Flavor Compunds of Noni Fruit (Morinda citrifolia L.) Juice - ACS

Chapter 5

Flavor Compunds of Noni Fruit (Morinda citrifolia L.) Juice 1

2

3

Guor-Jien Wei , Tzou-Chi Huang , An-Shan Huang , and Chi-Tang Ho Downloaded by CORNELL UNIV on July 18, 2012 | http://pubs.acs.org Publication Date: December 1, 2003 | doi: 10.1021/bk-2004-0871.ch005

1

1

Department of Food Science, Rutgers, The State University of New Jersey, 65 Dudley Road, New Brunswick, NJ 08901-8520 Department of Food Science, National Pingtung University of Science and Technology, 912, Pingtung, Taiwan Kraft Inc., 200 DeForest Avenue, East Hanover, NJ 07936

2

3

Morinda citrifolia (Rubiaceae), commonly known as noni, is a plant typically found in the Hawaiian and Tahitian islands. It is believed to be one of the most important plants brought to Hawaii by the first Polynesians. The yellow fruits have a dinstinctive "grenade-like" shape and can grow to a size of 12 cm in diameter. It has a foul taste and a soapy smell when ripe. The juice of noni fruit has been shown to prolong the life span of mice implanted with Lewis lung carcinoma. It was proposed that the fruits of noni might suppress the growth of tumors by stimulating the immune system. In recent years, noni juice has been sold in the US market as a nutraceutical supplement. The volatile aroma compounds identified in the fresh and riped noni fruits is described here.

52

© 2004 American Chemical Society In Nutraceutical Beverages; Shahidi, F., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2003.

Downloaded by CORNELL UNIV on July 18, 2012 | http://pubs.acs.org Publication Date: December 1, 2003 | doi: 10.1021/bk-2004-0871.ch005

53 Morinda citrifolia (Rubiaceae), commonly known as noni, is a plant typically found in the Islands of Hawai and Tahiti. It is believed to be one of the most important plants brought to Hawaii by the first Polynesians (/). The plant is a small evergreen tree, growing in open coastal regions and in forest areas, up to about 1300 feet above sea level. This plant is identifiable by its straight trunk, large green leaves and its distinctive "grenade-like" yellow fruit. The fruit can grow to a size of 12 cm in diameter and results from coalescence of the inferior ovaries of many closely packed flowers. It has a foul taste and a soapy smell when ripe. The bark, stem, root, leaf, and fruit have been used traditionally as a folk remedy for many diseases including diabetes, hypertension, and cancer (2,5). Currently, noni fruit juice is sold as a nutraceutical and dietary supplement. In earlier studies several nonvolatile compounds including acetyl derivatives of asperuloside, glucose, caproic acid and caprylic acid were identified in fruits (/). In recent studies (4,5), several new glycosides were isolated and identified from Hawaii noni fruits. Figure 1 shows the structures of these new compounds, NB-1, NB-2, NB-3, NB-4 and NB-10. These glycosides contain hydrolyzable fatty acids, such as octanoic acid and hexanoic acid, and alcohols, such as, 3methyl-3-buten-1 -ol. There is only one published paper concerning volatile compounds of noni fruit (6). A total of 51 detectable volatiles from ripe noni fruit were reported. Twenty acids representing 83% of the total volatiles were identified. It is interesting to note that among them, octanoic (58 %) and hexanoic acids (19 %) dominated the volatile profile. In this study, compare the constituents of noni fruit volatiles collected by SPME (solid phase microextraction) and steam distillation methods were compared.

Materials and Methods

Sample Preparation Solid-Phase Microextraction (SPME): Noni fruit (340g) were blended and then mixed with 100 mL of water and 150 g of sodium chloride. The temperature of the water bath was 50 °C. Steam distillation: Noni fruit (340) was blended and mixed with 300ml and 150 g of sodium chloride. The volatiles were dissolved in hexane for GC/AED or GC/MS analysis.

In Nutraceutical Beverages; Shahidi, F., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2003.

54 ο.

HOCH . 2

O0O(CH ) Œ3 2

6

OH HO— /^OH

H o a v ^ /


HOHO^

NB-1

H

O

Ck^

/

OH

CH

/ ^ ^ X HO._ \ ^

^ ^ "OH

CH

2

CH

H

3 v

X

H

2

NB-3

HOŒ 2

OCO(CH )4Œ3 2

NB-4

H

O

H

^

° - ^

^

/

N

^

O

H

^

n

Œ

0 H

0

^ ^ ^

oaXCH ) Œ 2

6

3

OH

NB-10 Figt/re 1. Glycosides identifiedfromHawaiian noni fruits.


