Physical-chemical evaluation of UHT and pasteurized Milk commercialized in Londrina - PR

Resumo

This study aimed to evaluate the chemical composition and physical-chemical properties of UHT and pasteurized whole milk of different brands commercialized in Londrina city.  Five brands of UHT milk and 5 other brands of pasteurized whole milk were purchased from retail market in Londrina between February to April in 2009. The  physical-chemical evaluation of UHT and pasteurized milk samples consisted of milk fat, total dry matter (gravimetric method), stability to 68% alcohol, titrable acidity (TA), density and cryoscopic index. All tests were performed in triplicate with 3 replications. The sample 3 of UHT whole milk presented suspicious water addition due to the low acidity and defatted dry matter concentration compared to the limit set by law. Another sample had instability problems with alcohol in some of the repetitions. All samples showed fat within the limits established by Brazilian law for UHT whole milk. In pasteurized milk, it was determined that the sample 9 had a cryoscopic index and defatted dry matter below the recommended requirement by Brazilian law. The remaining samples showed levels of defatted dry matter within the legal limits for pasteurized whole milk. All pasteurized milk samples showed levels of acidity and fat according for Brazilian law. The study concluded that both types of milk showed some irregularities showing the need to revise the procedures for quality control of each company to reach the criteria require by law.

DOI: http://dx.doi.org/10.14685/rebrapa.v1i1.8