From Single Constituents to Metabolomics in Food Quality Analysis

Until now, a wide range of laboratory approaches has been employed for control of organic food quality and authenticity. In addition to widely used light isotope measurement based methods, various spectroscopic and/or chromatographic have been traditionally used for quantification of nutritionally important and biologically active single constituents typical for particular food crop. Recently, fingerprinting / profiling strategies have become promising tools for a more comprehensive characterisation of metabolome, a set of low molecular weight (≤ 1500 Da) primary and secondary metabolites occurring in food commodities. It is assumed that not only phenotype of particular living organism but also external factors, including way of farming, may influence characteristic metabolome compositions. High resolution mass spectrometry either coupled with ultra performance liquid chromatography (UPLC) and/or gas chromatography (GC) represent challenging analytical options. To avoid discrimination of some matrix components, minimal or no sample preparation is required prior to instrumental measurement. These requirements are met for instance by solid phase micro extraction (SPME) sampling technique coupled to GC/MS: volatile metabolites fingerprint is collected in sample headspace. Similarly, in last decade introduced, ambient mass spectrometry (AMS) offers a very relevant solution in metabolomics studies. It should be noted, that instead of target analysis of individual ´quality markers´, metabolomics is based on non-target analysis; identification of all compounds occurring in sample metabolome is not necessarily needed in the first phase, the entire data set consisting of instrumental sample ´signals´ is classified by advanced chemometric techniques. In our most recent research projects, we have implemented a novel approaches based both on SPME-GC/MS and AMS. In the latter case, a unique ionization source Direct Analysis in Real Time (DART) coupled with a high resolution time of flight mass spectrometer (HR-TOFMS) is employed for fast metabolomic fingerprinting / profiling. Several case studies will illustrate the potential of these novel approaches to examine food origin

Authentication of organic tomatoes, wheat, and related products

There is an increasing consumer demand for food cultivated by organic farming practices. Because of higher price of these products, there is a need for development and validation of analytical methods, which allow discrimination between organic and conventional food products. This contribution concerns with one of the novel methods of food analysis, the metabolomic fingerprinting/profiling by the ambient mass spectrometry employing Direct Analysis in Real Time (DART) ion source coupled with Orbitrap mass spectrometer. The method based on metabolomics for organic food authenticity was evaluated. In this study, a wide set of wheat and wheat products samples from both organic and conventional production was analyzed (whole wheat, flour and pasta grown in four different localities in Italy, including eight varieties of wheat). For extraction, aqueous methanol and cyclohexane were chosen as the best solvents to obtain a broad spectrum of polar and nonpolar metabolites, respectively. Tomatoes and respective tomato sauces was also analyzed in this study. Tomatoes were grown under both organic and conventional conditions (two Italian localities, three varieties). Instrumental analysis was performed using DART-Orbitrap-MS. In addition to metabolomic fingerprinting, identification of some markers has been conducted. In an organic fraction, triacylglycerols were the main group of identified analytes, while in an aqueous fraction, predominantly organic acids, amino acids and sugars were identified. Samples were classified using sophisticated chemometric tools like Principal component analysis (PCA) and Partial least squares-Discriminant analysis (PLS-DA). This research was carried out within the AuthenticFood project (FP7 ERA-Net project no. 249667, CORE Organic II)

Influence of grass mulch application on tubers size and yield of ware potatoes

The aim of the experiment was to investigate the effect of grass mulch and the term of its application on the yield and quality of potatoes and weed biomass under organic system. The experiment with 2 varieties of early potatoes (Finka and Katka), 2 row spacings (28 000 and 38 000 tubers per hectare) and 2 terms of grass mulch application (after planting and after second hoeing) was carried out in the Czech Republic in 2008. Results showed that the yield was influenced mostly by mulching (55.9 %), then by variety (39.2 %) and by growth structure (4.9 %). The highest yield was reached in the variant with grass mulch applicated after planting. The yield of this variant increased statistically about 9.3 t/ha in comparison with control variant (bare soil). Results of the weed control showed a positive effect of grass mulch on weed biomass, where the lowest weed biomass was found out in variant with grass mulch applicated after planting (weed biomass was lower by 67.6 % in comparison with the control variant - bare soil)

Effect of organic, low-input and conventional production systems on pesticide and growth regulator residues in wheat, potato and cabbage

The Nafferton factorial systems comparison (NFSC) experiments facilitate the investigation of effects of, and interaction between, three production system components - a) rotational position, b) fertility and c) crop protection management - in organic, conventional and low-input crop management systems. This paper presents first results on pesticide and growth regulator residues observed over a period of two years. Residues were only detected for three (Chlormequat, Chlorothalonil and Aldicarb) of the 28 pesticides used in the experiments. As expected, residue levels were affected by the crop protection practices, but significant effects of fertility management practices were also detected. This indicates that the human health risks associated with pesticide residues may increase in low input systems which attempt to reduce the environmental impact of conventional farming systems by switching to organic matter based fertilisation regimes

