GoodFood Bit(e)s

GoodFood project deals with Food Safety and Quality and, although multidisciplinary, originates as an Information Society Technology (IST) initiative, which is an interesting and complementary viewpoint when talking about food. From this interesting side road, important contributions can be made, but given that the Agrofood arena is extremely large, it is easy for an IST specialist to miss a general view. These GoodFood Food ‘Bites' are intended to offer to any interested people -non specialists on Food Technology- elements to build up a little bit of knowledge.

Apart from statements extracted from textbooks and our own experience, some of the information contained in these ‘bites' has been elaborated from (and in some cases merely transcripted from) the following very interesting reports that deserve their due merit, and can be further explored by any interested reader :

(2002) Report from Tekes (National Technology Agency of Finland ) ‘Technological Trends and Needs in Food Diagnostics'

(2002) Expert Report from the Institute of Food Technologist ‘Emerging Microbiological Food Safety Issues. Implications for control in the 21st century'

(2004) Report from the French Senate ‘Les nouveaux apports de la science et de la technologie à la qualité et à la sûrete des aliments'

GoodFood logos explanations

Apart from nice and witty pictures logos should convey some meaning. In Goodfood material a couple of logos can be seen. Here follow the rationales that are behind them.

This first logo was designed by SSSA.

The central point is a well known masterpiece of Giuseppe Arcimboldo (1530-1593). Our intention was to embody in this image the popular saying ‘we are what we eat'. This statement of popular wit, which almost has a version in every idiom, is in fact of German origin: Man ist, was man isst (probably one of the few examples of musicality of the German language that a non-German can appreciate). With this sentence and this image we want to make evident how important for our wellbeing is not only food but its proper control in terms of safety and quality. In our logo the Arcimboldo painting is divided in sectors to exemplify that when we talk about food we must consider the whole food chain , which consists of different steps in which there is room for improvements regarding food safety and quality.

The second logo was designed by CSIC-CNM

In this case the logo intention was to show that food monitoring is the technological objective of GoodFood. In this way, food is the main target of all the ambient intelligence based in Microsystems that will be developed in the project. Our aim is to provide tools that could be deployed in order to provide closer, more automatic and more frequent control of food with the aim of increasing the safety and quality of the food chain.

In a way, both logos are a graphical form of GoodFood logo: bringing the lab to the foodstuff… from the land to the market.

Agrofood: one of the earliest innovation arenas.

Possibly we cannot allow us renouncing to innovate in such a traditional arena as agrofood. Probably we can not even avoid it. But, in any case, the word traditional should not misguide us: innovation in the agrofood is not a recent matter. Unlike other fields, the onset of its evolution has not been the information revolution, nor the previous industrial revolution by that matter. Agrofood is so linked to our survival that it hardly could have waited so long. Producing enough food to satisfy the needs of a growing human population means obtaining raw material in sufficient quantity and quality. The search for sufficient resources has resulted in countless innovations over the last ten thousand years, from the appearance of agriculture to present times. Not to mention the social leaps, the organizative evolution enabled by agrofood procedures. This social transformation took us from hunter-gatherers to herdsmen and then to sendentary settlers allowing to divert some precious time and energy from mere survival to civilization.

Here follow a few examples of those early innovations in the agrofood field. In the case of agriculture, for instance, irrigation began 7000 years ago and olives were first converted into oil at the same time in Egypt. Crop rotation was introduced in the 17th century, and the use of chemical fertilizers, the mechanisation of labours and first phytosanitary treatments date back to the 19th century. In livestock farming, animal selection started 6000 years ago and stabling dates back to the 14th century. In the 19th century intensive livestock farming took form and the first genetic improvements were introduced by directed crossbreeding. Intensive fishing also dates back to the 14th century. The overfishing of the 20th century has driven fish industry into aquaculture, which again is not a rather new discipline. Mollusc aquaculture was know in the 1st century: Romans harvested mussels and Japanese oysters. Even 4000 years ago fresh water carps were cultivated in China.

Food quickly goes bad due to the action of microorganisms (bacteria & fungi), the catalytic action of enzymes and it also looses characteristics by physical reactions (as when bread hardens). Our ancestors did not know the ultimate reasons but they knew that food spoiled, that raw materials riped according to their own biological rythm and that it was not enough to store them to have them available anytime, so there was always a need of promoting their preservation for enabling its consumption anytime, anywhere.

The benefits of drying food were long known. Salting and smoking were traditional ways of drying. Salting herring and cod (allowing a year around conservation) managed to feed the growing European population in the 13th and 14th century. Modern lyophylisation (also known as freeze drying) was perfected in 19th century and incorporated in the food industry in 1958, but long ago the Incas took profit of the Andean Altiplano weather conditions (low atmospheric pressure and harsh cold at night) to preserve food in such way (incidentally, the same process that helped preserving the Inca mummies).

Freezing by itself has been used since ancient times but its modern use began for preserving food during transport (fish, England XVIII). 1929 marks the onset of domestic freezing that brought the production of frozen food in household portions, one of those examples of mutual impact of agrofood and social evolution.

