Healthy Foods: The Challenge of High Consumer Acceptance and Disease Prevention
A large variety of effects during transportation, processing, and packaging can impair the safety or quality of our foods. For all phases of the product life cycle – starting with tests on the animal feed, single components, and complex substance mixtures right through to proof of functionality required for health claims – the experts in the Fraunhofer Group for Life Sciences can provide you with competent advice.
The most important selling point for a food product, namely its taste, is at the same time a highly sensitive product feature. To analyze this feature the Group not only performs analytical tests in a sensory laboratory, but particular emphasis is also placed on evaluation by a well-trained sensory panel. The Group can thus detect and systematically influence the formation of off-odors from precursor substances and their dependence on production and process parameters; solutions developed by the Group in this context include the new high-frequency field method for pasteurization and sterilization as well as the customized design of packaging systems in the Group’s competence center for “Active and Intelligent Packaging”.
Foods that provide an additional physiological benefit allow consumers to place a focus according to their individual requirements, for example to prevent overweight and cardiovascular diseases. The Fraunhofer Group for Life Sciences develops processes for this purpose and adapts food formulations. Bioactive additives to satisfy the increasing health awareness of consumers entail completely new challenges. The Group’s holistic approach is clearly visible in the example of omega-3 fatty acids: dramatically shrinking marine fish stocks and issues of product safety and odor prompted Fraunhofer scientists to explore alternative resources for fish oil capsules, which are very popular because of their high content of omega-3 fatty acids. A promising result was found to be eicosapentaenoic acid (EPA), which also belongs to the omega-3 fatty acids. An efficient manufacturing process based on the marine microalga Phaeodactylum tricomutum is now also available, and the Group’s photobioreactors meet all criteria for an industrial EPA production. The proof of efficacy required for making health claims can finally be provided by the Group by means of validated in vitro tests which enable quick verification of the functionality in cell and tissue cultures, and by means of the standardized CaCo-2 test for absorption analyses. Even a three-dimensional vascularized intestinal model is available for absorption, toxicity, and metabolism studies.
Food safety at all stages of the product life cycle
Consumers in Europe today have access to the whole array of foods produced worldwide. Our multifaceted and complex diet is, however, also very susceptible to unwanted perturbation. Consumers take it for granted that their food is safe and of high quality – indeed safety must be ensured at all stages of the food production chain. This holds true for the production of the ingredients during crop growing or animal rearing and also for the processing and low-germ or aseptic filling and finishing of the food products right through to optimal packaging processes and materials. The Fraunhofer Group for Life Sciences offers solutions for all stages of the product life cycle in the food industry.
Industry today faces three major challenges in order to guarantee the safety of foods. In addition to microorganisms, it is in particular chemical contaminants and allergens which are of relevance for food safety. In order to avoid these risks, the Fraunhofer Group for Life Sciences optimizes processes and develops and applies suitable analytical monitoring methods for all stages of the food production process on behalf of its clients.
The key technologies of the 21st century – biological and genetic engineering – are increasingly used also in the food and animal feed industries. Users of these technologies who call on the services of the Fraunhofer Group for Life Sciences can safely assume that the most recent R&D findings in these areas are taken into consideration. New additives lead to modifications in the composition of our foodstuffs and animal feeds. Our specialists are prepared to conduct the necessary investigations on individual food and feed components, but also in complex substance samples.
Some substances generated in situ during the production process may affect product quality. They can be detected by ultra-trace analysis even in complex food matrices. The Fraunhofer scientists are thus creating the basis for optimizing existing processes in such a way that these contaminants are not generated at all or only in much lower quantities.
In addition to their technical know-how, the Fraunhofer scientists have many years of experience in the assessment of potential health hazards. Risk assessment and highly sensitive analytics complement each other to enable safe foods providing great pleasure to be offered to consumers.
Screening methods of molecular and cell biology
In addition to the traditional chemical analyses and toxicological investigations, the Fraunhofer Group for Life Sciences develops screening and express tests based on molecular biological procedures. These are developed individually to respond to specific problems in industry or for food quality monitoring – such as microbial contamination or the occurrence of allergens – and can thus be used in a customer-specific manner. By using high-throughput PCR and chip-based procedures, whole batches can be tested quickly and at low cost. In the future, effect-based cell assays will also play an important role in this context.
