Case Study - Food and Beverage
Food & Beverage Odor amelioration efficacy
Measuring the effect of odor ameliorating “actives” in foods: Aqueous solutions that contained food related odors identified as commercially important were treated separately with ameliorating substances. How well the added substances worked to decrease odor in a model solution was determined by measuring headspace concentrations of odorants before and after treatment utilizing headspace stir bar sorptive extraction (HS SBSE). Volatiles were analyzed by thermal desorption, cryo-focusing, gas chromatography mass spectrometry.
Odorous compounds from sweet potatoes
A method was developed and tested to identify and measure volatile components generated from sweetpotato bread as it baked for the purpose of determining if hazardous chemicals identified by the National Space and Aeronautical Agency (NASA)’s maximum allowable concentrations list (SMACs) were present. A 14.5kL enclosed chamber made of polyethylene and polyvinylchloride was constructed to mimic conditions of a small enclosed food preparation space on board a NASA spacecraft. Volatiles generated from sweetpotato bread as it baked in a portable bread machine inside the enclosed chamber were extracted by thermal desorption tubes containing polydimethylsiloxane foam plugs and a portable pump. Tubes were thermally desorbed and components were analyzed by gas chromatography-mass spectrometry. Results indicated sweetpotato bread baked in a portable bread machine produced compounds identified as potentially hazardous including aliphatic alkanes, saturated C3-C8 aldehydes, ethanol, limonene, and furan containing components. The next step is to measure the concentrations of potentially hazardous compounds and determine if they exceed limits delineated by SMACs.
Volatiles from different varieties of watermelon
Volatile and semivolatile compounds were extracted by stir bar sorptive extraction from watermelon puree and headspace obtained from 4 different varieties. Analysis was conducted by gas chromatography mass spectrometry. More than 36 compounds were detected. 10 were positively identified with authentic standard confirmation. The compound present in greatest abundance varied according to variety.
Carbonated beverage sulfur off-odor
A sulfur off-odor was reported in specific lots of diet cola. The client was unable to successfully identify the chemical nature of the odorant and samples were sent to VAC for further analysis. Upon receipt at the VAC lab, sulfur odor was noticeable upon simple organoleptic analysis of the diet cola. A series of extraction methods (coupled with GCMS analysis) proved unsuccessful including long term SPME fiber and SBSE exposure to liquid sample, and liquid sample headspace. A dynamic device that trapped volatiles in thermal desorption tubes sealed and immersed in 1 oC water bath proved successful at identifying the odorous component as dimethyl sulfide.
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