Evolución de la contaminación de superficies durante los procesos productivos en pymes del sector cárnico

Abstract

Diseases transmitted by foods are due to ingestion of contaminated foods by microorganisms or chemical substances. They cover a wide spectrum of sickness, the most common is that one associated with gastrointestinal problems, and they constitute an important public health problem, as neurological, gynaecological, immunological or other symptoms that can even take the patient to death are also caused. Population growth and massive movement of people, together with new foods and ingredients and new consumption trends (based especially on fast food) appearance, are some of the factors which have helped to increase the percentage of people who have suffered a foodborne disease, as well as appearance of new foodborne diseases. Foods contamination can be produced in any stage of production, storage and distribution chain or conservation and preparation until its consumption. On the industrial level, we know that in order to prevent contamination, operating instructions of the processes and cleaning and disinfection activities have to be detailed and respected, and some standardised methodologies of prediction and control of contamination must be applied, especially a suitable HACCP (Hazard Analysis Critical Control Point). Biofilm presence in work surfaces of factories is the main cause of foods contamination apart from the one that come from working with alive animals for meat extraction, in case of meat products. Biofilms stuck on surfaces, are groups of microorganisms that generate extra-cellular polymeric substances which cover them, protecting them from unfavourable environmental conditions and from detergents and disinfectants attack. So maintaining surfaces in contact with foods in an optimal hygienic condition is of vital importance in order to avoid or minimise products contamination. To do this, it is indispensable a suitable definition and a correct implementation of a Cleaning and Disinfection Programme. The purpose of this is the destruction of pathogenic microorganisms in the surfaces and the medium that surround them, and the considerable reduction of microorganisms that damage foods, avoiding the existence of microorganisms, free or making up biofilms, in the surfaces. Many resources and efforts have been allocated to study systematics and products for cleaning of factories, and methodologies for sample gathering of hygienized surfaces and their analysis in order to evaluate the possible existence of microbiological contamination. However, studies that evaluate what happens in such surfaces with the passing of time in a work day have been barely developed, forgetting that, although we can start our production operations in aseptic conditions, microbiological contamination of some foods themself, as meat, can be collected by surfaces where they are worked and be transmitted to other foods that are placed there later. Taking this into account, in our study we have carried out, in a first stage, on the one hand an inspection of the hygienized surfaces in a series of small and medium enterprises (slaughterhouses, quartering rooms and cured cold meat factories), besides evaluate cleaning and disinfection methodologies, and, on the other hand, an evaluation of surfaces contamination in the middle of the work day and, in some cases, at the end of the work day, in order to know if correction measures of the possible contamination in surfaces during production activities strikes are accurate. In all cases mesophilic aerobics, enterobacter, Listeria monocytogenes and Salmonella were analysed. As a result of our study, we have obtained data that indicate that, despite the absence of a rigorous selection of cleaning and disinfection products in such companies, or an exhaustive training of the cleaning personnel to guarantee a strict implementation of the established methodologies, analysis results on hygienized surfaces are not bad when they are evaluated by common sampling with cotton buds. We have also seen that accumulation of contamination or its increment in the course of the work day, in surfaces in which take place a continuous renovation of the foods supported there, lead to very high microbiological values in most cases, and by virtue of that it is highly recommended to establish intermediate cleaning measures, at least part-time. We show in our study the possibility of implementation of some of them, practical and easy, to avoid quality of products made in the last hours deterioration. In the second part of our study, we have taken two classic surfaces of meat work factories, two cutting boards, to analyse them by updated methodologies that allow us collecting the sample contamination in a much more rigorous way than sampling with cotton buds (for which many studies indicate an effectiveness of existing contamination collection always below 30 %). Such boards (recently withdrawn from companies once applied cleaning and disinfection usual procedures) were evaluated by direct epifluorescent microscopy (DEM). Results obtained reveal the existence of important amounts of organic contamination and biofilms in such elements, even though, analysed by sample gathering with cotton buds, they are not suspicious of containing so high contamination.