Screening natural antioxidants in peanut shell using DPPH-HPLC-DAD-TOF/MS methods

Area of Science:

• Agricultural Science
• Analytical Chemistry
• Food Science

Background:

• Peanut shell is an abundant agricultural byproduct from oil production.
• It contains valuable natural compounds, including antioxidants.
• Efficient methods are needed to identify and quantify these compounds for potential applications.

Purpose of the Study:

• To develop and apply a rapid, efficient method for screening and identifying natural antioxidants in peanut shells.
• To quantify the identified antioxidant compounds.
• To evaluate the radical scavenging capacity of the identified compounds.

Main Methods:

• Utilized a novel DPPH-HPLC-DAD-TOF/MS assay for simultaneous screening and identification of antioxidants.
• Employed 1,1-diphenyl-2-picrylhydrazyl (DPPH) reaction to detect antioxidant activity via changes in HPLC peak areas.
• Confirmed compound identity using High-Performance Liquid Chromatography with Diode-Array Detection and Time-of-Flight Mass Spectrometry (HPLC-DAD-TOF/MS).

Main Results:

• Successfully identified three major antioxidant compounds in the methanolic extract of peanut shell: 5,7-dihydroxychromone, eriodictyol, and luteolin.
• Quantified the contents as 0.59 mg/g for 5,7-dihydroxychromone, 0.92 mg/g for eriodictyol, and 2.36 mg/g for luteolin.
• Luteolin exhibited the strongest radical scavenging capacity among the identified compounds.

Conclusions:

• The DPPH-HPLC-DAD-TOF/MS assay is a powerful tool for rapid identification and quantification of natural antioxidants in complex matrices like peanut shells.
• Peanut shells are a rich source of bioactive compounds, particularly luteolin, eriodictyol, and 5,7-dihydroxychromone.
• This study provides a foundation for the value-added utilization of peanut processing byproducts through the extraction of high-value antioxidants.