Inter-laboratory validation study of two immunochemical methods for detection of processed ruminant proteins

Area of Science:

• Food safety and animal feed analysis.
• Development and validation of immunoassay techniques.
• Regulatory compliance in animal nutrition.

Background:

• Processed animal proteins (PAPs) are crucial components in aqua feed.
• Concerns exist regarding the potential for ruminant PAPs contamination in non-ruminant feed.
• European regulations set limits for ruminant PAPs to prevent disease transmission.

Purpose of the Study:

• To evaluate the efficacy of two immunoassays for detecting ruminant PAPs in non-ruminant PAPs.
• To assess the suitability of these methods for monitoring aqua feed.
• To ensure compliance with safety standards for animal feed ingredients.

Main Methods:

• An interlaboratory study involving 14 participants.
• Testing of two immunoassays, including MELISA-TEK with an enhanced extraction kit.
• Analysis of 21 samples: 6 blanks and 15 spiked with ruminant material (0.5%-2.0%) sterilized at 133°C or 137°C.

Main Results:

• Both immunoassays demonstrated high specificity and sensitivity (≥97%).
• Concordance and accordance between assays exceeded 95%.
• Accurate detection of ruminant PAPs at 0.5% and higher in non-ruminant PAPs was achieved.

Conclusions:

• The validated immunoassays are suitable for monitoring ruminant PAPs in non-ruminant PAPs intended for aqua feed.
• These methods support the safe re-introduction of processed animal proteins in aquaculture.
• The assays meet the regulatory requirement for detecting ruminant contamination below the 2% threshold.