Effect of liposome-encapsulated nisin and bacteriocin-like substance P34 on Listeria monocytogenes growth in Minas frescal cheese

The efficacy of liposome-encapsulated nisin and bacteriocin-like substance (BLS) P34 to control growth of Listeria monocytogenes in Minas frescal cheese was investigated. Nisin and BLS P34 were encapsulated in partially purified soybean phosphatidylcholine (PC-1) and PC-1-cholesterol (7:3) liposomes. PC-1 nanovesicles were previously characterized. PC-1-cholesterol encapsulated nisin and BLS P34 presented, respectively, 218 nm and 158 nm diameters, zeta potential of -64 mV and -53 mV, and entrapment efficiency of 88.9% and 100%. All treatments reduced the population of L monocytogenes compared to the control during 21 days of storage of Minas frescal cheese at 7 degrees C. However, nisin and BLS P34 encapsulated in PC-1-cholesterol liposomes were less efficient in controlling L monocytogenes growth in comparison with free and PC-1 liposome-encapsulated bacteriocins. The highest inhibitory effect was observed for nisin and BLS P34 encapsulated in PC-1 liposomes after 10 days of storage of the product The encapsulation of bacteriocins in liposomes of partially purified soybean phosphatidylcholine may be a promising technology for the control of food-borne pathogens in cheeses. (C) 2012 Elsevier B.V. All rights reserved.

Luzes femininas: a felicidade segundo Madame du Châtelet

As luzes do Iluminismo francês consagradas por certa história da filosofia foram indubitavelmente as masculinas. As presenças de Voltaire, Rousseau e Diderot nas pesquisas e nas obras sobre o período são quase absolutas. A finalidade deste artigo é explorar as Luzes francesas, particularmente, a questão ética da felicidade, pelo olhar de uma razão tão ilustrada quanto a de Voltaire, Rousseau ou Diderot, porém de saiotes e espartilho: o pensamento de Émilie du Châtelet (1706-1749). Pouco conhecida pelo público brasileiro e menos estudada ainda pelos dix-huitièmistes locais, Madame du Châtelet, marquesa de berço, escreveu, por volta de 1746, um Discurso sobre a felicidade. O exame de algumas das teses e propostas éticas contidas nesse opúsculo é uma oportunidade instigante para se entenderem um pouco melhor não só as Luzes francesas, mas, sobretudo, a sensibilidade e as angústias das mulheres de vanguarda da França pré-revolucionária.