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 areas 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 by the milk collectors. In addition, the microbiological quality of milk is very important which directly concern not only with milk spoilage but also consumer's health
Keeping in view the above mentioned factors, study was conducted to determine the physico-chemical, microbiological and adulterants in processed milk in Punjab. A total of 30 samples of UHT and 30 samples of pasteurized milk were collected and examined from production units in Punjab.
Density in UHT milk ranged from 22.53+0.08 to 28.44+0.27 and in pasteurized milk ranged from 23.43+0.35 to 27.21±0.17. Conductivity in UHT milk ranged from 9.72+0.38 to 11.33+0.28 and in Pasteurized milk ranged from 9.13+0.08 to 10.13±0.18. Freezing point in UHT milk ranged from -0.49+0.006 ºC to -0.45±0.005 ºC and in pasteurized milk brands ranged from -0.47+0.002 ºC to -0.45+0.008 ºC. Fat in UHT milk ranged from 3.74+0.17 % to 3.99+0.31 % and in Pasteurized milk fat ranged 3.46+0.09 % to 3.60+0.01. SNF in UHT milk ranged from 7.65+0.30 % to 8.03+0.66 % and in Pasteurized milk SNF ranged from 7.57+0.13 % to 7.89+0.08 %. Protein in UHT milk ranged from 3.16+0.11 % to 3.24+0.03 %, in Pasteurized milk protein ranged from 2.92+0.09 % to 3.05+0.03.
Lactose in UHT milk ranged from 3.90+0.01 % to 4.08+0.04 %, in Pasteurized milk lactose ranged from 3.69+0.16 to 4.05+0.04. Ash in UHT milk ranged from 0.70+0.003 % to 0.75+0.003 %, in Pasteurized milk ash ranged from 0.54+.08 % to 0.73±0.01 %. Water added in UHT milk ranged from 6.36+0.33 % to 11.11+0.06 % in Pasteurized milk water added ranged from 8.74±0.04 % to 11.54+0.02 %. pH in UHT milk ranged from 6.67+0.01 to 6.82+0.008, in Pasteurized milk pH ranged from 6.38+0.19 to 6.76+0.11. Acidity in UHT milk ranged from 0.15+0.03 % to 0.16+0.06 % and in Pasteurized milk acidity ranged from 0.14+0.003 % to 0.16+0.01 %.
TPC in Pasteurized milk ranged from 5.0 x 104+1.2 x 104 to 6.8 x 104+2.3 x 104 . Coliform count in Pasteurized milk ranged from 62+3.84 to 378+25.98. Staph aureus Count in Pasteurized milk ranged from 63.33+4.41 to 275.32+17.32.
All UHT milk brands were found negative for TPC, Coliform, Staph aureus and Yeast and Mold count.
The qualitative tests adulterants were performed by (M.A.T) Kit.
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 water addition was one of the major factors present in every segment of milk marketing which decreases the fat and SNF content of milk and markedly effect the physical and chemical quality of milk. Consumers may also be facing potential public health hazards caused by chemical adulteration and food borne pathogens in the milk.