Analysis for Extraneous Matter

Abstract

Analysis for extraneous matter is an important element both in the selection of raw materials for food manufacturing and for monitoring the quality of processed foods. Defect action levels (DALs) of specific products are established for amounts of extraneous matter considered unavoidable and of no health hazard. However, the presence of extraneous material in a food product is unappealing, can pose a serious health hazard to the consumer, and represents lack of good manufacturing practices and sanitary conditions in production, storage, or distribution of food. This chapter provides an overview of basic official methods to isolate extraneous matter from foods, using a series of physical and chemical means to separate the extraneous material for identification and enumeration. Major concerns in the analysis of food products for extraneous matter by traditional methods are the subjectivity of methods and the availability of adequately trained analysts. The chapter also includes an overview of more sophisticated techniques to pinpoint the nature and source of contaminants (x-ray radiography, x-ray microtomography, electrical conductance, impact-acoustic emission, microscopy techniques, near-infrared spectroscopy, and enzyme-linked immunosorbent assays).