Salmonella typhimurium
survived freeze-drying at a platen temperature of 120 F (48.9 C) and also, though to a much lesser degree, at 160 F (82.6 C). The extent of the survival at these temperatures was dependent on the composition of the model system employed. The incidence of damage immediately after freeze-drying was greater for cells dried at the higher platen temperature and was influenced by the composition of the menstruum in which the cells were dried. In model systems having protein-dominant isotherms, survival during subsequent storage depended greatly on relative humidity, with recovery highest at relative humidities below those corresponding to moisture contents at which a monomolecular layer is formed. In menstrua having a higher sugar content, survival was best at low relative humidities corresponding to a very low equilibrium moisture content in the model system used. Damage during storage tended to be a function of the composition of the gels in which the organisms were freeze-dried, and also depended greatly on the presence of air and on the relative humidity. The maximal percentage of damage usually occurred at the low relative humidities as storage time increased.
RESUMO -Os ácidos graxos possuem diversas aplicações industriais e servem de substratos para inúmeros produtos, principalmente dentro da indústria alimentícia, onde um alto grau de pureza se faz necessário e é dificilmente alcançado quando sua produção envolve catalisadores químicos. Além disso, a reação de hidrólise geralmente necessita de altas temperaturas e pressões para ocorrer, o que pode ser contornado com o uso de enzimas (lipases) como catalisador, as quais utilizam condições reacionais mais brandas. Dentro deste contexto, este projeto teve como principal objetivo avaliar o processo de hidrólise enzimática do óleo de soja em um reator de leito fixo tubular usando como catalisador a enzima Lipozyme TL IM e avaliar os efeitos da razão mássica água/substrato e da temperatura no rendimento da reação por meio de um planejamento experimental. As reações de hidrólise foram realizadas a temperaturas de 20, 25 e 30°C, em concentrações de 4, 8 e 12% de água em relação à massa total e tempo de residência de uma hora. Nas melhores condições, foi produzido um óleo com acidez final de 24,46%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.