Vacuum-steam pulsed blanching (VSPB) enhances drying quality, shortens the drying time of gingers by inactivating enzymes, altering texture, microstructure and ultrastructure

Abstract

Exploring new blanching technology can help to deal with the challenge of better preservation of fruits and vegetables in food industry. In current work, vacuum-steam pulsed blanching (VSPB) was employed to ginger and its effect on peroxidase (POD) inactivation, drying behavior, texture profiles, microstructure, ultrastructure, phytochemicals (6, 8, 10-gingerols and 6-shagaol) and antioxidant capacity were investigated. Results showed that VSPB inactivated POD completely within 4 cycles. The starch granules gelatinized, the plasma membrane ruptured, the cell wall degraded and fractured gradually during the VSPB process under the action of thermal effect and pressure fluctuation, these changes further led to texture softening and shortening of drying time. Compared to the untreated ginger, VSPB reduced the drying time by 4.41%–22.79%. In the case of dried quality, it was found that the 6, 8, 10-gingerols, total phenolics and antioxidant capacity of dried products under three cycles blanching treatment were higher by 20.2%, 53.0%, 22.4%, 28.6%, 14.0% (DPPH), and 13.4% (FRAP) compared to that of the unblanched dried ginger. The findings in current work indicate VSPB is a promising technique for ginger as it enhances drying process and improve the dried quality through efficiently inactivating the enzymes, altering the texture, microstructure and ultrastructure.