Detection of pasteurized milk adulteration through official methods

Abstract

The quality of milk consumed is a constant concern of dairy industry and healthcare-related authorities, technicians as well as consumers. The most serious problems are the various frauds which cause economic losses, risks to consumer health and, sometimes, problems for industries, such as the decrease in industrial output. Many foods are subject to fraud, but milk is one of the most commonly spoofed. The purpose of this study was to determine the presence of fraudulent substances and assess the physico-chemical properties of pasteurized milk produced in dairies from the North region of Paraná. Eighty samples were evaluated in the period from March to June 2014 and carried out specific methods for detection of restoratives: starch, alcohol, chloride and sucrose; neutralizers: bicarbonate and sodium hydroxide; preservatives: chlorine, sodium hypochlorite, hydrogen peroxide and formaldehyde. The evaluation of physico-chemical characteristics was carried out through the following analyses: density at 15° C, cryoscopic index, Dornic titratable acidity, 72 alizarol stability, pH, alkaline phosphatase, peroxidase, fat, total solids, non-fat solids, urea, protein and lactose. Non-standard samples were observed for the following analyses: fat (12.5%), non-fat solids (5%), density (1.25%), cryoscopy (3.75%), pH (48.75%), urea (1.25%). Frauds were observed by addition of water and sucrose (3.75%), presence of hypochlorite (5%) and occurrence of skim milk (12.5%). The evidence together can assist in detecting fraud most commonly performed in pasteurized milk, but does not show in which thread might have occurred. However, if not detected, the quality of the product cannot be assured since many frauds have been carried out in a balanced way hindering its detection.