Effect of Common Cooking and Drying Methods on Phytochemical and Antioxidant Properties of Corchorus olitorius Identified Using Liquid Chromatography-Mass Spectrometry (LC-MS)

Abstract

In this study, Corchorus olitorius leaves were subjected to different thermal treatments (blanching, boiling, drying, frying, and steaming) and analyzed for proximate composition, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity. Furthermore, Fourier transform infrared spectroscopy (FTIR) was used to identify functional groups, while metabolites were identified with LC-MC. The TPC and antioxidant activity of C. olitorius were significantly (p < 0.05) increased by cooking and drying. The steam-cooked sample had the highest TPC (18.89 mg GAE/g) and TFC (78.42 mg QE/g). With ABTS, FRAP, and DPPH assays, the steam-cooked sample exhibited the highest antioxidant activity of 119.58, 167.31, and 122.23 µM TE/g, respectively. LC-MS identified forty-two (42) metabolites in C. olitorius that included phenolic acid derivatives, flavonoid derivatives, and amino acid derivatives. Overall, steaming appears to be the best cooking method, with respect to the retention of phytochemical compounds and antioxidant activity.

The impact of thermal pretreatment on phytochemical profiles and bioactivity of freeze-dried lily bulbs (Lilium lancifolium)

“…However, a considerable increase in the total content of phenolic acids was observed in certain pretreated samples, specifically S10—F and B6—F, which had been subjected to steaming and blanching. Similar results were reported by Ncube, who observed a significant increase in the content of phenolic acids such as chlorogenic acid and crypto-chlorogenic acid in blanched Corchorus olitorius ( Ncube, Dlamini, & Beswa, 2022 ). According to Feumba Dibanda, phenolic acids with conjugated structures, such as ferulic acid and p -coumaric acid, which are found in fruits and vegetables, may be present in esterified forms ( Feumba Dibanda, Panyoo Akdowa, Rani, Metsatedem Tongwa, & Mbofung, 2020 ).…”

Study of the Preparation and Quality of Gastrodia elata with Different Drying Processes

“…This study con rmed the changes in total phenolic content of Bletilla striata scented tea following different drying treatments [16] . However, Ncube Buyile and colleagues [17] showed that the total phenolic content of Corchorus olitorius leaves was increased by cooking. The difference may be related to the phenolic species.…”