But talking of food preservation we should not forget heat. 10,000 years ago cooking food in recipients was a generalized practice. Heat makes food go bad more slowly (eliminates microorganisms), but also give food a different taste and facilitates digestion on many cases (like in the case of pulses). The employ of heat has known different forms, from the traditional smoking to the new electromagnetic heating or irradiation, not forgetting the bain marie, the 1679 pressure cooker (that lead to the autoclave) and pasteurisation (1860).

Heat is also intimately linked to canning as a preservation process. Appert led the way sterilising sealed jars in 1809 as a result of a 1795 prize set by Napoleon to whom could find a means of preserving food for army and navy use (another agrofood innovation led by a mobility ‘social’ demand). In 1810 Peter Durand of England patented the use of tin-coated iron cans instead of bottles.

More about historic canning and bottling: ancient cultures stored cereals in silos in the ground and learnt to consume the oxigen with a fire before sealing them. Greek sealed amphoras as well for transport and storing. Glass bottles could be seen scarcely in Rome, but they were not more widely spread till XVII. On the other hand, the wooden barrels with metal hoops, which are of celtic origin, were quite common in Rome 2000 years ago.

Another traditional way of food preservation was fermentation. In this case it is the action of microorganisms what creates suitable conditions for preserving food, whilst also modifying the product giving it new characteristics, taste and aroma. Fermentation can take different forms: dairy, alcoholic, malolactic, acetic, citric acid. Different fermentation products are dairy products, sausages & ham, vinegar... and of course which ancient civilization has not brewed its own wine, beer, cider, alcohol fermented milk or corn...?

Food preservation

Since most foods either carry or eventually acquire bacteria, molds, or yeasts, microorganisms are the major causes of food spoilage. Other factors leading to deterioration or spoilage are the natural enzymes present in some foods and various chemical reactions, particularly oxidation.

Among the major processes for food preservation are cooling or freezing, dehydration, canning, smoking, salting, candying, and the addition of chemical preservatives and inhibitors. Often several principles are applied in combination, such as freeze drying.

Techniques for preserving food from natural deterioration, following harvest or slaughter, date to prehistoric times. Among the oldest methods of preservation are drying, refrigeration, and fermentation. (The practice of preserving food can be traced to prehistory, when fruits and vegetables were dried, cereal grains were parched, and fish and game were salted and dried. These age-old methods developed very slowly and were purely empirical--fermentation, drying, smoking, and curing with salt being the principal techniques.) Modern methods include canning, pasteurization, freezing, irradiation, and the addition of chemicals.

The modern objective of food preservation includes concern for food quality, for economy, and, especially, for convenience in addition to the prevention of spoilage. Colour or appearance, flavour, texture or consistency, and nutritive value are the major quality factors.

Bacteria and fungi (yeasts and molds) are the principal types of microorganisms that cause food spoilage and food-borne illnesses. Foods may be contaminated by microorganisms at any time during harvest, storage, processing, distribution, handling, or preparation. The primary sources of microbial contamination are soil, air, animal feed, animal hides and intestines, plant surfaces, sewage, and food processing machinery or utensils.

Bacteria are unicellular organisms that have a simple internal structure compared with the cells of other organisms. Bacterial populaton grows as a result of the division of one bacterial cell into two identical bacterial cells, a process called binary fission. The factors that influence the growth of bacteria include nutrient availability, moisture, pH, oxygen levels, and the presence or absence of inhibiting substances (e.g., antibiotics). The nutritional requirements of most bacteria are chemical elements such as carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur, magnesium, potassium, sodium, calcium, and iron. The bacteria obtain these elements by utilizing gases in the atmosphere and by metabolizing certain food constituents such as carbohydrates and proteins.Temperature and pH play a significant role in controlling the growth rates of bacteria. Bacteria may be classified into three groups based on their temperature requirement for optimal growth: thermophiles (55°-75° C), mesophiles (20° -45° C), orpsychrotrophs (10°-20° C). In addition, most bacteria grow best in a neutral environment (pH equal to 7). Bacteria also require a certain amount of available water for their growth. Growth may be controlled by lowering the water activity--either by adding solutes such as sugar, glycerol, and salt or by removing water through dehydration.

The two types of fungi that are important in food spoilage are yeasts and molds. Molds are multicellular fungi that reproduce by the formation of spores (single cells that can grow into a mature fungus). Spores are formed in large numbers and are easily dispersed through the air. Once these spores land on a food substrate, they can grow and reproduce if conditions are favourable. Yeasts are unicellular fungi that are much larger than bacterial cells. They reproduce by cell division (binary fission) or budding.

The conditions affecting the growth of fungi are similar to those affecting bacteria. Both yeasts and molds are able to grow in an acidic environment (pH less than 7). The pH range for yeast growth is 3.5 to 4.5 and for molds is 3.5 to 8.0. The low pH of fruits is generally unfavourable for the growth of bacteria, but yeasts and molds can grow and cause spoilage in fruits. The amount of available water in a food product is also critical for the growth of fungi.

Enzymes are large protein molecules that act as biological catalysts, accelerating chemical reactions without being consumed to any appreciable extent themselves. The activity of enzymes is specific for a certain set of chemical substrates, and it is dependent on both pH and temperature.

