates was collected. 80.1% of the respondents were familiar with the terminology of the label use by and best before while 69.6% indicated to know the difference between the meaning of the two labels. Judging edibility of food products at home occurs mainly by a combination of checking visually and smelling (82.5%), followed by looking at the shelf life date (67.5%) or tasting (50.4%). About half of the consumers is aware of and appreciates the difference between the two labels during this judgment. Most of the consumers interpret shelf life labels and dates with some flexibility, with variation depending upon the type of food product under consideration. Overall, the share of consumers willing to eat expired refrigerated products was lower than for expired products stored at ambient temperature: 19.1% for refrigerated raw products (e.g. meat and fish); 34.7% for refrigerated ready-to-eat products (e.g. deli-meat, cheese products, smoked fish); 61.0% for canned products (e.g. conserves) and drinks (e.g. beer) and lastly 69.3% for other products generally stored at ambient temperature (e.g. bread, unopened UHT milk, chocolate, cereals). Differences linked to age and gender are discussed. The suboptimal understanding and application of the EU date label framework by consumers may lead on the one hand to increased food disease burden by consuming certain expired use by products allowing growth of pathogens. On the other hand discarding food at the shelf life data in case of a best before date contributes to food waste by consumers. A better understanding of the shelf life labels use by (referring to food safety) and best before dates (referring to food quality) by consumers should be promoted.     

Protecting child health by preventing school-related foodborne illnesses: Microbiological risk assessment of hygiene practices,drinking water and ready-to-eat foods in Italian kindergartens and schools

The purpose of this study was to evaluate hygiene and microbial safety in 26 Italian school catering establishments. This involved monitoring the microbiological quality and safety of ready-to-eat foods (n = 395), drinking water (n = 43), food contact surfaces (n = 139), and food handlers (n = 249). Food samples analyses revealed an adequate level of microbiological quality and safety. Of particular concern was the isolation of Salmonella spp. and Listeria monocytogenes in 5.8% and 1.9% of raw vegetable samples, respectively. Escherichia coli counts exceeded the microbial reference standards in 8.6% of soft cheeses samples and in 27.3% of multi-ingredients preparations. Staphylococcus aureus counts exceeded the reference limits only in 5.7% of soft cheeses samples. The hygienic level of food contact surfaces was very high, since only 1.4% of samples showed unacceptable contamination. Concerning the food workers' hands, the results showed that the total bacterial count, coagulase positive staphylococci and Enterobacteriaceae levels exceeded the reference standards in 18.1%, 10.4%, and 11.2% of cases, respectively. The results of the water analyses indicated that 47.8% of the tap water and 10.0% of drinking water samples examined were found to be non-conforming to law limits. In conclusion, since children have a relatively lower immunity than adults, additional safety measures are needed to protect them from foodborne pathogens and high microbial contamination in school lunches. Consequently, our results suggest that various changes in the timing of food preparation and holding temperatures are needed, and good manufacturing practices and HACCP principles need to be applied more rigorously.     

Potential of high-throughput sequencing for broad-range detection of pathogenic bacteria in spices and herbs

A broad-range culture-independent method was developed and evaluated regarding its sensitivity of detection of pathogenic bacteria in spices and herbs, with focus on paprika powder. The method involved DNA extraction using cetyltrimethylammonium bromide (CTAB), 16S rDNA amplification using universal bacterial polymerase chain reaction, and high-throughput sequencing on Illumina MiSeq platform. The sensitivity of the method was evaluated with series of model samples contaminated at different levels with Salmonella enterica and Escherichia coli (as representatives of Gram-negative bacteria) and Staphylococcus aureus (as a representative of Gram-positive bacteria). For spices (paprika, black pepper), the method had a screening-level sensitivity with limits of detection in the range of 10⁴–10⁵ CFU/g, and a semi-quantitative response. Low sensitivity (LOD ≥10⁷ CFU/g) was observed with herbs (oregano, parsley). The developed method demonstrated a good potential for microbiological screening of spices, with a prospect of further improvement of sensitivity based on progress in high-throughput sequencing technology.