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Graphical abstract This proof-of-principle study describes the development of a rapid and easy-to-use DNA microarray assay for the authentication of giant tiger prawns and whiteleg shrimp. Following DNA extraction and conventional end-point PCR of a 16S rDNA segment, the PCR products are hybridised to species-specific oligonucleotide probes on DNA microarrays located at the bottom of centrifuge tubes (ArrayTubes) and the resulting signal patterns are compared to those of reference specimens. A total of 21 species-specific probes were designed and signal patterns were recorded for 47 crustacean specimens belonging to 16 species of seven families. A hierarchical clustering of the signal patterns demonstrated the specificity of the DNA microarray for the two target species. The DNA microarray can easily be expanded to other important crustaceans. As the complete assay can be performed within half a day and does not require taxonomic expertise, it represents a rapid and simple alternative to tedious DNA barcoding and could be used by crustacean trading companies as well as food control authorities for authentication of crustacean commodities. Supplementary Information The online version contains supplementary material available at 10.1007/s00216-021-03440-2.

The reformulation of dairy products to contain less added sugar can contribute to reducing sugar consumption, thereby reducing the risk of non-communicable diseases. The objective of this study was to investigate the microbial ecology of reformulated yoghurt, which was produced using bi-enzymatic modification of lactose to increase its sweetness by a factor of 2–3. Ultimately, this reformulation strategy could reduce the amount of added sugar needed for equal sweetness of the end product. The bi-enzymatic modification relied on utilisation of a β-galactosidase enzyme to convert the milk sugar lactose to galactose and glucose, followed by the enzymatic conversion of the glucose moiety to fructose using a glucose isomerase. The microbial ecology of reformulated yoghurt produced with two mixed starter culture preparations containing either Streptococcus (S.) thermophilus and Lactobacillus (Lb.) delbrueckii or S. thermophilus, Lb. acidophilus and Bifidobacterium sp. strains, was analysed during fermentation and cool storage using 16S rRNA based metagenomics. None of the yoghurt samples showed a significant difference in microbial composition between sweetness-enhanced and regular milk at all sampling time points during manufacture and storage of yoghurt. However, a significant difference between the microbiota of inoculated milk before and after fermentation was observed. In both types of yoghurt, the starter culture genera dominated the microbial ecology at the end of fermentation as expected, reducing the possibility of growth of potentially pathogenic or spoilage bacteria possibly resulting from a changed carbohydrate spectrum.

Seafood is particularly susceptible to the substitution of species. In order to guarantee authentic seafood products, seafood processors and traders must perform self-checks on the authenticity of imported and purchased goods. However, the conventional Sanger sequencing of PCR products for the authentication of seafood species is time-consuming and requires advanced infrastructure. DNA microarrays (DNA chips) with species-specific oligonucleotide probes represent a rapid alternative to sequencing-based species authentication. So far, though, only DNA microarrays for the authentication of land vertebrate species have achieved market success. In this work, a user-friendly DNA microarray assay was developed for the authentication of ten important food fish species that can be performed in four to five hours from start to end. The assay was tested with authenticated specimens from 67 different fish species, and by comparing the probe signal patterns all target species and even closely related non-target species could be distinguished.

Artichoke (Cynara scolymus L.) and artichoke leaf extracts (ALE) have a long history as a traditional part of the Mediterranean diet as well as in folk medicine for the treatment of dyspeptic disorders. Although several biological mechanisms of action have been suggested, e.g. increased biliary secretion leading to an increased cholesterol elimination and/or inhibition of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity resulting in a decreased cholesterol biosynthesis, convincing and conclusive human studies investigating the blood cholesterol lowering properties of artichoke or ALE are currently limited. The aim of the present study was to isolate, characterize and determine minor artichoke compounds with regard to their blood cholesterol lowering potential, bitter taste sensation and antioxidant potential. Liquid chromatographic isolation techniques (Sephadex LH-20) in combination with analytical methods (HPLC-DAD-MS and HPLC-DAD) were successfully employed to separate, characterize, and quantify minor artichoke compounds. In commercially available ALE the following compounds were identified: 8-deoxy-11-hydroxy-13-chlorogrosheimin, cryptochlorogenic acid, chlorogenic acid, neochlorogenic acid, cynarin, cynaratriol (tentatively), grosheimin, 8-deoxy-11,13-dihydroxygrosheimin, luteolin-7-O-rutinoside, luteolin-7-O-glucoside, and cynaropicrin. Most of these compounds were liquid chromatographically described for the first time. The concentration of essential ALE compounds, namely chlorogenic acid, cynarin, and luteolin-7-O-glucoside, was in the range of 0.35–18.34, n.d.-1.02, 0.04 – 10.65 mg/g ALE, respectively. Cynaropicrin, the predominant bitter ALE principle, was present at concentrations between

