Extraction and physicochemical characteristics of high pressure-assisted cold brew coffee

Abstract

Over the past decade, cold brew coffee has gained increasing popularity due to its perceived smoother, sweeter, and less acidic sensory profile than the hot brew counterpart. However, the preparation of cold brew coffee is time-consuming, ranging from 6 to 24 h of extraction at refrigerated to room temperature. To address this challenge, the present study explored the feasibility of using high pressure processing (HPP) treatment to accelerate the extraction and evaluated its effects on physicochemical and sensory properties of the brew. In addition to preparing brews using the conventional coffee grounds, whole beans were also evaluated. Results from this study showed that HPP treatment could increase both extraction rate and extraction yield, especially for the whole beans, at ∼72 % and ∼36 % levels, respectively. At the same concentration, cold brew samples prepared from beans had lower polyphenol, caffeine and chlorogenic acid, but higher titratable acidity contents than brews from coffee grounds. These differences might have resulted in unique sensory profiles for bean-brewed coffee. In addition, when infused with nitrogen gas, the bean-brewed samples had a more stable and smoother foam head than the ground-brewed counterparts, implying that bean-brewed coffee may be promising for enhancing the nitrogen-infused coffee beverages.