Analysis Of Flavor Volatiles Research Articles

Evaluation of Sequential-SBSE and TF-SPME Extraction Techniques Prior to GC-TOFMS for the Analysis of Flavor Volatiles in Beer

Sequential-Stir Bar Sorptive Extraction (Seq-SBSE) was investigated as a technique for the extraction and concentration of volatiles in beer prior to gas chromatography–time-of-flight mass spectrometry (GC–TOFMS) analysis for standard solutions prepared in an imitation beer solvent. Twenty-seven beer analytes across a range of polarities (Ko/w’s) were investigated. The technique provided acceptable quantitation for most of the 27 analytes investigated, but calibration curves for five of the most polar analytes were nonlinear. Thin Film SPME (TF-SPME) sample preparation, which has recently been shown to provide quantitative extraction of polar analytes, was compared to Seq-SBSE results for the standard solutions. TF-SPME provided linear calibration curves for all 27 analytes. To compare test precision, a commercial sample of beer was analyzed in triplicate by both techniques. Eighty-five analytes were detected by Seq-SBSE with an average percentage of relative standard deviation (%RSD) of 9.7% and 95 analytes were detected by TF-SPME with an average %RSD of 8.9%. Triplicate samples from three brands of commercial beers at the end of shelf life were analyzed. Ten potential off-flavor chemicals analyzed by TF-SPME were subjected to principal component analysis. Examination of principal component analysis (PCA) loadings results showed the most significant concentration differences in off-flavor chemicals in the different brands occurred with E-2-nonenal, 3-methyl-2-butene-1-thiol, and vinyl guaiacol. Studies showed that some analytes showed better detection sensitivity by Seq-SBSE, while other analytes were detected with higher sensitivity by TF-SPME. Linear least squares correlation coefficients for calibration curves were higher for Seq-SBSE except for highly polar volatiles, while TF-SPME was able to quantitatively detect more chemicals including highly polar ones. TF-SPME appears to be an excellent supplemental technique for the analysis of beer volatiles.

Quantitative Analysis of Flavor Volatiles in Beer Using Headspace Solid-Phase Microextraction and Gas Chromatography–Flame Ionization Detection (HS-SPME-GC-FID)

Quantitative Analysis of Flavor Volatiles in Beer Using Headspace Solid-Phase Microextraction and Gas Chromatography–Flame Ionization Detection (HS-SPME-GC-FID)

Evaluation of Sake by an Odor Sensor

The qualities of Japanese sake were analyzed by an odor sensor. Analysis of flavor volatiles in the 15% ethanol solution by the odor sensor indicated that substances such as isoamyl acetate, ethyl caproate, and isoamyl alcohol can be discriminated. When 35 samples of Japanese sake were analyzed with the odor sensor, the results correlated with those of an expert panel with a coefficient of 0.56. The above results suggest that classification of the quality of Japanese sake is possible using an odor sensor in place of a human panel.

MICROWAVE and SPOUTED BED DRYING of FROZEN BLUEBERRIES: the EFFECT of DRYINGAND PRETREATMENT METHODS ON PHYSICAL PROPERTIES and RETENTION of FLAVOR VOLATILES

Frozen blueberries (Vaccinium corymbosum L cv. ‘Elliott’) were dried in a microwave and spouted bed combined dryer (MWSB) at 70C air temperature and 3.7 W/g microwave power (wet material). the effect of pretreatment using a 2.5% Ethyl Oleate & 0.2 NaOH dipping solution followed by sucrose osmotic treatment was investigated. the drying kinetics of MWSB drying was compared with spouted bed (SB) drying with dipping treatment, and with tray drying. the rehydration ratio, the color, and the bulk density of MWSB dried blueberries were compared with those of freeze, tray, and SB drying. the drying time needed to reduce blueberry moisture content from 82.5% to 15% (wet basis) using MWSB drying was 1/19 and 1/24 (with and without pretreatment) of the time for tray drying. the MWSB drying resulted in a low bulk density and more reddish and less blue color compared with other methods. MWSB dried frozen blueberries exhibited a higher rehydration ratio in short soaking times. Analysis of flavor volatiles by GC/MS identified ten heat-generated compounds. Microwave heating generated three unique flavor compounds (2-Butanone, 2-methyl butanal, and 3-methyl butanal). Freeze-dried frozen blueberries lost several flavor compounds including the typical blueberry aroma, the 1, 8-Cineole.

Flavor Analysis of rin/+ and Other Tomato hybrids and Inbreds Using Sensory and Chemical Methods

Consumer dissatisfaction with commercial tomato (Lycopersicon esculentum Mill.) eating quality is well-known. An array of tomato cultivars were tested for overall flavor by experienced or trained taste panels over several seasons. Fruit were also analyzed for aromatic volatiles, soluble solids (SS), and titratable acidity (TA). `Solar Set' was the most consistent cultivar for overall flavor, always ranking in the most preferred statistical group. Cultivars that were bred for increased firmness, either by crossing firm lines (ultrafirms) or that were heterozygous for the ripening inhibitor (rin) gene, tended to rank low in overall flavor and sweetness. Comparisons made included ultrafirm lines, rin/+ hybrids with one to three backcrosses to the high-flavored parent of `Solar Set' (Fla. 7060), Fla. 7060, and `Solar Set' with two rin backcrosses. Experienced panel ratings were highest for Fla 7060 followed by the rin/+ hybrids (in descending order of backcrosses to Fla. 7060), followed by the ultrafirm lines. SS and TA were highest in one ultrafirm (SS = 9.1, TA = 0.68) and lowest in one of the rin/+ hybrids (SS = 6.3, TA = 0.37) while the rest of the samples showed intermediate values. Analysis of flavor volatiles showed Fla. 7060 to be generally higher in most volatiles compared to the ultrafims and two of the rin/+ hybrids. Significant differences were found for methanol, ethanol, 1-penten-3-one, hexanal, trans-2-hexanal, trans-2-heptenal, cis-3-hexenol, 2+3-methylbutanol, 6-methyl-5-hepten-2-one, 2-isobutylthiazole, and geranylacetone.

EFFECT OF TEMPERATURE ON THE QUALITY OF MUSCLE FOODS

ABSTRACTHeating/cooking alters a food's flavor precursors yielding a product with a new pleasing taste. While heating to a high temperature destroys most pathogens thereby enhancing safety, it also alters the food's flavor by changing the precursors and final flavor components of the food. For example, heating meat to above 77C not only destroys many foodborne pathogens but also causes major changes in level of desirable flavor precursors. Many of these changes are due to alteration in activity of endogenous hydrolytic enzymes as well as heatinduced structural and functional changes. Heating induces differential production and distribution of flavor principles and flavor precursors. A secondary effect of temperature on food‐flavor is its direct affect on analysis of flavor volatiles, i.e., high purge temperatures bias analysis of flavor components by production of new and destruction of existing components. This paper focuses on the structure/function relationship of meat proteins and their proteolytic products as they relate to meat flavor and end‐point cooking temperature. The paper also will address the effect of analytical temperature on meat flavor analysis.