Effects of variable-temperature drying on the qualities and sweet-substance profile of Zizyphus jujuba Mill. cv. Junzao

Yaxuan Liao; Yuxing Liu; Weida Zhang; Hao Dong; Liqing Yang; Jiajun Zhang; Yunuo Wang; Shaobo Cheng; Guogang Chen

doi:10.1016/j.fochx.2024.101361

Effects of variable-temperature drying on the qualities and sweet-substance profile of Zizyphus jujuba Mill. cv. Junzao

Food Chem X. 2024 Apr 6:22:101361. doi: 10.1016/j.fochx.2024.101361. eCollection 2024 Jun 30.

Authors

Yaxuan Liao¹, Yuxing Liu¹, Weida Zhang¹, Hao Dong², Liqing Yang¹, Jiajun Zhang¹, Yunuo Wang¹, Shaobo Cheng^{1

3}, Guogang Chen^{1

3}

Affiliations

¹ College of Food Science and Technology, Shihezi University, Shihezi, Xinjiang 832000, PR China.
² Shihezi Testing Institute of Quality and Metrology, Shihezi 832000, PR China.
³ Research Center of Xinjiang Characteristic Fruit and Vegetable Storage and Processing Engineering, Ministry of Education, Shihezi, Xinjiang 832000, PR China.

Abstract

The changes in the qualities and sweet-substance levels of Junzao jujube during variable-temperature drying (VTD) were investigated. The results showed that VTD retains the original color of jujube, reduces its hardness and chewiness, and decreases its wrinkling while shortening the drying time by 13.2% compared with that of constant temperature drying (CTD). "Electronic-tongue" taste analysis showed that the sweetness of VTD jujube is significantly higher than that for CTD. This is shown to be related to the contents of sucrose, fructose, and glucose, as well as the activities of invertase and sucrose synthase enzymes. In addition, the content trends for sweet amino acids are correlated with the temperature gradient used in VTD. Thus, the present study elucidates the factors governing the transformation of sugar substances in jujube during VTD, as well as providing a practical reference for the application of VTD in the jujube industry.

Keywords: Quality change; Soluble sugar; Sugar conversion related enzymes; Sweet substances; Variable-temperature drying; Zizyphus jujuba Mill. cv. Junzao.