Browsing by Subject "Kaffee"

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    The potential of certification for climate change mitigation in the agri-food sector : a case study of carbon neutral certified coffee from Costa Rica
    (2017) Birkenberg, Athena; Birner, Regina
    Advancing economic, social and environmental sustainability in the agri-food sector is increasingly pursued by various actors along global value chains. One option to address sustainability concerns is to use voluntary sustainability standards and certifications/labels as market-based governance tools for self-regulation. Recently, the demand for particular climate standards and labels has increased, however little is known about their potential and challenges. Individual aspects of such voluntary sustainability certifications have been investigated, such as the effectiveness and impact of certifications or the purchasing decisions of consumers. However, a holistic and interdisciplinary approach by considering the complete value chain is rare and, thus challenges are overlooked and proposed solutions remain limited in scope. Moreover, LCA-based certifications addressing climate change mitigation present a new field of research. Against this background, this thesis aims to elicit the challenges and potential of sustainability certification in the agri-food sector. Taking the case of the world’s first carbon neutral certified coffee, the complete chain – from standard development to consumer choices – has been examined. This coffee is produced by Coopedota, a Costa Rican cooperative of small-scale farmers, and exported to a family-run specialty coffee roaster, Hochland Kaffee Hunzelmann GmbH, in Germany. In the case under consideration, a newly released and highly prescriptive standard for carbon neutrality, the Publicly Available Specification (PAS) 2060, has been adopted since 2011. PAS 2060 is the first independent international standard for carbon neutrality that provides a common definition and a recognized method that is based on a life cycle assessment (LCA). To achieve carbon neutrality, the respective greenhouse gas (GHG) emissions are compiled, before continuous reduction activities are executed and the residual GHG emissions are offset by purchasing carbon credits. Costa Rica is relevant because it is actively pursuing carbon neutrality at the national level and the case of Coopedota serves as a pioneer in this field. In this thesis, an interdisciplinary case study approach is used to investigate in a holistic manner the challenges of carbon neutral certification in the agri-food sector. The study is guided by a conceptual framework developed from relevant literature on voluntary sustainability standards. The three specific objectives of the thesis are: (1) identify the success factors that made the carbon neutral certification in Coopedota possible and understanding the major challenges related to the standards implementation; (2) estimate the potential of on-farm carbon sequestration to compensate for the coffee carbon footprint and reduce carbon offsetting; and (3) estimate the willingness to pay for a carbon neutral label among German consumers of specialty coffee. This thesis contains three main chapters in addition to a general introduction and discussion. The first chapter addresses existing knowledge gaps regarding the role of social network dynamics, actor characteristics and linkages for successful pioneering in sustainable development, and investigates the challenges of implementing PAS 2060 by Coopedota. Qualitative research methods, such as in-depth interviews, participatory social network and process mapping as well as field observations were applied. The study found the prior achievements of the cooperative (e.g. compliance to ISO norms) and a ‘fertile ground’ in terms of ongoing climate change mitigation policies, as important factors for the successful implementation of the standard. Further success factors were a strong central and visionary actor and a diverse network of supporting actors from science, business and politics. The main challenges in implementing the carbon neutral certification were the acquirement of reliable farm data and the advertisement and communication of a carbon neutral label. The second chapter focuses on the problem that biogenic carbon sequestration is rarely considered in LCA-based standards. To estimate the annual potential of biogenic carbon accounting in coffee-agroforestry systems (CAFS) a literature review was conducted and the carbon sequestration based on a carbon inventory at the coffee farms was modeled. The results of a 20-year simulation show that on average, CAFS at Coopedota can compensate the carbon footprint of coffee by approximately 160% annually. Simultaneously, a trade-off between carbon sequestration and productivity at reduced inputs appears, which should be minimized. In the third chapter a marginal willingness to pay (WTP) of € 1.70 for a carbon neutral label was identified on a 250g package of specialty coffee by a discrete choice experiment among German consumers. Yet this marginal WTP was lower than the marginal WTP among the same consumers for direct trade claims or a Fair Trade certificate. Direct trade claims refer to the situation where direct trade relations