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

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.