Water and formalin adulteration of milk sold in markets around Soroti city

Abstract

This research was carried out from Soroti city in eastern Uganda. It involved collecting fresh milk samples randomly from farmers, vendors and then dairy shops and qualitatively determining formalin and water adulterants, determining the most commonly used adulterant of fresh milk in the collected samples and determining the Specific gravity of milk adulterated with water and the key players in adulteration of fresh milk sold in markets around Soroti city Among the farmers, vendors and dairy shops. This experiment was carried out for a period of one month from 3rd October to 2nd November collecting milk samples from the three categories to qualitatively assess the extent of adulteration of fresh milk with water and formalin in markets around Soroti city. A total of thirty fresh milk samples were collected from farmers, vendors and dairy shops in markets around Soroti city; ten samples were randomly collected from each category. Water was detected by lactometer reading. Milk was poured into a (100 ml) measuring cylinder and a lactometer dropped in the milk to slowly sink. The lactometer reading was taken and recorded in Lactometer degree (°L) when the reading was below the standard then the sample was considered to be adulterated with water. Lactometer was used to determine the specific gravity of milk detected with water. Lactometer consists of a long narrow graduated glass stem Formalin was detected by adding 5mls conc. sulfuric acid with a little amount of ferric chloride was added to a 10 ml milk sample in a test tube without shaking. The appearance of violet or blue color at the junction of two liquid layers indicated the presence of formalin. The mean Specific gravity was 1.0262 and 1.0226 for milk obtained from farmers and vendors respectively which were lower than the standard (28 to 32) while the mean specific gravity of milk obtained from the dairy shops was within the range of pure milk which is 28to 32. The results clearly suggest that water was the most common adulterant in almost all sample of raw milk collected. 80%, 60% and 30% of the samples from vendors, farmers and dairy shops respectively were adulterated with water because their lactometer reading were below the standard and that vendors adulterate milk most with water. However, none of the samples contained formalin. It could therefore be inferred that the consumers need to be more cautious regarding the quality of raw milk. Awareness, access to information, proper monitoring can be subsidiary to control this unethical practice. It is also recommended to monitor the corrected lactometer reading (CLR) at different level of milk collection regularly.