First ring-trial validation of real-time PCR methods for the quantification of allergenic food ingredients

Accurate detection and differentiation of adulterants in food ingredients and herbal medicines are crucial for the safety and basic quality control of these products. Ophiocordyceps sinensis is described as the only fungal source for the authentic medicinal ingredient used in the herbal medicine “Cordyceps”, and two other fungal species, Cordyceps militaris and Isaria tenuipes, are the authentic fungal sources for food ingredients in Korea. However, substitution of these three species, and adulteration of herbal material and dietary supplements originating from Cordyceps pruinosa or Isaria cicadae, seriously affects the safety and reduces the therapeutic efficacy of these products. Distinguishing between these species based on their morphological features is very difficult, especially in commercially processed products. In this study, we employed DNA barcode-based species-specific sequence characterized amplified region (SCAR) markers to discriminate authentic herbal Cordyceps medicines and Cordyceps-derived dietary supplements from related but inauthentic species. The reliable authentication tool exploited the internal transcribed spacer (ITS) region of a nuclear ribosomal RNA gene (nrDNA). We used comparative nrDNA-ITS sequence analysis of the five fungal species to design two sets of SCAR markers. Furthermore, we used a set of species-specific SCAR markers to establish a real-time polymerase chain reaction (PCR) assay for the detection of species, contamination, and degree of adulteration. We confirmed the discriminability and reproducibility of the SCAR marker analysis and the real-time PCR assay using commercially processed food ingredients and herbal medicines. The developed SCAR markers may be used to efficiently differentiate authentic material from their related adulterants on a species level. The ITS-based SCAR markers and the real-time PCR assay constitute a useful genetic tool for preventing the adulteration of Cordyceps and Cordyceps-related dietary supplements.

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Effect of food matrix and thermal processing on the performance of a normalised quantitative real-time PCR approach for lupine (Lupinus albus) detection as a potential allergenic food

Food Chemistry ◽

10.1016/j.foodchem.2018.04.079 ◽

2018 ◽

Vol 262 ◽

pp. 251-259 ◽

Cited By ~ 13

Author(s):

Caterina Villa ◽

Joana Costa ◽

Cristina Gondar ◽

M. Beatriz P.P. Oliveira ◽

Isabel Mafra

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Thermal Processing ◽

Lupinus Albus ◽

Allergenic Food ◽

Food Matrix ◽

Quantitative Real Time Pcr ◽

Effect Of Food

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Effect of inulin on the human gut microbiota: stimulation ofBifidobacterium adolescentisandFaecalibacterium prausnitzii

British Journal Of Nutrition ◽

10.1017/s0007114508019880 ◽

2008 ◽

Vol 101 (4) ◽

pp. 541-550 ◽

Cited By ~ 440

Author(s):

Carlett Ramirez-Farias ◽

Kathleen Slezak ◽

Zoë Fuller ◽

Alan Duncan ◽

Grietje Holtrop ◽

...

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Bifidobacterium Longum ◽

Control Period ◽

Bifidobacterium Bifidum ◽

Bifidobacterium Adolescentis ◽

Food Ingredients ◽

Bifidobacterium Animalis ◽

Bacterial Groups

Prebiotics are food ingredients that improve health by modulating the colonic microbiota. The bifidogenic effect of the prebiotic inulin is well established; however, it remains unclear which species ofBifidobacteriumare stimulatedin vivoand whether bacterial groups other than lactic acid bacteria are affected by inulin consumption. Changes in the faecal microbiota composition were examined by real-time PCR in twelve human volunteers after ingestion of inulin (10 g/d) for a 16-d period in comparison with a control period without any supplement intake. The prevalence of most bacterial groups examined did not change after inulin intake, although the low G+C % Gram-positive speciesFaecalibacterium prausnitziiexhibited a significant increase (10·3 % for control periodv.14·5 % during inulin intake,P = 0·019). The composition of the genusBifidobacteriumwas studied in four of the volunteers by clone library analysis. Between three and fiveBifidobacteriumspp. were found in each volunteer.Bifidobacterium adolescentisandBifidobacterium longumwere present in all volunteers, andBifidobacterium pseudocatenulatum,Bifidobacterium animalis,Bifidobacterium bifidumandBifidobacterium dentiumwere also detected. Real-time PCR was employed to quantify the four most prevalentBifidobacteriumspp.,B. adolescentis,B. longum,B. pseudocatenulatumandB. bifidum, in ten volunteers carrying detectable levels of bifidobacteria.B. adolescentisshowed the strongest response to inulin consumption, increasing from 0·89 to 3·9 % of the total microbiota (P = 0·001).B. bifidumwas increased from 0·22 to 0·63 % (P < 0·001) for the five volunteers for whom this species was present.

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