Influence of drying method on extraction ratio, fatty acid compositions and antioxidant activity of tomato seed oils

The influences of different drying methods, including hot-air drying, vacuum drying, microwave drying and vacuum-freeze drying, on the extraction ratio, fatty acid compositions and antioxidant activity of tomato seed oils (TSOs) were investigated. Results showed that the extraction ratio of TSOs was significantly affected by different drying methods and the high extraction ratio of TSOs obtained from microwave drying was 23.17%. TSOs obtained from vacuum-freeze drying were poorer in saturated fatty acid (22.33%) , but richer unsaturated fatty acid (77.67%) compared to other drying methods. IC50 values of TSOs obtained from hot-air drying (35℃) , hot-air drying (65℃) , vacuum drying, microwave drying and vacuum-freeze drying were 10.5, 12.1, 8.6, 9.1 and 8.3mg/mL, respectively. It clearly demonstrated that TSOs obtained from vacuum-freeze drying had higher antioxidant activity than those other TSOs.