Effects of Hypobaric Treatments on the Quality, Bioactive Compounds, and Antioxidant Activity of Tomato.

Abstract

Hypobaric treatment is becoming a potential technology to protect fruits from postharvest decay. The objective of this study was to investigate the effects of hypobaric treatments on storage quality, bioactive compounds, and antioxidant activity of tomato fruit. In this study, green tomatoes (cv. "Fen guan") were treated with hypobaric pressures (0.04 and 0.07 MPa) at ambient temperature (20 ℃) for 28 d. The results showed that under hypobaric storage, the respiration rates significantly declined and the respiratory peaks postponed 12 and 8 d by 0.04 and 0.07 MPa treatments, respectively, compared to control. Total soluble solid, titratable acidity, ascorbic acid, and lycopene were retained by hypobaric treatment. Moreover, ascorbic acid contents treated with 0.04 and 0.07 MPa were, respectively, 37% and 26% higher than control at day 24 and the contents of total polyphenols were, respectively, 1.28 and 1.11 times higher than control. Production and accumulation of toxic substances were significantly restrained. The ethanol content decreased, respectively, by 53% and 84% than control. At later storage period, the superoxide dismutase activity in treated fruits was about 0.58 U/(g·FW·min), whereas only 0.29 U/(g·FW·min) in control. Hypobaric treatment not only maintained a high activity of superoxide dismutase and peroxidase (POD), but also improved antioxidant capacity. All the results indicated that hypobaric treatment was a potential helpful method to protect the quality and nutrition of tomato and prolong ripening of tomato. Furthermore, the effect of 0.04 MPa hypobaric treatment was found better than 0.07 MPa.