Development of emulgels formulated with sweet fennel oil and rhamsan gum, a biological macromolecule produced by Sphingomonas.

In this work, a current application of rhamsan gum, a biological macromolecule which belongs to the sphingans group, as an efficient stabilizer of emulsions and emulgels is investigated. The main objective of this investigation was 1) to study the influence of glycerol and sweet fennel oil concentration on microfluidized emulsion properties; and 2) to develop stable emulgels stabilized with rhamsan gum. The emulsions and emulgels were characterized by droplet size, rheological properties, physical stability and microstructure. An analysis by surface response methodology of the results obtained revealed that essential oil concentration was the most determining factor affecting emulsion mean droplet sizes and rheological properties. An optimal emulsion with minimum d4,3 was obtained for the sample formulated with 10 wt% sweet fennel oil and 0 wt% glycerol. However, all of these emulsions suffered destabilization by creaming. The results of the rheological characterization of emulsions formulated with the biological macromolecule showed that the addition of 0.2 wt% of rhamsan gum allows an emulgel with enhanced physical stability to be obtained. Thus, we provide valuable information concerning the use of rhamsan gum as emulsion stabilizer and the development of stable emulsions and emulgels for use in the food industry.

ent-Labdane Diterpenoids from the Aerial Parts of Eupatorium obtusissmum.

Six new ent-labdane diterpenoids, uasdlabdanes A-F (1-6), were isolated from the aerial parts of Eupatorium obtusissmum. The new structures were elucidated through spectroscopic and spectrometric data analyses. The absolute configurations of compounds 1 and 2 were established by X-ray crystallography, and those of 3-6, by comparison of experimental and calculated electronic circular dichroism spectra. The antiproliferative activity of the compounds was studied in a panel of six representative human solid tumor cell lines and showed GI50 values ranging from 19 to >100 µM.

Detection of Enterotoxigenic Clostridium perfringens in Raw Beef by Polymerase Chain Reaction.

A polymerase chain reaction (PCR) procedure was developed for direct detection of Clostridium perfringens strains with potential for food poisoning in raw beef samples. An oligonucleotide primer pair was used to amplify a 364 base pair sequence internal to the C. perfringens enterotoxin gene. One milliliter portions of the meat homogenates were inoculated into cooked meat medium (CMM) or reduced Fluid Thioglycollate (FTG) medium and incubated at 37°C. Portions sampled at 2, 4, 6, 8 and 24 h of enrichment were assayed for detection of the enterotoxin sequence by PCR. Amplification of the 364 bp sequence could be detected in 6 h by agarose gel electrophoresis and as early as 2 h by hybridization to a 150 bp digoxigenin (DIG)-labeled probe. To increase the sensitivity of the detection assay a commercial chromosomal deoxyribonucleic acid (DNA) extraction assay was compared with a nested PCR approach. Both methods allowed detection of less than 1 log10 colony forming units (CFU)/g of C. perfringens strains harboring the enterotoxin gene, with no interference with the background microflora present in the raw ground beef.