Phytochemicals and antioxidant activity of different fruit fractions (peel, pulp, aril and seed) of Thai gac (Momordica cochinchinensis Spreng)

• Published in: Food chemistry 2011-08, Vol.127 (3), p.1138-1145
• Main Authors: Kubola, Jittawan, Siriamornpun, Sirithon
• Format: Article
• Language: English
• Subjects: Antioxidant activity; Biological and medical sciences; Carotenoid; Flavonoid content; Food industries; Fundamental and applied biological sciences. Psychology; Momordica cochinchinensis Spreng; Phenolic acid
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2011.01.115

► The highest content of lycopene and beta-carotene were found in ripe gac fruit. ► Major phenolic acids found in gac fruits were hydroxybenzoic acids and hydroxycinnamic acids. ► The highest content of rutin and luteolin were in aril. ► Pulp (red fruit) showed the highest apigenin content. ► The highest content of lutein was found in peel (yellow fruit). Three fractions (peel, pulp and aril) of gac fruit (Momordica cochinchinensis Spreng) were investigated for their phytochemicals (lycopene, beta-carotene, lutein and phenolic compounds) and their antioxidant activity. The results showed that the aril had the highest contents for both lycopene and beta-carotene, whilst peel (yellow) contained the highest amount of lutein. Two major phenolic acid groups: hydroxybenzoic acids and hydroxycinnamic were identified and quantified. Gallic acid and p-hydroxybenzoic acid were found in all fractions. Ferulic acid and p-hydroxybenzoic acid were most evident in pulp. Myricetin was the only flavonoid found in all fractions. Apigenin was the most predominant flavonoid in pulp (red), whereas rutin and luteolin gave the highest content in aril. The extracts of different fractions exhibited different levels of antioxidant activity in the systems tested. The aril extract showed the highest FRAP value. The greatest antioxidant activities of peel and pulp extracts were at immature stage, whereas those in the seed extracts increased from mature stage to ripe stage. The contents of total phenolic and total flavonoid in peel and pulp decreased during the fruit development stage (immature>ripe fruit) and subsequently displayed lower antioxidant capacity, except for the seed.