The living tissues of plants and animals maintain a balance of enzymatic activity. This balance is disrupted upon harvest or slaughter. In some cases, enzymes that play a useful role in living tissues may catalyze spoilage reactions following harvest or slaughter. The chemical reactions catalyzed by the enzymes result in the degradation of food quality, such as the development of off-flavours, the deterioration of texture, and the loss of nutrients

Although microorganisms are usually thought of as causing spoilage, they are capable under certain conditions of producing desirable effects such as certain types of fermentation. An important food preservation method combines salting to control microorganisms selectively and fermentation to stabilize the treated tissues.

LOW-TEMPERATURE PRESERVATION

Storage at low temperatures prolongs the shelf life of many foods. In general, low temperatures reduce the growth rates of microorganisms and slow many of the physical and chemical reactions that occur in foods.

Rrefrigeration is used to store foodstuffs at low temperatures, thus inhibiting the destructive action of bacteria, yeast, and mold. Many perishable products can be frozen, permitting them to be kept for months and even years with little loss in nutrition or flavour or change in appearance. Before mechanical refrigeration systems were introduced, ancient peoples, including the Greeks and Romans, cooled their food with ice transported from the mountains. Wealthy families made use of snow cellars, pits that were dug into the ground and insulated with wood and straw, to store the ice. In this manner, packed snow and ice could be preserved for months. Stored ice was the principal means of refrigeration until the beginning of the 20th century, and it is still used in some areas.

In India and Egypt evaporative cooling was employed. If a liquid is rapidly vaporized, it expands quickly. The rising molecules of vapour abruptly increase their kinetic energy. Much of this increase is drawn from the immediate surroundings of the vapour, which are therefore cooled. Cooling caused by the rapid expansion of gases is the primary means of refrigeration today. The technique of evaporative cooling has been known for centuries, but the fundamental methods of mechanical refrigeration were only discovered in the middle of the 19th century.

Freezing

It is a method of preserving food by lowering the temperature below 0ºC to inhibit microorganism growth. The method has been used for centuries in cold regions, and a patent was issued in Britain as early as 1842 for freezing food by immersion in an ice and salt brine. It was not, however, until the advent of mechanical refrigeration that the process became widely applicable commercially. In 1880 a cargo of meat shipped from Australia to Britain under refrigeration accidentally froze, with such good results that the process was at once adopted for long-distance shipments and other storage.

CONTROLLING WATER ACTIVITY

Foods containing high concentrations of water are generally more susceptible to deterioration by microbial contamination and enzymatic activity. The water content of foods can be controlled by removing water through dehydration or by adding solutes to the food. In both cases the concentration of solutes in the food increases and the concentration of water decreases.

Foods with substantial acidity, when concentrated to 65 percent or more soluble solids, may be preserved by mild heat treatments. High acid content is not a requirement for preserving foods concentrated to over 70 percent solids. Jellies and other fruit preserves are prepared from fruit by adding sugar and concentrating by evaporation to a point where microbial spoilage cannot occur. The prepared product can be stored without hermetic sealing, although such protection is useful to control mold growth, moisture loss, and oxidation.

Drying

The principal methods of drying, or dehydrating, food are by forced-air drying, vacuum drying, or vacuum freeze-drying. Each of these methods involves adding heat to aid in the removal of water

Curing

Curing reduces water activity through the addition of chemicals, such as salt, sugars, or acids. There are two main types of salt-curing used in the fish industry: dry salting and pickle-curing. In dry salting the butchered fish is split along the backbone and buried in salt (called a wet stack). Brine is drained off until the water content of the flesh is reduced to approximately 50 percent (the typical water content of fresh fish is 75 to 80 percent) and the salt content approaches 25 percent. In pickle-curing, fish are preserved in airtight barrels in a strong pickle solution formed by the dissolving of salt in the body fluids. This curing method is used for fatty fish such as herring

Smoking

Traditionally, smoking was a combination of drying and adding chemicals from the smoke to the fish, thus preserving and adding flavour to the final product. However, much of the fish smoked today is exposed to smoke just long enough to provide the desired flavour with little, if any, drying. These products, called kippered fish, have short shelf lives, even under refrigeration, since the water activity remains high enough for spoilage organisms to grow.

THERMAL PROCESSING

Thermal processing is defined as the combination of temperature and time required to eliminate a desired number of microorganisms from a food product.

Canning

Nicolas Appert, a Parisian confectioner by trade, is credited with establishing the heat processing of foods as an industry. In 1810 he received official recognition for his process of enclosing food in bottles, corking the bottles, and placing the bottles in boiling water for various periods of time. In the same year Peter Durand received a British patent for the use of containers made of glass, pottery, tin, or other metals for the heat preservation of foods. In 1822 Ezra Daggett and Thomas Kensett announced the availability of preserved foods in tin cans in the United States. Tin-coated steel containers, made from 98.5 percent sheet steel with a thin coating of tin, soon became common. The establishment of the canning process on a more scientific basis did not occur until 1896, when the microorganism Clostridium botulinum, with its lethal toxin causing botulism, was discovered by Émile van Ermengem. The thermal processes of canning are generally designed to destroy this microorganism. Sterilization requires heating to temperatures greater than 100° C. However, C. botulinum is not viable in acidic foods that have a pH less than 4.6. These foods can be adequately processed by immersion in water at temperatures just below 100° C.

