1. Research project objectives The aim of the proposed research will be to develop an innovative analytical procedure that will allow direct monitoring of the emission of terpenes from citrus fruits during their storage under different temperature conditions. Additionally, the research project proposes an approach in which metabolic pathways of terpenes determined during tests in citrus fruit samples will be developed. 2. Research project methodology Terpenes are secondary metabolites formed in plants. Many substances of this group have bioactive properties. Despite the fact that the biological activity of substances of plant origin is lower compared to pharmacological agents, their physiological effect is noticeable when they constitute an important part of a diet. Therefore, it is important to determine the amounts of substances with health promoting effects that are delivered to the body. In the metabolomics studies, the most commonly used analytical techniques are liquid chromatography techniques for non-volatile substances and gas chromatography techniques in the case of volatiles. They ensure high efficiency of identification and quantification, but the results cannot be obtained in real time. In order to get a detailed insight into the processes occurring inside the fruit, a procedure should be developed that would allow monitoring the changes in concentrations of selected chemical compounds in real time. This project proposes complementary use of two-dimensional gas chromatography with mass spectrometry (GC×GC-MS) and mass spectrometry with a proton transfer reaction (PTR-MS). The proposed test procedure would enable simultaneous qualitative and quantitative determination of selected chemical compounds from the terpene group. As part of the presented project, the implementation of two research stages is planned. In the first stage, the focus will be on the development of the analytical procedure, its optimization and validation. The tests will be carried out using model fluids whose composition of the volatile fraction is limited only to the content of the selected terpenes. This approach will make it possible to observe changes in the content of terpenes over time when storing samples under different temperature conditions. In the second stage, real samples of citrus fruits will be tested. Compounds from the terpene group are not very stable, so they can be very sensitive to changes in external conditions. For this reason, changes in secondary metabolite concentrations will be monitored continuously in real time. As a result, it will be possible to develop metabolic pathways for selected terpenes in citrus fruits. 3. Expected impact of the research project on the development of science Based on the analysis of specialist literature, it can be concluded that analysis of the volatile fraction of fruit can provide valuable information on the content of substances that have a bioactive effect, the consumption of which can have a positive impact on human health. Unfortunately, currently there is no detailed information on real-time monitoring of metabolic changes of selected volatile chemicals in fruits that occur during storage. Using the analytical procedure proposed in the project, a targeted analysis of the content of terpenes will be possible, which are secondary metabolites of citrus fruit. Quantitative determinations using the PTR-MS technique will be preceded by identification using multidimensional gas chromatography. This solution is an innovative approach, never before used in the metabolomics of fruit. In summary, the expected results of the basic research presented above may not only extend the knowledge of analytical chemistry and instrumental methods, but also enable the development of metabolic pathways that can then be used in metabolic engineering.
Determination of the metabolic pathway of selected terpenes in citrus fruits using the PTR-TOF-MS technique
F. Maggi
2019-01-01
Abstract
1. Research project objectives The aim of the proposed research will be to develop an innovative analytical procedure that will allow direct monitoring of the emission of terpenes from citrus fruits during their storage under different temperature conditions. Additionally, the research project proposes an approach in which metabolic pathways of terpenes determined during tests in citrus fruit samples will be developed. 2. Research project methodology Terpenes are secondary metabolites formed in plants. Many substances of this group have bioactive properties. Despite the fact that the biological activity of substances of plant origin is lower compared to pharmacological agents, their physiological effect is noticeable when they constitute an important part of a diet. Therefore, it is important to determine the amounts of substances with health promoting effects that are delivered to the body. In the metabolomics studies, the most commonly used analytical techniques are liquid chromatography techniques for non-volatile substances and gas chromatography techniques in the case of volatiles. They ensure high efficiency of identification and quantification, but the results cannot be obtained in real time. In order to get a detailed insight into the processes occurring inside the fruit, a procedure should be developed that would allow monitoring the changes in concentrations of selected chemical compounds in real time. This project proposes complementary use of two-dimensional gas chromatography with mass spectrometry (GC×GC-MS) and mass spectrometry with a proton transfer reaction (PTR-MS). The proposed test procedure would enable simultaneous qualitative and quantitative determination of selected chemical compounds from the terpene group. As part of the presented project, the implementation of two research stages is planned. In the first stage, the focus will be on the development of the analytical procedure, its optimization and validation. The tests will be carried out using model fluids whose composition of the volatile fraction is limited only to the content of the selected terpenes. This approach will make it possible to observe changes in the content of terpenes over time when storing samples under different temperature conditions. In the second stage, real samples of citrus fruits will be tested. Compounds from the terpene group are not very stable, so they can be very sensitive to changes in external conditions. For this reason, changes in secondary metabolite concentrations will be monitored continuously in real time. As a result, it will be possible to develop metabolic pathways for selected terpenes in citrus fruits. 3. Expected impact of the research project on the development of science Based on the analysis of specialist literature, it can be concluded that analysis of the volatile fraction of fruit can provide valuable information on the content of substances that have a bioactive effect, the consumption of which can have a positive impact on human health. Unfortunately, currently there is no detailed information on real-time monitoring of metabolic changes of selected volatile chemicals in fruits that occur during storage. Using the analytical procedure proposed in the project, a targeted analysis of the content of terpenes will be possible, which are secondary metabolites of citrus fruit. Quantitative determinations using the PTR-MS technique will be preceded by identification using multidimensional gas chromatography. This solution is an innovative approach, never before used in the metabolomics of fruit. In summary, the expected results of the basic research presented above may not only extend the knowledge of analytical chemistry and instrumental methods, but also enable the development of metabolic pathways that can then be used in metabolic engineering.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
