Blackwell Science, LtdOxford, UKJFQJournal of Food Quality046-9428Copyright 2005 by Food & Nutrition Press, Inc., Trumbull, Connecticut.2005286370Original ArticleFLAVOR CHARACTERIZATION OF MANDARIN CULTIVARS Y. ELMACI and T. ALTUG FLAVOR CHARACTERIZATION OF THREE MANDARIN CULTIVARS (SATSUMA, BODRUM, CLEMANTINE) BY USING GC/MS AND FLAVOR PROFILE ANALYSIS TECHNIQUES YESIM ELMACI and TOMRIS ALTUG Department of Food Engineering Engineering Faculty Ege University 3500 Bornova Izmir, Turkey Accepted for Publication May 20, 2004 ABSTRACT The flavor characteristics of three mandarin cultivars: Satsuma (Citrus unshi), Bodrum (Citrus deliciosa) and Clemantine (Citrus reticulata) from the Aegean region of Turkey and changes throughout storage were investigated by using GC/MS and descriptive flavor profile analysis techniques. The key aroma impact compounds were detected as limonene, g-terpinene, p-cymene, myrcene, a-pinene, b-pinene and a-terpinolene in all samples. Limonene and g-terpinene accounted for approximately 88% in all three cultivars. An offflavor character was developed during storage by increase of limonene and decrease of g-terpinene percentages. Flavor of mandarins consisted of sweet, sour, floral, lemon, orange and cellulose characters. Dimethyl anthranilate, which was found to be specific to Clemantine mandarins, contributed to the floral orange blossom character. INTRODUCTION Mandarin is among the most popular citrus consumed as fresh fruit primarily because of its delicate flavor (Shaw 99). Flavor compounds of mandarin juice and mandarin peel were analyzed by Shaw (99) and Moshonas and Shaw (997). Mandarin essence oil has been analyzed by Moshonas and Shaw (972), Coleman and Shaw (972), and Shaw (977, 979). Shaw et al. (98) demonstrated that aroma compounds such as dimethyl anthranilate, thymol, g-terpinene, and b-pinene contribute to the charac- Corresponding author. TEL: 0090-232-3884000/3034; FAX: 0090-232-3427592; EMAIL: tomris@food.ege.edu.tr Journal of Food Quality 28 (2005) 63 70. All Rights Reserved. Copyright 2005, Blackwell Publishing 63
64 Y. ELMACI and T. ALTUG teristic flavor of mandarin juice and mandarin peel essence oil. Steuer et al. (200) used a new NIRS method and found that the major compounds in mandarin essence oil are limonene (77.3%), a-terpinene (4.2%), a-pinene (.8%), myrcene (.7%), b-pinene (.%) and terpinolene (0.6%). Evans and Rouseff (200) stated that octanal, b-ionone, furaneol, myrcene (E,E)2,4- decadianel, unknown (overripe fruit aroma), homofuraneol, linalool, limonene, vanillin and methional accounted for 47% of the overall aroma in mandarin (Dancy and Sunburst) juice. In the present study, volatile constituents of three mandarin cultivars (Satsuma, Clemantine and Bodrum) from the Aegean region of Turkey were identified by gas chromatography-mass spectrometry (GC/MS) analysis. Sensory evaluation was performed by using descriptive flavor profile analysis. The effect of storage on mandarin flavor was investigated by using both techniques. MATERIALS AND METHODS Materials A 30 kg sample of fresh fruit for each cultivar (Satsuma, Clemantine and Bodrum) was supplied by Türkmenoğlu Ltd. Company. Fruit samples were kept at +2C and analyzed within 24 h after harvest. Storage studies were conducted by keeping mandarin samples in storage cabinets at +5C and 90% RH. Mandarins were analyzed every 3 weeks to determine the changes in flavor quality during storage. METHODS Extraction of Flavor Compounds for GC/MS Analysis The flavor compounds were extracted in triplicate by using headspace extraction technique as suggested by Hansen et al. (989). Mandarin fruits were sliced in half and juiced with an electrical juice maker with a rotating head; 45 g of mandarin juice obtained from 0 pieces of fruit was transferred into a gas-washing bottle and placed in a 40C water bath for 20 min. Nitrogen gas (60 ml/min) was bubbled through the content in the bottle, exiting through a glass tube containing 300 mg Porapak Q (50 80 mesh). Porapak Q tube was removed after h of gas stripping, and the retained volatiles were eluted from the polymer by using 2 ml diethyl ether. The eluate was concentrated to 0.08 g by gently blowing nitrogen gas over the surface in a v-bottom vial.
