Projects / Programmes
Biochemical and biophysical characterization of natural compounds
January 1, 2014
- December 31, 2017
| Code |
Science |
Field |
Subfield |
| 4.03.00 |
Biotechnical sciences |
Plant production |
|
| 1.05.00 |
Natural sciences and mathematics |
Biochemistry and molecular biology |
|
| Code |
Science |
Field |
| B420 |
Biomedical sciences |
Nutrition |
| Code |
Science |
Field |
| 4.01 |
Agricultural and Veterinary Sciences |
Agriculture, Forestry and Fisheries |
| 1.06 |
Natural Sciences |
Biological sciences |
Researchers (20)
Organisations (2)
Abstract
Phenolic substances are secondary plant metabolites, known to modulate the activity of numerous enzymes and cell receptors. They are effective against UV radiation and play part in the protection against pathogenic organisms. Phenolics crucially influence nutritional, sensory and commercial quality of foods of plant origin. Their intake has positive health effects: they exhibit antioxidative, antiviral, antiallergenic, cardioprotective and anticarcinogenic effects. The influence of phenolic substances contained in food depends on their resorption from the digestive tract, the permeability of the membranes for these molecules/ions and so for their ability to cross the membrane barriers as well as on their stability in the body fluids. The results of in vivo investigations about the bioavailability and metabolism of phenolic substances could not successfully explain the fate of individual substances in the body. It is not known how the molecules reach the target cells and what is their effect/reaction in the target cells. For some of the phenolic molecules/ions it is well known that they break into smaller molecules/ions, while the other are very probably absorbed unchanged through the cells of the stomach epithelium with the help of the transport protein bilitranslocase or through the walls of the small intestine, this being followed by the transformation into derivatives. The main goals of the program are to understand the mechanisms of the entrance of the phenolics into the cell and their action on the level of molecular reactions and model organisms. These investigations will give data on their bioavailability. They will start on the level of molecular interactions of phenolic substances with lipids, proteins (enzymes) and DNA as well as with various food components (fibre, lecitins, proteins, metal ions). Studies of the transport of the phenolic substances through the cell membrane in the presence or absence of different transport systems will follow. The interactions of different phenolic substances will be studied also in different cell systems (studies of localization, the influence on the proteom level). The mechanisms of antimicrobial and modulatory effect (synergistic/antagonistic) in combination with other interesting substances will also be studied. Spin catchers and DPPH test will provide firsthand observation about of the effect of phenolic substances or plant extracts: how effective are they in decreasing the number of the free radicals. Phenolic substances are not very stable and they degrade according to temperature, pH, oxygen content, humidity etc. In food industry, different natural substances (polysaccharides, proteins and lipids) are already being used as framework to encapsulate the phenolic substances. The substances used can be of plant, animal, marine or microbial origin, the stability of encapsulated phenolic substances and their bioavailability will also be studied.
Significance for science
Complementarity of the partners within the program group and already established cooperation with other research institutions at home and abroad and consequently the possibility of using numerous experimental methods will enhance studies of the topics in question from many different aspects (chemical, physical, biological). Therefore it is realistically to predict that the results of the experimental work will be published in several publications.
Studies of bioavailability of phenolic compounds are very up to date due to the fact that in vitro effects of phenolics could not be always correlated to their biological effects. We predict that the obtained results will provide better correlation between phenolics transport across membranes and their structure. On the other side, only few publications in the literature are dealing with interactions of phenolics with blood plasma proteins. It is reasonable to believe that such interactions do occur and that they are of great importance for the efficacy and stability of the phenolics. It has been shown that some polyphenols inhibit hydrolytic enzymes in the digestive tract and consequently decrease resorption of bile acids and of cholesterol.
Newly gained results will contribute to the development of food industry at home and world-wide. Consumers have been expressing a growing interest in natural additives in foods. This resulted in a growing need for replacing synthetic food additives with natural identical ones or herbal extracts. Phenolic compounds are, due to their antimicrobial and antioxidant effects, potentially interesting compounds for such replacing. A weak point is that their use is based mainly on their in vitro determined positive impact to the health of the human organism. They show antioxidant, antivirus, antiallergenic, cardio protective and anti-carcinogen effects but are part of human diet, being present in fruits, vegetables and spices, people eat for years. A question which has to be answered now is how well they work in vivo. Beside this, physicochemical interactions of phenolics with food components provides a series of thermodynamic parameters which will allow modeling of phenolic compounds usage and plant extracts as natural or nature-identical substitutes to synthetic additives. One of the obstacles to the use of phenolic substances of natural origin or to phenolic compounds rich extracts in foods is their bitter taste. But this can be overcome by encapsulation of phenolic compounds with lipids, polysaccharides or proteins.
Significance for the country
The expected results and gained knowledge will be quite important for food and pharmaceutical industry. Phenolic compounds greatly affect sensory and physico-chemical properties of foods. Knowing mechanisms of their transformations in organisms and their interactions with food components will be used in planning of processing and preservation of plant origin foods. Studying mechanisms of stabilization with various methods of encapsulation will be a base for the development of products with high added value because instability of phenolic compounds in various physico - chemical conditions represents a main barrier to the use of plant extracts and pure phenolic compounds as food additives or nutritional supplements. Understanding transport mechanisms of phenolic compounds (either as free, encapsulated in various systems, or as plant extracts) through cell membranes and their transport in human organism, or their bioavailability, will provide a background for more appropriate use of phenolics as potential natural food additives. We expect that encapsulating phenolic compounds will increase their stability and their bioavailability. The selection of plant extracts from blueberry, pomegranate, oil seed cake and skins for further investigation is based on the results of our previous research.
Newly gained results will be carefully monitored and if patentable, patent applications will be prepared and contacts established with potential users. Intellectual property will be protected according to the rules of participating institutions.
Funding of the proposed program by the Slovenian Research Agency will make a state-of-the-art research, aimed to understand mechanisms of phenolics action and transport based on model systems (lipid membranes, proteins) or their bioavailability, possible. The program will provide a deeper understanding of these mechanisms not only on the level of model systems but further down to the cell level.
As the research will be performed at Biotechnical Faculty of University of Ljubljana and Institute Josef Stefan, the results and findings will be readily incorporated in educational processes. Graduate and postgraduate students will get an opportunity to be involved in the research when their theses will be prepared.
We have selected for further investigations only fruit extracts of those plants which are indigenous in Slovenia, like blueberries, pomegranates or by-products of processing in the food industry such as oil seed cakes or skins. Our selection is based on the obtained results of our previous program; selected plants are also part of folk medicines associated with relief of certain health problems. The final aim of the research is to extend the use of indigenous plants to products with high added value, thus contributing to sustainable development of several Slovenian regions.
Most important scientific results
Annual report
2014,
2015,
2016,
final report
Most important socioeconomically and culturally relevant results
Annual report
2014,
2015,
2016,
final report
