Milk production, handling, storage, transportation and marketing of milk is handled in a primitive way in Pakistan. Mostly middle man and contractors are involved in the collection, marketing and distribution of milk. Most of the milk is produced in rural sareas and transported to cities where it is supplied to milk plants and also to house consumers. During transportation and distribution there is no refrigeration involved. Middle man adds ice to keep the milk cool and prevent from spoilage. In addition, they also add chemical to kill bacteria and prevent spoilage of milk.

Adulteration of milk is one of the most serious issue in the dairy sector of Pakistan, causing not only major economic losses for the processing industry, but also major health risks for the consumers. Milk is a perishable item and to prevent the spoilage of milk various chemicals are added. In addition to that microbiological quality of milk is very important which directly concern not only with milk spoilage but also consumer health

Keeping in view this study the main object of this study is to determine the hysico-chemical, microbiological and adulterants in raw and processed milk available in Lahore. The raw milk samples ware collected from local market of Lahore city Gawalas, Retail milk shops, Small Dairy Farms sale points and Milk Plants collection centers. A total of 80 samples of raw and 40 samples of processed milk were collected from Lahore

Raw milk samples were collected from Retail milk shops and Gowalas at four different locations of Lahore city i.e. Defence, Allama Iqbal Town, Samanabad and Inside the wall city, from Small Dairy Farms sale points Sakhian pul and Shadera Town areas. Five samples were also collected from experimental dairy farm of UVAS and collection centers of 4 companies.

UHT and Pasteurized milk samples of five different brands were collected from Lahore. A total of 120 milk samples were collected for Physico-chemical, Microbiological and Chemical Adulterants study.

Physico-chemical, microbiological analysis and adulterants detection tests were performed in WTO Laboratory , University of Veterinary and Animal Sciences, Lahore. Color, Taste and flavor of most of the samples were found normal in color, taste and flavor except a few samples of raw milk from shops and Gawalas. Temperature of raw milk was ranged from 4.80±0.096 °C to 30.48±0.611 °C. UHT brands were at ambient temperature and Pasteurized milk brands were stored at refrigeration temperature.

Density in raw milk was ranged from 18.100±0.575 to 27.738±0.16203, lowest in Gawalas and highest in UVAS Dairy. In UHT milk ranged from 26.142±0.088 to 28.222±0.3 15 and in pasteurized milk ranged from 26.280±0.527 to 27.377±0.147.

The highest mean of freezing point recorded was -0.325±0.0 10 °C in Gawalas and lowest -0.542±0.003 °C observed in UVAS Dairy milk. URT milk ranged from -0.487±0.006 °C to -0.463±0.007 °C and in pasteurized milk brands ranged from -0.480±0.002 °C to - 0.455±0.008 °C.

Fat in raw milk ranged from 4.038-0.056% to 6.340±0.060% lowest was in shops and highest in UVAS Dairy milk. UHT fat ranged from 3.472±0.006% to 3.492±0.006% and in Pasteurized milk fat ranged 3.452±0.020% to 3.495±0.005%.

SNF in raw milk ranged from 5.386±0.13745% to 8.226±0.026% lowest in Gawalas and highest in UVAS Dairy. In UHT milk fat ranged from 7.465±0.033% to 8.082±0.09151% and in Pasteurized milk SNF ranged from 7.563±0.125% to 7.905±0.023%.

Protein in raw milk ranged from 2.131±0.060% to 3.162±0.017%, lowest was in shops and highest was in UVAS Dairy. In UHT milk protein ranged from 2.99 1±0.026% to 3.2 10±0.038%, in Pasteurized milk protein ranged from3.001±0.053 to 3.146±0.009. Lactose in raw milk ranged from 2.768±0.067% to 4.364±0.041%, lowest was in Gawalas and highest in UVAS Dairy. In UHT milk lactose ranged from 3.827±0.011% to 4.107±0.050%, in Pasteurized milk lactose ranged from 3.870±0.070 to 4.020±0.044.

Ash in raw milk ranged from 0.512±0.017% to 0.786 ±0.004%, lowest was in Gawalas and highest in UVAS Dairy farm. In UHT ash ranged from 0.698±0.0 1 1% to 0.739±0.007%, in Pasteurized milk ash ranged from 0.689±.008% to 0.739±0.007%.

Water added in raw milk ranged from 0 to 36.527±1.945%, lowest was in UVAS Dairy farm and highest Gawalas milk. In UHT water added ranged from 5.939±1.094% tol2.229±0.407% in Pasteurized milk water added ranged from 6.975±0.045% to 12. 150± 1.769%.

pH in raw milk ranged from 6.726±0.019 to 7.052±0.027, lowest was in UVAS Dairy and highest was in Gawalas milk, In UHT milk pH ranged from 6.839±0.019 to 6.870±0.0 19, in Pasteurized milk pH ranged from 6.800±0.024 to 6.886±0.03 1.

Acidity in raw milk ranged from 0.147±0.001% to 0.161±0.000%, lowest was in Gawalas and highest was in Dairy plant collection centers. In UHT milk acidity' ranged from 0.158±0.003% to 0.161±0.003% and in Pasteurized milk acidity ranged from 0.158±0.003% to 0.161±0.003%.To study the microbiological quality, total plate count (TPC), coliform count and S. aureus count were made.

TPC in raw milk ranged from 2.9 x iO± 2.2 x i04 to 1.7 x l0 ± 8.1 x 10± 8.1 x 106. Lowest was in UVAS Dairy farm and highest was in Gawalas milk, in Pasteurized milk TPC ranged from 5.0 x 10±l .2 x i04 to 6.8 x 10±2.3 x 104.

Coliform count in raw milk ranged from 3.1 x i0± 3.0 X 102 to 4.4 x i05 ± 4.3 X i03.
Lowest was 3.1 x i± 3.0 X 102 in UVAS dairy farm and highest was in Gawalas milk.
In Pasteurized milk Coliform count ranged from 58±3.856 to 344±161.272.
Staph aureus Count in raw milk ranged from 6.4 X l0±6.7 X 102 to 8.7 X 10±2.2 X i0
Lowest was in UVAS Dairy farm and highest was in Shops milk, in Pasteurized milk Staph aureus Count ranged from 61.87lO.901 to 276.62±105.178.
All UHT brands were found negative for TPC, Coliform count and Staph aureus count.
The qualitative tests adulterants were performed by (M.A.T). Kit.
In raw milk the major adulterants found were Urea, Formaldehyde, Hydrogen peroxide,
Neutralizers, Boric acid and QAC. All adulterants were found negative in the milk of
UVAS dairy farm.
In UHT and Pasteurized brands the adulterants found were Salt, Sugar, Starch and
Hydrogen peroxide.
Conclusion
On the basis of present finding, it is concluded that multiple factors can markedly affect the quality of milk. Water addition was one of the major adulteration present in every step of milk marketing. All the raw milk samples were found inferior for their Phsicochemical quality. In processed milk the fat percentage was in the normal range while other parameters were inferior. Microbiological contamination was also higher in raw and pasteurized milk samples. Adulteration of milk with chemicals such as caustic soda, urea, formalin, hydrogen peroxide, sugar and salt were also detected in raw and processed milk. The high microbiological contamination and presence of chemical adultrants in raw and processed milk showed that the milk constitutes a potential public health hazard.