55


SPME Analysis The SPME holder, SPME fibers (75 μιη Carboxen/PDMS) and a 0.75 mm id inlet liner were purchased from Supelco, Inc. (Bellefonte, PA). The sampling time was 30 min and desorption time was 2 min. GC/MS Analysis. GC/MS analysis was performed on an Agilet 5973 GC/MS equipped with a fused silica capillary column (Supelcowax-10, Supelco, 30 m χ 0.25 mm i.d. χ 0.25 mm film thickness). The injector temperature was 275°C. The GC oven temperature was programmed as follows: 40°C for 10 min, increased to 240°C at a rate of 4°C/min, and held at 240°C for 10 min. A 0.75 mm id inlet liner in the GC injection port was used for SPME, instead of a larger volume 2 mm id liner. GC/AED Analysis. An Agilet 6890 GC coupled with a G2350A atomic emission detector was employed for GC/AED analysis.

Results and Discussion Figure 2 shows the SPME-GC/AED profile of noni volatiles and Figure 3 shows the GC/AED profile of volatiles isolated from noni by steam distillation. In both Figures, the top panel is the profile obtained from the C channel and the bottom panel is the profile obtained from the S channel. AES (atomic emission spectroscopy) used for this study is a method to identify an atom by measuring the emission of a photon of radiation released by the electrons of the atom after they are excited to a higher energy level (7). With the combination of GC-AES, it is possible to detect elements in compounds leaving the column. In the interface, the eluent is atomized and excited by microwave-energized helium plasma that is coupled to a diode-array optical emission spectrometer. Because of the high sensitivity of the detector, we were able to identify several minute quantities of sulfur-containing compounds previously not identified in noni fruit. Table 1 lists the volatile compounds identified in nonifruitjuice. The most abundant compounds were octanoic and hexanoic acids, as well as their corresponding methyl and ethyl esters. In a previous report, we indicated the isolation of a tridisaccharide fatty acid ester, 2,6-di-0-(fi-D-glucopyranosyl)-lO- hexanoyl-fi-D-glucopyranoside and two disaccharide fatty acid esters, 6-0(fi-D-glucopyranosyl)-l-O-hexanoyl^-D-glucopyranoside and 6-0-(β-Ώglucopyranosyty-l-O-octanoyl-fi-D-glucopyranoside (Figure 1)fromthe Hawian noni fruit (4,5). It is obvious that the sugar esters of fatty acids are the precursors of these acids and esters in noni fruit. They are also the major contributors to the soapy aroma of the ripe noni fruit. Besides hexanoic acid and octanoic acid, a series of medium chain fatty acids such as heptanoic, nonanoic and decanoic


56 Table I. Volatile compounds identified from ripe fruits of Morinda citrifolia


Compounds Acids Formic acid Acetic acid Butanoic acid Hexanoic acid Heptanoic acid Octanoic acid 2-Octenoic acid Nonanoic acid Decanoic acid Aldehydes and Ketones Acetaldehyde 2-Methylbutanal 3-Methylbutanal 2-Pentanone 3- Methyl-2-butanone 2-Hexanone Hexanal 2-Heptanone 2-Hexenal Furfural Benzaldehyde Alcohols Ethanol 2-Methyl-3-buten-l-ol 1-Butanol 3-Methyl-3-buten-l-ol 3-Methyl-2-buten-l-ol Benzyl alcohol Esters Ethyl acetate Butyl acetate Methyl 2-methylpropanoate Methyl butanoate Ethyl butanoate Butyl butanoate 4-Pentenyl butanoate Methyl 3-methylbutanoate 3-Methyl-3-buten-l-yl 3-methylbutanoate

Steam distillation

SPME

trace trace + +++ + ++++ + + +

+ + + ++++ + ++++ + + +

n.d. + + + + + + + + + +

+ + + + + + + + + + +

+ + + +++ + n.d.

+ + + ++ + trace

+ + + + + + + + +

+ n.d. + + + + + + ±



57 Table I continued. Methyl 2-methylbutanoate Methyl hexanoate Ethyl hexanoate Butyl hexanoate 4-Pentenyl hexanoate 3-Methyl-3-buten-l-yl hexanoate Hexyl isovalerate Methyl heptanoate Methyl ocatanoate Ethyl octanoate Butyl octanoate 3-Methyl-3-buten-l-yl octanoate Methyl 2-octenoate Methyl 3-octenoate Methyl 6-octenoate Methyl nonanate Methyl 5-nonenoate Methyl decanoate Ethyl decanoate Methyl 4-decenoate Ethyl 4-decenoate Methyl salicylate Methyl hexadecanoate Terpenes Linalool oxide (Z)-3,7-Dimethyl-1,3,6-octatriene (+)-4-Carene D-Linionene Ocimenol Terpineol Sulfur Compounds Methanethiol 5-Methyl thioacetate Dimethyl disulfide Methyl 3-methylthiopropanoate Ethyl 3-methylthiopropanoate Methionic acid

