Changes in physicochemical, antioxidative, and sensory properties in espresso coffee during refrigerated storage and their impacts on coffee milk

Abstract

Coffee is a widely consumed commodity. Beside its stimulating effects, it also has beneficial health effect. The objective of this study was to observe the changes in physicochemical, antioxidant and sensory properties of espresso coffee during refrigerated storage to determine its shelf-life as ingredient for coffee milk. The analysis used in this study were pH, color, antioxidant activity, total phenolic content, and sensory test as triangle test and hedonic of flavor, aroma, body, and color. The results showed that espresso coffee has quality degradation in both chemical (pH and antioxidant) and sensory properties during refrigerated storage. The lightness of coffee milk made from espresso coffee after four-day storage significantly increased. Although there was changes in pH of espresso coffee, it didn't change the pH of coffee milk produced. The reduction of antioxidant capacity could be observed from espresso coffee after 2 days storage, while the reduction of total phenolic content was observed after 4-day storage. Interestingly, the highest hedonic score was found in both of coffee products stored for 4 day in the refrigerator. The shelf life of espresso coffee for making coffee milk was six days based on triangle test.