Carsten Fauhl-Hassek

Validated Modeling for German White Wine Varietal Authentication Based on Headspace Solid-Phase Microextraction Online Coupled with Gas Chromatography Mass Spectrometry Fingerprinting

An untargeted analytical approach combined with chemometrics using the volatiles of German white wine was investigated regarding the usefulness for verifying botanical origin. A total of 198 wine samples of Riesling, Müller-Thurgau, Silvaner, Pinot Gris, and Pinot Blanc were examined applying headspace solid-phase microextraction online coupled with gas chromatography mass spectrometry. The resultant three-dimensional raw data were processed by available metabolomics software. After data treatment, a partial least-squares discriminant analysis (PLS-DA) model was validated. External samples were correctly classified for 97% Silvaner, 93% Riesling, 91% Pinot Gris/Blanc, and 80% Müller-Thurgau. This model was related to monoterpenoids, C13-norisoprenoids, and esters. Further, 100% prediction for a two-class model of Riesling versus Pinot Gris/Blanc was confirmed by 74 additional samples measured independently. Hence, the strategy applied was, in particular, reliable and relevant for white wine varietal classification. In addition, the superior classification performance of the Riesling class was revealed.

Authentication of the Botanical and Geographical Origin of Distillers Dried Grains and Solubles (DDGS) by FT-IR Spectroscopy

Distillers dried grains and solubles (DDGS) were investigated with attenuated total reflection FT-IR spectroscopy both directly in their solid state and as the isolated oils (fat fractions). The collected spectra were evaluated in a first step with principal component analysis (PCA) according to the botanical origin (corn, rice, wheat) and the geographical origin (Canada, China, European Union, India, United States) of the DDGS. In a second step, statistical models were constructed for the characterization of the botanical and geographical origin using linear discriminant analysis (LDA) and soft independent modeling of class analogy (SIMCA). For this purpose, the botanical origin was investigated more deeply for corn and wheat as the most important raw materials used for DDGS production. Also, the geographical origin was investigated exemplary for corn DDGS, derived from China and the United States. Models were validated by a randomized batchwise procedure and showed satisfactory classification rates, in most cases better than 80% correct classification.

Screening for sulfate in distillers dried grains and solubles by FT-IR spectroscopy.

Distillers Dried Grains and Solubles (DDGS) are an animal feed containing varying levels of sulfur. As ruminants are susceptible to high sulfur diets, sulfur content is of major interest to the parties involved. The variation in levels of sulfur in DDGS is mainly due to sulfate derived from the addition of sulfuric acid during the production. ATR/FT-IR spectroscopy was used to determine sulfate levels in 90 DDGS samples from various origins (Canada, China, EU, and U.S.A.). Specific absorption bands for sulfate at 615 and 1107 cm(-1) enabled the analysis of sulfate in the DDGS matrix. Besides direct quantification (using band at 615 cm(-1)), PLS regression was applied for the prediction of sulfate using FT-IR spectra and calibration with reference values analyzed by capillary electrophoresis. An extended calculation on the total sulfur estimated that 11% of the DDGS samples analyzed in this study featured sulfur contents higher than 0.80%.

Origin authentication of distillers’ dried grains and solubles (DDGS)—application and comparison of different analytical strategies

In the context of products from certain regions or countries being banned because of an identified or non-identified hazard, proof of geographical origin is essential with regard to feed and food safety issues. Usually, the product labeling of an affected feed lot shows origin, and the paper documentation shows traceability. Incorrect product labeling is common in embargo situations, however, and alternative analytical strategies for controlling feed authenticity are therefore needed. In this study, distillers’ dried grains and solubles (DDGS) were chosen as the product on which to base a comparison of analytical strategies aimed at identifying the most appropriate one. Various analytical techniques were investigated for their ability to authenticate DDGS, including spectroscopic and spectrometric techniques combined with multivariate data analysis, as well as proven techniques for authenticating food, such as DNA analysis and stable isotope ratio analysis. An external validation procedure (called the system challenge) was used to analyze sample sets blind and to compare analytical techniques. All the techniques were adapted so as to be applicable to the DDGS matrix. They produced positive results in determining the botanical origin of DDGS (corn vs. wheat), and several of them were able to determine the geographical origin of the DDGS in the sample set. The maintenance and extension of the databanks generated in this study through the analysis of new authentic samples from a single location are essential in order to monitor developments and processing that could affect authentication.

