Light microscopy in combination with computer image analysis for the identification of processed animal protein in feed

Food production is a complex process, with the ultimate objective of the food industry and food safety regulators being to ensure that food reaching the consumer is safe and wholesome. For food derived from animals, the hazard may originate from a number of sources including the consumption by food producing animals of contaminated feed. This is the case of the protracted outbreak of mad-cow disease, for which a feed ban has been introduced [1]. Microscopy and polymerase chain reaction (PCR) together, are the official accepted methods for detection of animal proteins in feed [2] [5]. Nevertheless, neither of two methods fits all the requirements for the accurate identification of prohibited ingredients of animal origin. Light microscopy in combination with computer image analysis (IA), which is based on the identification of bone particles or tissues in feedingstuffs, has been also proposed. Findings in these studies have indicated that the use of the microscopic method in association with IA to identify the origin of processed animal proteins (PAPs) appears promising, especially as a complementary method to the DNA-based ones. This paper explored the potential of the use of microscopy in combination with IA measurements in distinguishing between different PAPs.