WP2. Development, implementation and validation of relaxation models for dairy products Main beneficiary: University of Warmia and Mazury in Olsztyn
As clearly indicates in the title, the WP encompasses development (adaptation) of theoretical models of relaxation processes, their numerical implementation into a software package that will be user-friendly and based on terminology clear to interdisciplinary community and industry (consequently the parameters derived by the software will have a clear meaning and can straightforwardly be compared with outcomes of other methods) and a thorough validation of the models against a large data set obtained within WP4. The WP also involves a development of an “expert system” – a system that will guide the user towards the most appropriate models for data analysis depending on the specific characteristics of the system (state, composition, admixtures, etc.)
WP3. Integration of FFC and time-domain NMR relaxometry and adaptation of experimental protocols
Main beneficiary: STELAR Srl
FFC – NMR and TD-NMR can be exploited separately, providing unique inside into dynamics and structure of dairy products. This WP aims at establishing experimental strategy and developing theoretical models and software to consistently and thoroughly interpret data sets obtained by both methods. This concept is innovative in a general sense – to our knowledge such a combined approach has not been exploited so far even by NMR specialists in academia. The core of the methods is as follows.
FFC-NMR: relaxation rates measured over a broad frequency range (from 10kHz to 10MHz or higher) in a single experiment – access to molecular motion on the time scale from milliseconds to nanoseconds, exceptional opportunity to reveal mechanisms of motion, possibility to observe specific relaxation effects, such as Quadrupole Relaxation Enhancement, that serve as very sensitive indicators of subtle changes in molecular dynamics and arrangement. TD-NMR: relaxation rats measured at a single frequency (18 MHz) – one can detect relaxation processes of much different time scales, from very fast relaxation of solid fractions to very slow relaxation of liquids (water), one can attribute the relaxation components to specific pools of molecules, specific experimental procedures (double-quantum experiments) reveal geometrical restrains of molecular mobility and immobilized molecular fractions (due to, for instance, crysta llization).
WP4. Dynamical and structural properties of dairy products by means of NMR relaxometry
Main beneficiary: Middle East Technical University
The concept of treating dairy (food, in general) products as advanced materials and perform a thorough, quantitative analysis of their molecular properties has been exploited only recently – consequently, there is almost no knowledge about molecular dynamics in dairy products. Extensive NMR relaxometry experiments for various kinds of dairy products will be performed and analysed in terms of models developed in WP2. The purpose of the studies is as follows:
- to test theoretical models against a large set of experimental data, ensuring consistency between FFC-NMR and TD-NMR
- to gain knowledge on dynamical properties of dairy products on the molecular level (also for the profit of WP5 and WP6);
- to establish links between relaxation features and macroscopic properties of dairy products
- to generate a data base of NMR relaxometry results for a variety of dairy products to be used for quality and authenticity evaluation
The research strategy involves studies of model systems – molecular mixture of progressively increasing complexity: from simple systems such as water solutions of proteins to composite mixtures, including several molecular fractions and mimicking dairy products. This approach is needed to identify relationships between relaxation features and specific dynamical properties (such as water diffusion on protein surface, changes in populations of immobilized molecules, restricted mobility of water molecules entrapped in pores created by macromolecular networks). The knowledge gained from investigations of model systems is essential for credibility of conclusions drawn from analysis of NMR relaxometry data for dairy products.
WP5. Application of NMR relaxometry to selected challenges of dairy science and technology Main beneficiary:Hochschule Weihenstephan-Triesdorf
Dairy science and technology faces numerous challenges associated with the need of maintaining expected rheological and macroscopic properties of products (proper gelation, lack of phase separation, proper hydration and water content, avoiding agglomeration of macromolecules, etc) under restrains caused by cost of alternate ingredients and their quality. At the same time the products should have a long shelf-life under demanding conditions (heat, high or low humidity) and high nutrition value that may not be compromised by adding ingredients that give the requested macroscopic and sensory feature for the price of health hazard. Even at first glance one sees that knowledge gained in WP4 and proper modelling are of essence for addressing them – to give examples: to avoid phase separation one has to enquire into interactions between water and the macromolecular fraction to keep water molecules strongly bounded (entrapped) in the matrix, to enhance viscosity by adding hydrocolloids one has to reveal the mechanism of slowing down diffusion of water molecules in the presence of hydrocolloids – one can easily be continued. With increasing role of alternate sources and demand for personalized food new questions continuously emerge. The list will, however, grow together with the growing understanding between physicists and food scientists, that is one of the aims of the project – food scientist must know which kind of problems can be addressed by NMR relaxometry, physicists must be able to translate the problems to the language of molecular motion and relaxation processes
WP6. NMR relaxometry markers of quality and authenticity of dairy products
Main beneficiary:Conte Ricerche Srl
To profit from NMR relaxometry for quality and authenticity investigations, one does not need to perform quantitative analysis of the data. The key to that is to construct reference “master” curves attributed to specific products, the quality of which is confirmed by conventional methods and authenticity ensured. For this purpose a large number of experiments needs to be performed to reach a proper statistics. The key factor is certification of NMR relaxometry. The project is a step in this direction. Certification must aim at a specific product and we are realistic with this respect. Taking about credibility, one should also be aware of “trust issues”: one draws curves and claims on this basis that some products are authentic or not. Certification is a solution to that, but one needs to reach understanding going beyond of just a comparison with a “master curve”. Therefore specific relaxation markers will be identified (to capture the meaning of markers – such as: how much the relaxation rate decreases between 10kHz and 100kHz frequency, what is the frequency position of QRE picks, etc…) to access quality and authenticity. The outcome of WP4 will be of much use to attribute the markers to specific effects and understand their meaning (faster decrease of relaxation rates – strong bounding of water molecules to protein surface, etc.) Reaching this kind of understanding is essential for “conscious” exploitation of NMR relaxometry methods.