Optimisation of corn silk tea production, and its antioxidant profile

Abstract

Following COVID-19 pandemic, functional foods and beverages continue to develop, especially those with high antioxidant activity. The functional beverage from corn silk can be processed into brewed tea. The critical points in the making process of corn silk tea are the drying equipment, drying temperature, and drying time. With efficient method, corn silk tea can produce high antioxidant activity. The present work optimised the temperature and drying method based on antioxidant activity. The results of the present work are expected to be used in micro/small/medium enterprises (MSMEs) to produce corn silk herbal tea. The present work used Randomised Block Design (RBD) with two factors; drying temperatures (45, 55, and 65°C) and drying equipment (cabinet and oven) for 5 h. The analysis carried out was antioxidant activity and profiling using LC-HRMS (liquid chromatography high-resolution mass spectrometry) that ran in a positive (+) mode. The processing of corn silk tea using cabinet drying at 65°C for 5 h produced antioxidant activity of 82.00 ± 0.75%. This was higher than commercial black tea (81.71 ± 0.15%) and commercial green tea (78.37 ± 0.43%). The analysis using LC-HRMS showed that the corn silk tea contained betaine (N,N,N-trimethylglycine) (RT 0.928), 6-methylquinoline (RT 4.741), hesperidin (3’,5,7-trihydroxy-4’-methoxyflavanone) (RT 302.07817), luvangetin (10-methoxy-2,2-dimethylpyrano[3,2-g]chromen-8-one) (RT 258.08837), embelin (2,5-dihydroxy-3-undecyl-1,4-benzoquinone) (RT 13.074), and eucalyptol (1,8-cineole) (RT 13.325).