exist; however, they are not certified and only declared by the retailer, as in the case of the family-run coffee roaster Hochland Kaffee Hunzelmann GmbH. Moreover, a positive synergistic effect was discovered for the combination of the carbon neutral label with direct trade claims. However, a public awareness on the contribution of agriculture to climate change is missing, as is the familiarity of the public with carbon concepts. Concluding, LCA-based certification for carbon neutrality can be a promising market-based tool for the agri-food sector to mitigate climate change. Such certification holds promise because it addresses recent demands for climate relevant information on agri-food products, while benefitting producers, the environment and consumers alike. Examples of these benefits include a potential increase in resource use efficiency, identification and minimization of GHG emission hot spots and trustworthiness among consumers due to the prescriptive nature of the standards. Additionally, the interdisciplinary case study approach enabled the identification of multi-faceted challenges and recommendations. One recommendation is that an agricultural perspective needs to be integrated into the standard by, for example, enabling the accounting of biogenic carbon sequestration. Such carbon accounting would prevent criticism of carbon offsetting and foster synergies between climate change mitigation, sustainability, and resilience. Particularly in the case of higher carbon prices, carbon accounting would be economically interesting but further research is needed to provide a robust dataset to enable it. Independent from a potential premium price for the label, access to capital and governmental support programs, especially for smallholders in less developed countries, can foster the implementation of greener technologies and allow stakeholders to benefit from increased efficiencies. The findings of this thesis indicate that coupling a carbon standard with existing sustainability standards, which use similar datasets, could ease the acquirement of reliable farm data on GHG emissions and reduce costs. Moreover, a coupling of standards could ensure additional sustainability practices, beyond the climate aspect, as already associated by consumers. This study also indicates that to establish markets for carbon neutral products, consumers first have to be aware of the extent of the agri-food sector’s contribution to climate change and consumer responsibility in tackling this problem through their purchasing behavior. This thesis further illustrates the importance of innovators in advancing development goals. Taking action on climate change mitigation and shaping a more sustainable agri-food sector requires strong initiatives and visionaries on the ground, as exemplified by the pioneering case of Coopedota.
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    Trace analysis of acrylamide by high-performance thin-layer chromatography coupled to mass spectrometry
    (2011) Alpmann, Alexander; Schwack, Wolfgang
    Planar-chromatography (High-Performance Thin-Layer Chromatography, HPTLC) is a rapid and cost-effective offline separation method. Through advances in the automatization of each step the system reproducibility, from application and development to detection, has been improved. This makes planar-chromatography a highly reliable technique. HPTLC shows a couple of features that make it unique. There is great flexibility concerning application, development and detection that distinguishes HPTLC from other techniques. Especially the parallel development of up to 36 tracks per plate, the possibility of pre-chromatographic derivatization on the stationary phase, application volumes from nL up to mL, two-dimensional development, automated single or multiple development, and the multiple detection with different methods (UV, fluorescence, bioluminescence, etc.) have to be emphasized. A further advantage over column- (LC) and gas-chromatography (GC) is the single use of the stationary phase. This leads to a high tolerance towards sample matrix and allows for reducing sample preparation. Because of these aspects, planar-chromatography is an interesting tool for each analyst. However, in the last years hyphenation with mass spectrometry (MS) did not make great advancements in comparison to HPLC and GC: thus, planar-chromatography became less attractive. Therefore an existing universal hyphenation (ChromeXtract by Dr. Luftmann), that was based upon a plunger for elution, was improved (publication 1). The original version of the plunger did not allow any elution from glass backed plates, since they broke easily under the pressure applied during clamping. It was difficult to adjust the pressure depending on the experience of the operator. Furthermore, solvent leakage was possible because of insufficient sealing of the cup-point. For a reproducible contact pressure that was independent from the experience of the operator, a commercial torque wrench was used for clamping of the plates. This guaranteed reproducible contact pressure. The installation of a small plastic buffer into the plunger ensured a slight kind of attenuation. This decreased the frequency of leakage from over 50 % to below 5 %. An important criterion of applicability