19.1 Introduction
With an increasing need of better control systems for many food processes,
interest has become focused towards on- or in-line control at the production
stage. The food processing industry needs a fast, standardised, objective and
cost-effective tool to control and improve quality.
Sensor applications range from security controls to landmine detection and
from health screening to quality control. In this chapter we want to describe the
possible contributions of sensor systems towards hygiene in food processing, i.e.
sensors that control the quality of food by giving a response to a certain property of
food. The chapter can provide only an overview of highlights in the field of
sensors; these examples of the main principles as well as many other systems are
described in much more detail in dedicated books (Balteset al., 1999; Gardner and
Bartlett, 1999; Kress-Rogers and Brimelow, 2001; Eggins 2002; Tothill, 2003).
Samples in the food industry are diverse and variable and the food industry
has a great need for rapid sensor techniques on the production line. These
techniques should be low cost, easy to operate and fast, in the best case on-line
for real time quality monitoring of raw material, processing and final product.
For Hazard Analysis Critical Control Point (HACCP) purposes, physical sensors
as listed in Table 19.1, have found their application in the food industry off- and
on-line. They represent the critical parameters of pressure, temperature, relative
humidity, water activity and pH, which are some of the factors for controlling
the microbial hygienic environment in the production plant. However, there is
still a need for rapid sensor techniques for determining the microbial and sensory
quality in the production line for the detection of bacterial contamination.
Physical sensors will therefore not be discussed, because they are not directly
19 Improvinghygienic control by sensors
M. Bu»cking, Fraunhofer IME Germany, and J. E. Haugen,
Matforsk AS, Norway