Chemical and phytochemical characteristics of local corn silk powder of three different varieties

Abstract

Corn silk is a part of the corn plant that is still considered to be waste from corn processing; however, corn silk is actually known to have the potential to be developed as functional food ingredients and/or nutraceuticals. The potential applications of corn silk are closely related to its chemical composition and the action mechanisms of its bioactive compounds, which have beneficial effects on human health, such as flavonoids and phenolics. This study aimed to investigate the chemical and phytochemical characteristics of local corn silk powder of three different varieties, i.e. Bisma, Arjuna, and Srikandi Putih. Phytochemical and proximate analyses were conducted on each sample of corn silk powder. The total phenolic content was examined using the Folin- Ciocalteau method, while the beta sitosterol was analysed by gas chromatography and the antioxidant activity of the extract was evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. The results show that all samples had different amounts for their moisture, ash, protein, fat and carbohydrate contents from the proximate analyses. The Bisma variety of corn silk powder reveals the highest fat and protein contents, which are 0.30%±0.02 and 17.70 ±0.47, respectively. Furthermore, the highest total phenolics, total flavonoids, beta-sitosterol contents and antioxidant activity for the corn silk powder are also demonstrated by Bisma; i.e. 8262.93±178.59 μg gallic acid equivalent (GAE)/g for total phenolics, 236.03±8.37 μg gallic acid equivalent (GAE)/g for total flavonoids, 1343.93±78.44ppm for beta-sitosterol and 73%±1.09 for antioxidant activity. Thus, it may be suggested that among the three local varieties of corn silk, a corn silk powder from the Bisma variety could be developed as a source of bioactive compounds and nutrients to convert corn silk from being waste into value-added corn products.