Estudo comparativo entre métodos direto e indireto para quantificação de lactose em leite UHT

Abstract

Milk is a very special type of food due to its rich composition, its main constituents being water, protein, fat, minerals and also vitamins. In the current scenario, many products have been formulated in order to meet the needs of different types of public, a common example is the availability of lactose-free milk, created especially for the consumers with lactose intolerance. There are different ways to quantify lactose in dairy products, including High Performance Liquid Chromatography (HPLC), which is a precise and safe method, but at a high cost. Another option widely used in dairy products is cryoscopy, equipment that measures the freezing point of milk, which changes by decreasing or increasing the amount of components, especially lactose. Therefore, the present study aimed to correlate the two analyzes in relation to the quantification of lactose in UHT milk. For this, different milk samples were subjected to lactose hydrolysis, using the enzyme lactase. The samples containing different concentrations of lactose were analyzed by HPLC and by cryoscopy. It was observed that, when in high concentrations, lactose can be analyzed by cryoscopy, however, for low concentrations of lactose, cryoscopy did not present sensitivity.