An overview of the legislation and light microscopy for detection of processed animal proteins in feeds

Abstract

From the first cases of bovine spongiform encephalopathy (BSE) among cattle in the United Kingdom in 1986, the route of infection of BSE is generally believed by means of feeds containing low level of processed animal proteins (PAPs). Therefore, many feed bans and alternative and complementary techniques were resulted for the BSE safeguards in the world. Now the feed bans are expected to develop into a "species to species" ban, which requires the corresponding species-specific identification methods. Currently, banned PAPs can be detected by various methods as light microscopy, polymerase chain reaction, enzyme-linked immunosorbent assay, near infrared spectroscopy, and near infrared microscopy. Light microscopy as described in the recent Commission Regulation EC/152/2009 is the only official method for the detection and characterization of PAPs in feed in the European Union. It is able to detect the presence of constituents of animal origin in feed at the level of 1 g/kg with hardly any false negative. Nevertheless, light microscopy has the limitation of lack of species specificity. This article presents a review of legislations on the use of PAPs in feedstuff, the detection details of animal proteins by light microscopy, and also presents and discusses the analysis procedure and expected development of the technique.

Light microscopy with differential staining techniques for the characterisation and discrimination of insects versus marine arthropods processed animal proteins

“…EU 51/2013 (European Commission, 2013b) for the official control of feed. The staining reagent colours some major mineral constituents, like hydroxyapatite and calcium phosphates (e.g., tricalcium phosphate), both well represented in bones (EURL-AP, 2013;Liu et al, 2011). Assuming an adaptation of the microscopic method for other PAPs, such as insect material, several aspects must be considered.…”

Detection of Animal Products in Ruminant Feeds by Microscopy and Real Time PCR

“…Nevertheless, microscopy cannot determine the species of animal matter and requires a skilled operator [22]. Moreover the lower limit of detection of MBM in feeds by microscopic analysis, as mentioned previously, was 0.025% w/w; already an interlaboratory study by the European Union reached an upper limit of 0.1% w/w [39].…”

“…Parts of organs, skin, and other soft tissues are generally absent, or if present, barely detectable [22]. Qualitative chemical analyses were performed as confirmatory tests [23][24][25].…”

Immunological detection of osteocalcin in meat and bone meal: a novel heat stable marker for the investigation of illegal feed adulteration

“…A second test may also be carried out using 42 variant or alternative methods, in order to improve the detection of certain types of animal 43 constituents or to further specify the origin of the animal constituents. The microscopic-based 44 method reliably detects heat-and pressure-stable particles of animal origin like bone 45 fragments, teeth, hair, gills or scales which are resisting the legally required MBM treatment 46 of 133 o C for 20 min at 300 kPa (Liu et al 2011). However, by applying the microscope 47 approach it is not possible to distinguish between species or genus in samples containing 48…”