Chardonnay grape seed pomace (GSP) is a waste byproduct of wine production. Researchers at Washington State University have found that the antioxidant capacity of coffee is enhanced by adding a small amount of GSP. The appearance, taste or aroma of the coffee is not changed significantly by this process.
Researchers added 0% (control), 6.25%, 12.50%, 18.75% or 25% GSP to coffee and tested the results on two consumer panels. The first panel assessed the coffee samples with sweeteners, milk and cream options available, while the second assessed the coffee samples served black.
Consumer were asked to evaluate the five treatments individually using a 9-point hedonic scale. Acceptance of appearance, aroma, taste, flavor and overall acceptance was tested using a ‘check all that apply’ questionnaire. The effects of antioxidant levels in GSP coffee samples was determined by using an oxygen radical absorbance capacity test.
GSP increased the antioxidant capacity of the coffee compared to the control (0% GSP). No significant differences were found among replacement values.
When compared to the control, the results show that GSP could be added at 6.25% replacement without meaningfully affecting the overall consumer acceptance of coffee. When more than 6.25% GSP was added, the coffee beverage was in general less accepted by the consumers with them describing the coffee as more milky, tan, diluted, watery, and mild. The researchers believe that the results may be useful in the development of other avenues for use of grape seed pomace, or a new coffee beverage. They also noted that further investigation might validate the free radical scavenging capacity of GSP coffee and its potential health benefits.
Full research has been published in the Journal of Food Science.