Biofilm formation by Vibrio parahaemolyticus on food and food contact surfaces increases with rise in temperature

Vibrio parahaemolyticus is recognized as a human foodborne pathogen that is mostly associated with seafood. This pathogen can form a mature biofilm on food and food contact surfaces during food processing. The present study investigated V. parahaemolyticus biofilm formation at various temperatures on shrimp, crab, and stainless steel coupons, using the biofilm formation index (BFI) method on microtiter plates. The results were also confirmed by field emission scanning electron microscopy. Both the BFI values and cultural counts revealed that V. parahaemolyticus biofilm formation was stronger at higher temperatures than at lower temperatures. Biofilm formation differed according to the growth surface type and growth temperature. It was found that higher temperatures (15–37 °C) induced stronger biofilm formation whereas 4 and 10 °C resulted in attachment of the bacterial cells as monolayers. It could be concluded that temperatures of 25–37 °C result in significantly stronger biofilm formation as well as exoprotease and AI-2 production on food and food contact surfaces, indicating that these temperatures might be threatening conditions for food safety.     

Substratum attachment location and biofilm formation by Bacillus cereus strains isolated from different sources: Effect on total biomass production and sporulation in different growth conditions

Bacillus cereus, an endospore forming human pathogen associated with foodborne diseases, can form biofilms and attach to surfaces of processing equipment in the food industry. It is a consistent source of contamination and/or cross contamination of processed food products. The objective of this study was to understand substratum attachment location and biofilm formation behavior of B. cereus strains under different growth conditions. A total of 60 strains isolated from food, human, or farm and a number of reference strains were used in this study. Substratum attachment locations of these strains in 96-well microtiter plates were highly diversified among these strains. Strains isolated from food showed higher preference to attach at the air-liquid interface during early stage of biofilm formation. To the best of our knowledge, this is the first report showing the level of substratum attachment location and biofilm formation of B. cereus strains isolated from different sources. Substratum properties did not affect biofilm formation location when a number of selected strains were grown on stainless steel coupon, indicating that biofilm formation location might be independent of the type of substratum. Substratum attachment location and biofilm formation related phenotypes such as total biomass production, number of sessile cells, and sporulation were closely correlated. Substratum attachment location and sporulation behavior were strongly affected during biofilm formation under nutrient stress condition. The number of spores was significantly increased in biofilms grown under nutrient stress condition even though total biomass formation was lower. Our results on substratum attachment location and related biofilm formation behavior are substantially important for food industries where different surfaces are prone to B. cereus attachment, particularly for setting up and implementing clean in place (CIP) protocols.     

The rise of inorganic nanomaterial implementation in food applications

The amalgamation of nanoparticles (NPs) with food industry has improved the quality of our lives despite the discovery of some plausible health concerns arising from the inclusion of NPs. Certain physical properties such as fine particle size, high surface area, and high reactivity are the preeminent reasons for the frequent application of NPs in a diversified range of industrial applications. The contribution of inorganic nanomaterials (INMs) is of great significance considering its potential for development of the food industry. Therefore, the toxicological impact on human health causes by INM-associated food applications is an issue currently being addressed. Albeit there being plenteous associations with nanomaterials in the food industry, inclusion of INMs is chiefly found in food packaging. INMs are also used to encapsulate sustenance supplements, develop sensors, or detectors that are utilizable in food applications and to boost the growth of crops. Only a limited number of elements such as Zn, Al, Ti, Au, Ag, Si, Cu, Co, and Fe and/or their derivatives have been documented as possible INMs befitting food applications. Implementation of most INMs is still in the research and development stage, and applications in the food industry are yet to find approval owing to health concerns. In this review recent findings, benefits, detriments, conveniences, and risks that are associated with INMs in food applications are discussed.     

The HACCP system implementation in small businesses of Madrid’s community

The main goal of this paper is addressed to evaluate the HACCP system implementation in small food industries of Madrid’s autonomous community. Important practical barriers about HACCP development have been identified. There were investigated the manufacturing food industries of animal origin during 5 years, between 1999 and 2003. The research analyzed areas concerning business demand, legal requirements and quality management systems, food industry size, human resources, technical support and assessors, prerequisites, time scale and HACCP implementation official assessment. Conclusions have met the beginning of HACCP system implementation by food industries following the application of a strategic plan and public health program, as well as several difficulties in small food industries with regard to HACCP system applying, and the fundamental influence of prerequisites implementation and management commitment on effective HACCP system. To overcome such barriers, it is proposed a strategy, which includes all different stakeholders.     

