Application of Scharer's quantitative method for the determination of residual alkaline phosphatase activity in standard Minas / Aplicação do método modificado de Scharer para a determinação quantitativa da atividade de fosfatase alcalina residual em queijo minas padrão

Milk pasteurization is a critical issue in the dairy industry, and failures in this process can affect final product safety. Scharer's enzymatic method is still traditionally used to verify pasteurization efficiency compliance, and it is based on screening for residual alkaline phosphatase in milk. Although several methods are used to quantify enzymatic activity to assess milk pasteurization efficiency, there is a small amount of published data regarding the use of these methods to quantify alkaline phosphatase in cheese. In this study, the Scharer's modified method was used to determine the levels of residual alkaline phosphatase in standard minas cheese, before and after 20 days of ripening. The cheeses were made using raw or pasteurized milk with the addition of different concentrations of raw milk (0; 0.05%; 0.10%; 0.20%; and 0.50%). In the fresh cheese samples, the method showed a sensitivity of only 0.50% with the addition of raw milk to the pasteurized milk used to make cheese. In addition, levels of up 0.20% of raw milk in pasteurized milk, the concentrations of phenol was inferior to 1μg phenol/g of dairy product which is the preconized indicator value for adequate pasteurization.

A pasteurização do leite é um ponto crítico na indústria de laticínios, e falhas nessa etapa comprometem a segurança do produto. O método enzimático de Scharer é tradicionalmente utilizado na verificação da eficiência da pasteurização e baseia-se na pesquisa da atividade de fosfatase alcalina residual em leite. Embora vários métodos estejam disponíveis para avaliar a eficiência da pasteurização, há um número reduzido de dados publicados baseados na quantificação da atividade da fosfatase alcalina em queijo. Neste estudo, o método modificado de Scharer foi utilizado para determinar os níveis de fosfatase alcalina residual em queijo minas padrão, antes e após 20 dias de maturação. Os queijos foram feitos com leite cru ou com leite pasteurizado com adição de diferentes concentrações de leite cru (0, 0,05%, 0,10%, 0,20% e 0,50%). Nas amostras de queijo fresco, o método apresentou sensibilidade apenas com 0,50% de adição de leite cru ao leite pasteurizado utilizado na fabricação de queijo. Em níveis de adição de até 0,20% de leite cru no leite pasteurizado, as concentrações de fenol se mostraram inferiores a 1μg de fenol/g de produto lácteo, que é o valor preconizado como indicador de pasteurização adequada.

Novel methods for the encapsulation of meglumine antimoniate into liposomes.

The antimonial drug, meglumine antimoniate, was successfully encapsulated in dehydration-rehydration vesicles and in freeze-dried empty liposomes (FDELs). High encapsulation efficiencies (from 28 to 58%) and low weight ratios of lipids to encapsulated antimony (from 1:0.15 to 1:0.3) were achieved. These formulations, contrary to those obtained by conventional methods, can be stored as intermediate lyophilized forms and reconstituted just before use. The efficacy of FDEL-encapsulated meglumine antimoniate was evaluated in hamsters experimentally infected with Leishmania chagasi. A significant reduction of liver parasite burdens was observed in animals treated with this preparation, when compared to control animals treated with empty liposomes. In contrast, free meglumine antimoniate was found to be inefficient when administered at a comparable dose of antimony. This novel liposome-based meglumine antimoniate formulation appears to be promising as a pharmaceutical product for the treatment of visceral leishmaniasis.

Novel methods for the encapsulation of meglumine antimoniate into liposomes

The antimonial drug, meglumine antimoniate, was successfully encapsulated in dehydration-rehydration vesicles and in freeze-dried empty liposomes (FDELs). High encapsulation efficiencies (from 28 to 58 percent) and low weight ratios of lipids to encapsulated antimony (from 1:0.15 to 1:0.3) were achieved. These formulations, contrary to those obtained by conventional methods, can be stored as intermediate lyophilized forms and reconstituted just before use. The efficacy of FDEL-encapsulated meglumine antimoniate was evaluated in hamsters experimentally infected with Leishmania chagasi. A significant reduction of liver parasite burdens was observed in animals treated with this preparation, when compared to control animals treated with empty liposomes. In contrast, free meglumine antimoniate was found to be inefficient when administered at a comparable dose of antimony. This novel liposome-based meglumine antimoniate formulation appears to be promising as a pharmaceutical product for the treatment of visceral leishmaniasis.