Detection of cheese whey in raw milk preserved with bronopol ® through high performance liquid chromatography (Detecção de soro lácteo por cromatografia líquida de alta eficiência em amostras de leite cru conservadas por bronopol ® )

High performance liquid chromatography was used in order to detect cheese whey in samples of raw milk preserved with Bronopol ® . Six samples were collected and divided in 45 aliquots of 40mL. From these, 15 were used as control and stored frozen, 15 were added with Bronopol ® and stored at 7oC, and the other 15 were added with Bronopol ® and stored at 30oC. In all groups, five levels of cheese whey addition (0, 2, 5, 10, and 20%) were tested. The samples were submitted to high performance liquid chromatography on the 2 nd , 4 th , and 8 th days of storage. A completely random design was used, following the factorial scheme (5x3x3) and the results were compared through the non-parametric Kruskal-Wallis test. There was no difference among the treatments (P>0.05), which allows the conclusion that raw milk preserved with Bronopol ® may be used for the RESUMO