FLAVOR CHARACTERIZATION OF MANDARIN CULTIVARS 65 GC/MS Analysis Separation of the volatiles was accomplished by using a Hewlett Packard model 6890 GC/5973 MSD gas chromatographie unit with a 30 m 0.25 mm HP 909S-433 (Hewlett Packard, Palo Alto, CA) HP-5MS column. The column temperature was programmed as 55C for 9 min; 7.5C/min to 220C, and held for 30 min with helium as the carrier gas at ml/min flow rate. The injector and detector temperatures were set at 280C and 275C, respectively. Identification of the flavor compounds was carried out by using the same conditions described above. The electron voltage was 70eV and the mass range was m/z 35 300. Sensory Evaluation Descriptive flavor profile analysis (Shamaila et al. 993) was applied by using five assessors. The assessors were trained on the flavor profile technique by using standards of flavor compounds and mandarin fruits for a period of 3 months. Flavor of the mandarins was evaluated by using eight to ten fruits of each cultivar. Samples were given to the assessors at room temperature and round table discussion was conducted. The intensity of each character and overall quality were evaluated on a 0 5 scale (TS-5546 988). Spider web diagrams were obtained using Microsoft Excel 5.0. Statistical Analysis Analysis of variance (ANOVA) and Duncan tests were performed on the GC/MS and flavor analysis data, and the results were evaluated at 95% confidence level (Mead 988). RESULTS AND DISCUSSION GC/MS and Flavor Profile of Fresh Mandarin Fruits Volatiles of three mandarin cultivars identified by GC/MS analysis are listed in Table. The key aroma impact compounds were detected as limonene, g-terpinene, p-cymene, myrcene, a-pinene, b-pinene and a-terpinolene in all samples. Total percentage of the mentioned volatiles were calculated as 94.85% in Satsuma, 97.78% in Bodrum and 94.66% in Clemantine mandarins, with limonene and myrcene being highest in Satsuma, g-terpinene, a-pinene, b- pinene and a-terpinolene in Bodrum and p-cymene in Clemantine mandarins. Dimethyl anthranilate was detected in Clemantine (2.5%) and Bodrum (0.05%) mandarins. The differences between the percentages of volatiles of mandarin samples were found to be statistically significant (P < 0.05).
66 Y. ELMACI and T. ALTUG TABLE. FLAVOR COMPOUNDS IDENTIFIED IN MANDARIN CULTIVARS BY GC/MS Name of compound Satsuma (% area) Bodrum (% area) Clemantine (% area) a-pinene.89 2.95 0.75 Sabinene 0.2 0.9 b-pinene 0.77.95 0.26 Myrcene 3.5 2.5.83 p-cymene 0.2.9 4.04 a-terpinene 0.20 0.63 Limonene 80.88 67.98 73.57.4-diethylbenzene 0.22 g-terpinene 7.24 20.02 3.57 a-terpinolene 0.35.8 0.70 Linalool 0.54 0.3 a-terpineol 0.08 0.05 cis-dihydrocarvone 0.24 Ethanone 0.36 0.2 0.72 4-ethylacetophenone 0.22 0.3 0.44 d-elemene 0.08 a-copaene 0.05 b-elemene 0.28 Dimethyl anthranilate 0.05 2.5 trans-caryophyllene 0.06 a-humulene 0.04 L-decene.32 D-germacrene 0.3 a-farnesene 0.23 0.07 Phenol 2,6-bis (,-dimethylethyl) 0.80 0.55 0.98 d-cadinene 0.06 The descriptive terms developed by assessors for the standards of the major compounds identified by GC/MS analysis are given in Table 2. Limonene, g-terpinene and p-cymene were described as having mainly citrus character while having orange, lemon and herbaceous notes. Myrcene was characterized by sweet and balsamic notes, and a-pinene and b-pinene were characterized by pine and cellulose notes. a-terpinolene was assessed as having a plastic character while dimethyl anthranilate was assessed to have a floral-orange blossom note. Figure shows that the flavor of mandarins consisted of sweet, sour, floral, lemon, orange and cellulose characters. Sweet character was detected to be more intense in Satsuma and Clemantine, while sour and lemon characters were highest in Bodrum sample (P < 0.05). Clemantine mandarins that involved dimethyl anthranilate peak on GC/MS chromatograms were detected to have the most intense floral orange blossom character.
