A comparison of the stability of beverage cloud emulsions formulated with different gum acacia- and starch-based emulsifiers.

The performance of several hydrocolloids (3 gum acacias, 1 modified gum acacia, and 3 modified starches) in stabilizing beverage emulsions and corresponding model beverages was investigated employing different core materials, emulsifier usage levels, and storage temperatures. Concentrated emulsions were prepared using orange terpenes or Miglyol 812 (comprising medium-chain triglycerides, MCT) weighted 1:1 with ester gum, stored at 25 or 35 degrees C, and analyzed on days 0, 1, and 3. On day 3, model beverages were made from each emulsion, stored at both temperatures, and analyzed weekly for 4 wk. Stability of concentrated emulsions was assessed by measuring mean particle size and by visual observations of ringing; beverage stability was judged similarly and also by loss of turbidity. Particle size measurements showed concentrated emulsions containing gum acacia or modified gum acacia with either core material were stable over 3 d storage at both temperatures whereas those made with modified starches were not, destabilization being faster at 35 degrees C. Beverages based on orange terpenes, in contrast to Miglyol, yielded smaller mean particle sizes, both on manufacture and during storage, regardless of hydrocolloid used. Visual observations of ringing generally supported this finding. Modified gum acacia was evaluated at both recommended and higher usage levels, stability increasing in the latter case. In general, all gum acacia and modified gum acacia emulsifiers were superior in stability to those based on modified starches, at either temperature, for orange terpene-based beverages. In Miglyol-based beverages, similar results were seen, except 1 modified starch performed as well as the gum acacia products.

Comparison of breath and in-mouth collection for the measurement of oral malodorous compounds by gas chromatography using sulfur chemiluminescence detection.

Volatile sulfur compounds (VSCs), specifically hydrogen sulfide, methyl mercaptan and dimethyl sulfide, are generally considered to be the primary volatiles responsible for 'morning' malodors in breath. To date, the 'gold standard' for detecting VSC concentrations in breath is the use of gas chromatography coupled with sulfur chemiluminescence detection. Breath gas is often collected in a polypropylene syringe and then aliquots are injected into a gas chromatograph for analysis. The objective of this work was to compare the Twister™ bar in-mouth extraction methodology for measurement of VSCs with the gas syringe breath-sampling collection technique. The Twister bar technology captures malodorous compounds in the mouth as opposed to breath gas. Using these techniques, comparable results were obtained in studies demonstrating the efficacy of a proprietary oral malodor counteraction system.

Use of cation-exchange resin for the detection of alkylpyridines in beer.

A method has been devised whereby trace amounts of certain basic compounds, such as pyridines, may be detected and semi-quantified in beer in the presence of an excess of other flavour constituents including pyrazines. The method involves steam distillation of beer under reduced pressure and subsequent passage of the distillate through a column of weakly acidic Zerolit cation-exchange resin. The resin is eluted with aqueous sodium chloride, the eluate extracted with organic solvent and the concentrated extract analysed by gas chromatography coupled with mass spectrometry. Using this technique with multiple ion detection, a series of alkylpyridines was readily detectable in beers and worts at levels below 1 ppb.