Pasteurization

Pasteurization is the application of heat to a food product in order to destroy pathogenic (disease-producing) microorganisms, to inactivate spoilage-causing enzymes, and to reduce or destroy spoilage microorganisms. The relatively mild heat treatment used in the pasteurization process causes minimal changes in the sensory and nutritional characteristics of foods compared to the severe heat treatments used in the sterilization process.

The temperature and time requirements of the pasteurization process are influenced by the pH of the food. When the pH is below 4.5, spoilage microorganisms and enzymes are the main targets of pasteurization.The typical processing conditions for the pasteurization of fruit juices include heating to 77° C and holding for 1 minute, followed by rapid cooling to 7° C. In addition to inactivating enzymes, these conditions destroy any yeasts or molds that may lead to spoilage. When the pH of a food is greater than 4.5, the heat treatment must be severe enough to destroy pathogenic bacteria. The typical heat treatment used for pasteurizing milk is 72° C for 15 seconds, followed by rapid cooling to 7° C. Other equivalent heat treatments include heating to 63° C (145° F) for 30 minutes, 90° C (194° F) for 0.5 second, and 94° C (201° F) for 0.1 second. The high-temperature-short-time (HTST) treatments cause less damage to the nutrient composition and sensory characteristics of foods and therefore are preferred over the low-temperature-long-time (LTLT) treatments.

Since the heat treatment of pasteurization is not severe enough to render a product sterile, additional methods such as refrigeration, fermentation, or the addition of chemicals are often used to control microbial growth and to extend the shelf life of a product.

Foodborne illness

There are more than 200 known diseases caused by pathogens, their toxins, or other substances transmitted through food. A cause has not been identified for more than half of all those recognized foodborne diseases. Also, sometimes new information allows to link illness to activities or foods that had previously been unrecognized as a source of foodborne illness. Some pathogens cause a gret number of illnesses but the fatality is very small. Others cause few illnesses, but many of those illnesses are fatal. Once eaten a contaminated food, the onset of the symptons can vary from less than one hour to several weeks. Again, the length of illness varies greatly. Some illnesses resolve within a day or two, but others linger for weeks, may cause chronic disease, and even death.

Foodborne illness can be reduced to three factors: the pathogen, the host, and the environment in which they interact.

The host age, gender, place of residence, ethnicity, unerlying health affects the individual’s susceptibility to infection and illness. Knowledge, attitudes and practices related to health and diet affect exposure to pathogens. Susceptibility to infectious disease is the inability of the host’s body to prevent or overcome invasion by pathogenic microorganisms. Susceptibility is increased by conditions that alter the host defenses and suppress the function of the immune system. Many factors cause changes in the immune system function, such as age, health conditions (e.g. AIDS, cancer), pregnancy, nutritional satus, and antacid/ medication use. An important contributor to microbial pathogenicity and human illness is the changing human population and its behavior. The portion of the population that is elderly continues to grow, and large numbers of individuals have conditions necessitating the use of immnuosuppressive drugs or drug combinations with unknown effects, potentially increasing their susceptibiity to foodborne illnesses. Unlike physiology factors that mostly affect the host susceptibility, the exposure to foodborne pathogens are tied to human behaviour, specifically consumption, food handling, and preparation proceures. The combination of proper hygiene and sanitation related to food handling and preparation, appropriate methods of refrigeration and freezing, and thorough cooking of foods comprises a very effective aproach to preventing foodborne illness. An approach that should not be underestimated since food manufacturers cannot consistently provide foods guaranteed to be free of pathogens. In fact, as new issues emerge, some will be best addressed through the application of control technologies during food production and processing, but others may be best addressed at the consumer level through modification of exposure or susceptibility.

Pathogenicity is the ability to casue illness. Some pathogens cause illness by infecting the human host, while others produce toxins that cause illness when consumed. Foodborne illness is caused then by viral, bacterial, or parasitic infections; toxins produced during microbial growth in food; and toxins produced by algal and fungal species.

The infectious dose varies greatly depending on the pathogen. In some cases, it may take more than 100 millions cells of one pathogen to cause illness, while the infectious dose of an extrremelly virulent pathogen might be less than 10 cells. Some pathogenic microorganisms are significantly more virulent tant others. Virulence may vary within species, subspecies, and even different strains.

Moreover, pathogens are living microorganisms that rapidly adapt and evolve. In fact, at optimal growth conditions a pathogen could evolve in a matter of hours. They do it in two ways, by mutation or by genetic exchange. Environmental forces may select a mutation that confers an advantage in the face of a particular adverse condition (such as acidity and temperature). Those adverse conditions are called environmental stress, and some we use to control pathogens proliferation. In addition, environmental stresses can create microorganisms with greatly enhanced mutation frequencies, increasing their adaptation opportunities. These new microorganisms also may more readily share genetic material with other remoted related species. Transfer of the genetic material encoding virulent factors may create rapidly a new pathogen from a previous unpathogenic microorganism.

Like any use of antibiotics in medicine, the addition of antibiotics to animal feed or production agriculture has the potential to promote the development and dissemination of antibiotic-resitant microorganisms. In addition, antibiotics, like other environmetnal stresses, may accelerate the rate of microbial mutations.

