Characterization of Typical Potent Odorants in Cola-Flavored

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Characterization of Typical Potent Odorants in Cola-Flavored Carbonated Beverages by Aroma Extract Dilution Analysis Yaowapa Lorjaroenphon, and Keith R. Cadwallader J. Agric. Food Chem., Just Accepted Manuscript • DOI: 10.1021/jf504953s • Publication Date (Web): 21 Dec 2014 Downloaded from http://pubs.acs.org on January 5, 2015

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Journal of Agricultural and Food Chemistry

TITLE: Characterization of Typical Potent Odorants in Cola-Flavored Carbonated Beverages by Aroma Extract Dilution Analysis

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AUTHORS:

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Yaowapa Lorjaroenphon† and Keith R. Cadwallader‡*

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†

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Department of Food Science and Technology, Faculty of Agro-Industry, Kasetsart

University, 50 Ngamwongwan Road, Bangkok, 10900, Thailand ‡

Department of Food Science and Human Nutrition, University of Illinois at Urbana-

Champaign, 1302 West Pennsylvania Avenue, Urbana, Illinois, 61801 *Corresponding author. Phone: 217-333-5803. Fax: 217-333-1875. E-mail: [email protected].

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1 ACS Paragon Plus Environment


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ABSTRACT:

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The aroma-active compounds in typical cola-flavored carbonated beverages were

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characterized using gas chromatography-olfactometry (GCO) and GC-mass spectrometry (GC-

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MS). The potent odorants in the top three US brands of regular colas were identified by aroma

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extract dilution analysis (AEDA). Among the numerous odorants identified, eugenol (spicy,

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clove-like, sweet) and coumarin (sweet, herbaceous) were predominant in all colas. Other

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predominant odorants in at least one brand included guaiacol (smoky) and linalool (floral,

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sweet), while 1,8-cineol (minty, eucalyptus-like) was a moderately potent odorant in all colas.

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Determination of the enantiomeric compositions indicated that (R)-(-)-linalool (34.5%) was a

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more potent odorant than the (S)-(+)-enantiomer (65.6%) due to its much lower odor detection

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threshold. In addition, lemon-lime and cooling attributes determined by sensory descriptive

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analysis had the highest odor intensities among the eight sensory descriptors. The aroma profiles

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of the three colas were in good agreement with the potent odorants identified by AEDA.

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KEYWORDS: cola-flavored carbonated beverage; potent odorant; aroma extract dilution analysis; enantiomer; sensory descriptive analysis

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INTRODUCTION: Carbonated beverages are the largest segment of soft drink industry, and cola is the

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predominant flavor accounting for 54.0% of the global revenues generated by the soft drink and

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bottled water industry.1 The sales of cola-flavored carbonated beverages in 2010 were about $14

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billion of the soft drink market in the United States.2,3 According to product labels and published

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literature, the uniqueness and complexity of cola is a result of the mixture of natural flavors

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derived from vanilla extract and essential oils of citrus, cassia or cinnamon, coriander, nutmeg,

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and neroli. 4,5

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Despite its popularity, there are only a few studies about the flavor chemistry of cola.

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Cola aroma has been studied by both sensory6 and instrumental7-9 techniques. Headspace

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volatiles of de-carbonated colas were evaluated by solid phase microextraction (SPME) and

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dynamic headspace analysis.8 These researchers reported that terpenes and aldehydes were the

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major volatiles and those in highest abundance were limonene and a mixture of α- and γ-

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terpineol. Limonene along with γ-terpinene and p-cymene were identified as the three most

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abundant headspace volatiles in off-flavored cola.7 Another study asserted that (Z)-terpin

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hydrate could be used as a volatile marker to differentiate cola stains from the dark color stains

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caused by other beverages including beer, coffee, black tea, Oolong tea, and green tea.9

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However, the potent odorants of cola have not been reported. Gas chromatography-

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olfactometry (GCO), which uses the human nose as a detector of GC, was developed and applied

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to indicate the odorants from the complex mixture of both aroma volatiles and odorless volatiles.

