California’s Central Valley produces 75% of the state’s wine grapes, generating large amounts of pomace waste that create environmental concerns. With rising demand for healthier oils, cold-pressed grape seed oil offers a sustainable solution. However limitedrelated research has focused on this wine region. This project aimed to (1) identify factors influencing extraction efficiency and oil quality, and (2) assess profitability for small-scale and low-income farmers.

In total, 500 g of seeds were separated, cleaned, and dried. Seed size was measured in 10 replicates with a caliper, and seed weight was the mean of 50 seeds in triplicate. Oil extraction was performed using a Luzrise 1800W Oil Press under varied conditions: temperatures of 0-200 °C and seed moisture of 0-10%. Oil color was measured by a spectrophotometer at 420, 520, and 620 nm. Density was determined by dividing the oil’s weight by the volume. Viscosity was measured with a Rotary Viscometer. Odor was evaluated manually.

The results showed that Pinot Noir seeds were the largest, and Ruby Cabernet seeds were the smallest. Red grape seeds ranged from medium to dark brown, whereas white varieties exhibited a greenish-brown hue. Oil yield was strongly influenced by seed water content and extraction temperature, with an extraction rate of 7.2% observed at 6% water content and 49 °C. Seed separation rates were higher for red grapes (45% for Pinot Noir and 40% for Tempranillo) than white varieties. Oil density ranged from 0.905 to 0.930 g/mL, with Pinot Noir demonstrating the highest density. Viscosity differences were negligible. Red seed oils showed greater yellow absorbance, while white seed oils were greener. Sensory evaluation found Syrah and Pinot Noir oils nutty and fruity, Chardonnay grassy, and others acceptable. Estimated revenue per ton of pomace reached USD 1,450 for Pinot Noir, USD678 for Tempranillo, and USD 457 for Syrah, suggesting grape seed oil can provide supplementary income for low-income farmers.