However, precautionary measures against undesired contaminants during the production process are not the only issue of decisive importance in the modern food industry. It is also vital that the species purity of the raw materials used can be guaranteed. The processing industries are increasingly demanding express tests for an initial analysis of raw materials. The Fraunhofer Group for Life Sciences is therefore intensively developing such test systems to enable low-cost and quick determination of the species purity of raw materials based on a lab-on-a-chip system.
Once packaged, only sufficiently stable foods can be stored for a prolonged period of time without losing their high quality and posing a risk to consumer safety. This is achieved by treating not only the actual food product, but also subjecting the packaging material to a decontamination process. Wet-chemistry processes are still mostly used for sterilization today. The validation of the efficacy of these sterilization processes in industrial use is one of the focuses of the Fraunhofer life sciences institutes. As a future alternative to wet-chemistry procedures, the use of gas plasmas is actively being explored. Decontamination and sterilization will thus soon be able to be performed non-thermally and, above all, without leaving any residues.
Currently very popular are convenience products – for example double-fresh meals, which are complete meals composed of different raw ingredients that are packaged together. For these highly sensitive convenience products, scientists have also found a special solution: antimicrobial substances which are integrated directly into the packaging material help preserve the high quality of the packaged foods.
There is furthermore a trend towards food products whose natural ingredients have been modified as little as possible. Food producers can only fulfill both these consumer wishes using very gentle preservation techniques – and this represents another challenge. Fraunhofer scientists have developed a novel high-frequency heating method for the gentle preservation of foods.
Interactions with packaging materials
Packaging materials and utensils which come into contact with foodstuffs have to be tested and assessed for their suitability. We develop the physico-chemical analytical methods required for this – in particular for trace and ultra-trace analyses and for permeation analyses. We have many years of experience studying interactions between packaging materials and the packaged goods, in particular regarding the migration of additives from polymers or paper into food products. Migration tests and migration modeling in this context are among the services we offer, in addition to the identification of off-odors or odor losses through the packaging. The Fraunhofer Group for Life Sciences has recently started undertaking research aimed at assessing consumer exposure to migrating substances.
The most important test procedures have been accredited according to DIN EN ISO/IEC 17025. The Fraunhofer Group for Life Sciences shares its experience and competence by participating in all relevant European and national committees for the standardization and assessment of food contact materials.
Quality in tune with pleasure
The continuous pasteurization or sterilization methods used today involve slow temperature adjustment processes and long treatment times. This considerable thermal stress often results in a substantial loss of flavor and important nutrients and often also modifies the color and texture of the food. Remarkable increases in quality can be achieved by heating up temperature-sensitive foods quickly and evenly. For fluid and pasty foods we have already been able to develop an effective procedure: by using electrical high-frequency fields, these foods can now be heated very quickly and gently.
Food design for optimal food texture
Food texture is an important factor contributing to the customer’s sensory pleasure. Proteins and fibers play a decisive role here. The search for appropriate raw materials and the systematic modification of the vegetable proteins and fibers obtained from these are one focus of research in the Fraunhofer Group for Life Sciences. Different procedures – thermal, physical, or enzymatic – can be used for such modifications. Products such as baked goods and pasta or homogenized products such as salad creams, drinks, spreads, ice cream, and meat pastes each have their own specific texture. Using the methods developed by the Fraunhofer scientists, ingredients can be tailored to a wide range of different types of products.
The specific flavor of a food product is the result of a complex interaction of many different factors. Numerous research and development activities in this area are therefore aimed at gaining a better understanding of the process-structure-property relationships. The relationship between flavor and texture, for example, has not yet been comprehensively elucidated, nor has the impact of processing and hygienization methods on the preservation of flavors.
Novel ingredients with special technological or health properties may also affect the taste of a food product. Fraunhofer scientists are exploring to what extent unwanted flavor properties are caused by new additives and are developing new strategies to avoid these.
The Fraunhofer scientists have many years of experience in sensory analytics. A well-trained sensory panel and a sensory analytics laboratory are available. Physiological investigations and in vivo monitoring complement the analytical equipment for the characterization of flavors. This means it is possible to assess the sensory contribution of specific ingredients, taking into account the complexity of food matrices.
Research and development in this area are not only focused on the characterization of existing flavors, but we also explore the formation of flavors from their respective precursor substances and their dependence on manufacturing and process parameters. Based on these results, the Fraunhofer Group for Life Sciences develops for its partners concepts to optimize the desired flavor impressions and to avoid the formation of off-odors.
Our expertise covers not only the original flavors of foods, but also the possibilities for optimally preserving these by means of tailored packaging systems.
