Biotecnología en el Sector Agropecuario y Agroindustrial
versión impresa ISSN 1692-3561
In this study we implemented the technique of UV-Visible spectrophotometry, a useful tool for determining the concentration of Lactulose in 21 types of Colombian commercial UHT milk with different fat contents, Lactose-free and enriched with vitamins, minerals and fiber, and evaluate the intensity of heat treatment to which they were subjected. As a criterion of confidence of the method was determined accuracy (about 92% recovery), precision instruments (less than 9,0%), linearity in the range (0,9996), LD (0,026 mg/mL) and LC (0,083 mg/mL) was further selectivity and reproducibility. Lactulose levels were between 0,7 and 6,8 mg/mL and these results did not influence the composition of fat. Lactose-free milks showed the lowest levels of lactulose and mineral enriched the majors. In general, the variation found may be due to differences in heat treatment which was applied, initial lactose content, pH, phosphate concentration and subsequent period and storage conditions. These milks were also characterized physicochemically and microbiologically. The values obtained were in agreement with those reported by the Ministry of Health and are therefore unfit for human consumption.
Palabras llave : Lactulose; enriched commercial milks; UV-Vis; lactose; standardization.