Pathogenic microorganisms can be introduced at any point in the food chain. Some pathogen contamination is the result of production agriculture conditions, because the farm environment has so many oportunities for contamination that complete control is impossible. Other times, contamination occurs from environmental sources during processing. Some pathogens are introduced during handling and food preparation, either through inadequate human sanitation or through cross-contamination by contact witho other foods.

Pathogen control can be divided into three goals: prevent pathogen contamination, inactivate pathogens present in the food, and prevent or limit pathogen growth. Companies take numerous steps to prevent or minimize contamination of raw ingredients and unfinished product by using god manufacturing practices. The processing technologies used to inactivate pathogens vary by food product. Foods may be washed or rinsed with organic acids, sanitizers or other antimicrobial agents. Thermal processing heats a particular food to a specific temperature for a given time. Cooking and pasteuriztion are examples of this thermal processing. Non thermal processing technologies use other means to inactivate pathogens, such as pulsed electric fields, high pressure, or ultraviolet radiation. Other processing methods may change the characteristics of the food in a way to control pagthogens. For example, fermentation, drying and salting all change parameters of the food in a controlled manner to inhibit the pathogen growth.

We cannot expect to solve the problem of microbiological food saftey to the point of havig a zero risk food supply. Even a food free of pathogens when it leaves the processing facility can become contaminated by the time it is consumed.

Moreover, we want to consume safe food but we do not want to eat pills. Some foods cannot withstand rigorous processsing for safety and retain satisfactory sensory characteristics and sometimes nutritional profiles. Therefore, not all foods are made available in sterile conditions. The consumer demand for safe ‘fresher’ products is the driving force for alternative processing technologies that in spite of their potential will not be able to control all pathogens in all foods.

Modern Food Safety Management (I). Risk analysis.

According to the Codex Alimentarius Commission on food hygiene, food safety is the assurance that food will not cause harm to the consumer when it is prepared and/or eaten according to its intended use. This definition is, however, hampered by the caveat that an absolute level of food safety cannot be obtained. It has therefore been recognized that instead, an acceptable level of risk has to be defined.

Risk analysis is a management tool for governmental bodies to define an appropriate level of protection and establish guidelines to ensure the supply of safe food. Risk in this context is defined as a health effect caused by a hazard in a food and the likelihood of its occurrence. Risk Analysis is useful to decide which hazards should be prevented, eliminated or reduced to acceptable levels.

Risk analysis consists of three elements:

Risk assessment is the use of scientist data to identify, characterize and measure the risks involved with a food. The criteria for measuring those risks are the incidence and severity of food related illnesses, the principal risk factors associated with illness, the number and predisposing conditions of high-risk populations, and the prevalence and virulence of the involved pathogen (or other illness origin). In food safety regulations and policy development, risk assessment should not only consider the likely impact of a particular food safety problem and protective measures but also the urgency and controversy surrounding an issue. The final risk estimate should always contain information about assumptions made, and the degree of the variability and uncertainty in all steps of the risk assessment procedure.

Risk man????????º???agement is defined as the process of weighing policy alternatives in the light of the results of risk assessment and selecting and implementing appropriate control options. The outcome of the risk management process is the development of standards, guidelines and other recommendations for food safety. If necessary, controls and regulatory measures are adopted.

Risk communication is defined as an interactive process of exchange of information and opinion on risk among scientists, policy makers, and the public during the risk assessment and management process.

Throughout the world, food production, preparation and distribution have become increasingly complex, and raw materials are often source globally. New primary production technologies and food manufacturing practices are introduced all the time, food consumption patterns and the demographic structure of many countries change continuously. The implementation of Food Safety should be seen as an ongoing process, which is influenced by environmental, socio-economical, political and cultural factors.
New, flexible tools are required for evaluating and managing new food safety challenges.

Microbiological criteria have historically been used to accept/reject food lots at different steps of the food chain. These criteria are currently thought of limited use, though. Pathogens of concern often have a low incidence rate in a food-stuff or raw materials and are frequently not equally distributed, leading to statistical limitations for the usefulness of food testing.

This is why, taking the safety assurance as a goal, the HACCP approach should be consider wherever possible in the production chain moving the focus from food testing to better process control. Sure, a Food Safety Objective, which is a????????º??? statement of a maximum frequency and/or concentration of a microbiological hazard in a food at the time of consumption that provides an appropriate level of consumer protection, must be first identified. By projecting the possible growth of bacteria between production and consumption, a processing safety objective at the time of the production can be established. This can be used to define performance criteria for the production process. Now the process criteria and product criteria that will be needed to achieve this performance can be defined. A process criterion might be time and temperature of a processing step, a product criterion might be the pH of a product, and for these parameters the proper critical limits can be set.

In any case, food-borne microorganisms are continuously changing due to their inherent ability to evolve and their amazing capacity to adopt to different forms of stress, so an eye should be kept on the direct testing of the presence of pathogens in food from time to time and improved methods would be always welcome.

Modern Food Safety Management (II). Food Safety Objectives, Good Manufacturing Practises and Hazard Analysis and Critical Control Points

Food safety management is a flexible and science based framework built on Food Safety Objectives (FSOs), which in turn are based on risk assessments and implemented with good manufacturing practices (GMPs) and Hazard Analysis and Critical Control Points (HACCP) systems, thus linking public health food safety goals and performance standards.

