Nutritional and pharmaceutical applications of bioactive compounds in tropical fruits

Abstract

During the past two decades our international scientific group investigated in vitro the physicochemical and nutritional characteristics of some cultivars of durian at various stages of ripening, mangosteen and new cultivars of snake fruit in comparison with widely used avocado, kiwifruit and mango, and in vivo their influence on laboratory animals. The main objective of the present study was to screen and compare the properties of water and ethanol extracts of selected exotic fruits and the influence of their physiologically active compounds on human health. The bioactive compounds were extracted with water and ethanol using similar procedures as are used in pharmaceutical applications and daily fruit consumption. Various analytical methods were used to detect biologically active metabolites derived from exotic fruits (polyphenols, flavonoids, flavanols, tannins, anthocyanins and ascorbic acid), antioxidant radical scavenging assays (DPPH, FRAP, CUPRAC, and ABTS), Fourier transform infrared (FT-IR) and ultraviolet (UV) spectroscopy, two (2D-FL) and threedimensional (3D-FL) fluorimetry. The correlation between the polyphenols and other bioactive compounds, and their antioxidant activities, is reported for the studied fruit extracts. The properties of the soil, where the investigated fruits were grown, were studied as well. Supplementation of diets with exotic fruits positively affected the plasma lipid profile and antioxidant activity in rats fed cholesterol-containing diets. The interaction between drugs and serum albumin plays an important role in the distribution and metabolism of drugs. The properties of polyphenol extracts of exotic fruits showed the ability to quench serum albumin by forming complexes similar with the ones formed between the proteins and pure flavonoids such as catechin and quercetin. In conclusion, new application of fluorimetry and FTIR spectroscopy for rapid estimation of the quality of exotic fruits in particular and for any fruits and vegetables in general is presented. It is necessary to promote a consumption of exotic fruits (a rich source of natural antioxidants) as a supplement to everyday human diet and for pharmaceutical applications.