Journal of Nutrition Science Research
Open Access

As the production and demand for milk is increasing day by day, a greater frequency of milk adulteration has been seen in India followed by the other countries. The term Adulteration refers to the withdrawal of the components of milk and addition of substances to modify its consistency, taste without buyer’s knowledge, which includes water, sucrose, starch, formalin, ammonium sulphate, benzoic acid, soap, salicylic acid, urea etc.

Water: Most commonly water is used as an adulterant, to increase the milk volume through dilution. It results in the reduction of nutrients present in the milk like solid contents and proteins. But if the water is contaminated it can cause serious health problems especially to children.

Starch: Starch is also the most added adulterant. It is added in milk as an adulterant to increase the solid content and thickening of milk. But excess of starch in milk can cause diarrhea due to the effects of undigested starch in colon. Its accumulation in body can be very dangerous for the diabetic patient.

Glucose: Generally, lower levels of glucose are present naturally in the milk but its higher levels are added as an adulterant to increase the reading of lactometer.

Sucrose: Generally, the sugar present in milk is Lactose but to increase the carbohydrate content of milk sucrose is added. So that density of the milk is increased. This way the milk can be adulterated and will not be detected during lactometer test.

Formalin: Formalin is generally used as a preservative in milk to increase its shelf life but its increased concentration in milk can be very harmful.

Ammonium Sulphate: It is a commonly known chemical fertilizer. It increases the density of watered milk and also raises the lactometer reading by adjusting the density of milk.

Urea: It is added in milk as an adulterant to provide whiteness and to elevate the consistency of milk. Also for leveling the contents of solid-not –fat (SNF) which are present in natural milk. The presence of urea overburdens the kidneys because then they have to filter out more content of urea.

Soap: Soaps are most commonly added adulterant to emulsify and to give the characteristic white colour to the milk. Addition of soap in milk can cause gastro-intestinal problems.

Benzoic acid and Salicylic acid: They are added in the milk to increase the shelf life of the milk. Low levels of benzoic acid and salicylic acid are naturally present in the milk which causes no adverse effect on our health but their increased concentration can be harmful [1-6].

Material and Methods

Collection of the samples: Forty raw samples were collected from dairy owners from different regions of Western U.P. The samples were collected from nearby areas in the morning to be transported easily without any delay. The samples were collected in 50ml screw capped sterilized bottles (Borosil). All possible precautions were taken to avoid external contamination during the time of collection of samples and during processing.

Preparation and Storage of the samples: In most of the cases, freshly drawled milk samples were analyzed. But few cases where the storage of milk was required due to some reasons then those milk samples were prevised by using 0.4% formalin. After that the samples were warmed to 37- 40°C by transferring it to the beaker and keeping it in a water bath maintained at 40 - 45°C. Stirred slowly for proper homogenisation. Sample was mixed thoroughly by pouring back into the bottle without shaking it, mixing to dislodge any residual fat sticking to the sides and was poured back in the beaker. Sample was then allowed to come to the room temperature (26- 28°C) and was taken immediately for analysis [7].

Analysis of milk samples: The samples of raw milk were analyzed for physical characteristics and the presence of adulterants. The tests for adulterants included Soap test, Urea test, Glucose test, Starch test, Formalin test, Salicylic acid test, Ammonium sulphate test, Sucrose test, Benzoic acid test.

Method used for estimation: The detection of the added adulterants was done according to “FSSAI manual” for Methods of Analysis of Foods- Milk and milk products.

Results

(Table 1; Figure 1) (Table 2, 3; Figure2)

Figure 1: Analysis of Different Colours of Milk Samples.

Table 1: Physical properties of milk.

Figure 2: Analysis of Adultrants Found in Milk Samples.

Table 2: Detection of adulterants in milk samples.

Table 3: Analysis of different adulterants found in the milk samples.

Discussion

In our study, 40 samples were tested at room temperature (27 ̊C) out of which 29 milk samples were found to be white, 5 light yellow and 6 were found to be yellowish white in colour with pH ranges from 6.0-7.0. These findings were supported by Judkins and Mack[2] , in their study they showed that the normal milk has yellow colour due to the presence of fat and casein. Variations in colour can be due to the differences in nature of cattle feed consumption, breed of cattle or the the fat and solid content of milk.

As per our analysis, out of 40 samples, 8 milk samples were of very good quality. 27 samples were of moderate quality white 5 samples were of very poor quality. Out of 40 milk samples adulteration of glucose (80%) and ammonium sulphate (80%) was highest, followed by formalin (70%), urea (65%), sucrose (62.5%), benzoic acid (62.5%), salicylic acid (17.5%) and soap (12.5%) respectively, while starch was absent in all the tested milk samples. Similar findings were observed by Kandpal et al[6] in their study.

Conclusion

This study clearly signifies that the quality of milk is not fully appropriate according to the standards of FSSAI and the adulteration in milk is still being practiced at high rates in western U.P. We don’t have proper quality control system which can check the quality of milk that is sold on regular basis. Consumption of the adulterated milk can lead to serious health issues; the consumer must be aware regarding the milk adulteration and its adverse effects on health. Therefore, authorities’ should run awareness programme’s related to milk adulteration on a wide scale. It may help in decreasing such malpractices.

References

1. Chakravorty S, Chakravarty A (2011) An Investigation of adulteration in milk obtained from different localities of Varanasi city. IJRA 5: 120-123.

Google Scholar

2. Chandra H, Srivastava J, Tripathi MK, Rai N, Chauhan S, et al. (2008) Contaminated milk production in the villages of district Dehradun (UK), India. Int J Life Sci 2: 51-59.

Google Scholar

3. Judkins HF, Mack MJ (1955) The Principle of dairying. 3rd Rev. John Wiley & Sons, Inc. NY. Pp: 31.
4. Khan MTG, Zinnah MA, Siddique MP, Rashid MHA., Islam MA, et al. (2008) Physical and microbial qualities of raw milk collected from bangladesh agricultural university dairy farm and the surrounding villages. Bangl J Vet Med 6: 217-221.

Indexed at, Google Scholar, Crossref

5. Wadekar Sanjeevani B, Chavan BR, Menkudale GV (2011) Survey on adulteration of the milk received from government mil scheme in Nanded town. Interlink Research Analysis 1:32-35.

Google Scholar

6. Kandpal SD, Srivastava SK, Negi KS (2012) Estimation of quality of raw milk (open & branded) by milk adulteration testing kit. Indian J Community Health 24(3):188-192.

Indexed at, Google Scholar

7. IS 1479 (Part II) – 1961 (Reaffirmed 1997) Methods of test for Dairy Industry- Chemical Analysis of Milk. Bureau of Indian Standards, New Delhi.