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Aroma extract dilution analysis (AEDA), which is frequently used, is a screening method used to

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rank the relative potency of aroma-active compounds found in foods.10,11 It has been used to



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identify the potent odorants in foods, beverages, and non-foods, including pomegranate juice12

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and scented candle.13

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The present study aimed to determine the potent odorants in the top three U.S. brands of

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regular cola-flavored carbonated beverages on the basis of AEDA. The aroma-active

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compounds in typical cola were characterized using GCO and GC-mass spectrometry (GC-MS).

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The most impact aroma-active compounds were then identified by AEDA. These results of this

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study can provide a foundation for further studies leading to the identification of key aroma

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components and improvements in the flavor and shelf-life stability of cola-flavored carbonated

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beverages.

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MATERIALS AND METHODS:

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Materials

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The top three US brands of regular cola-flavored carbonated beverages (Coca-Cola®,

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Pepsi® and RC®; designated as cola A, cola B and cola C, respectively) and the references used

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in sensory evaluation (Table 1) were purchased from local markets (Urbana, IL) during 2010-

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2011. Odor-free water used in this experiment was prepared by boiling deionized-distilled water

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to two thirds of its initial volume.

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Chemicals

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General reagent or HPLC grade chemicals, such as anhydrous diethyl ether, anhydrous

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sodium sulfate, dichloromethane, hydrochloric acid, sodium bicarbonate, and sodium chloride,

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were obtained from Fisher Scientific (Fair Lawn, NJ). Ultra high purity (UHP) nitrogen and

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UHP helium were purchased from S.J. Smith (Davenport, IA).


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Reference standard compounds. The standard compounds used to confirm the structures

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of the aroma compounds listed in Table 2 were supplied by the companies given in parentheses:

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compounds nos. 1-6, 8b, 9-11, 13, 14, 16, 19-22 (22a and 22b), 24, 25 (25a and 25b), 26-29,

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mixture of 30 and 34, 31 (31a and 31b), 32, 37, 38, 41, 43, 45-49, 51, 52, 56, and 57 (Sigma-

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Aldrich, St. Louis, MO); 12 (TCI, Portland, OR); 33, 36, and 39 (Bedoukian, Danbury, CT); 40

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(Firmenich, Princeton, NJ); mixture of 53 and 54 (Alfa Aesar, Lancashire, United Kingdom); 8a,

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22a, 58 (Fluka, Buchs, Switzerland). 2,3-Dehydro-1,8-cineol (compound no. 7) was synthesized

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according to the published literature.14

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Isolation of Volatile Compounds Odor-free deionized-distilled water (200 mL) and diethyl ether (150 mL) were added to

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the extraction chamber of a continuous liquid-liquid extraction (CLLE) apparatus (part no.

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Z562440; Sigma-Aldrich) equipped with 5 °C condenser, 48 °C water bath (250-mL distillation

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flask), and magnetic stirrer. One can of cola sample (355 mL) was poured through the cooled

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condenser to avoid loss of aroma compounds, and rinsed with 50 mL of water. After extraction

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for 18 h at a condensation rate of 2 drops/s, the solvent layer was concentrated to 50 mL by

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Vigreux column distillation at 43 °C. The volatile compounds were isolated from any non-

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volatile compounds by solvent assisted flavor evaporation (SAFE) according to the litelature.13,15

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The aroma extract was fractionated with aqueous 0.5 M NaHCO3 (3 × 20 mL) into acidic

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(aqueous phase) and neutral-basic (organic phase) fractions. The aqueous layer was acidified to

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pH 2 with aqueous 4 N HCl, and extracted with diethyl ether (3 × 20 mL). Each fraction was

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washed with saturated aqueous NaCl (2 × 15 mL), concentrated to 10 mL by Vigreux column



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distillation, and dried over 2 g of anhydrous Na2SO4. The ether extract was further concentrated by Vigreux column distillation to 350 µL, and kept at -70 °C until analysis.

