The Effect of Fermentation and Drying on Clicanthus Nutans Lindai Extract Chemical Constituents and Bioactivity

Abstract

In this study, two processes (fermentation and drying) were conducted on Clicanthus Nutans Lindau, which is well-known for its antioxidant activities. The aim of this research is to investigate the effects of these processes towards the Total Phenolic Content (TPC), antioxidant activity and the crude yield of the leaves. For the fermentation process, the fermentation time is varied for 6, 12, 24, 48 and 72 hours. For drying, oven drying (40, 45 and 50°C, freeze-drying and shade drying are investigated. Blanching was also conducted for oven dried samples (90°C for 1 minute). It was found that 12 hours fermentation produced the highest yield corresponding to Total Phenolic Content at 0.33 while 6 hours fermentation produced the highest Antioxidant Activity and yield at 2.218 x 10-10 mg/mL and 0.64 . On the other hand, 48 hours fermentation produced the highest overall extract yield at 0.64 . Analysis for antioxidant activity was carried out using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Folin-Ciocalteau method for Total Phenolic Content. Thermal inactivation kinetics (blanching) has been investigated for oven drying samples. Results showed that 40°C oven drying and 50°C oven drying with blanching has better retention of bioactive constituents. Blanching has no significant effect on phenolic content but has increased the crude extract for higher temperature oven drying. It has no positive effect on antioxidant activity. Drying is also a better processing method compared to fermentation as drying has slightly favorable results in all three aspects. Through comparison with extraction time of 60 minutes for 40°C oven drying and 6 hour fermented samples, yield of total phenolic content and overall yield of oven dried sample is higher than fermented sample by 4.14 and 0.39 respectively as well as showing better antioxidant activity.