Nutritional potential, chemical profile and antioxidant activity of Chichá (Sterculia striata) nuts and its by-products.

The Sterculia striata nut commonly known as chichá is consumed raw or toasted inBrazil but information on its chemical composition and antioxidant activity are scarce in the literature. In this work, the nutritional composition, minerals profile, lipid composition and phenolic compounds profile of chichá nuts and its by-products (pellicle and shell) were determined. The results showed that the nuts and the cake contain considerable amount of fibers and proteins and are rich in minerals (Fe, Mn and Cu). Oleic acid was the main fatty acid (37.8%), and PPO (36.0%) and POP (15.6%) were the main triacylglycerides present in the chichá oil. The phytosterols β-sitosterol, stigmasteroland campesterol (1848.5μgg-1, 542.2μgg-1 and 186.3μgg-1, respectively), and the γ-, δ-, α- and β-tocopherol (8.85; 2.10; 1.64, and 0.11mg100g-1, respectively) were identified in the oil. The antioxidant activity (ABTS and FRAP assays) followed the order pellicle>shell>nuts (13.25 and 84.65; 8.71 and 64.3; 5.85 and 36.79μmolTEACg-1, respectively). The main phenolic compounds identified in the extracts were ellagic and ferulic acids; ellagic and protocatechuic acids; and protocatechuic, ellagic and methoxyphenylacetic acids for the nuts, shells and pellicle, respectively. A strong positive correlation was observed between total phenolic content and antioxidant activity determined by ABTS and FRAP assays (r=0.9067, p<0.01; and r=0.9584, p<0.01; respectively). Collectively, the results showed that the chichá is a nut of high nutritional value, rich in bioactive compounds.