An FSO is a statement of the maximum frequency and (or concentration of a microbiological hazard in a food at the time of consumption that provides the appropriate level of protection. An FSO helps translate the public health goal into measurable objectives during production and processing. An FSO is based on risk assessment, which clearly identifies the hazard being analysed, assesses possible exposure to the hazard, characterizes the nature of the hazard, and characterizes the risk associated with the hazard. Key considerations during risk assessment include how much of the pathogen is required to cause illness, the severity of the illness, and the portions of the population most susceptible and most likely to be exposed to the hazard. Because the FSO must be met at the time of consumption, it must take into account the likelihood that the pathogen would multiply under typical conditions during storage and distribution.

HACCP is a management tool used by food manufacturers to enhance food safety by implementing preventive measures at certain steps of a process. It also can be applied at other points in the food system. HACCP (which originally was a preventive scheme proposed by the NASA in 1959 to avoid microbial contamination in astronauts food) has seven principles:

1 conduct a hazard analysis
2 determine the critical control points
3 establish critical limits
4 establish monitoring procedures
5 establish corrective actions
6 establish verification procedures
7 establish recordkeeping and documentation procedures

HACCP has not been limited to food processing. It has been used worldwide to improve food safety in distribution, food service, and retail. (Even has been used to develop tips on proper food handling and preparation procedures in the home). However, HACCP may not be appropriate for all circumstances. It is not possible to have a valid HACCP plan when a scientific analysis does not identify any point that meets the critical control point criteria. The application of HACCP to primary production is particularly limited because all its principles generally cannot be achieved. Well-defined, science based good agricultural practices should be further developed for specific commodities.

GMPs are prevention oriented practices. At the manufacturing step, they involve equipment design and cleaning, facility sanitation, worker sanitation and pest control. Food safety management does not end once a food is processed. GMPs are designed to prevent the food from recontamination while it remains at the processing facility. For some foods, certain types of packaging not only protect product quality and facilitate distribution but also prevent contamination and minimize pathogen growth. Storage conditions, such as limited humidity and refrigeration temperatures, are key methods to prevent or minimize pathogen growth for many foods.

Although microbiological testing has may uses, sometimes other approaches are necessary to effectively and efficiently reach public health food safety goals. Microbiological testing of finished food products has statistical and technical limitations that must be recognized when it is used. As the amount of microbial contamination gets low, the chances of accurately identifying contaminated food plummets, especially when the contamination is not uniformly distributed throughout the food. In addition, our current testing methods are not always sufficiently sensitive to find low level contamination. As a result negative test results do not guarantee that a food is not contaminated with pathogens. As the amount of contamination in the food decreases, the food safety emphasis should focus on further controlling processing conditions through the application of science-based HACCP systems.

Examples of science based food safety improvement in the last past centuries are the refrigeration of perishable foods, pasteurization of milk, and commercial canning of low acid foods. Past food policies have been more the combinatorial result of addressing specific problems than the result of a comprehensive and coordinated effort. In modern food safety policies information is key. Food safety is a moving scenario (the pathogens change, the foods available change, their origin broadens, the processing technologies and the control techniques change as well) and the related new information has to be incorporated as it becomes available. This will guarantee the maximum benefit for the resources invested in food safety.

Appropriate and aggressive data collection throughout the food production and processing system is essential for valid risk assessments and the resulting food safety improvements. Improved analytical systems are needed to gather better data about pathogens in the food production and processing environments. More sensitive quantitative methods are necessary for assessing pathogen growth, survival and inactivation.

Size, portability, cost, ease of use and connectivity advantages of microsystems increase the opportunity and number of controls, they may be done closer to the foodstuff and grant a faster response to alarm conditions. Their promptness can be very useful in the safety loop of HACCP systems, and their availability could help defining new critical points that otherwise would be unpractical.

Food Diagnosis and new tools

Due to some of its applications, GoodFood, a Priority II Integrated Project devoted to microsystems and communications, comes into contact with biotechnology. In this way, GoodFood is aiding to cross-link biotechnology, one of the key technologies of the so called Society of Knowledge, with the stepping stones of the Society of Information (small technologies, networks and communications).

Food diagnosis is a derivative of a broder diagnostic area involving medical, veterinary and environmental scenarios as well. Innovations and the application of new technologies to the diagnostic arena is apealling because they can prove useful to so many different fields. Although, this wide commercial potential can find problems at the final implementation phase due to different markets constraints and legal regulations, the synergies between those different fields are there at least at R&D level.

Food diagnosis is rather new and can still be seen as an emerging bussiness niche, and as such it still faces some uncertainties. Undoubtely the interest on food analysis can only grow due to the ever increasing demand of food safety. This evolution is mostly driven by consumers concerns and public bodies interest in reinforcing the confidence on public food safety systems somewhat battered in recent times. How food safety is managed has a huge impact on the image of food processing companies as well. However, food companies are not exactly compelled to include new food saftey methods if they imply additional costs since it is not clear that consumers will accept to pay an extra cost on something they assume they have to be provided safe by itself. So it is quite convenient that new methods for food safety and quality assessment bring not only procedural benefits but be cost effective as well. The possibility, for instance, of these methods to be extended to improve different food processing stages could pave the way to long term economical profits, boosting the interest of introducing new technologies from the food companies' point of view.

