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Imprinted Polymers as Coffee Sensors

Periodic Reporting for period 2 - IPCOS (Imprinted Polymers as Coffee Sensors)

Reporting period: 2017-01-01 to 2018-12-31

Food quality is a global key priority area where technological advances in terms of quality control have been limited. In the area of coffee quality there are issues related to the identification and quantification of specific targets for a variety of problems, such as control of the coffee variety, to the ability of profiling different varieties based on different concentrations of key components. The vast majority of these problems are currently addressed by techniques such as mass spectrometry, high pressure liquid chromatography, gas chromatography couples with mass spec. These are very costly approaches that require technical personnel highly specialised. The aim of the IPCOS Network is to bring innovation to the field of food quality by developing a project focused on obtaining chemical sensors using the molecular imprinting technology in the coffee industry. The project offered an international, multidisciplinary and intersectorial doctoral training programme that has allowed the development of new approaches to obtain optical and electrochemical sensors. The project has focused on three main targets: a) chlorogenic acids, b) cafestol and kaurene terpenes, c) caffeine and its metabolites, all of which have been shown to have an impact on consumers’ health. This project has brought together 2 academic teams, 1 large international company, one non-profit research centre of excellence, supported by 4 associated teams, including two SMEs with a very multidisciplinary and multisectorial expertise. The IPCOS training program has provided the fellows with acquisition of knowledge ranging from polymer chemistry, biosensors and analytical chemistry to production and quality control, industrial research and development, entrepreneurship and marketing. The program has ensured that all the ESRs are now equipped with a set of unique scientific and transferable skills that together with a strong development of innovation and entrepreneurship ethos, that has inspired and enhanced their career perspectives.
The IPCOS project aimed to the development of novel sensors for analysis of coffee products. The scientific work was divided in three different work packages.
WP1: Chlorogenic acids and derivatives
A series of p-coumaroylquinic acids derivatives was synthesized, characterized and used for their quantification in coffee, achieving deliverables D1.1 and D1.2 and resulting in two publications in peer-reviewed journals. Substantial work has been conducted towards the development of a sensor based on imprinted polymers for chlorogenic acid, as deliverables D1.3 D1.4 D1.5 and D1.6 have been achieved. Additionally, deliverable D1.7 has been also achieved by the determination of the chlorogenic acids content during the decaffeination process and the development and optimization of the purification of crude caffeine at a pilot plant level

WP2: Cafestol and 16-OMC
The extraction and purification of cafestol and 16-OMC was successfully achieved, which was used in the characterisation of later synthesized MIPs for the two target compound using a covalent approach, achieving deliverables D2.1 D2.2 and D2.3. A colorimetric assay for the determination of Robusta coffee was developed and is currently under consideration for patent by UNITS, corresponding to deliverable D2.4. Additionally, an HPLC method has been developed for the quantification of acrylamide levels in Arabica and robusta coffee (D2.5)

WP3: Caffeine and its metabolites
The synthesis and characterization of MIPs for xanthines, based on previous screening of functional monomers, has given interesting results, resulting in the achievement of deliverables D3.1 D3.2 D3.3 and D3.4. A manuscript currently under review for a peer-reviewed journal. The development and validation of a sensor for xanthines analysis was achieved (D3.5) which resulted in one publication in peer-reviewed journal (Open Access). Additionally, the sensor for xanthines has been validated also in artificial salivary samples (D3.7).

WP4: Training (WP4)
All ESRs have undertaken an extensive program of scientific training since their recruitment, in different areas of chemistry including organic, polymer, analytical and computational chemistry, electrochemistry and sensoring. Moreover, the IPCOS network organized a substantial complementary training programs targeting professional and personal development (appendix, Table 1). All the fellows have also attended a number of courses run by their respective doctoral programs.

WP6: Dissemination and outreach
The ESRs and the members of the teams, both beneficiary and partner organisations, have been actively involved in the dissemination and outreach program. With 8 papers, plus at least three more in preparation, multiple presentations in 10 international conferences, and over 30 outreach events, the IPCOS teams have provided sustained dissemination and outreach.
Of particular interest is the participation and presentation of the IPCOS project during EXPO2015 in Milan (Italy) where the team reached a wide and numerous audience, and also the COFFEE EXPO in 2018 in Trieste, where presentations about the value of collaborations between SME/international companies and academic teams via the Marie Curie Action was particularly welcomed and attracted a lot of interest.
The global impact of both food safety issues and sensor technologies requires full technical knowledge and appreciation in the context of the commercial and societal aspects that could impact the future development of these fields.

This project presented an innovative approach for the development of sensing elements using molecular imprinted polymers, for food quality applications, in particular coffee components. The consortium has successfully developed polymers that can bind and detect, via a colorimetric assay, chlorogenic acids, which are key components in coffee. The teams have also developed a colorimetric assay which allows the detection of 16-O-Me Cafestol. This assay allows to differentiate between Arabica and Robusta, and can be applied to both green beans and roasted coffee beans. This finding is currently being submitted as a patent application. Interestingly during the course of the project ESRs 4 and 5 carried out significant work on the use of electrochemistry applied to coffee components, in particular xanthines. The use of a bare carbon electrode for the detection and quantification of caffeine was demonstrated on numerous commercial samples. This work, published open access and not covered by patent, will be of use to numerous food industries that wish to evaluate caffeine content in commercial products. The electrochemistry set up is very cheap and easy to use and therefore will have impact on quality control in the food industry that uses caffeine. Furthermore as a result of the secondment of ESR2 to partner Demus Spa, a novel methodology for the purification of the crude caffeine obtained from the decaffeination process was developed. A new pilot plant has been set up and when this is scaled up to fully operational it will allow significant savings and will have economic impact but also environmental impact, allowing higher recovery of this important component.
Members of the IPCOS consortium
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