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Identification of Aroma-Active Compounds The aroma extracts were analyzed by gas chromatography-olfactometry (GCO) and GCmass spectrometry (GC-MS). GCO. GCO was conducted using a 6890 GC (Agilent Technologies, Inc., Santa Clara,

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CA) equipped with a flame ionization detector (FID) and olfactory detection port (DATU

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Technology Transfer, Geneva, NY). The aroma extract (2 µL) was injected in the cool on-

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column mode (+3 °C oven tracking mode) to avoid injection bias and reduce the chance for

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thermal degradation of any labile compounds. Separations were performed on RTX®-Wax and

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RTX®-5 SILMS capillary columns (both 15 m × 0.32 mm i.d. × 0.5 µm df; Restek, Bellefonte,

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PA). The column effluent was split 1:5 between the FID (250 °C) and olfactory detection port,

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respectively. The oven temperature was programed from 40 °C to 225 °C at a ramp rate of

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10 °C/min for the RTX®-Wax column or a ramp rate of 6 °C/min for the RTX®-5 SILMS

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column, with initial and final hold times of 5 and 20 min, respectively. The flow rate of the

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helium carrier gas was 2 mL/min.

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GC-MS. The GC-MS system consisted of a 6890 GC/5973 mass selective detector

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(Agilent Technologies, Inc.). One microliter of extract was injected into either the Stabilwax®

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(30 m × 0.25 mm i.d. × 0.25 µm df; Restek) or SACTM-5 (30 m × 0.25 mm i.d. × 0.25 µm df;

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Supelco, Bellefonte, PA) capillary columns in the cool on-column mode (+3 °C oven tracking

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mode). The initial oven temperature was 35 °C. After 5 min, the oven temperature was

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increased at 4 °C/min to the final temperature (225 °C for Stabilwax® or 240 °C for SACTM-5),


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and held for 20 min. The flow rate of helium carrier gas was 1 mL/min. The mass spectra were

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recorded in full scan mode (35-300 a.m.u., scan rate 5.27 scans/s, interface temperature 280 °C,

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and ionization energy 70 eV).

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The retention index (RI) of each compound was calculated using the retention time (RT)

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of that compound compared against the RTs of a series of standard n-alkanes.16 The aroma-

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active compounds were positively identified based on comparison of their RI values (on two

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different polarity stationary phases), odor properties, and mass spectra against those of authentic

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standard compounds to avoid erroneous identifications. A compound was considered to be

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tentatively identified if no authentic standard was available for comparison. In this case mass

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spectra were compared against those in the NIST2008 mass spectral database, and retention

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indices were compared to literature values.

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Aroma Extract Dilution Analysis The aroma extract was diluted stepwise (1:3 (v/v)) using diethyl ether as described

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previous.13,17 Each dilution was performed by GCO on RTX®-Wax column. The sniffing time

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for each panelist was about 30 min per run. The flavor dilution (FD) factor for a specific

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odorant, which is the highest dilution at which panelists can smell that compound, was reported

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based on averaging the log3FD factors of three panelists (1 female and 2 males; 20-47 years)

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after rounding off to the nearest whole number.

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Determination of Enantiomer Composition

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The enantiomeric compositions of selected aroma-active compounds were investigated

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by GC-FID using an InertCapTM CHIRAMIX column (30 m × 0.32 mm i.d. × 0.25 µm df; GL



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Sciences Inc., Tokyo, Japan). Two microliters of the aroma extract or standard solution (~1 ppm

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in dichloromethane) was injected in the hot split (5:1) mode at 250 °C. The oven temperature

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program started from 100 °C for 1 min, then was ramped at 1 °C/min to 180 °C, and held for 10

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min. Helium was used as a carrier gas at a flow rate of 2.5 mL/min. The configuration of each

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chiral compound was determined based on comparison of its retention time against that of an

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authentic standard compound. The relative composition of each enantiomer pair in cola A was

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based on the average from four aroma extracts.

