Statements and opinions of the Committee
Opinion on the importance of water in food processing and in the nutritional aspect, developed by the Committee on Food and Nutrition Sciences and the Committee on Human Nutrition Science during the 10th Conference in the series "Food, nutrition and health", Warsaw, 7/11/2018
Water is a key compound necessary for life. In each type of food, it occurs in a greater or lesser amount, ensuring not only the appropriate technological and sensory quality of food, but also deciding about the durability of the food. For technological reasons, it is very important to determine the water activity, which proves its availability for enzymatic processes or the development of microorganisms.
Most of the plant and animal raw materials are characterized by high water activity, close to unity. At such values, the development of microorganisms takes place, and the degradation of bioactive compounds or enzymatic reactions causing food spoilage occur with the greatest intensity. Hence, in order to extend the shelf life of food, most of the water is removed from the raw material by way of e.g. evaporation or drying. In recent years, unconventional technologies have been gaining importance, including microwave, magnetic oscillating fields, high hydrostatic pressures, pulsed electric fields, ultrasound, ultraviolet, radio wave heating, ohmic heating, pulsed X-rays and others. They gradually begin to replace or support the existing, classic methods of food preservation due to the acceleration of technological processes based on heat and mass exchange, reducing the energy consumption of these processes and the possibility of obtaining a product with better quality.
The second important technological feature of water is the food plasticizer function. During the storage of dry products, as a result of moisture sorption or an increase of ambient temperature, the compounds may transform from an amorphous state to a rubbery state, which results, among others, in clumping, shrinkage, loss of crunchiness or acceleration of crystallization. The water released during the crystallization of the components of the dry product is adsorbed by the amorphous part of the product, which in turn initiates a number of unfavorable changes, e.g. acceleration of chemical reactions, protein denaturation, destruction of membranes, release of encapsulated components. Furthermore, it is important to determine the storage conditions or optimal water content in the product, which will ensure the maintenance of the quality of dry products for a long time.
Water also plays an important role in cheese technology. First of all, it determines the consistency and degree of hardness of the cheeses and the speed of maturation of the cheeses. It also directs the action of bacteria during the maturation process. It is important to select the appropriate range of water activity of the cheese mass, which, on the one hand, will enable the production of microbiologically safe cheeses by inhibiting the growth of unfavorable bacteria, and, on the other hand, will enable the optimal development of beneficial bacteria, necessary for the production of ripened cheeses. The water activity determines, first of all, the microbiological stability of the product, the physical, mechanical and chemical properties of the cheeses, i.e. the content of proteins, vitamins, color, taste, nutritional value, stability and durability of the ingredients, as well as packaging and storage or the solubility and texture of the products. In the event of failure to meet the water activity criteria, there are, among others, to errors in holes due to the activity of lactic acid bacteria. In order to ensure the appropriate quality of cheeses during their production, the water activity should be controlled, the change of which is possible as a result of controlling the water content and the content of dissolved substances in the water phase of the cheese by adding salt, changing the maturation conditions (pH, temperature, grain size) and storage or appropriate packaging material.
Proper hydration of the body is necessary to maintain the proper state of human health, including the ability to exercise and efficient functioning in the cognitive sphere. Water ensures the proper course of food digestion and nutrient absorption, the excretion of metabolic products and toxins, maintaining a constant body temperature and regulating the body's water-electrolyte and acid-base balance. The need for water depends on many environmental factors, such as the type and amount of food consumed, ambient temperature, climate, physical activity, and individual factors such as age and physiological conditions in women (feeding, menstruation) and diseases, especially with fever. Without water, an adult can only survive for 3 days. Recommended water consumption by an adult living in moderate ambient temperature and with moderate physical activity is 2-4% of body weight or 1 mL per 1 kcal of food consumed, which corresponds to 2000-2500 mL/day. The source of water for the human body are beverages and solid food. The imbalance between the amount of water consumed and the amount of water excreted from the body leads to dehydration to a degree depending on the level of negative water balance. Too little water consumption may have a physiological, environmental or cultural background, including the structure of the diet, e.g. the amount of fruit and vegetables consumed, most of which are high in water, and the consumption of fats, sweets and cereals, which are foods with low or very low water content. Moderate dehydration has nonspecific symptoms and therefore often goes undiagnosed, however conditions of chronic dehydration, even mild degrees, seriously disrupt the functioning of the body and increase the risk of certain diseases, especially of the excretory system. The majority of Poles, regardless of age, consume too little water, and sweetened beverages predominate among the drinks consumed. This structure of beverage consumption is a proven risk factor for obesity. With this in mind, the Committee on the Human Nutrition Science of the Polish Academy of Sciences, together with the Polish Society of Nutrition Sciences, appointed a group of experts representing various scientific institutions and developed a position entitled "The role of proper hydration in healthy eating and the desired changes in the habits of Poles regarding fluid consumption", which was published in the journal Nutrition Human and Metabolism (No. 4, 2017) and posted on the websites of the Committee on the Human Nutrition Science of the Polish Academy of Sciences and the Polish Society of Nutritional Sciences.