+ ++ ++ + + + + + + + + + + + + + + + +

+ + + + + n.d. + + + +

+ +++ ++ + + + + ++++ + + + + + + + + ++ + + + + + trace trace trace trace trace trace + + + + + trace



L

11 13

J—L

12

14

15

Figure 2. SPME-GC/AED profile of Noni: Top C-channel, bottom S-channel. 1. methyl butanoate; 2. methyl hexanoate; 3. ethyl hexanoate; 4.methyl octanoate; 5. ethyl octanoate; 6. 3-methyl-3-butenyl 3-methyl 3-butenoate; 7. methyl decanoate; 8. ethyl decanoate; 9. 2-methylbutanoic acid; 10. 3-methyl-3-butenyl octanoate ; 11.5-methyl-5-hexenoic acid; 12. hexanoic acid; 13. heptanoic acid; 14. octanoic acid; 15. decanoic acid; A. methanethiol; B. S-methyl thioacetate; C. dimethyl disulfide; D. methyl 3-methylthiopropanoate; E. methionic acid.

il

10



i 34

10

11

Figure 3. GC/AED profile of volatilesfromnoni by steam distillation: Top Cchannel, bottom S-channel. 1. 2-heptanone; 2. methyl hexanoate; 3. ethyl hexanoate; 4. methyl-3-buten-l-ol; 5.methyl octanoate; 6. butyl hexanoate; 7. ethyl octanoate; 8. 3-methyl-3-butenyl octanoate; 9. hexanoic acid; 10. octanoic acid; 11. decanoic acid; A. S-methyl thioacetate; B. dimethyl disulfide; C. methyl 3-methylthiopropanoate; D. ethyl 3-methylthiopropanoate; E. methionic acid.

* K O Bl S attar 1B1 «.«EikME&JMC» t>>

i £ D 3 A, Ciifcon 179 0*ΈΑ*&Ο_ΟΒ3β.Ο)



60 acid were also characterized from both the steam distillate and the headspace of ripe noni fruit. In addition to sugar fatty acid esters, glycoside of 3-methyl-3-buten-l-ol were also identified in the nonvolatile extract of noni fruits (4). In the present study, a relatively large quantity of 3-methyl-3-buten-l-ol was observed in the volatile components of nonifruitjuice. Thirty-two esters were identified in noni juice. It is not surprising that the esters of hexanoic acid and octanoic acid are the major esters identified. Two new esters were tentatively characterized. The mass spectral data of both compounds are very similar. They have a base peak at m/z 68, followed by m/z 57, 127 and 41 fragments. CI-MS data show that these compounds have molecular weights of 182 and 212, respectively. Figure 4 shows the proposed fragmentation pathway for the generation of m/z 41, 57 , 68 and 127 ions. They are also derived from 3-methyl-3-buten-1 -ol which exists as one of the major glycosides in nonifruit.The molecular weight of these two compounds have also been reported by Farine et al (C02Ο

CH3-S-CH2-CH2-C-SC0A

Methionic acid

ROH 0

R

R= -CH Methyl ester R=-CH CH Ethyl ester 3

2

3

Figure 5. Proposed biosynthetic pathway for methyl and ethyl esters of 3methylthiopropanoate.

References 1. Levand, O.; Larson, H. Plant Med. 1979, 36, 186-187. 2. Hirazumi, Α.; Furusawa, E. Proc. WestPharmacol.Soc. 1994, 37, 145-146. 3. Hirazumi, Α.; Furusawa, E. Proc. WestPharmacol.Soc. 1996, 39, 25-27. 4. Wang, M . ; Kikuzaki, H.; Csiszar, K.; Boyd, C.D.; Maunakea, Α.; Fong, S.F.T.; Ghai, G.; Rosen, R.T.; Nakatani, N.; Ho, C.-T. J. Agric. Food Chem, 1999, 47, 4880-4882. 5. Wang, M.; Kikuzaki, H.; Jin, Y.; Nakatani, N.; Zhu, N.; Csiszar, K.; Boyd, C.D.; Rosen, R.T.; Ghai, G.; Ho, C.-T. J. Nat.Prod. 2000, 63, 1182-1183. 6. Farine, J.P.; Legal, L.; Moreteau, B.; Le Quere, J.L. Phytochemistry 1996, 41, 433-438. 7. Skoog, D.A.; Leary, J. J. Principles of Instrumental Analysis, 4 Ed. Saunders College Publishing: Orlando, FL, 1992, pp. 196-232. th


Flavor Compunds of Noni Fruit (Morinda citrifolia L.) Juice - ACS

Recommend Documents