loading page

Impact of steaming and roasting heat-treatment on physico-chemical, functional and digestibility of walnut kernel
  • +3
  • Xiaoyan Zhao,
  • Xiangrui Ren,
  • Hongkai Liu,
  • Meng Wang,
  • Xiaowei Zhang,
  • Haifang Hu
Xiaoyan Zhao
University of Jinan

Corresponding Author:[email protected]

Author Profile
Xiangrui Ren
Author Profile
Hongkai Liu
Author Profile
Meng Wang
University of Jinan
Author Profile
Xiaowei Zhang
Author Profile
Haifang Hu
Xinjiang Academy of Forestry Sciences
Author Profile


In order to develop the application of walnut kernel, the effect of steaming and roasting treatment on the physicochemical and functional properties of walnut kernel at 95 ºC for different time (15, 20 and 30 min) was investigated, and compared to those of untreated sample. Scanning electron microscopy suggested that heating treatment had a notable effect on the microstructure of walnut kernel, especially the steam heating. Both treatments significantly increased the enthalpy, vitro protein digestibility, viscosity, G′ and G″ (P < 0.05), the order from high to low was steaming > roasting > untreated. All samples contained the amounts of essential amino acids, the amino acid score (AAS) of samples by steaming was the highest compared to that of the untreated and roasting, and the only limiting amino acid of walnut kernel before or after heat treatment was lysine. In addition, the protein of walnut kernel after heating treatment with the extension of time contained more α-helix and random coil structures compared to the untreated sample, while β-sheet and β-turns structures decreased. Moreover, the thermal treatment could cause the changes of the water/oil holding capacity, foaming and emulsifying properties of walnut kernel flour. When there were differences between the results of steaming and roasting samples, it was concluded that the water played an important role in steaming. These results suggested that the thermal treatment as an effective approach could improve the physico-chemical, structural and functional properties of walnut kernel and be potentially applied in the food processing.
01 Jun 2023Submitted to Journal of the American Oil Chemists' Society
01 Jun 2023Submission Checks Completed
01 Jun 2023Assigned to Editor
02 Jun 2023Review(s) Completed, Editorial Evaluation Pending
15 Jun 2023Reviewer(s) Assigned
26 Jul 2023Editorial Decision: Revise Major
17 Aug 20231st Revision Received
17 Aug 2023Assigned to Editor
17 Aug 2023Submission Checks Completed
17 Aug 2023Review(s) Completed, Editorial Evaluation Pending
19 Aug 2023Reviewer(s) Assigned
08 Sep 2023Editorial Decision: Revise Minor
12 Sep 20232nd Revision Received
12 Sep 2023Submission Checks Completed
12 Sep 2023Assigned to Editor
12 Sep 2023Review(s) Completed, Editorial Evaluation Pending
17 Sep 2023Editorial Decision: Revise Minor
18 Sep 20233rd Revision Received
18 Sep 2023Submission Checks Completed
18 Sep 2023Assigned to Editor
18 Sep 2023Review(s) Completed, Editorial Evaluation Pending
25 Sep 2023Editorial Decision: Accept