A trio – packaging, shelf-life, and quality
For all those involved in the food manufacturing process it is important to ensure a high level of food quality. This holds true not only for food manufacturers and filling companies, but also for the producers of packaging materials. Providing services to assess the quality status of foods and to identify the reasons for quality loss during storage are key areas of our work. We develop problem-specific analytical methods to determine quality parameters and the kinetics of quality changes in food products.
This is complemented in a very special way by our competence center for “Active and Intelligent Packaging“. In this center we test the efficacy of active and intelligent packaging systems regarding, for example, their ability to preserve food quality, or their ability to monitor and indicate the condition of the packaged food or the package even during transportation and storage.
Intelligent packaging solutions
Polymer films with active functions such as oxygen scavenging or release of antimicrobial agents, sometimes in combination with indicator functions, are currently an important focus of our research and development activities. Oxygen indicators, for example, are able to indicate leaks in inert gas packaging, but also act as tamper-proof elements and so increase the safety of foods.
Depending on the packaged goods, there are different requirements for the barrier properties of the packaging material, such as gas and vapor permeability. During sterilization of ready-to-serve meals in plastic packaging (with an EVOH barrier layer), for example, the oxygen barrier of the polymer material is weakened, leading to the effect known as “retort shock”. Oxygen scavengers integrated into the polymer can minimize the effects resulting from the reduction of the barrier function during the sterilization process.
As a matter of course, only preservatives approved for use in foods by the relevant authorities are employed in the development of antimicrobially active polymer packaging materials. The aim of this development work is not to introduce preservatives into the packaged food, but to achieve protection where it is required: on the outer surface of the foods. Traditional packaging films are coated with an active layer, from where very small amounts of antimicrobially active substances diffuse to the food surface and become effective there. Even very small amounts of an antimicrobially active substance can inhibit the growth of microflora on the food surface and are thus an effective link in the hygienic chain.
Food products providing additional health benefits
Leading food manufacturers have predicted increasing demand for foods which provide an additional physiological benefit. The development of such food products will become an important research area for the future of this sector. Top priority is the prevention of obesity and cardiovascular disease; other topics of high importance are the strengthening of the immune system and overall fitness. Nowadays, consumers are wanting more than ever before food constituents that support a healthy diet. However, healthy foods are not medications – and therefore consumers expect not only the promised contribution to a healthy diet, but also a pleasant taste.
Foods with optimized nutritional value
Many of our foodstuffs have a very high calorie density. Simply reducing their sugar and/or fat content will normally also reduce the sensory pleasure from eating this food product. Both the texture and taste impression will change decisively. The Fraunhofer Group for Life Sciences is developing optimized food formulations with reduced sugar and fat contents by using appropriate substitutes. Different ingredients (of natural origin whenever possible), for example fat substitutes based on vegetable proteins, when skillfully combined allow the calorie content to be reduced without adversely affecting the pleasure of eating the food or its digestibility.
Despite overnutrition in large numbers of the population, nutritional deficits also play a role in certain population groups. Elderly people, for example, often eat too little protein, and in many cases there is also a fiber deficit. Food products supplemented with additional nutrients are well suited to compensate such deficits. Supplementation with these ingredients may, in fact, change the texture of the food, however, this is taken into account accordingly during product development.
Formulations containing ingredients of vegetable instead of animal origin are also increasingly being demanded by consumers. This substitution also requires individual adjustments of the formulation, something the Fraunhofer scientists are able to do. Protein concentrates and protein isolates, which can for example be used for this purpose, can be manufactured on a pilot scale in standardized quality.
Bioactive food ingredients and functional food
Consumers are consciously making a decision in favor of food products with bioactive supplements and trust that the promised effect is delivered. In order to protect consumers, approvals for health claims are granted only if efficacy has been proven. This proof represents a new scientific challenge for our scientists. Completely new methods and test procedures have to be developed to enable initial proof of efficacy prior to the clinical trials.
Research on bioactive substances begins with the detection and identification of novel ingredients of vegetable or marine origin. Sea fish in particular is considered to be a healthy food because it has a high content of essential amino acids and omega-3 fatty acids. The recommended daily intake of omega-3 fatty acids is currently about 500 mg. For patients with increased triglyceride levels, even three to four grams of omega-3 fatty acids per day are recommended. These large amounts are difficult to take in by eating fish, which is why corresponding capsules are offered as supplements. The omega-3 fatty acids they contain have so far been isolated from fish oil, a byproduct of fish meal production. Fish meal and fish oil, however, are also necessary to produce fish food for aquaculture. As aquaculture is one of the strongest growing sectors of the agroindustry, the price of fish meal and fish oil is likely to go up considerably in the future, and the demand for these products may pose a further threat to the already highly endangered fish stocks. Another important aspect concerns ensuring the quality of the fish oil. Lipophilic environmental pollutants readily accumulate in fish with a high fat content and must be removed with sophisticated methods during isolation of the omega-3 fatty acids so as to guarantee purity and meet safety standards. For many people, the strong inherent odor of fish oil capsules is also a reason for refraining from taking such dietary supplements.
