Microstructural Modification and Sorption Capacity of Green Coffee Beans

Area of Science:

• Food Science
• Materials Science

Background:

• Green coffee beans (GCB) require pre-roasting treatments to optimize their properties.
• Understanding the impact of various drying and puffing techniques on GCB microstructure is crucial for flavor development.

Purpose of the Study:

• To investigate the effects of different pre-roasting treatments on green coffee bean (GCB) pore structure, sorption capacity, and flavor compound extraction.
• To identify optimal treatment methods for enhancing GCB characteristics.

Main Methods:

• Treatments included hot air drying (HD), freeze-drying (FD), short-time heating with puffing (SHP), and microwave with puffing (MWP) at various levels.
• Evaluated effects on color, porosity, microstructure, citric acid sorption, and caffeine/chlorogenic acid extraction yield.

Main Results:

• MW60P treatment resulted in favorable GCB pore structures and significantly increased caffeine and chlorogenic acid extraction yields.
• Increased porosity and improved pore size distribution after MW60P enhanced citric acid sorption capacity.
• Most treatments showed minimal color change, with MW60P being particularly effective for microstructure enhancement.

Conclusions:

• Microwave treatment at 60 seconds with puffing (MW60P) is an effective method for enhancing GCB microstructure.
• MW60P significantly improves GCB sorption capacity and the extraction yield of key flavor compounds.
• This optimized microstructure benefits the overall quality and flavor profile of roasted coffee.