The influence of the growth promoting implants Synovex (SYN), Ralgro (RAL), and Revalor (REV) on the fatty acid profiles of subcutaneous fat, intramuscular fat, and phospholipids of 32 beef steers (eight steers per treatment, and eight controls) was studied. Fatty acid compositions and profiles of conjugated linoleic acid (CLA) isomers were determined by a combination of GC and triple-column Ag+-HPLC. Only small differences could be observed between the different treatment groups. The amount of saturated fatty acids relative to monounsaturated fatty acids was increased by all growth promoting implants in subcutaneous fat (P

The distribution of the potential anticarcinogenic fatty acid cis-9,trans-11-octadecadienoic acid (rumenic acid) and other trans and cis fatty acids in milk fat of different ruminants and non-ruminants including human milk was determined by gas-liquid chromatography. The CLA isomer cis-9,trans-11 was the predominant found. Its variation in milk fat of the bulk and individual samples was substantial (0.07 – 1.35% of FAME). Because feed composition and rumen microflora influence isomerisation of linoleic acid in the rumen, factors such as farm management and season were taken into consideration. CLA in milk of all ruminants was season-dependent and there exists a close positive correlation to trans vaccenic acid. Ewe milk is rich in CLA (1.1%). Among non-ruminants mare milk was nearly CLA-free (0.09%). Human milk contained significantly more CLA (0.42%, P < 0.01) in comparison wih the analyzed milk of the other monogastrides. There are differences between milk- and non-milk drinkers. The arrangement of the species according to the increasing CLA concentration in milk is: mare, sow, woman, goat, cow, ewe. The higher CLA content of ruminant milk compared with non-ruminant species is inversely correlated to the content of PUFA and partly to MUFA.

The abilities of lipases produced by the fungus Geotrichum candidum to selectively fractionate mixtures of conjugated linoleic acid (CLA) isomers during esterification of mixed CLA free fatty acids and during hydrolysis of mixed CLA methyl esters were examined. The enzymes were highly selective for cis-9,trans-11–18∶2. A commercial CLA methyl ester preparation, containing at least 12 species representing four positional CLA isomers, was incubated in aqueous solution with either a commercial G. candidum lipase preparation (Amano GC-4) or lipase produced from a cloned high-selectivity G. candidum lipase B gene. In both instances selective hydrolysis of the cis-9,trans-11–18∶2 methyl ester occurred, with negligible hydrolysis of other CLA isomers. The content of cis-9,trans-11–18∶2 in the resulting free fatty acid fraction was between 94 (lipase B reaction) and 77% (GC-4 reaction). The commercial CLA mixture contained only trace amounts of trans-9,cis-11–18∶2, and there was no evidence that this isomer was hydrolyzed by the enzyme. Analogous results were obtained with these enzymes in the esterification in organic solvent of a commercial preparation of CLA free fatty acids containing at least 12 CLA isomers. In this case, G. candidum lipase B generated a methyl ester fraction that contained >98% cis-9,trans-11–18∶2. Geotrichum candidum lipases B and GC-4 also demonstrated high selectivity in the esterification of CLA with ethanol, generating ethyl ester fractions containing 96 and 80%, respectively, of the cis-9,trans-11 isomer. In a second set of experiments, CLA synthesized from pure linoleic acid, composed essentially of two isomers, cis-9,trans-11 and trans-10,cis-12, was utilized. This was subjected to esterification with octanol in an aqueous reaction system using Amano GC-4 lipase as catalyst. The resulting ester fraction contained up to 97% of the cis-9,trans-11 isomer. After adjustment of the reaction conditions, a concentration of 85% trans-10,cis-12–18∶2 could be obtained in the unreacted free fatty acid fraction. These lipase-catalyzed reactions provide a means for the preparative-scale production of high-purity cis-9,trans-11–18∶2, and a corresponding CLA fraction depleted of this isomer.

The quantities of the biologically active isomer of conjugated linoleic acid (CLA) – C18:2 c9t11 – in 139 German foods were analysed by capillary gas chromatography (results are given as a % of all identified fatty acid methyl esters). The CLA content ranged from 0.40% (Gouda) to 1.70% (Jurassic cheese, Old Emmentaler) in dairy products, from 0.11% (rabbit) to 1.20% (lamb) in meat, and from 0.01% (pike-perch) to 0.09% (carp) in fish. CLA could be detected in neither vegetable fats or oils nor in margarines (CLA

During one year's period bulk milk samples were collected monthly from three different types of farms: 1. conventional farming - indoor feeding with silages the whole year, 2. conventional farming - grazing during summer season, 3. ecological farming - grazing during summer season. Conjugated linoleic acids (CLA), trans vaccenic and other trans isomers of milk fatty acids were analyzed. Variation of CLA in milk fat was substantial (0.26 to 1.14 % of total methyl esters) and was season-dependent. The lowest percentage of CLA (0.34 %) was found in the group, fed only fermented roughage and concentrates (most intensive production farm) the highest (0.80 %) in the ecologically produced milk fat. The concentration of CLA and trans vaccenic acid was positively correlated. There is a growing interest in CLA, considered to be beneficial in prevention of carcinogenesis. Its percentage in milk products can be increased through a suitable dietary regimen.