This is the starting point for the research work of the Fraunhofer Group for Life Sciences, with the aim being to develop alternatives for the controlled manufacture and recovery of high-quality, low-odor dietary supplements.
For the production of eicosapentaenoic acid (EPA), which also belongs to the omega-3 fatty acids, an efficient manufacturing method based on algae has been developed. The marine microalga Phaeodactylum tricomutum is the starting point here. It is cultured in photobioreactors specially designed to assure optimal light supply to all algal cells via customized flow control. In addition, all relevant operating parameters, such as the components of the medium, have been optimized to meet all prerequisites for industrial EPA production. High growth rates, a high EPA content, and a manufacturing process which uses nothing but sunlight as energy source have thus been achieved. Likewise, importance has been attached to low production costs for the reactors.
Proteins and fibers with cholesterol-lowering effects are, for example, also recovered from vegetable raw materials. The definition of food formulations, food production procedures, and conditions for the storage of food is another important research topic, in order to identify the effect of these processes on bioactivity and to enable process optimization. The physico-chemical behavior of the novel ingredients and their interactions with the food matrix are investigated in order to enable transfer of the desired physiological effect of the food to a wide range of different foodstuffs.
In vitro and in vivo proof of functionality
Validated in vitro tests can quickly provide results at low cost for the process of functionality testing. The development of in vitro tests with cell and tissue cultures to enable the physiological effects of novel food ingredients to be characterized is an active area of work of the institutes of the Fraunhofer Group for Life Sciences.
For absorption analyses, the standardized CaCo-2 test is available. For absorption, toxicity, and metabolism studies a three-dimensional vascularized intestinal model has been developed. This model is based on a matrix with a blood vessel equivalent (BioVaSc – Biological Vascularized Scaffold), on which intestinal cells and endothelial cells are cultivated physiologically – under conditions resembling those in the human intestine. Different parameters of this supply cycle such as flow rate, mass flow, pressure, and pulse can be computer-controlled and modulated. The 3D intestinal test system can be used to study the absorption, toxicity, and bioavailability of orally administered substances.
The influence of processing steps and storage conditions on the bioavailability and efficacy of the active ingredient can also be investigated in these in vitro systems. First statements about possible health claims can thus be made in a short space of time. The number of time- and labor-intensive intervention studies can thus be reduced; these in vivo tests can also be conducted by the Fraunhofer Group for Life Sciences in-house or in close cooperation with external clinics.
The Group closely collaborates with the responsible authorities and expert committees. At an international level too, the scientists engage in an intense exchange of ideas and experience, for example with the Japanese authorities, which issued regulations for the authorization of functional food as early as 1991.
Functional food should not only be healthy but also tasty. Key factors for the success of a product in the marketplace, besides its proven health effects, are quality and the pleasure of eating it.
Flavor, most specifically taste and odor, as well as texture and mouthfeel are key aspects we also keep in mind when developing functional foods.
Food chain management – safety from the seeds to the finished product
The safety and quality of foods are becoming of ever greater interest to consumers and represent an important competitive aspect for companies operating in the food sector. Food chain management looks upon the food production process as an integral process and thus offers an optimal approach for ensuring food quality and traceability. It takes into account all the stages that a food product goes through, from the initial production via processing and retailing right through to the consumer.
“Food Chain Management” is also the name of a Fraunhofer alliance. A total of 10 Fraunhofer institutes from different Fraunhofer groups are collaborating in this alliance in order to carry out joint projects and translate the most recent scientific findings into products and solutions to solving these tasks.
A new approach in food chain management is also integrating the disciplines of microelectronics and logistics. This close dovetailing is spawning new competences and research approaches on a technological and also on a consumer-oriented basis.
The Fraunhofer Food Chain Management Alliance is thus well qualified to provide consulting and R&D services to major companies and small and medium-sized enterprises, and also to funding authorities and institutions at national, European, and worldwide levels.
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