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Sensory Descriptive Analysis The human subject protocol number 11249 was approved by The University of Illinois at

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Urbana-Champaign Institutional Review Board (IRB). Ten panelists (students and staff; 7

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females and 3 males; 22-38 years) were selected based on the participants’ abilities to detect and

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describe differences in aroma characteristics. They were trained for approximately 15 h to

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evaluate the aroma (by nose) of authentic cola samples consisting of different brands, lots,

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packages, and colas stored under various conditions. Terminologies with definitions and

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commercially available references were developed, and are listed in Table 1. Cola-flavored

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carbonated beverage (50 mL) was prepared in 125-mL Teflon sniff bottle (Nalgene PTFE wash

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bottle without siphon tube; Nalge Nunc International, Rochester, NY). The bottles were covered

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with aluminum foil, and labeled with randomly generated 3-digit codes. In order to minimize

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nasal irritation caused by high levels of carbon dioxide, the sample bottles were kept open at

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room temperature for 30 min before evaluation which allowed most the of carbon dioxide to

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passively escape. The serving orders of test samples were randomized, and the colas were

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presented one at a time to panelist. In individual booths, panelists evaluated the samples by


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gently squeezing the bottle and sniffing the expressed air. They were asked to rate the intensity

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of each attribute on 15-cm line scale with two end anchors from none to strong.

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Statistical analysis. The mean score of each attribute/term was calculated, and then

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plotted to establish the aroma profile as spider web plots. Analysis of variance (ANOVA) was

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performed by SAS® program (SAS institute Inc., Cary, NC) to detect significant differences

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among cola samples. If there was significant difference (p-value < 0.05), the least significant

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difference (LSD) was used to check which samples differed.

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RESULTS AND DISCUSSION: The top three US brands of regular cola-flavored carbonated beverages were chosen for

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comprehensive aroma analysis. Continuous liquid-liquid extraction (CLLE) method was used to

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isolate the aroma compounds from colas because de-carbonation and extraction could be

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performed at the same time. The odor representativeness of extract was checked by using strip

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paper, and the aroma extract obtained from each cola by CLLE had a characteristic cola-like

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odor. This confirmed that the extract contained the typical aroma-active compounds of the colas.

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Volatile Components Total ion chromatograms were similar for all three cola-flavored carbonated beverages.

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Monoterpenes and sesquiterpenes were the major compounds in all colas. Among these, the

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most abundant were limonene (8), α-terpineol (31), and γ-terpinene (10). However, not all

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volatile compounds found in foods significantly contribute to food aroma. In the past, flavor

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scientists were not successful in creating aroma models from the most abundance volatiles. For

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this reason, gas chromatography-olfactometry (GCO) has been applied to help identify trace-



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level potent odorants and to distinguish aroma-active compounds (odorants) from volatiles that

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contribute essentially no odor.

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Aroma-Active Components A combined total of 58 odorants were detected in the colas (Table 2), of which two were

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unidentified. Most of the odorants found in colas originate from the flavoring ingredients

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including vanilla extract and essential oils of citrus, cassia or cinnamon, coriander, nutmeg, and

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neroli.4,5 However, some may have been derived from non-volatile components, for example,

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furfural (20) which was reported as acid hydrolysis product of d-fructose.18 Moreover, some of

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these compounds can be derived from other odorants such as formation of α-terpineol (31) from

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limonene (8) due to acid-catalyzed reaction.19

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It should also be noted that the highly volatile aroma compounds with RI values on polar

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column (RTX®-Wax) less than 1000 were not identified in the present study. They might be lost

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during extraction and concentration the extract or might not be present in the colas considering

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the list of ingredients used in cola flavorings. Essential oils are generally obtained by distillation

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methods which cause loss of highly volatile compounds.

