Analysis of Volatile Compounds in Noni Fruit (Morinda citrifolia L.) Juice by Steam Distillation-Extraction and Solid Phase Microextraction Coupled with GC/AED and GC/MS
GUOR-JIEN WEI1*, CHI-TANG HO2,3 AND AN SHUN HUANG4
1. Department of Nutrition and Health Sciences, Kainan University, No.1 Kainan Road, Luzhu Shiang, Taoyuan, Taiwan, R.O.C.
2. Department of Food Science, Rutgers University, 65 Dudley Road, New Brunswick, NJ 08901, U.S.A.
3. Graduate Institute of Food Science and Technology, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, Taiwan, R.O.C.
4. Kraft Foods, 200 DeForest Avenue, East Hanover, NJ 07928, U.S.A.
(Received: July 10, 2010; Accepted: November 8, 2010)
ABSTRACT
Morinda citrifolia (Rubiaceae), also known as noni, is a plant found in the Hawaiian and Tahitian islands. It is considered as one of the most important plants brought to Hawaii by the first Polynesians. The yellow fruits have a distinctive “grenade-like” shape and can grow up to a size of 12 cm. It has a foul taste and a soapy smell when ripe. 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. Here we addressed the volatile compounds in the fresh and ripe noni fruits. Carboxylic acids, aldehydes, ketones, alcohols, esters, terpenes and six organosulfur compounds were isolated by SDE and SPME, and further identified by GC/AED and GC/MS. The sulfur compounds identified may make a major contribution to the characteristic flavor of noni fruit juice. SPME is useful to recover low boiling point and low molecular weigh compounds; in contrast, SDE owns higher extraction capacity and higher recovery for polar compounds. SPME and SDE can provide complementary information; when use together, a deep understanding of aroma profile of food systems can be expected.
Key words: gas chromatography-atomic emission detector (GC/AED), gas chromatography-mass spectrometry (GC/MS), Morinda citrifolia (Rubiaceae), organosulfur compounds, solid phase microextraction (SPME)