Guava fruit (Psidium guajava L.) as a new source of antioxidant dietary fiber

Guava (Psidium guajava L.) is a tropical fruit, widely consumed fresh and a lso processed (beverages, syrup, ice cream, and jams). Pulp and peel fracti ons were tested, and both showed high content of dietary fiber (48.55-49.42 %) and extractable polyphenols (2.62-7.79%). The antioxidant activity of po lyphenol compounds was studied, using three complementary methods: (i) free radical DPPH. scavenging, (ii) ferric reducing antioxidant power assay (FR AP), and (iii) inhibition of copper-catalyzed in vitro human low-density li poprotein (LDL) oxidation. All fractions tested showed a remarkable antioxi dant capacity, and this activity was correlated with the, corresponding tot al phenolic content. A 1-g (dry matter) portion of peel contained DPPH. act ivity, FRAP activity, and inhibition of copper-induced in vitro LDL oxidati on, equivalent to 43 mg, 116 mg, and 176 mg of Trolox, respectively. These results indicate that guava could be a suitable source of natural antioxida nts. Peel and pulp could also be used to obtain antioxidant dietary fiber ( AODF), a new item which combines in a single natural product the properties of dietary fiber and antioxidant compounds.