| Author | Ahmad, Imran |
| Call Number | AIT Thesis no.PH-01-8 |
| Subject(s) | Milk--Quality--Evaluation
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Science, School of Environment, Resources and Development
|
| Publisher | Asian Institute of Technology |
| Abstract | A rapid, simple and inexpensive technique for the assessment of raw milk
microbiological quality was developed as an alternate to the presently available
methods, which are either time consuming or require costly instrumentation. The
technique was based on the principle of methylene blue dye reduction test
(MBRT). Due to the metabolic activity of viable bacterial cells, blue color of the
dye reduces to white. This change in color was measured by a specially designed
light sensing probe (LSP). The probe was capable of producing voltage signal,
which was used in developing models for estimating raw milk microbiological
quality in terms of standard plate count (SPC) and MBRT. A high correlation of
(R2
) 0.907 was found between SPC and MBRT (n=75). The R2 values of SPC and
MBRT versus LSP were found to be 0.814 (SEE = 0.526) and 0.803 (SEE =
2.358), respectively, using multiple linear regression analysis. The performance of
the developed models was evaluated by comparing experimental value of SPC and
MBRT with estimated values which yield a fairly good correlation i.e., R2
= 0.852
and 0.799, respectively. Based on these models an on-line microbiological quality
assessment scheme was developed using a PC AID interface board. Hence, it
becomes possible to predict and display the microbiological quality of raw milk in
terms of SPC (CFU/ml) and MBRT (h) in real time. Later, the sensitivity of the
LSP was measured by constructing two probes and performing the test
simultaneously. The maximum percent difference was found to be 0.5 between the
several predicted values. |
| Year | 2001 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Postharvest and Food Process Engineering (PH) |
| Chairperson(s) | Jindal, Vinod K.; |
| Examination Committee(s) | Athapol Noomhorm ;Rakshit, Sudip K. |
| Scholarship Donor(s) | Asian Institute of Technology (Partial Scholarship) |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2001 |