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The odor activity value (OAV) concept has been used to estimate the degree for which a

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particular volatile contributes to the overall aroma of food. It defined as the ratio of the

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concentration of an aroma compound in the food to its odor detection threshold in the food

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matrix. The accuracy of an OAV depends on accurate quantification and determination of odor

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threshold. However, the odor detection thresholds of some compounds, especially unknowns,

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cannot be measured. For this reason, aroma extract dilution analysis (AEDA) was used to


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indicate the impact of aroma compound in colas in the present study. This technique can rank

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the odorants by their relative potency on the basis of OAVs in air.

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Potent Odorants The flavor dilution (FD) factors of all odorants found in the colas are shown in Table 2.

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Eugenol (51) (spicy, clove-like, sweet) and coumarin (56) (sweet, herbaceous) were predominant

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odorants in all colas. These odorants have been reported in cinnamon and cassia (Chinese

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cinnamon) oils.20,21 Eugenol is also a common volatile compound of nutmeg oil.22

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Guaiacol (41) (smoky note) was a potent odorant in colas A and B, while linalool (22)

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(floral, sweet) had high odor potency in cola C. Linalool also had relatively high potency in cola

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A. This odorant is reported as one of the most aroma-active compounds contributing to the

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overall flavor of lemon oil23 and orange peel oil.24 It is also a major component of the essential

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oils of coriander25 and neroli.26 In addition, linalool is reported as a dominant alcohol in orange

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oil27, and it was perceived in highest aroma intensity after octanal and wine lactone.28

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The compound 1,8-cineol (9) (minty, eucalyptus-like) was a moderately potent odorant in

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all colas. It was reported as one of the most impact aroma compounds in orange peel oil.24 This

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compound was also the second most abundant volatile found in cinnamon oil distillated from

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root bark.20 1,8-Cineol is not only present naturally in essential oils, but also reported as a

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secondary degradation product of limonene and α-terpineol by acid-catalyzed reactions.19

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However, the most abundant volatiles, including limonene, α-terpineol, and γ-terpinene,

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had low odor potencies in the colas. The FD factors of highly potent odorants found in citrus oil,

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such as neral (30) and geranial (34), were also low in all colas because of their possible

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degradation by acid-catalyzed reactions. It is well known that citral (a mixture of neral and



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geranial) is extremely unstable under acidic conditions resulting in the formation of various

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products.29 The half-life of citral in carbonated soft drinks is about six days.30 Oxidation of

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citral can occur under certain conditions31, but this is unlikely to occur in carbonated beverages

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due to the very low level of oxygen. The degradation mechanism for citral has already been

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proposed.30-33 Neral (cis-isomer) and geranial (trans-isomer) can rearrange by isomerization

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reactions. Then, p-menthadien-8-ols can be converted directly from neral by the series of acid-

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catalyzed reactions starting from cyclization. These intermediates are further degraded by

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disproportionation, redox, and dehydration reactions to form α,p-dimethylstyrene (17) and p-

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cymene (11) which are more stable. The compound 2,3-dehydro-1,8-cineol (7) is also formed as

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a result of the deterioration of citral by acid-catalyzed reactions. It is very unstable in acid

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conditions, but it is found at low levels in colas due to the steady-state reached among various

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precursor compounds via reversible acid-catalyzed reactions.33 It should be also noted that this

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compound was as a predominant odorant in lemon-lime carbonated beverages.14

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Among the three brands, the aroma profile of cola A was the most complex. Additional

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moderately potent odorants in cola A included methyleugenol (46) (hay-like, dried grass), 4-

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terpineol (25) (earthy, soapy, woody), (E)-cinnamaldehyde (48) (cinnamon-like, sweet), (Z)- and

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(E)-isoeugenols (53 and 54) (clove-like, sweet), and an unknown with an RI of 2399 on the

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RTX®-wax column (55) (clove-like, sweet). It is interesting to note that 4-terpineol, which is a

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major volatile in nutmeg oil34, may be a degradation product of some terpenes via acid-catalyzed

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reactions.19 It was also reported to be a potent odorant in a stored emulsion of lemon oil in an

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aqueous citric acid solution.23

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β-Damascenone (40) (apple sauce, sweet) was another moderately potent odorant in cola C. Vanillin (58), however, was not detected by GCO in this beverage. This finding suggests that


