Bioactive compounds and volatile compounds of Thai bael fruit (Aegle marmelos (L.) Correa) as a valuable source for functional food ingredients

Abstract

Bael fruit (Aegle marmelos (L.) Correa) is an attractive and characteristically sweet aroma fruit, native to Southeast Asia, known to be a good source of natural antioxidants and bioactive compounds. In this study, the results showed that fully ripe Thai bael fruit pulps had total, soluble, and insoluble dietary fiber contents of 19.84, 11.22, and 8.62 g/ 100 g dry weight (dw), respectively. Determination of antioxidant activities by 2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging and ferric reducing antioxidant power (FRAP) assays resulted in 6.21 μg dw/ μg DPPH and 102.74 μM trolox equivalent (TE)/ g dw, respectively. It was also found to have total phenolic, total flavonoid, total carotenoid, and ascorbic acid contents of 87.34 mg gallic acid equivalent (GAE)/ g dw, 15.20 mg catechin equivalent (CE)/ g dw, 32.98 μg/ g dw, and 26.17 mg/ 100 g dw, respectively. Volatile compounds in bael fruit pulp were analyzed using the solid-phase microextraction (SPME)/ gas chromatography (GC)/ mass spectrometry (MS) method. A total of 28 volatile compounds were identified, and the dominant components were monoterpenes and sesquiterpenes. Among these components, limonene was the major constituent producing the characteristic bael fruit flavor.