Brewing Temperature and Particle Size Affect Extraction Kinetics of Cold Brew Coffee in Terms of Its Physicochemical, Bioactive, and Antioxidant Properties

ABSTRACT

The aim of this work was to analyze the influence of brewing temperature and coffee particle size on the evolution of physicochemical, bioactive, and antioxidant properties of Mexican cold brew coffee (CBC). The brewing process was carried out at two extraction temperatures (10 ± 0.5°C and 25 ± 0.5°C) and two particle sizes: medium (MG, 0.70–1.70 mm) and fine (FG, 0.43–0.71 mm). CBC brewing showed a complex relationship between brewing temperature and coffee grind particle size. The increase in brewing temperature enhanced the extraction rate. However, the particle size conditioned the extraction equilibrium time and final CBC properties. MG accelerated the brewing extraction rates to reach equilibrium in CBC properties (~7 h for 25ºC and ~12 h for 10ºC), while FG induced slower extraction rates and prolonged extraction times (above 12 h for both temperatures). However, FG produced CBC with higher bioactive compound content, darker color, and slightly less acidity than MG.

KEYWORDS:

• Cold brewing process
• brewing kinetics
• modeling
• extraction parameters
• Mexican coffee

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors acknowledge the financial support of Dirección de Apoyo a la Investigación y Posgrado, Universidad de Guanajuato, Mexico (Project No. [CIIC 076/2018].