RESUMO
Raw milk (RM), reconstituted condensed milk (CM) and three types of reconstituted milk powders (SMPs) were heated indirectly at 80-140°C for 4 s. Native ß-lactoglobulin after 90°C treatment of RM was 1132±167 mg/L but no reliable quantities were estimated at temperatures >100°C, whereas 218±43 mg/L residual α-lactalbumin were found at 130°C. Average lactulose contents from 51 to 1549 mg/L were detected at ⩾100°C; average furosine was 1.9 and 126.5 mg/L in raw and 140°C treated milks respectively. The behaviour of heated CM was similar to that of heated RM except for higher furosine concentration. Reconstituted SMPs contained high quantities of lactulose and furosine, the ratio of which was lower than in similarly treated RM. Among the market milks analysed, the group of high-pasteurised milks was highly variable; i.e. native ß-lactoglobulin was 69-2831 mg/L, lactulose 0-824 mg/L and furosine 3.3-68.8 mg/L.
Assuntos
Manipulação de Alimentos/métodos , Leite/química , Animais , Bovinos , Laticínios/análise , Temperatura Alta , Lactalbumina/análise , Lactoglobulinas/análise , Lactulose/análise , Lisina/análogos & derivados , Lisina/análiseRESUMO
Several EC Directives have been promulgated to protect allergic individuals but no rule has been established with regard to allergen cross-contamination caused by shared transport vehicles or common processing equipment. The aim of this research was to quantify, by enzyme-linked immunosorbent assay (ELISA) or real-time polymerase chain reaction, the presence in meat- or fish-based foods of four allergens (milk, egg, crustaceans and molluscs) that was not indicated either in the list of ingredients or in the label alert. In the time frame of 2007-2009, a total of 723 samples were subjected to 1983 analyses. The percentage of samples scoring positive ranged between 1.8% and 6.8% over the 3 years, and the concentrations of undeclared allergens found were 0.3-13.3 mg kg⻹ for milk (ß-lactoglobulin) and 0.21-12 mg kg⻹ for egg white proteins. On this basis, the possibility of cross-contamination serious enough to raise public health concern cannot be dismissed.
Assuntos
Alérgenos/análise , Proteínas Alimentares/análise , Produtos Pesqueiros/análise , Contaminação de Alimentos , Rotulagem de Alimentos , Produtos da Carne/análise , Alérgenos/efeitos adversos , Alérgenos/genética , Animais , Bovinos , Galinhas , Proteínas Alimentares/efeitos adversos , Proteínas Dietéticas do Ovo/efeitos adversos , Proteínas Dietéticas do Ovo/análise , Ensaio de Imunoadsorção Enzimática , Produtos Pesqueiros/economia , Hipersensibilidade Alimentar/dietoterapia , Hipersensibilidade Alimentar/prevenção & controle , Inspeção de Alimentos , Humanos , Itália , Lactoglobulinas/efeitos adversos , Lactoglobulinas/análise , Limite de Detecção , Produtos da Carne/economia , Reação em Cadeia da Polimerase em Tempo Real , Frutos do Mar/efeitos adversos , Frutos do Mar/análiseRESUMO
The development of a rapid, simple and accurate analytical method aimed at the detection and quantification of bovine milk in either ovine or caprine milk samples by means of CE-MS analyses of whey proteins with high-ionic strength and presence of acidic running buffer is described. The high-ionic strength buffer was used in order to minimize the problems with the adsorption of the proteins onto the fused-silica capillary wall. The acidic running electrolyte, pH 1.9, was used to support the production of positive ions in electrospray. Highly linear dependences of the ratio of the sum of non-bovine beta-lactoglobulins (ovine or caprine) to the total beta-lactoglobulins in milk mixture (bovine plus ovine or bovine plus caprine) vs. the volume percentage of added bovine milk in ovine (or caprine) milk were obtained. This technique allowed the fast and reliable evaluation of milk adulteration. The amount of bovine milk added into the "non-bovine" ones can be well within the concentration range of 5-95%.