Wine and must

This book contains information obtained from authentic and highly regarded sources. Reasonable efforts have been made to publish reliable data and information, but the authors, editors and publishers cannot assume responsibility for the validity of all materials or the consequences of their use. The authors and editors have attempted to trace the copyright holders of all material reproduced in this publication and apologise to copyright holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged, please write and let us know so we may rectify in any future reprint.

Vibrational spectroscopy in practice: Detection of mineral oil in sunflower oil with near- and mid-infrared spectroscopy:

Fourier transform infrared spectroscopy becomes increasingly important for detecting adulterations in food due to a minimal sample preparation and a fast nondestructive measurement. Sunflower oil is a popular food ingredient, which might be contaminated or even adulterated by compounds with health concerns such as mineral oil. In this context a feasibility study was performed to compare the suitability of near- and mid-infrared spectroscopy for detecting mineral oil in sunflower oil. For this purpose, sunflower oils spiked with mineral oil in the concentration range of 0.001–1.0% w/w were analyzed by Fourier transform near- and mid-infrared spectroscopy, respectively, and spectra data were preprocessed prior to partial least squares regression. Hereby, the data preparation was optimized for each technique to account for model performance influences. The model performance was fairly similar for both approaches with a slightly better precision and thus limit of detection (near infrared 0.12% w/w, mid infrared 0.16% w/w) for the near-infrared-based model compared to the mid-infrared model. Consequently, both techniques are considered suitable for the determination of mineral oil in sunflower oil in the context of food authentication.

Non-targeted detection of paprika adulteration using mid-infrared spectroscopy and one-class classification – Is it data preprocessing that makes the performance?

A method for the non-targeted detection of paprika adulteration was developed using Fourier transform mid-infrared (FT-MIR) spectroscopy and one-class soft independent modelling of class analogy (OCSIMCA). One-class models based on commercially available paprika powders were developed and optimised to provide >80% sensitivity by external validation. The performances of the established models for adulteration detection were tested by predicting spiked paprika samples with various types of fraudulent material and levels of adulterations including 1% (w/w) Sudan I, 1% (w/w) Sudan IV, 3% (w/w) lead chromate, 3% (w/w) lead oxide, 5% (w/w) silicon dioxide, 10% (w/w) polyvinyl chloride, and 10% (w/w) gum arabic. Further, the influence of data preprocessing on the model performance was investigated. Relationship between classification results and data preprocessing was identified and specificity >80% was achieved for all adulterants by applying different preprocessing methods including standard normal variate (SNV), first and second derivatives, smoothing, and combinations thereof.

1. Treffen des wissenschaftlichen Netzwerkes zur Authentizitätsprüfung von Lebens- und Futtermitteln

ZusammenfassungDie Authentizitätsprüfung von Lebens- und Futtermitteln umfasst eine große Bandbreite an Fragestellungen, Matrizes, analytischen Techniken und Forschungsansätzen, weshalb die Vernetzung von öffentlichen Instituten eine immer größere Rolle spielt. Um den Austausch zwischen Experten auf eine breitere Basis zu stellen, organisierte das Bundesinstitut für Risikobewertung (BfR) erstmals eine bundesweite Veranstaltung für öffentliche Institute mit dem Titel „Status quo der Authentizitätsprüfung von Lebens- und Futtermitteln - Analytische Routineverfahren und Forschungsansätze“. Auf Einladung des BfR berichteten Expertinnen und Experten diverser Einrichtungen des Bundes, der Landesüberwachungsbehörden und Universitäten am 13. und 14. Juni 2016 in den Tagungsräumen des BfR über ihre bisherigen Erfahrungen und Aktivitäten in der Echtheitsüberprüfung – Authentizitätsprüfung – von Lebens- und Futtermitteln. Das Ziel des BfR, mit dieser Veranstaltung den wissenschaftlichen Austausch in diesem aktuellen Forschungsgebiet durch den Aufbau eines Expertennetzwerkes zu fördern, wurde erreicht.AbstractAuthentication of food and feed covers a broad range of topics, matrices, analytical techniques and research approaches. To address future challenges of authenticity testing, cooperation among public institutes becomes more and more important. In this perspective, the Federal Institute for Risk Assessment (BfR) organized a German-wide meeting (translated title: Status quo of authenticity testing of food and feed – methods for routine analysis and research approaches) to improve scientific exchange opportunities among expert of public research institutes and regulatory bodies. Experts of federal institutes, federal state surveillance bodies and universities were invited by the BfR to report about their experiences and activities related to authenticity testing of food and feed. The scientific exchange within this up to date research field was successfully promoted by the development of an expert network with this BfR event.