Evaluation of SICAN performance for biofouling mitigation in the food industry

Biological fouling in food industry leads to an increase in maintenance costs, decreases operational efficiencies and promotes food contamination leading to economic losses and the dissemination of foodborne pathogens. In order to maintain production efficiency and hygienic standards, cleaning in place (CIP) procedures are required. However, the existence of critical zones shielded from the main flow carrying the CIP disinfectants requires new strategies for reducing biofilm buildup and/or easy to clean surfaces. In this work, a Diamond-Like Carbon (DLC) coating modified by incorporation of silicon (a-C:H:Si or SICAN), was evaluated regarding bacterial adhesion, biofilm formation and cleanability. Assays included the natural flora present in industrial water (from a salad washing line) and Escherichia coli, one of the most persistent foodborne microorganisms.Results show that bacterial adhesion and biofilm formation on SICAN and stainless steel were similar, thus surface modification was not able to prevent biological fouling development. However, it was verified that after performing a cleaning protocol with chlorine, reduction of bacterial counts was much higher in SICAN (about 3.3 Log reduction) when compared to stainless steel (1.7 Log reduction). Although full biofilm recovery was observed on both surfaces 18 h after treatment, an operational window was identified for which processes with cleaning intervals of about 6 h could potentially use SICAN surfaces on critical areas (such as dead zones, crevices, corners, joints) and therefore operate at a much higher hygienic level than the one attained with stainless steel.     

Plant essential oils as food preservatives to control moulds,mycotoxin contamination and oxidative deterioration of agri-food commodities – Potentials and challenges

Stored food items are frequently contaminated by fungal infestations, mycotoxins secreted by toxigenic fungi, and free radical generation due to oxidative stress. In order to ensure the safety of food items, there is a need for control measures which are effective by antimicrobial, mycotoxin inhibitory as well as antioxidative action. Some synthetic chemicals used as preservatives have been reported to cause harmful effects to consumers and the environment. Different plant essential oils (EOs), naturally occurring plant-based volatile components, have often been reported to possess strong antimicrobial and antioxidant potential. Some EO formulations are currently used as food preservatives and are kept in the category “GRAS” in view of their favourable safety profile. Being volatile in nature, such EOs may be used as plant-based fumigants for stored food commodities. Hence, EOs may play a significant role in overcoming storage losses and in enhancing food shelf- life. This review presents an overview on EOs reported to have prominent efficacy against storage fungi, mycotoxins, and as antioxidants. In addition, safety concerns and future prospects as plant-based preservatives are also discussed.     

Carbon dioxide sensors for intelligent food packaging applications

Recently, the demand for safe and high quality foods, as well as changes in consumer preferences have led to the development of innovative and novel approaches in food packaging technology. One such development is the smart or intelligent food packaging technology. Intelligent packaging has enabled to monitor and communicate information about food quality. This technology also helps to trace a product’s history through the critical points in the food supply chain. In general, occurrence of elevated CO₂ gas level is the prime indicator of food spoilage in packed foods and also its maintenance at optimal levels is essential to avoid spoilage in foods packed under modified-atmosphere packaging (MAP) conditions. Hence, a CO₂ sensor incorporated into food package can efficiently monitor product quality until it reaches the consumer. Although much progress has been made so far in the development of sensors monitoring CO_2, most of them are not versatile for food packaging applications and suffers from limitations such as high equipment cost, bulkiness, and energy input requirement, including safety concerns. Therefore, the development of efficient CO₂ sensors that can intelligently monitors the gas concentration changes inside a food package and specific to food packaging applications is essential. In the present review, progress on the development of different types of CO₂ sensors such as optical sensors, polymer opal films, polymer hydrogels, etc., which can be readily applicable to food packaging applications, is discussed.     

The specific anti-biofilm effect of gallic acid on Staphylococcus aureus by regulating the expression of the ica operon

Staphylococcus aureus (S. aureus) biofilms are of considerable interest in food safety because biofilms can increase the risk of food contamination and enhance the pathogenicity of bacteria. The ica-encoded polysaccharide intercellular adhesin (PIA) plays an important role in biofilm formation. In this study, the MIC of gallic acid against S. aureus in suspension and in biofilms was 2 mg/mL and 4 mg/mL, respectively. Quantitative crystal violet staining of biofilms showed that 2 mg/mL gallic acid can effectively inhibit biofilm formation and the ESEM images clearly showed the three-dimensional biofilm morphology of the S. aureus and the resulting anti-biofilm effect. The determination of viable bacteria in the biofilm revealed that gallic acid penetrated the biofilm to kill S. aureus, the bactericidal effect on the biofilm bacteria was comparable to that of planktonic bacteria. We further explored the influence of gallic acid on ica family gene expression and polysaccharide slime formation in S. aureus biofilm formation. The results showed that icaR was significantly activated that; icaA and icaD were downregulated in a dose-dependent manner with increasing concentrations of gallic acid; however, the expression of icaB and icaC was not significantly affected. The polysaccharide slime formation was reduced as well. Based on these results, gallic acid, as a natural substance, may play an important role in the food industry.     