The conclusion was that due to the enormous importance of water, resulting from its role in the human body and importance in obtaining raw materials and food production, it is necessary to offer only water of high nutritional and technological quality for human consumption and use in food processing, which quality should be monitored systematically.
Opinion on technological and nutritional aspects related to the use of food additives and packaging materials, developed by the Committee on Food and Nutrition Sciences and the Committee on Human Nutrition Science during the 11th Conference in the series "Food, nutrition and health", Warsaw, 26/11/2019
During the conference, issues related to the latest technological solutions in the production of packaging materials, the use of food additives, as well as their impact on product quality and consumer health were discussed.
Konsument powinien zwrócić szczególną uwagę na fakt, iż potencjalnym zagrożeniem związanym z przyjmowaniem substancji dodatkowych jest jednostronna dieta i nadmierne spożycie wielu produktów o wysokim stopniu przetworzenia i długim terminie przydatności do spożycia.
Food additives are a group of substances intentionally added to food for the purpose of, inter alia, ensuring microbiological safety, maintaining the appropriate quality of the product by limiting adverse changes after its production. They also include compounds such as vitamin C (ascorbic acid) or citric acid. Furthermore, the addition of certain substances allows to obtain the appropriate technological effect (including sausages without casings), which is, in a way, forced on the producers by the consumers themselves. It should be noted that often the use of mixtures of food additives instead of a single compound allows to maintain a similar effect and reduce their amount added to the product due to the synergistic action. It should be emphasized that additional substances are regulated not only in terms of the possibility of using individual substances and the type of food to which they can be added, but also the maximum allowable dose is regulated. At the same time, there is a very large group of foods, mainly unprocessed or low-processed foods, such as vegetables, fruits or certain types of dairy products, for which additives must not be used. High availability and widespread use of food additives by producers (with the need to declare their use in the product composition) may raise consumer concerns about their excessive use. Therefore, the rational use of additives is in the interest of both the producer and the consumer. The consumer should pay special attention to the fact that a one-sided diet and excessive consumption of many highly processed products with a long shelf life is potential risk related to the intake of additional substances.
The food additives used in food processing, apart from drugs and pesticides, can be classified as the most toxicologically tested substances with which humans come into contact. They are subject to ongoing safety analysis of their use and verification of the acceptable daily intake (ADI) in the light of current scientific reports, thanks to which the consumer can be sure that the substances present in the food are safe for health. Such an approach to the subject is rarely mentioned in the popular science press and the media, so consumers have a wrong image of food processors, considering that the use of food additives is a deliberate action of food producers, aimed at deteriorating its quality and producing the product at lower costs.
Food packaging, in addition to its primary goal of protecting the product, must also meet stringent safety requirements, including those related to the migration of various compounds from the packaging material to food. Among the various packaging materials, special attention was paid to plastic food packaging and biodegradable packaging and the prospects for their use in the light of the new requirements of the Circular Economy. In the ecological context, there are currently trends to reduce the material consumption of packaging production, the use of bio-renewable resources, the production of fully bio-compostable packaging or the re-use of used packaging.
It should be said that a balanced diet, containing the right proportions of nutrients and adapted to the needs of the human body, and consisting of food with various degrees of processing, is the best recipe for maintaining health until old age. In the light of current knowledge, such a diet is safe in the context of potential, undesirable effects resulting from excessive intake of additional substances with food, and at the same time allows to enjoy the taste of many dishes, thanks to increasing their durability and enhancing sensory features.