FLAVOR CHARACTERIZATION OF MANDARIN CULTIVARS 67 TABLE 2. DESCRIPTIVE TERMS DEVELOPED BY THE ASSESSORS FOR THE MAJOR FLAVOR COMPOUNDS IDENTIFIED BY GC/MS Flavor compound Limonene g-terpinene p-cymene Myrcene a-pinene b-pinene a-terpinolene Dimethyl anthranilate Descriptive terms Citrus, sweet, orange, lemon Citrus, herbaceous Citrus Sweet, balsamic Sharp, pine Woody, cellulose, pine Plastic Floral, orange blossom Portakal Sellüloz Tümizlenim 5 4 3 2 0 Tatlilik Eksilik satsuma bodrum klemantin Limon Cicegimsi FIG.. FLAVOR PROFILES OF SATSUMA, BODRUM AND CLEMANTINE MANDARINS GC/MS and Flavor Profiles of Stored Mandarin Fruits GC/MS analysis of stored samples has shown that percentage of limonene increased in all mandarin samples while the percentages of g- terpinene, myrcene and a-terpinolene decreased at the end of the storage periods. Phenol, 2,6-bis (,-dimethylethyl) in Satsuma, Bodrum and Clemantine mandarins increased throughout the storage period. The flavor profiles of the stored Satsuma, Bodrum and Clemantine mandarins (Figs. 2, 3 and 4) showed that all the characters decreased (P < 0.05) during storage. Off flavor note appeared and increased during storage. Lemon
68 Y. ELMACI and T. ALTUG Mold Overall 5 4 Sweet 3 Lemon off flavor 2 0 Sour 0. week 8. week Off flavor Floral Cellulose Lemon Orange FIG. 2. FLAVOR PROFILE OF STORED SATSUMA MANDARINS Overall 5 Mold 4 3 Sweet 2 Off flavor 0 Sour 0. week 9. week Cellulose Floral Lemon FIG. 3. FLAVOR PROFILES OF STORED BODRUM MANDARINS off flavor in Satsuma, orange off flavor in Clemantine and mold character in Satsuma and Bodrum mandarins increased throughout the storage and the intensity of overall flavor was also decreased (P < 0.05). The interpretation of GC/MS and flavor profiles revealed that the off flavor character occurs during storage by an increase of limonene and a decrease of g-terpinene and other major compounds. Phenol, 2,6-bis (,-dimethylethyl) was also detected to be responsible from the mold character that appeared and increased through-
FLAVOR CHARACTERIZATION OF MANDARIN CULTIVARS 69 Overall 5 Orange off flavor 4 3 Sweet 2 Off flavor 0 Sour 0. week 2. week Cellulose Floral Orange FIG. 4. FLAVOR PROFILES OF STORED CLEMANTINE MANDARINS out storage in all samples. The evaluation of GC/MS and sensory data have shown that Satsuma, Clemantine and Bodrum mandarins can be stored 8, 2, and 9 weeks, respectively, without imparting significant (P < 0.05) changes in flavor quality. ACKNOWLEDGMENTS The authors wish to acknowledge the support of E.U. Research Fund and Türkmenoğlu Ltd. Company in this research. REFERENCES COLEMAN, R.L. and SHAW, P.E. 972. Analysis of tangerine essence oil and aroma oil. J. Agric. Food Chem. 20(6), 290 292. EVANS, K.C. and ROUSEFF, R.L. 200. Characterization of aroma active compounds in mandarin (Citrus reticulata blanco) juice using gas chromatography-olfactometry. Fifty-second Citrus Processor s Meeting. Lake Alfred, FL, October 8. HANSEN, A., LUND, B. and LEWİS, M.J. 989. Flavor production and acidification of sourdoughs in relation to starter culture and fermentation temperature. Lebensm.-Wiss. Technol. 22, 45 49.
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