Technology Details:
Urea is a natural component of milk. Unscrupulous people add urea to milk to fraudulently increase its solids-not-fat content. FSSAI has set the upper limit of urea in milk at 70 mg/100 ml. Milk containing urea more than 70 mg/100 ml is considered adulterated. A rapid paper-based strip has been developed for the detection of added urea in milk. The prepared strip is yellow in color. The test involves dipping of the strip in milk samples followed by visualization of color of the strip after 3 min. The color of the strip changes to dark red in urea adulterated milk samples while in pure milk samples, the strip color either remains yellow or it turns into light pink. The intensity of the dark red color produced in the strip is proportional to the amount of urea present in the milk sample. Normal processing of milk such as pasteurization, boiling etc does not affect the efficacy of the strip. The developed strip can detect presence of more than 80 mg/100 ml of added urea in milk. The shelf life of the strip is more than 5 months at refrigeration temperature. The test can be used at milk reception centres and also at house hold level. The colour change in urea detection strip also occurs in presence of neutralizers. Hence, the presence of urea will be confirmed only in the absence of neutralizers – which can be ascertained by neutralizer detection strip. The colour distinction between adulterated and non-adulterated milk is clear. The cost of consumables per test is less than Rs. 1.00. The test can be performed even by non-technical person. The method has been validated at a NABL accredited laboratory.