The problem with current testing practice is that it is a slow process, even a several days process in some cases. This is a large time span separating the problem origin and the corresponding corrective action. In the meantime costs due to spoiled raw materials or products build up and even the corporative image can suffer if food safety is in question too. There is an obvious need of faster testing methods. However, the penetration and acceptance of already developed rapid methods has been slow, probably due to the fact that one-shift methods are still rare. Breakthroughs in biosensors/microsystem based solutions should be welcome if they enable fast and sensitive enough systems that take us closer to the real time diagnosing ideal. Microsystems potentialities can lead as well to the development of low cost, simple and automated equipment that could be made portable or placed on-site. These on-line characteristics can make microsystems useful not only assessing food quality and safety, but finding applications at process control level and then impacting positevily on production costs.

Microsystem based solutions can be useful as well in reinforcing food safety management tools. Traditional approaches rely on end-product testing for microbiological presence. However there are cases, specially associated to pathogens that occurr in low numbers and are non-randomly distributed, where this end-product testing will lead to an unacceptable rate of false-positive and false-negative results. For this reason, food safety management schemes have lately moved from product safety to process safety. In those schemes, prevention is the main goal. Food Safety at the manufacturing stage is seeked through the adoption of GMP/GHP (Good Manufacturing and Hiygiene Practices), previous good agricultural practices as well, and by including safety related controls in the manufacturing process control. This approach is linked to the so called HACCP (Hazard Analysis Critical Control Point) procedures that consist of a systematic, scientific approach to identify specific hazards and stablish appropriate control systems at the critical steps of the production chain where they can have a more positive influence in product safety. However, the lack of reliable data at these critical steps could limit the usefulness of this approach. For instance, microbiological parameters can not be used as critical control points parameters because current detecting methods are not fast enough for the efficient feed-back that an HACCP approach demands. Fast and on-site biosensors/microsystems could be of real use from this point of view.

GoodFood Project: A description

The rationale

Food safety and quality assurance play an important role for the improvement of the quality of life of all citizens. Nowadays agrofood industry relies mainly in tests performed with laboratory based systems, which are well accepted due to the good accuracy, but lack of flexibility and normally are time consuming and expensive. Thus, there is a real interest in looking for new solutions based on novel technologies. Immunosensors, DNA chips, electrochemical devices, portable multisensing systems, etc…, may be of high importance in the future if they benefit from the introduction of Micro(nano)technologies and systems. The combination of microfabrication, nano and bio technologies, computer sciences and advanced communication strategies will lead to a novel series of instrumentation fully adapted to the requirements of the agrofood field, as they will bring well appreciated advantages on:

o Miniaturisation, allowing portable instrumentation and minimally invasive systems for field and at-line tests.
o Fast response, enabling the time reduction of the assays and thus on-line food screening applications.
o Cost reduction of the sensing devices and of the reagents required, allowing more extensive tests of the full agrofood chain.
o Electronics reading, enabling the implementation of smart communication strategies and local decision-taking nodes which are the basis of autonomous systems.

Micro(nano)systems may be very adequate for food screening applications because of a reduction of time for tests and of the reagents required, and because of the improvement of the capabilities of communication that enables setting a smart information loop useful for risk management at all stages of the food chain. Microsystems solutions may be also readily applied to the improvement of the food production when combined with smart decision taking systems

What to understand by Micro(nano)systems

Micro(nano)systems, also known as MNEMS, are miniaturised systems, that is, a gathering of elements interacting orderly among them and with the environment. In the more general case, you can single out in them sensors, processing units and actuators. Micro(nano)systems technologies derive from well known and always evolving silicon technologies. The combination of standard microelectronic processes with silicon micromachining techniques has opened the door to the fabrication, in high numbers and at low cost, of devices with more degrees of freedom and more transduction principles in their interaction with the environment, thus giving rise to a huge variety of smart sensors, actuators and systems that take advantage of scaling factors that occur when going down from macro to micro. Further technological pushes, demand pulls, new processes and materials, advanced miniaturization tools and multidisciplinary approaches are extending these capabilities to different fields of application and also into the nano domain.

Information based Food Safety & Quality

Why mixing micro(nano)technologies and Food Quality and Safety? Why considering an information based Food Quality and Safety system? It is well known that last century food crisis brought into place new safety schemes at different decision levels. For instance, Risk Analysis came into place at regulation level, and Good Manufacturing Practices (GMP) and Hazard Analysis and Control of Critical Points (HACCP) were proposed at producer level. All these new tools are in fact systematic information based systems and therefore they can benefit from leading Information Society Technologies. An information based Food Quality and Safety system should not only help us to do better what we did in past, but it will be necessary to face the new societal and economical challenges that are in fact increasing the risk associated to food: logistics is becoming more complex and global, the origin of food is more diverse and while the distance between producers and consumers is increasing delivery times are shortening; the domestic logistics chain is also something we have to pay more attention, too, with the really fresh food and the frozen food claiming their share in consumer favour, and the increasing distance we travel to buy our food in current urban lay-outs.

