species identification - News - FoodAuthenticity2024-03-29T08:26:48Zhttps://www.foodauthenticity.global/blog/feed/tag/species+identificationValidation of a Multiplex Real-Time PCR Assay for Allergenic Nuts in Processed Foodshttps://www.foodauthenticity.global/blog/validation-of-a-multiplex-real-time-pcr-assay-for-allergenic-nuts2022-07-21T14:18:17.000Z2022-07-21T14:18:17.000ZMark Woolfehttps://www.foodauthenticity.global/members/MarkWoolfe<div><p><a href="{{#staticFileLink}}10661712054,RESIZE_400x{{/staticFileLink}}"><img class="align-center" src="{{#staticFileLink}}10661712054,RESIZE_400x{{/staticFileLink}}" width="225" alt="10661712054?profile=RESIZE_400x" /></a></p>
<p>This paper details the within-laboratory and inter-laboratory trial validation of a multiplex real-time PCR method for the simultaneous, sensitive and specific detection and semi-quantitative estimation of the nut species - peanut, hazelnut, walnut and cashew in processed food. The assay developed for the 4 species of nuts (peanut, hazelnut, walnut and cashew) was based on a TaqMan™ real-time PCR method, which targeted multicopy sequences from mitochondrial, ribosomal RNA genes and chloroplasts, respectively. A series of prepared cookies, sausages, sauce powders, and veggie burgers spiked with different amounts of the 4 defatted nuts were used for the validation trials.The within-laboratory trial checked the specificity, crosstalk, sensitivity [limit of detection (LOD) including asymmetric LOD], precision and trueness of the assay. The inter-laboratory trial with 12 participating laboratories conducted both qualitative and quantitative determinations, and determined trueness/recoveries, precision, and measurement uncertainty. Using multicopy target sequences, a very sensitive detection of the allergenic ingredients is possible. Within the collaborative trial, a concentration of 0.64 mg/kg (i.e. approx. 0.1–0.2 mg “nut” protein/kg) could be reliably detected in a processed cookie matrix. With regards to quantitative analysis, there was insufficient recovery data (bias) resulting in measurement uncertainties of more than 50%. The results of in-house tests suggest that roasting of nuts is the main factor inducing deviant (low) recoveries.</p>
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<p>Read the full <a href="http://link.springer.com/article/10.1007/s00003-022-01385-x#Tab5" target="_blank">open access paper</a></p></div>Study on Reports of Fish and Seafood Labelling Around the World Reveal High Levels of Mislabellinghttps://www.foodauthenticity.global/blog/study-on-reports-of-fish-and-seafood-labelling-around-the-world-r2021-03-15T10:08:19.000Z2021-03-15T10:08:19.000ZMark Woolfehttps://www.foodauthenticity.global/members/MarkWoolfe<div><p><a href="http://storage.ning.com/topology/rest/1.0/file/get/8667559662?profile=RESIZE_930x" target="_blank"><img class="align-center" src="http://storage.ning.com/topology/rest/1.0/file/get/8667559662?profile=RESIZE_400x" width="350" alt="8667559662?profile=RESIZE_400x" /></a></p>
<p>The Guardian newspaper has made a study of 44 reports in over 30 countries of the labelling of 9,000 fish and seafood samples in catering and retail, which reveal that around 36% were mislabelled. The fish and seafood most susceptible to mislabelling were snapper, king scallops, and shark. </p>
<p>Read the article <a href="http://www.theguardian.com/environment/2021/mar/15/revealed-seafood-happening-on-a-vast-global-scale?CMP=Share_iOSApp_Other" target="_blank">here</a></p></div>Simultaneous Species Identification in Milk and Dairy Products Using Direct PCRhttps://www.foodauthenticity.global/blog/simultaneous-species-identification-in-milk-and-dairy-products-us2017-09-29T09:53:49.000Z2017-09-29T09:53:49.000ZMark Woolfehttps://www.foodauthenticity.global/members/MarkWoolfe<div><p>Thai researchers have successfully developed and validated <span>a triplex direct-PCR assay with capillary electrophoresis detection to identify the three common milk species: cow (</span><em>Bos taurus</em><span>), sheep (</span><em>Ovis aries</em><span>) and goat (</span><em>Capra hircus</em><span>). T</span><span>he assay amplified mitochondrial COI and cyt </span><em>b</em><span> genes and generated PCR products of 93, 173 and 231 bp for cow, sheep and goat, respectively. It was highly reproducible, specific to target species, sensitive, and showed 100% identification accuracy. Additionally, it was applicable to milk and dairy product samples.</span></p>
<p><span>Read the abstract at: <a href="http://www.fsigeneticssup.com/article/S1875-1768(17)30032-X/fulltext" target="_blank">Species identification in milk</a></span></p>
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