Opinion about the technological and health aspects of the use of unconventional and innovative techniques, developed by the Committee on Food and Nutrition Sciences and the Committee on Human Nutrition Science during the 12th Conference in the series "Food, nutrition and health", Warsaw, 24/11/2020
Among the unconventional and innovative methods of food processing and preservation, techniques that use cold plasma, ultrasound and pulsed electric field deserve attention. Cold plasma is a state of matter in the form of partially ionized gas (helium, argon, nitrogen, oxygen), containing, among others, electrons, ions, radicals, atoms or photons. When cold plasma is used in the food, it contributed to damage of cell walls and DNA as well as erosion of microbial cells. Cold plasma, due to its antimicrobial properties related to the presence of hydrogen peroxide, OH and NO radicals, singlet oxygen or ozone can be used in food as a method of its sterilization. Cold low pressure plasma technologies are environmentally friendly and recommended for use in the case of thermolabile products. Cold plasma can also be used to degrade pesticides, allergens, inactivate toxins or sterilize air, and to modify the physicochemical properties of materials or sol-gel transformations. Food decontamination by using cold plasma or acid electrolysed water (AEW) is one of the innovative methods of surface sanitization of raw materials or food preparations. Acid electrolyzed water is produced by selective membrane electrolysis from aqueous sodium chloride solutions. Thanks to this process, active forms of chlorine and reactive oxygen species are generated, which have high bactericidal activity. The use of acidic electrolysed water inhibits the growth of such microorganisms as Pseudomonas aeruginosa, Salmonella Enteritidis, Salmonella Typhimurium, Bacillus cereus, Listeria monocytogenes, Mycobacterium tuberculosis, Campylobacter jejuni, Enterobacter aerogenes, or Vibrio parahaemolytic.
Pulsed electric field (PEF) and ultrasound (US) are techniques supporting unit technological operations. This is the reason why they are increasingly used in the food industry. The use of PEF consists in acting on biological tissue with short pulses characterized by a high intensity of the electric field. This results in perforation of the tissue cell membrane. When using sound waves, changes in the cell structure of biological systems may occur as a result of cavitation or absorption of acoustic energy. Both of these methods can be used in order to enhance such processes as: drying (including freeze drying), osmotic dehydration, pressing, freezing or extraction. In the potato industry, the use of PEF contributes to the reduction of the cutting force and the reduction of fat absorption during frying in the production of French fries and crisps. The use of PEF may also increase the extractivity of pigments or elimination of enzymatic treatment, without reducing the pressing efficiency in the production of fruit juices. The use of PEF and US facilitates the development of the production of convenience food or food with designed properties. The use of a combination of these two techniques also affects the microbiological quality of food due to damage to the membranes and cellular structures of microorganisms. However, both PEF and US can lead to the formation of free radicals in food.
In some cases, the use of pulsed electric field or ultrasound is already common practice in the food industry. The limited knowledge of consumers about the use and impact of these technologies on food may determine their behavior in the food market. Similarly, in the case of cold plasma, due to its composition and the nature of the process, its use raises some consumer concerns, which may adversely affect the industrial implementation of this technology. At the same time, the effect of cold plasma on food nutrients is not sufficiently understood.
The use of novel, innovative food processing technologies brings many beneficial phenomena, such as the above-mentioned aspect of environmental benefits in the use of cold plasma, with the simultaneous effectiveness of this method in the elimination of pathogenic microorganisms and the degradation of environmental pollutants. In the case of the development and application of innovative food processing techniques, particular attention should be paid to the problem of the formation of the so-called processing toxicants. An example of such compounds is acrylamide, which is formed from precursors naturally present in food (free asparagine and reducing sugars), mainly when exposed to temperatures above 120 °C. The acrylamide is found not only in products subjected to traditional heat treatment methods, such as frying or baking, but also in pasteurized and sterilized foods. Acrylamide is present in expanded and extruded products, and some authors indicate a higher content of this compound in food heated in a microwave oven compared to traditional methods of heating food. It should be emphasized that the amount of acrylamide formed depends primarily on the raw material composition, i.e. on the amount of precursors of the acrylamide. The risk to human health is related to the neurotoxic and carcinogenic effects of acrylamide. Its widespread presence in processed foods rich in carbohydrates and confirmed adverse effects on human health indicate the need to monitor the content of acrylamide in food products. For this purpose, novel analytical methods are used, such as gas and liquid chromatography coupled with double mass spectrometry (GC-MS/MS and LC-MS/MS). Both methods allow the detection of compounds at very low detection levels. Consumer safety is ensured also by appropriate legal regulations limiting the content of contaminants in food, including process contaminants. In the case of acrylamide, the so-called benchmarks, different for different categories of foodstuffs. The use of emerging, innovative food production and processing technologies must take into account the safety aspect for the consumer of the manufactured products. Not only an immediate effect should be considered, but also long-term effects, including the health of future generations.
Food safety requirements that apply to an individual and an entire generation in a broad time context need to be considered simultaneously with the subjective needs of consumers. Many consumers, apart from satisfying their hunger, expect food that is easy to prepare, with additional health values, going beyond the nutritional value of food, but at the same time providing new, extraordinary culinary experiences. These challenges must be overcome by the food industry and gastronomy, maintaining a balance between the objectively measured quality of food and dishes and the subjective culinary expectations of consumers.