Vacuum-assisted block freeze concentration applied to wine

Vacuum is an assisted technique to improve the efficiency of freeze concentration process, and wine is an interesting raw material to be concentrated. In this study reported the vacuum-assisted block freeze concentration to force the separation of solutes from a frozen wine sample. By applying vacuum (40 kPa), the solids content in the concentrated fraction increased significantly compared to the initial value (8°Brix), reaching a value near of 21°Brix after 5 min, although decreasing over time, indicated that the concentrated extract was collected mostly in the first fractions. The efficiency achieved high values near of 90% in a short time (15 min, 45 ml of initial sample), with high values of ice purity over time of suction. The pH, alcohol, acidity and total polyphenol content increased significantly in the concentrated sample (50% of concentrate) compared the fresh wine. The color evaluation indicating that cryoconcentrate (50% of concentrate) was darker than the initial sample, with a ΔE* value > 40 CIELAB units. The vacuum-assisted block freeze concentration applied to wine is an effective technique to obtain a concentrated sample with attractive properties for possible gastronomic use.Industrial relevanceThe vacuum assisted block freeze concentration allows producing wine concentrates with attractive properties, such as a high solid content, darker color and higher alcohol content than the initial sample. In this work has applied vacuum (40 kPa) as an assisted technique to improve the efficiency of block freeze concentration applied to wine, obtaining promissory results.