Microbial food safety | Wine quality | Packaging safety and quality | Dairy quality and safety
Food Safety remains a major thrust, although nutritional and sensory quality are remain important. The overall objectives are to (i); advance the scientific knowledge relevant to both the descriptive, analytical challenges (presented here under risk assessment) and those which are of a constructive, solution-providing nature (mitigation tools and strategies) and (ii); the engagement of the industrial and civil community in the execution and application of this research. An overarching objective is to extend the palette of approaches to ensure that the work is successfully taken up by the intended end-user groups. To this end the industrial and civil society will more and more involved, via collaboration or other forms of participation. This will involve, amongst others, a closer contact with certain social science disciplines and a more “open-door” policy towards society as a whole.
Microbial food safety
Hazards of particular interest will include bacterial pathogens –Listeria monocytogenes – in particular but also Campylobacter spp. and Staphylococcus aureus, and migrants from food-contact materials. CBQF’s work in the development and application of models which describe phenomena fundamental to food safety – microbial inactivation and growth along the food chain and the migration of potentially toxic compounds from food contact materials – will be further developed with emphasis on making these models appropriate and useable. (…more)
The CBQF currently holds the largest collection of L.monocytogenes strains in the country, with 4893 food/food processing environment and 209 human clinical isolates.
The most important source of food contamination with L. monocytogenes is cross-contamination by the equipment and general food processing environment. Some strains cause persistent contamination of a food processing environment over several months/years, while others are recovered only sporadically. Therefore it may be necessary to launch ‘search and destroy’ operations in those food processing environments where persistent strains are identified, i.e. to locate the individual niches of persistent strains and to apply effective cleaning/sanitising regimes from laboratory research, to those specific areas. In the next two years, it is planed to identify particular niches of contamination with persistent strains in several cheese and processed meat plants and identify specific features contributing to the persistence of particular strains, the public health risk posed by these strains, and validate effective sanitation regimes for their control.
Campylobacter spp. is the leading cause of zoonotic enteric infections in most developed and developing countries. In the last few years, CBQF has been investigating the occurrence, levels, sources and routes of infection by this pathogen in raw chicken and the potential of these strains as human pathogens. Comparison of food with clinical isolates has also been performed. This work will expand in collaboration with as many hospitals and chicken producers as are willing to collaborate.
CBQF has been investigating the occurrence of S.aureus in foods and food processing environments. The prevalence of the pathogen in several groups of the population (food handlers, children and health professionals) has also been performed. Studies will continue on the characterization of the isolates concerning their virulence traits, mainly enterotoxin production and antibiotic resistance.
Safety and quality of traditional meat products
Physicochemical and microbiological characterization of several Portuguese traditional meat products is being performed aiming to evaluate food-poisoning risks associated with these products; selecting microorganisms naturally present showing inhibitory properties and having the necessary characteristics to be used as starter cultures.
Modelling of dynamic food safety phenomena
Inactivation of bacterial pathogens and the behaviour of these in the food chain is both important for description of the problem (Risk Assessment) and in developing strategies for their mitigation. The data gathering and incorporation into useable models will be performed jointly with the Risk Mitigation group. Regular workshops with industry and official bodies (2 per year at least) will continue to be held to ensure that all actors are updated.
Concerning wine as a product line; the metric of wine flavour, is the key issue to industry when it attempts to provide the consumer a pleasurable and recognizable “sensory experience” that will trigger a desire to repeat it. The definition of wine sensory quality has been an ongoing major topic of research for the last decades but the complexity of the chemical and biochemical mechanisms occurring during wine production, cannot be addressed by selecting iteratively, molecule by molecule and measuring the respective impact on quality. Therefore high throughput methodologies are required and are being developed, employing a non-target approach, using a multivariate array of sensors. The proper supervision and interpretation of this data driven process will allow to (i) monitor chemical changes during the process and (ii) to classify chemical profiles according to sensory quality.
The precocious oxidation of white wines is a major concern in the modern industry and we have taken a leading position in this field. A number of means of measuring the resistance to oxidation have been developed and the best, based on potentiometry, will be further refined..
Red wines are both an area of study and a model in which the interaction of small fruit phenolics interact with bacterial cells. These studies will employ a proteomic approach to further study the sub-lethal, physiological effects that phenolics have on, in the first instance, wine LAB. This is be extended to encompass the effects of these compounds on the intestinal microbiome.
The role of aromatic sulphur-containing compounds on the quality of wines has been studied for some time but new insights are being sought as to the role of yeast nutrition on the development of these critical odorants. CBQFs original work in this area will be further developed into the aminoacid metabolism.
Packaging safety and quality
Migration of chemical hazards from food contact materials. A probabilistic approach has been developed for describing the potential exposure risk from migrants from food-contact materials. This employs consumption data and mass transfer based models and both data streams will be refined in the following ways. (i) Mass transfer data (and subsequent models) for migration into solid foods, from inks and from silicone cooking utensils; (ii) Structure Activity Relationships – and how they modulate migration behaviour and (iii) exposure of of children to migrating hazards via widened and improved consumption surveys.
Dairy quality and safety
Traditional cheeses are an important area of study and in particular the impact of chemical anchors on the flavour of ovine cheeses.
Researchers working in the above topics: