Detection of undeclared animal by‐products in commercial canine canned foods: Comparative analyses by ELISA and PCR‐RFLP coupled with slab gel electrophoresis or capillary gel electrophoresis

• Published in: Journal of the science of food and agriculture Vol. 96; no. 5; pp. 1659 - 1665
• Main Authors: Hsieh, Ming‐Kun, Shih, Pei‐Yin, Wei, Chia‐Fong, Vickroy, Thomas W, Chou, Chi‐Chung
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 30.03.2016; John Wiley and Sons, Limited
• Subjects: adulterated products; animal byproducts; Animal Feed - analysis; Animals; Byproducts; canine canned food; canned foods; Capillarity; Capillary electrophoresis; capillary gel electrophoresis (CGE); cattle; chickens; Descriptive labeling; Dogs; Electrophoresis; Electrophoresis - methods; Electrophoresis - veterinary; ELISA; enzyme-linked immuno-sorbent assay (ELISA); enzyme-linked immunosorbent assay; Enzyme-Linked Immunosorbent Assay - veterinary; Foods; gel electrophoresis; Joining; Labelling; Pet food; pet foods; polymerase chain reaction; Polymerase Chain Reaction - methods; Polymerase Chain Reaction - veterinary; polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP); Polymorphism, Restriction Fragment Length; restriction fragment length polymorphism; sheep; slab-gel electrophoresis (SGE); Species Specificity; swine; vegan bone treat; canine canned food; capillary gel electrophoresis (CGE); slab-gel electrophoresis (SGE); vegan bone treat; polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP); enzyme-linked immuno-sorbent assay (ELISA)
• ISSN: 0022-5142; 1097-0010; 1097-0010
• DOI: 10.1002/jsfa.7268

BACKGROUND: The potential presence of undeclared animal by‐products in pet foods is not subject to routine examination. Previously published methods for species‐based identification of animal by‐products have not been used routinely owing to inconsistent results. The present study evaluated the utility of several approaches for accurate identification of animal by‐products in 11 commercial brands of canine canned foods. RESULTS: Canine canned foods from several countries were analysed by ELISA, PCR‐RFLP coupled with slab‐gel electrophoresis (SGE) and capillary gel electrophoresis (CGE) to test for evidence of by‐products derived from cattle, chicken, sheep or pig. While CGE‐based analysis detected all (24) animal‐derived by‐products that were reported for the 11 test samples, SGE and ELISA detected only 22/24 (92%) and 14/24 (58%) of labelled by‐products, respectively. In addition, undeclared animal by‐products were found using all three analytical approaches with CGE detecting more positives (19) than SGE (17) or ELISA (5). CONCLUSION: Significant disparities were evident between the labelled contents and the detected content of animal by‐products. CGE‐based testing for PCR products appears to provide greater sensitivity and accuracy than either SGE or ELISA‐based methods. As testing of commercial products becomes more reliable and mainstream, manufacturers will need to develop more thorough and accurate labelling protocols. © 2015 Society of Chemical Industry