Analysis of Clostridium botulinum toxigenic types A, B, and E for fatty and carbohydrate content.
Lyophilized, 48-hr log-phase vegetative cells were extracted with chloroform-methanol (2:1, v/v) and ethanol-ether (3:1, v/v) and then saponified with methanolic KOH. Gas-liquid chromatography of the methyl esters of extractable fatty acids revealed distinctive "pattern profiles" of Clostridium botulinum toxigenic types "A," "B," and "E." C. perfringens type "A" and Escherichia coli strain "B" were also studied in a similar manner and were found to give pattern profiles which were distinct even from those obtained for the C. botulinum microorganisms. Amino sugar content of the five microorganisms was determined by using a Beckman amino acid analyzer. The molar ratio of glucosamine to that of galactosamine was found to be of further assistance in distinguishing the individual microorganisms.
Stable gas-liquid chromatography column for fatty acid analysis
A mixed gas-liquid chromatography column of FFAP and Apolar-7CP has excelelnt thermal stability and shows excellent characteristics for the separation of the methylesters of fatty acids from Salmonella enteritidis call wall lipids.
Spray drying of dairy products: state of the art
Milk is extremely perishable, and yet, for a number of reasons, it has to be preserved for later consumption. The removal of water prevents the growth of micro-organisms and facilitates pres- ervation and storage of milk constituents. Spray drying is one of the most convenient techniques for producing milk powders and for stabilizing milk constituents. Before spray drying, the milk under- goes several processes (such as heat treatment, cream separation, membrane processes, vacuum evap- oration and homogenization). The chemical, physical, technological, nutritional, functional and microbiological properties of final products are influenced by a number of factors such as operating conditions, properties of the dairy products and storage conditions. The aim of this review is to de- scribe the process of spray drying of dairy products and to review the present and recent advance- ments of knowledge on the properties of spray-dried milk products, on modelling and water transfer simulation (drying and rehydration), dairy powders and the spray drying equipment and energy con- sumption.