Implementation of HACCP in food businesses: the way ahead

Food-borne diseases constitute an important public health problem in both developed and developing countries. Although their health and economic aspects are often obscured by insufficiency of data, available evidence on incidence and associated costs of medical care indicates that they are a major cause of morbidity, and a drain on resources. A joint WHO/FAO expert committee on food safety asserts that illness due to contaminated food is probably the most widespread health problem in the contemporary world, and an important cause of reduced economic productivity. Given the inadequacies of traditional approaches to food safety control, viz. inspection and end-product testing, there is a need to apply such other strategy of proven effectiveness as the Hazard Analysis Critical Control Points (HACCP) system which has been described as the most viable means for the prevention of food-borne diseases yet devised. While there is an extensive literature suggesting the effectiveness of HACCP in preventing food-borne diseases, food operators have yet to embrace it with the anticipated enthusiasm. This paper examines factors that are likely to hinder wider acceptance and practical implementation of HACCP in food operations and discusses measures to overcome them. It is concluded that HACCP training and education of food operators and food regulatory officials is a conditio sine qua non for the realization of the fullest benefits of the strategy.     

Phenotypic and genotypic characteristics of Listeria monocytogenes strains isolated during 2011–2014 from different food matrices in Switzerland

One hundred and forty two Listeria monocytogenes strains isolated from different food matrices in Switzerland between 2011 and 2014 were characterized with respect to their genotypic and phenotypic properties. Analyzed strains originated from various meat, milk, plant-associated food products and production environments as well as from other types of foods including fish, seafood, and ready to eat (RTE) products. The collection included serotype 1/2a (64%), 4b (15%), 1/2c (12%), 1/2b (7%) and 3c (3%). The strains were genetically diverse representing 61 MLST sequence types (ST) including 24 new STs. The most frequent clonal complexes (CC) were CC9 (15%) and CC121 (12%). PCR screening detected presence of the stress survival islet (SSI-1) in 50% of the strains. Phenotypic resistance to benzalkonium chloride (BC) was detected in 18% of the strains. The BC resistance genetic determinants qacH and bcrABC were detected in 80% and 12% of the strains, respectively. Most (n = 129) of the strains isolated from Swiss food matrices exhibited poor biofilm formation capacity and there were no correlations detected between strain serotypes, genotypes and biofilm production.     

Antioxidant properties of coriander essential oil and linalool and their potential to control Campylobacter spp.

Foodborne diseases remain common around the world with Campylobacteriosis being the most commonly reported zoonosis in the European Union in 2013. Campylobacter jejuni and Campylobacter coli are the main species associated with human illness. Furthermore, Campylobacter can develop biofilms which is becoming a major problem within the food industry. In addition to foodborne pathogens, oxidation is a non-microbial cause of deterioration of food causing loss of quality and safety. Thus, there is an urgent need in the food industry for new and effective strategies that can help prevent food contamination, spoilage and consequently, foodborne illnesses. Essential oils are known for their antimicrobial and antioxidant properties and are already widely used in the food industry. So, the aim of this work was to study the antimicrobial and anti-biofilm activity of coriander essential oil and its major compound linalool against C. jejuni and C. coli strains, as well as their effect in the quorum sensing (QS) system and their potential as antioxidants. Our results, demonstrated that both compounds have anti-Campylobacter activity, inhibited in vitro biofilm formation and promoted biofilm dispersion even at sub-MIC concentrations and interfered with the QS system through the inhibition of violacein production. Moreover, the essential oil and linalool were shown to have radical scavenging properties and lipid peroxidation inhibition ability which could make them potential alternatives to synthetic antioxidants. In sum, our results demonstrated the antibacterial, anti-biofilm, anti-QS and antioxidant potentials of the coriander essential oil and its major compound, linalool, suggesting that they could be used in the food industry to enhance shelf life of food products and increase food safety without requiring chemical additives or preservatives.     

