Flavonoids, Proanthocyanidins, Vitamin C, and Antioxidant Activity of Theobroma grandiflorum (Cupuassu) Pulp and Seeds

摘要

The ascorbic acid, flavonoids, and proanthocyanidins content and in vitro antioxidant activity of fresh pulps and seeds of cupuassu, harvested at three different times of the year, and in commercial frozen pulps were evaluated. Lipids, total phenolics contents, and antioxidant activities were the highest in the seeds, followed by fresh and commercial frozen pulps, respectively. The latter also showed a lower content of ascorbic acid (9—13 mg/100 g DW) when compared to fresh pulps (96— 111 mg/100 g DW). The 8-O-β-D-glucuronides and the corresponding 3"-sulfates of isoscutellarein (5,7,8,4'-tetrahydroxyflavone), hypolaetin (5,7,8,3',4'-pentahydroxyflavone), and 8-hydroxychrysoeriol (5,7,8,4'-tetrahydroxy-3'-methoxy-flavone), also known as hypoaletin 3'-methyl ether, were identified and quantified (31 mg/g DW) in cupuassu seeds. The same flavonoid profile was present in pulps although in much lower concentrations (0.5 to 2 mg/g DW). The two 8-hydroxychrysoeriol glycosides had not been previously reported in cupuasssu. The content of proanthocyanidin oligomers in seeds (23 mg/g DW), mainly of the epicatechin type, and the mean degree of polymerization (5.5) were calculated. No discernible effect of the harvesting period on the evaluated chemical aspects could be identified. Commercial frozen pulps contained a smaller amount of all these compounds than the fresh pulp, suggesting that these compounds were potentially degraded during processing/storage.