| Author | Bashir, Aftab |
| Call Number | AIT Thesis no. AE-92-12 |
| Subject(s) | Dried milk
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | A study on the quality of raw buffalo milk was made at three major milk collection centers,
situated in Punjab province, as well as at the entry point to the processing plant of Nestle-Milkpak
Ltd, Sheikhupura, Pakistan. The quality of spray dried milk powder, produced from the composite
sample of buffalo/cow's milk was examined and compared with five imported brands of dry milk
powder in terms of selected physico- chemical properties. The effect of storage conditions on
selected properties in locally produced diied milk powder was also examined.
The raw milk quality at the collection centers was significantly contaminated with SPC loads
of 3.6 x 106
/ml due to a lack of chilling facilities and negligence of hygienic practices at the subcenters. The quality of milk vaiied among t~e milk collection centers. The variation was in the
standard plate count (1.5 x 10 to 3.6 x 10 /ml), thermoduric count (2000 to 13000/ml) and
methylene blue reduction time (73 to 132 min). The quality of raw milk was found to change during
transportation from centers to the processing plant. The poor quality (high microbial load) of milk
from the sub-centers to the main centers, and the addition of hydrogen peroxide and ice to the milk
contributed to the vaiiation in the quality of the milk arriving at the processing plant, in
Sheikhupura.
There were significant differences in selected physico- chemical properties of spray dried milk
powder such as wettability, solubility, acidity, and standard plate count revealed amongs the different
lots produced in this study. Results on sensory evaluation for taste/flavor and color were not
significanty different between lots. The influence of storage temperatures and storage periods on
the miscibility, wettability, solubility, acidity and organoleptic characters, were determined. Low
temperature storage of 20°C had less effect on the miscibility, wettability, solubility and acidity
properties than the high temperature of 30°C. The comparison of imported brands and the locally
produced dried milk powder revealed differences in physico-chemical properties such as fat,
miscibility, specific gravity, solubility and wettability.
The study indicated that the quality of raw milk at different stages could be improved by
hygienic practices, such as providing chilling facilities at the sub-center level, introducing the self
collection systems and providing sufficient road tankers into service. |
| Year | 1992 |
| 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 | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Illangantileke, Sarath G. |
| Examination Committee(s) | Jindal, Vinod Kumar ;Athapol Noomhorm ;Nagarur, Nagendra N.
|
| Scholarship Donor(s) | British Government; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1992 |