Nutritional and nutraceutical characteristics of white and red Pithecellobium dulce (Roxb.) Benth fruits

Abstract – Introduction. Pithecellobium dulce is a legume native to tropical America that produces edible arils which can be white or red. The plant is also grown in Asia and, to date, predominantly fruits produced in Asia have been the subject of scientific studies. We studied white and red arils produced in America. Materials and methods. White aril and red aril fruits were evaluated in an array of reagent-based assays to determine nutritional and nutraceutical properties. Results and discussion. White arils and red arils showed similar physicochemical characteristics, with high content of vitamin C (79.7–82.6 mg·100 g–1 fresh weight) and dietary fiber (5.83–6.12% fw). The anthocyanin content of red arils (29.5 mg·100 g–1 fw, as cyanidin-3-glucoside equivalents) was similar to that of strawberry. Total phenolics (517 mg·100 g–1 fw, as gallic acid equivalents) and antioxidant activities (ABTS, 224 mg; DPPH, 223 mg, as vitamin C equivalents) of red arils were 1.3 times higher than those in white arils. The methanolic extract of red arils showed a higher α-glucosidase inhibition (IC50 2.9 mg·mL–1) than acarbose (IC50 4.9 mg·mL –1). The methanolic extract [(50, 100 and 500) μg per tube] of red and white arils showed positive-strong antimutagenic activities (inhibition in the range 25–70%) in the assay (Salmonella typhimurium YG1024 strain, 1-nitropyrene as mutagen, 200 ng per tube). We are reporting for the first time remarkably high characteristics (i.e., antioxidant, inhibition of α-amylase and α-glucosidase and content of dietary fiber) of P. dulce fruits, mainly of the red ones; properties which combined permit us to suggest that consumption of these fruits could have beneficial health effects in people with diabetes.