of this hyphenation is the repeatability of the extractions and thus the measurements. Thus, zones of xanthylethylcarbamat (XEC) and dansylpropanamid (DPA) were extracted after chromatographic development. Their specific masses were detected in positive ESI-mode. The relative standard deviation of the signal in single-ion-monitoring (SIM) mode was 18.6 % for XEC and 8.7 % for DPA. Linearity was given in the range of 10 to 200 ng/zone with a very good correlation coefficient (r > 0.9919). The limit of quantification at an S/N-ratio of 10 was calculated by means of the blank signal and amounted 52 and 160 pg/zone for XEC and DPA, respectively. Additionally, the influence of the elution solvent on the extraction of the HPTLC-plate and signal intensity was demonstrated with tests using different solvents. The second publication addressed the application of planar-chromatography hyphenated with MS by means of the modified ChromeXtractor on the determination of acrylamide in drinking water. The strict limit within the EU of 0.1 mug/L until then was only controlled through costly methods that were almost exclusively based on GC-MS or LC-MS/MS after applying intensive clean-up procedures. Thus it was aimed to develop a low priced and rapid alternative method for routine analysis based on HPTLC. Therefore a pre-chromatographic in-situ derivatization of acrylamide with a fluorescence marker was used. The product was detected densitometrically after chromatographic separation. During development of the method, the mass of the reaction product was determined for analysis of the derivatization step. With the aid of the modified ChromeXtract the product could be directly extracted from the plate and transferred to MS. The exact mass proved that instead of the originally used fluorescence marker dansylhydrazine the dimethylaminonaphthaline(Dan)-sulfinic acid reacts with acrylamide. Consequently, dansulfinic acid was synthesized and used for derivatization. To take advantage of the high tolerance of planar-chromatography towards various sample matrices, an approach was searched in order to skip sample preparation. However the necessity to use excess of reagent led to high background fluorescence. This allowed only a limit of detection of 20 mug/L. Thus, sample preparation and analyt enrichment was necessary to obtain a method able to control the maximum concentration. In accordance with DIN 38413-6 concerning determination of acrylamide in drinking water, activated carbon was used for analyte enrichment by means of solid phase extraction (SPE). An internal standard (dimethylacrylamide) was added prior sample preparation. The final extract was analysed as described. In spiked samples of drinking water, a 1000-fold lower limit of detection of 0.02 mug/L and a very good mean reproducibility across the whole system was shown, which suffices to control the maximum amount. A comparative study with measurements by LC-MS/MS revealed satisfactory correlation. Thus, for the first time a planar-chromatographic method for the determination of acrylamide at ultra-trace levels were presented. The third publication addresses the application of the developed method on a very complex food matrix like coffee. Several publications reported problems during determination of acrylamide in coffee. Therefore the extremely high tolerance of planar-chromatography towards sample matrix effects was used, allowing for a shortened sample preparation. The idea of a rapid method was followed by the extraction of commercial coffee samples by means of accelerated solvent extraction (ASE). This allowed for higher throughput during sample preparation. To remove a part of the co extracted matrix, the whole ASE-extract was cleaned by SPE with activated carbon and evaporated to a defined volume. This represented a simplification of common multistage extraction methods and clean-up steps, that aim for complete removal of co extracted matrix prior injection into LC- or GC-systems. In accordance with determination of acrylamide in drinking water, the extract was derivatized in-situ with the fluorescence marker Dansulfinic acid and detected densitometrically after chromatographic separation. The concentration of acrylamide was quantified by means of parallel preparation of three standard additions. Systematic errors and the influence of the sample were corrected by the calibration within the matrix. The linearity of the calibration (between r = 0.9825 and 0.9995) were acceptable. Good values were reached for the limit of quantification (48 mug/kg) and repeatability (rsd 3 %). After method development the acrylamide concentration of commercial coffee samples was determined, showing results being consistent with literature findings. Thus the applicability of the newly developed method to complex food samples was demonstrated. In summary, the present work shows the applicability of planar-chromatography hyphenated with mass spectrometry for sensitive determination of acrylamide. It was possible to quantify the analyte at ultra-trace levels using less instrumental effort and time than usual. Quantification in complex sample matrices was feasible in spite of a simplified sample preparation. These applications prove the relevance of planar-chromatography to solve current analytical problems.