The objectives of GoodFood

The generic objective of GoodFood is helping on bringing the lab to the foodstuff, from the land to the market, so hopefully extending the control of the total food chain beyond what today is affordable, by the application of Micro and Nanotechnologies to Food Safety and Quality Monitoring. More in detail, GoodFood is dealing with the detection of antibiotics residues, pesticides, mycotoxins, toxigenic fungi and some pathogenic bacteria. Apart from safety issues, GoodFood also addresses food quality and logistics. And, finally, it is developing Ambient Intelligence Solutions (AmI) applicable to food production. To cover these broad scope sensing scenarios GoodFood partners are doing fundamental and applied research in materials, structures, devices, systems and networks, and a set of demonstrators are being developed to be initially applied to three particular food targets: milk & dairy products, fruits, juices & wine, and finally fish. Those demonstrators are built on generic platforms that can be extended to other food targets by changing their specific chemical and biological interface. In the following sections, some of those activities are briefly reviewed.

Micro(nano)systems for Food Safety

In the field of Food Safety demonstrators are being developed to detect chemical and biological contaminants. Those chemical contaminants can be of artificial origin such as antibiotics and pesticides, or of natural origins such as mycotoxins. In the case of antibiotic detection a ‘shoe box’ size multichannel fluorescence immunosensor device is being pursued. So there is biochemistry in the system core (the immunological reaction) and micro(nano)technologies all around: in the exciting laser, in the special CCD camera, in the grating used to couple in and couple out the light, and in the microfluidic system that shall deliver the sample to the assay chamber with the aid of magnetic beads.

As mentioned above, pesticides and micotoxins detection is also within the scope of GoodFood. The same immunosensor approach is being addressed, although seeking this time a non-optical detection and therefore a less bulky and more robust device. Antibodies of commercial origin have been used when possible but new ones have been also developed within the project consortium when needed. Design of artificial receptors has also been attempted in order to avoid all the problematic of antibodies of animal origin.

Mycotoxins are produced by toxigenic fungi, and then we move to another detection scenario, that of live micro-organisms and the above mentioned biological contamination. Apart from Toxigenic Fungi, GoodFood also focus on pathogenic bacteria like Salmonella and Lysteria. In those cases we use DNA approaches. Again as an example of multidisciplinarity, different groups are working at the sensor end of the DNA chips, pursuing non-optical detection and multiassay systems, and other groups are dealing with the biomolecular end determining the interesting DNA sequences to be used as target and trying to simplify and speed up the pre-PCR protocols.

Micro(nano)systems for Food Quality

Apart from safety GoodFood also cares about quality. Fish freshness and fruit ripeness are good examples. The approach in this case is to fabricate compact and miniaturised chromatographic systems for gas and liquids. After the miniaturised separation columns, metal oxide sensors and microcantilevers properly functionalised are used for identification in the case of gases, and micro or nanoelectrodes are used in the case of liquids. In that way the volatiles emanated by fish, or the liquid constituents of milk can be analysed, or even both type of phases can be tested combining both devices in the case of wine, which has a rich wet chemistry and complex aromas as well.

Logistics activities

The logistics scenario covered by GF focus on storage and transport of climacteric fruit (apples, for instance). In the case of storage, a miniaturised multichannel infrared photometer is being developed for measuring gases of interest related to fruit status, such as, for instance, ethylene which is related to fruit ripeness. In this way, a given set of fruit status parameters could be monitored on line during the extended periods of time the fruit is stored in the preserving chambers and an optimal quality product can be delivered to the market. For transport, flexible RFID tags and the corresponding electronic Reader are being developed. The step further here is to integrate sensing capabilities into the tag: temperature, humidity, light intensity and, specially, gas sensing, so food status could be monitored continuously along the logistic chain.

Sensor networks

Ambient Intelligence is a rather convoluted expression coined in Europe in the current research framework, but to keep it short and understandable let us refer to its hardware basis: wireless sensor networks. In our case such a self organising wireless sensor network has been deployed in a vineyard in order to continuously monitor some environmental and plant parameters, such as temperature, light, soil humidity, trunk diameter. This information is gathered in field and transmitted to a central unit where is aggregated, displayed in a useful manner for an untrained operator and registered in a database where useful knowledge can be eventually extracted at a local level (water stress conditions, prediction of pest attack from temperature and humidity historic records, prediction of grape quality…) letting the producer to break the field in zones (zonation concept) and act accordingly saving resources and not mixing different grape qualities at harvest time, for instance. Reliable data transmission and robustness and low power consumption of the sensing nodes are a must to avoid frequent maintenance during the campaign. This is a nice application where micro(nano)sensors and information technologies leading to valuable knowledge extraction have shown promising in a production related scenario.

GoodFood perspecitives

It is our opinion that the inherent advantages of micro(nano)systems may play a role in the agrofood industry. GoodFood project was not designed to be the ultimate project to this respect but to pave the way to other projects to come to this arena. Sure, more research is needed at material, device and system level but quite a few technologies already tested in other bio-fields can be adapted to this application. Once micro(nano)technologies take root in the food related measurement domain, we may witness a movement from the nowadays centralized labs, with large and demanding equipment, towards decentralized labs furnished with more affordable equipment (in terms of cost and training), and in some special cases towards portable equipment that could be brought to the real point of need, in the same way as in the health domain a migration is envisaged from hospital, to the point of care and to home assistance. The faster, smarter and lower cost these pieces of equipment would become, the more feasible would be to turn them into autonomous nodes of a vast network, boosting the frequency of measurement in the space and time domain.