The contents of trans fatty acids (TFA) in 139 German foods were analyzed by capillary gas chromatography. The TFA analysis included myristelaidic acid (C14:1 t9), palmitelaidic acid (C16:1 t9), petroselaidic acid (C18:1 t6), elaidic acid (C18:1 t9), trans vaccenic acid (C18:1 t11), octadecadienoic acid isomers (C18:2 c9t12, C18:2 t9t12, and C18:2 t9c12), and 9 geometrical octadecatrienoic acid isomers (C18:3 n-3). Maximum TFA contents occurred in French fries (up to 34%), crisps (up to 22%) and in instant sauces (up to 22%). The TFA content in dairy products ranged from 2.0% (blue cheese) to 6.1% (Jurassic cheese), in meat products from 0.2% (cooked ham) to 8.6% (lamb), in fish from 0.4% (pollock) to 1.0% (carp), and in vegetable fats and oils and margarines from

During one year's period bulk milk samples were collected monthly from three different types of farms: 1. conventional farming, indoor feeding with silages throughout the year. 2. conventional farming, grazing during summer season, 3. ecological farming, grazing during summer season. The milk protein, fat and ash contents were significantly lower in ecologically kept dairy cows. The highest percentage of saturated fatty acids was found in the indoor group, whereas the trans fatty acid and linolenic acid contents were significantly higher in the ecological group. Dairy products are major sources of conjugated linoleic acid (anticarcinogens). There were enormous differences between the indoor group (0.34%) and the ecological group (0.80%). During the year, the most impressive variations were registered for the cholesterol-raising palmitic acid. The benefits for the consumer: low content of cholesterol-raising fatty acids, high content of cholesterol-lowering fatty acids and high percentage of anticarcinogenic fatty acids, cannot be realized by one system of farm management. Variationen der Milchzusammensetzung unter besonderer Berucksichtigung des Fettsauregehaltes im Jahresverlauf in Abhangigkeit vom Produktionssystem— Vergleich konventionell und okologisch. Im Verlauf einer einjahrigen Prufperiode wurden monatlich von drei unterschiedlich wirtschaftenden Betrieben aus der Sammelmilch Proben gezogen: 1. Konventioneller Betrieb, ganz-jahrige Silagefutterung; 2. Konventioneller Betrieb mit Weideaustrieb; 3. okologisch wirtschaftender Betrieb mit Weideaustrieb. Der Gehalt an Protein. Fett und Asche in der Milch der okologisch gehaltenen Kuhe war signifikant vermindert. Das Milchfett der ganzjahrig stallgehaltenen Tiere wies den hochsten Gehalt an gesattigten Fettsauren auf, wahrend die Milchkuhe aus okologischer Haltung den signifikant hoheren Gehalt an trans-Fettsauren und Linolensaure aufwiesen. Milchprodukte sind die Hauptquelle fur konjugierte Linolsaure (Anticancerogene). Es bestanden erhebliche Differenzen zwisehen den stallgehaltenen (0,34%) und den okologisch gehaltenen Milchkuhen (0,80%). Die starksten Variationen wahrend des Prufjahres wurden fur die cholesterolsteigernde Fettsaure Palmitinsaure registriert. Die Vorteile fur den Verbraucher: geringer Gehalt an cholesterolsteigernden Fettsauren, hoher Gehalt an cholesterolsenkenden Fettsauren und hoher Anteil anticancerogener Fettsauren sind nicht mit einem Futerungssystem zu realisieren.

The objectives of the present study were to examine the effect of a milk fat-depressing (MFD) diet on: 1) the activity of mammary acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), 2) ACC mRNA relative abundance and 3) distributions of conjugated linoleic acids (CLA) and trans-18:1 fatty acids (tFA) in milk fat. Twelve lactating Holstein cows were used in a single reversal design. Two diets were fed: a control diet (60:40% forage/concentrate) and an MFD diet (25:70% forage/concentrate, supplemented with 5% soybean oil). The MFD diet decreased (P: < 0 0.001) milk fat by 43% and ACC and FAS activity by 61 and 44%, respectively. A reduced ACC mRNA relative abundance (P: < 0.001) corresponded with the lower ACC activity. The fatty acids synthesized de novo were decreased (P: < 0. 002), whereas tFA were increased from 1.9 to 15.6% due predominantly to a change in trans-10-18:1 isomer (P: < 0.001). With the MFD diet, the trans-7, cis-9 and trans-10, cis-12 CLA isomers were elevated (P: < 0.001), in contrast to the decrease in trans-11-18:1 (P: < 0. 001) and cis-9, trans-11-18:2. The data were consistent with a dietary effect on mammary de novo FA synthesis mediated through a reduction in ACC and FAS activity and in ACC mRNA abundance. The results were compatible with a role of trans-10, cis-12 CLA in milk fat depression, but alterations noted in tFA and other CLA isomers suggest that they also may be important during diet-induced milk fat depression.