Indian perspective in food traceability: A review

India is the second largest producer of fruit and vegetables in the world. Fruit production in India has increased 89% in the last decade. In the present paper It is exposed the necessity for a proper traceability in the Indian food industry, because the sector is demanding an adequate system due to the precarious nature of existing supply chain, and to reduce the numerous cases of food safety incidents and fraudulence. This work also presents the existing traceability techniques in India which include RFID, Holograms, Barcode, Nuclear techniques and other tracking media to monitor production process. Furthermore it is revealed the initiatives implementation from APEDA and its association with GS1 India in the form of Anarnet, Peanut.net, Meat.net, and Grapenet for the Indian farming products, as well as several ICTs initiatives that are actively working in many states of India.However the development of an effective food traceability system is affected by a numbers of factors like restrictive government marketing standardization, insecure policies and unstable actions for food safety, underdeveloped and unorganized infrastructure in market area and the supply chains, from the farmers to non-existent cold chain facilities and small local stores, and inadequate agricultural practices with large number of small and medium industries and famers. Therefore an effective food traceability system is not only an important tool to manage food quality and safety risks, but also to promote the development of effective supply chain management in India.     

New food labelling initiatives in Australia and New Zealand

A key element of the review of food standards in Australia and New Zealand was the review of labelling provisions. This review resulted in a number of new labelling initiatives, three of which––percentage labelling of key or characterising ingredients, mandatory nutrition information panels and mandatory labelling of certain substances in foods that may cause severe adverse reactions––are discussed in this paper. These labelling initiatives exemplify the shift globally towards the provision of greater consumer information. The new food labelling standards in the joint Australia/New Zealand Food Standards Code were developed specifically to address two main regulatory objectives: the protection of public health and safety; and the provision of adequate information to consumers to enable them to make informed choices. The new provisions have been phased in over a period of two years which has enabled manufacturers to re-label their products as part of their scheduled periodic review of products.     

Assessment of the food control systems in the Sultanate of Oman

National food control systems are vital tools in governing the safety and quality of food intended for human consumption. This study of the Omani system was conducted to evaluate the effectiveness of the current food controls in place for protecting, in particular, the public health from emerging biological and chemical hazards. In response to this situation, a survey was undertaken within the different food safety authorities in Oman to examine the different elements of the national food control systems in terms of their existing food control management, food legislation, food inspection, food analysis laboratories and information, education and communications. Officials from the different authorities were interviewed and results were captured in prepared questionnaires. Overall examinations of the challenges, strength and weakness of the existing system have been highlighted. The findings of the study indicate significant progress is being made and the creation by the government of a national Centre for Food Safety and Quality is a significant positive step.     

A working procedure for identifying emerging food safety issues at an early stage: Implications for European and international risk management practices

There is a need for early identification of emerging food safety issues in order to prevent them from developing into health risks. In this paper, various existing methods and procedures which can be used for early identification of safety issues are reviewed, including the monitoring of the occurrence of specific hazards within the food supply, or the incidences of food-borne diseases, as well as the combination of these data with other data or with expert opinions. Some methods, including hazard analysis critical control points (HACCP), operate pro-actively by pre-defining indicators for hazards and follow-up measures. Vulnerability assessment focuses on potential weak spots within the food supply, whilst futures research employs foresight to enhance preparedness for future hazards and risks. A Delphi survey on food safety risk analysis conducted among professionals revealed concerns with various aspects of current procedures for dealing with emerging issues, and these are discussed. The Delphi respondents also attached great value to the involvement of stakeholders and the inclusion of a broader range of data into risk analysis. Indeed, holistic systems employing indicators from outside the food production chain are now being developed. In conclusion, a four-step procedure for the early identification of emerging issues is proposed.     

Evaluation of food safety training on hygienic conditions in food establishments

Food handlers' training is fundamental in order to ensure the safety of the foodstuff. However, the success of training programs that provide only information is unclear and changes in improper food practices are not usually achieved. Food training programs based on theoretical as well as practical activities have been revealed as an important tool in which food handlers can put information into practice. Thus, the objective of this study was to assess the influence of food safety training, based on both theoretical and practical approaches, on the microbiological counts of food contact surfaces, food tools, food equipment surfaces and hand washing in canteens and cafes of one university campus. After food safety training, total plate counts decreased about 60% in the case of canteens and almost 45% in cafes while moulds and yeasts decreased approximately 65% in canteens and 55% in cafes. In terms of location, the microbiological reductions observed were higher for food equipment in canteens and for food tools in cafes. The microbiological counts of food handlers' hands decreased after both food safety training and disinfection. Food safety training influenced the reduction of overall microbiological parameters. Parametric t-tests (after vs before training) indicated that reductions were statistically significant before and after disinfection for total plate counts. The decrease observed for total coliforms and Enterobacteriaceae, were statistically significant only before disinfection. The food safety programs cannot be based entirely on a theoretical approach but also on adequate training which includes a practical approach. The success of the microbiological reductions in the study was associated to the practical lessons which let the handler put into practice the knowledge acquired in the theoretical part.     

