Comparison of antioxidant activity between green and roasted coffee beans using molecular methods

Area of Science:

• Food Science and Technology
• Nutritional Biochemistry
• Antioxidant Research

Background:

• Coffee consumption is globally popular, linked to health benefits primarily from its antioxidant properties.
• Polyphenols in coffee contribute significantly to its antioxidant activity.
• Coffee roasting may modify polyphenol content and antioxidant capacity.

Purpose of the Study:

• To investigate how coffee roasting affects the antioxidant activity of different coffee varieties.
• To assess the impact of roasting on coffee's ability to protect DNA from radical damage.
• To evaluate the effect of coffee extracts on cellular antioxidant mechanisms.

Main Methods:

• Assessed antioxidant activity of 13 green and roasted coffee bean extracts using DPPH and ABTS radical scavenging assays.
• Evaluated DNA strand cleavage protection in 5 selected varieties against peroxyl and hydroxyl radicals.
• Measured glutathione (GSH) and reactive oxygen species (ROS) levels in C2C12 cells treated with coffee extract using flow cytometry.

Main Results:

• Roasting enhanced free radical scavenging activity in 8 out of 13 coffee varieties, with activity correlating to roasting time.
• Roasting reduced antioxidant activity in 5 varieties.
• Coffee extracts demonstrated dose-dependent increases in cellular GSH levels, indicating enhanced antioxidant defense.

Conclusions:

• Coffee roasting significantly influences antioxidant activity, with effects varying by coffee variety and roasting parameters.
• Differences in antioxidant capacity are linked to variations in polyphenol content and roasting-induced molecular changes.
• Coffee extracts can bolster cellular antioxidant defenses, suggesting potential health benefits.