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vanilla extract may be used at only a low concentration in cola C. The low level of vanillin is

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also supported by low potency of guaiacol (41) in the cola since both compounds are important

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aroma components of vanilla extract.35 Furthermore, it was indicated that the main component

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influencing the sweet note of cola C was coumarin, not vanillin. Coumarin mixed with vanillin

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is reportedly used in cream soda because it is not highly volatile and its aroma intensity is three

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times higher than vanillin.36 Tonga bean extract which contains coumarin has also been used as

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a vanilla substitute.36 However, coumarin, tonga bean and tonga extract are not permitted for use

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in human foods in the U.S.37 because of toxicity concerns.38 Although coumarin is prohibited for

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use as a flavoring compound, it occurs naturally in cinnamon oil20 and vanilla extract,39 which

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are natural flavors used in cola-flavored carbonated beverages.

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While AEDA is the useful screening technique to rank the aroma compounds in order of

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potency, the method is, however, based on the odor-activity of the aroma compound in air. The

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effect of the food matrix on cola odor was not taken into account in the present study. These

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potent odorants identified in colas were further analyzed by OAVs to correct for the limitations

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of AEDA. Additional sensory studies on an aroma reconstitution and omission models should be

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also conducted to verify the OAVs calculation.

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Enantiomeric Composition Cola A was chosen to investigate the enantiomeric composition of selected aroma-active

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compounds since some of them had high FD factors. Furthermore, different enantiomers may

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have different odor detection thresholds and odor characteristics. The chemical structures and

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enantiomeric distributions of chiral compounds identified in cola A are shown in Table 3. d-

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Limonene or the (R)-(+)-isomer (8b) was present in greatest abundance (97.2%). This is to be



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expected because it is well known that d-limonene is commonly present in citrus oils. The

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majority of d-limonene results in more odor characteristics of fresh citrus-like in the essential

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oils, while l-limonene has harsh, turpentine note.40

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Linalool found in natural flavor is usually present as a mixture of (R)-(-)-isomer (22a)

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and (S)-(+)-isomer (22b) at different ratios. The odor description of 22a is floral, woody

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lavender note, while 22b is perceived as sweet and floral.40 The enantiomeric composition of

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linalool in cola A was 34.5% of the (R)-(-)- and 65.5% of the (S)-(+)-enantiomer. (R)-(-)-

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Linalool is predominant in neroli oil, while (S)-(+)-linalool comprises 60-70% of coriander oil.41

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Although the amount of (S)-(+)-linalool in cola was almost two fold higher than (R)-(-)-linalool,

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the odor threshold in water of the latter enantiomer is about nine times lower than that of former

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stereoisomer (0.8 and 7.4 ppb, respectively42). Thus, at similar concentrations (R)-(-)-linalool

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should make a greater aroma contribution than (S)-(+)-linalool in cola-flavored carbonated

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beverage.

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In addition, the enantiomeric compositions of the 4-terpineols (51.0% of the (S)-(+)-

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isomer (25a) and 49.0% of the (R)-(-)-isomer (25b)) and α-terpineols (55.1% of the (S)-(-)-

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enantiomer (31a) and 44.9% of the (R)-(+)-enantiomer (31b)) in cola occurred as approximately

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racemic mixtures. The enantiomeric pairs of 2,3-dehydro-1,8-cineol (7), isoborneol (29) and

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borneol (32) were, however, not determined on the chiral GC capillary column because of their

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low concentrations in cola extracts.

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Sensory Analysis Aroma (by nose) of de-carbonated colas was described by eight attributes including lemon-lime, orange, brown spice, herbal, vanilla, caramel, cooling, and pine (Table 1). Citrus,


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caramel and vanilla have been reported as aromas and aromatics (aroma-by-mouth) of regular

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and diet colas by descriptive analysis.6 In the present study, all colas (A, B, and C) had similar

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aroma profiles, except the lemon-lime intensity in cola B was significantly lower than in colas A

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and C (p-value < 0.05) (Figure 1). Lemon-lime and cooling attributes were dominant attributes

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in all colas. Brown spice, herbal, and pine attributes were moderate intensities in all colas. The

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results of sensory analysis agreed well with potent odorants identified by AEDA (Table 2) when

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the odor characteristic of high FD factor compounds was considered. The low intensity of the

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lemon-lime note in cola B was probably due to the low potency of linalool (22) in that product.

