There is a need for a simple, inexpensive and reliable
method for rapid assessment of microbiological quality
of raw milk at the farm level and milk collection centers.
The MBRT estimates the bacterial load in milk indirectly
and permits faster grouping of raw milk samples
into different grades. The dye reduction time appears to
be inversely related to the initial bacterial content of the
sample (APHA, 1978). In general, the MBRT and SPC
of raw milk samples have been reported to be in good
agreement (Chuaprasert, 1984; Homhual, 2000).
Homhual (2000) proposed a technique for estimating
the quality of raw milk based on measuring the change
in blue color of dye-added milk over time by a light
sensor. However, there were considerable variations in
the output voltage patterns possibly due to the design of
the electrical circuit and lack of temperature control
mechanism. Therefore, the objective of present study
was to further investigate the application of light sensing
probes (LSPs) for assessing microbiological quality of
raw milk in an independent manner. In addition, a
secondary objective was to develop a computer-based
automated procedure for online grading of raw milk in
less than 1 h.