Kvalita pšenice v ekologickém zemědělství

Celosvětově rostoucí trend rozvoje ekologického zemědělství i výroby biopotravin je patrný zejména v posledním desetiletí. Roste zájem spotřebitelů o zdravé potraviny s dobrou výživovou hodnotou a důraz je kladen na přírodní původ potravin a nabídku výrobků prostých umělé chemie. Je důležité si uvědomit, že biovýrobky neznamenají pouze potravinářské produkty vyrobené bez uměle přidávaných chemických látek, ale značka bio především zaručuje spotřebiteli, že výrobek byl zpracován způsobem, který nezatěžuje životní prostředí. Obecně je u bioproduktů méně důležitá kvalita produkce než kvalita výrobní, kdy jsou jasně vymezena pravidla pěstování

Metabolomics Approaches and their Hidden Potential for Explaining the Mycotoxin Contamination Problem

Food is essential for life. On the basis of the previous sentence, consumers have a right to expect that the foods they purchase and consume will be safe, authentic and of high quality. On these premises, target compounds, such as mycotoxins, pesticides or antibiotics, have been commonly investigated on the food chain, and subsequently, were regulated by authorities. This raises the following question: may consumer be prevented to these risk exposures? Probably not, food chain is step-by-step longer and more complex than ever before. Note that food chain is affected by globalized trade, culture, travel and migration, an ageing population, changing consumer trends and habits, new technologies, emergencies, climate change and extreme weather events which are increasing foodborne health risks, especially for mycotoxins. Because of the fact that mycotoxins are natural toxic compounds produced by certain filamentous fungi on many agricultural communities. In fact, these toxins have adverse effects on humans, animals and crops that result in illnesses and economic losses. Nevertheless, so far mycotoxins and their modified forms have been mainly monitored in cereal and cereal-based products, however, may an early detection of mycotoxins be considered a reliable strategy? In this chapter, recent metabolomics approaches have been reviewed in order to answer this question and to understand future strategies in the field of mycotoxin contamination

Vliv povrchového mulčování brambor na kvalitu hlíz

Cílem tohoto pokusu bylo zhodnotit na dvou stanovištích (s různými půdně-klimatickými podmínkami) vliv travního mulče a netkané mulčovací textilie s ohledem na hlavní ukazatele vnitřní kvality hlíz. Výsledky prokázaly pozitivní vliv povrchového mulčování na obsah chlorogenové kyseliny (o 4 – 21 % vyšší obsah v závislosti na použitém mulči než u nemulčované kontroly), obsah aminokyselin (vyšší o 9 – 18 %), obsah sacharidů (vyšší o 2 – 12 %) a obsah kalysteginů (nižší o 3 – 14 %). Negativní vliv mulče na kvalitu hlíz byl zaznamenán u obsahu sušiny, vitamínu C (o 6 – 14 % nižší obsah v porovnání s nemulčovanou kontrolou) a glykoalkaloidů (o 10 – 36 % vyšší obsah)

Smartphone-based optical assays in the food safety field.

Smartphone based devices (SBDs) have the potential to revolutionize food safety control by empowering citizens to perform screening tests. To achieve this, it is of paramount importance to understand current research efforts and identify key technology gaps. Therefore, a systematic review of optical SBDs in the food safety sector was performed. An overview of reviewed SBDs is given focusing on performance characteristics as well as image analysis procedures. The state-of-the-art on commercially available SBDs is also provided. This analysis revealed several important technology gaps, the most prominent of which are: (i) the need to reach a consensus regarding optimal image analysis, (ii) the need to assess the effect of measurement variation caused by using different smartphones and (iii) the need to standardize validation procedures to obtain robust data. Addressing these issues will drive the development of SBDs and potentially unlock their massive potential for citizen-based food control

Mulč v pěstitelské technologii ekologicky pěstovaných brambor

Mulčování je přirozený přírodní proces, který se člověk naučil napodobit a stala se z něj uznávaná a účinná ochrana zemědělských plodin. Mulčem bývá většinou organický materiál, kterým pokrýváme povrch půdy v určité vrstvě. Použití mulče u ekologicky pěstovaných brambor mělo pozitivní vliv na nižší aktivitu kladení vajíček a následný výskyt larev mandelinky bramborové u rostlinného mulče, na nižší zaplevelení u černé mulčovací textilie, na zvýšení výnosu konzumních hlíz o 6,7 až 7,7 t/ha při použití rostlinného mulče (v porovnání s nemulčovanou kontrolou), trend ke zlepšení obsahu vitamínu C a kyseliny chlorogenové u hlíz pěstovaných pod mulčovací textilií a rostlinným mulčem

Leeches as Sensor-bioindicators of River Contamination by PCBs

The aim of the study was to evaluate the use of leeches of the genus Erpobdella as a means of assessing polychlorinated biphenyl contamination of watercourses. The River Skalice, heavily contaminated with PCBs, was selected as a model. The source of contamination was a road gravel processing factory in Rožmitál pod Třemšínem from which an estimated 1 metric ton of PCBs leaked in 1986. Levels of PCB were measured in leeches collected between 1992 to 2003 from 11 sites covering about 50 km of the river (the first sampling site upstream to the source of contamination and 10 sites downstream). The PCB indicator congeners IUPA no. 28, 52, 101, 118, 138, 153, and 180 were measured. Levels were highest at the four sampling sites nearest the source of pollution. The highest values of PCB congeners were found in 1992. PCB content decreased from 1992 to 2003 and with distance from the source. The study indicated that leeches of the genus Erpobdella are a suitable bioindicator of contamination in the surface layer of river sediments