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This finding was supported by the previous research which revealed that linalool has the highest

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FD factor in lemon-lime carbonated beverages.14 Furthermore, the cooling note of cola could be

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associated with a higher level of 1,8-cineol (9). The high potency aroma compounds were also

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responsible for the other aroma attributes, such as brown spice aroma from eugenol (51) or

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vanilla note from coumarin (56). Additionally, the moderately spicy note of cola A compared to

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the other colas was possibly the result of the impact of methyleugenol (46) and the isoeugenols

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(53 and 54).

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ABBREVIATIONS USED: AEDA, aroma extract dilution analysis; ANOVA, analysis of variance; CLLE,

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continuous liquid-liquid extraction; FD, flavor dilution; FID, flame ionization detector; GC-MS,

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gas chromatography-mass spectrometry; GCO, gas chromatography-olfactometry; LSD, least

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significant difference; OAV, odor activity value; RI, retention index; RT, retention time; SAFE,

326

solvent assisted flavor evaporation; SPME, solid phase microextraction; UHP, ultra high purity.

327 328



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Page 21 of 31


444

FIGURE CAPTION:

445

Figure 1. Aroma (by nose) profiles of cola-flavored carbonated beverages from sensory

446

descriptive analysis. Attributes followed by different italic superscript letters are significantly

447

different (p-value < 0.05) (n = 10; 7 females and 3 males; 22-38 years). Odor intensity was rated

448

on a 15-cm line scale.

449



Page 22 of 31

Table 1. Attributes, definitions, and references used for sensory descriptive analysis of cola-flavored carbonated beverages reference attribute

definition

product (Mfg.)

lemon-lime

aromatic reminiscent of lemon or lime

Sprite® (lemon-lime soda) (Coca-Cola

preparationa

intensityb

50 mL

7

50 mL

9

0.2 g

10

3g

9

10 mL

8

Co., Atlanta, GA) orange

Sunkist® (orange soda) (Sunkist

aromatic reminiscent of orange

Growers, Inc., Sherman Oaks, CA) brown spice

aromatic associate with allspice,

whole cloves (McCormick & Co., Inc.,

cinnamon, clove, mace, nutmeg (spicy) herbal

aromatic associate with dried herbs, hay

Hunt Valley, MD) dried long grass (cut into 2 cm.)

or grass vanilla

vanilla-like aroma

vanillin (compound no. 58; Fluka, Buchs, Switzerland)

caramel

sweet aromatic

Werther’s Original® (chewy caramels) (made in Germany for Storck USA L.P., Chicago, IL)


(50 ppm in water) 1 piece (~6 g)

6

Page 23 of 31


cooling

cooling aroma, but not identical to mint

Halls® (Mentho-Lyptus) (made in Canada; dist: Cadbury Adams USA

10 mL

7

(3.5 mg/mL water)

LLC, Parsippany, NJ) pine

a

aromatic reminiscent of pine needles

Pine-Sol® (original) (Fabricado Para

10 mL

the Clorox Co., Oakland, CA)

(100 ppm in water)

Prepared in 125-mL Teflon sniff bottle. bRelative intensity on 15-cm line with two anchor scales from none to strong.


7


Page 24 of 31

Table 2. Aroma-active compounds in three commercial brands of regular cola-flavored carbonated beverages determined by aroma extract dilution analysis RIb

FD factore

no.a

wax

RTX®-5

1

1019

939

2

1073

3

odord

A

B

NB α-pinene

camphorous, cool

27

Characterization of Typical Potent Odorants in Cola-Flavored

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