Foodborne diseases in Malaysia: A review

This paper reviews foodborne diseases occurring in Malaysia and the strategies taken by the Malaysian government. Half of the foodborne related diseases from the early 1990s until today were associated with outbreaks in institutions and schools, mostly due to unhygienic food handling procedures. Outbreak surveillance and monitoring, training and Hazard Analysis Critical Control Point (HACCP) implementation at food service establishments all play a vital role to prevent and/or reduce foodborne diseases. Some of the key agencies from the Malaysian Ministry of Health, academia, industries and research institutions continue to strengthen their collaboration and networking in order to coordinate the prevention and control of foodborne diseases and thus improve public health. Developments to date have shown improvement in surveillance and monitoring. In Malaysia, the main contributing factor to foodborne diseases was identified as insanitary food handling procedures which accounted for more than 50% of the poisoning episodes. Food handlers play a major role in the prevention of food poisoning during food preparation; hence, food handler training is seen as one of the main strategies to increase food safety practices. There are 125 accredited food handlers’ training institutes as of September 2010. The application of knowledge and skills from training into the workplace is important and reasons for limitations of training initiatives are discussed.     

Incorporating HACCP into national food control systems - Analyzing progress in the United Arab Emirates

Today governments and other parties involved in food control are under constant pressure to find more efficient and effective mechanisms to carry out their mandates for food control. This has led to international recognition of the importance of the HACCP system as a food control tool and guidance on the role of government agencies in the application of such a system has been developed. Based on this international guidance, four main elements identified as key activities have been used in this study to evaluate the progress of HACCP implementation in the UAE. The internal Strengths and Weaknesses, as well as the external Opportunities and Threats that the government is facing towards the implementation of a HACCP-based food control system have been identified. The analysis shows that the government’s dedicated role has been an essential driving force to encourage the implementation of a HACCP-based food control system. Some areas of difficulty, including the dependence on high levels of food imports, are highlighted.     

Production of biofilm by Listeria monocytogenes in different materials and temperatures

Listeria monocytogenes, considered as one of the most important foodborne pathogens, is easily found on surfaces, particularly in the form of a biofilm. Biofilms are aggregates of cells that facilitate the persistence of these pathogens in food processing environments conferring resistance to the processes of cleaning and may cause contamination of food during processing, thus, representing a danger to public health. Little is known about the dynamics of the formation and regulation of biofilm production in L. monocytogenes, but several authors reported that the luxS gene may be a precursor in this process. In addition, the product of the inlA gene is responsible for facilitating the entry of the microorganism into epithelial cells that express the receptor E-cadherin, also participates in surface attachment. Thus, 32 strains of L. monocytogenes isolated from different foods (milk and vegetables) and from food processing environments were analyzed for the presence of these genes and their ability to form biofilms on three different surfaces often used in the food industry and retail (polystyrene, glass and stainless steel) at different temperatures (4, 20 and 30 °C). All strains had the ilnA gene and 25 out of 32 strains (78.1%) were positive for the presence of the luxS gene, but all strains produced biofilm in at least one of the temperatures and materials tested. This suggests that genes in addition to luxS may participate in this process, but were not the decisive factors for biofilm formation. The bacteria adhered better to hydrophilic surfaces (stainless steel and glass) than to hydrophobic ones (polystyrene), since at 20 °C for 24 h, 30 (93.8%) and 26 (81.3%) produced biofilm in stainless steel and glass, respectively, and just 2 (6.2%) in polystyrene. The incubation time seemed to be an important factor in the process of biofilm formation, mainly at 35 °C for 48 h, because the results showed a decrease from 30 (93.8%) to 20 (62.5%) and from 27 (84.4%) to 12 (37.5%), on stainless steel and glass, respectively, although this was not significant (p = 0.3847). We conclude that L. monocytogenes is capable of forming biofilm on different surfaces independent of temperature, but the surface composition may be important factor for a faster development of biofilm.     

A review of food safety and food hygiene training studies in the commercial sector

This review summarises the methods and results of studies conducted worldwide on the effectiveness of food safety and food hygiene training in the commercial sector of the food industry. In particular it focuses on those studies that have tried to evaluate the effectiveness of such training. Forty-six studies of food hygiene training are included which used some outcome measure to assess the effectiveness of training. The short-term nature and variety of measures used limited the majority of studies. The need for the development of evaluation criteria of effectiveness of food hygiene training is discussed.