Heating-Aided pH Shifting Modifies Hemp Seed Protein Structure, Cross-Linking, and Emulsifying Properties

Qingling Wang, Yan Jin, Youling L. Xiong

Research output: Contribution to journalArticlepeer-review

93 Scopus citations


Alkaline pH12 shift treatment performed at varying temperatures (20-80 °C for 1, 5, and 60 min) was applied to structurally modify hemp seed protein isolate (HPI). The solubility of HPI (∼20%) was remarkably improved (p < 0.05) with elevating the temperature and prolonging the holding time, reaching 97.5% at 80 °C for 60 min. The treated HPI exhibited a strong tendency of forming soluble large aggregates. To limit lysinoalanine (LAL) production, heating was methodically controlled to 60 °C and 5 min, where the LAL content never exceeded 100 mg/100 g of protein and the loss of cysteine and lysine was also minimal. The emulsifying activity of HPI was improved by this mild pH shift-heating combination treatment as a result of the dissociation of protein subunits, unraveling of the tertiary structure, and exposure of hydrophobic groups. Moreover, the emulsion formed by the treated protein maintained a superior stability in particle size and distribution during storage.

Original languageEnglish
Pages (from-to)10827-10834
Number of pages8
JournalJournal of Agricultural and Food Chemistry
Issue number41
StatePublished - Oct 17 2018

Bibliographical note

Funding Information:
*Telephone: 859-257-3822. Fax: 859-257-5318. E-mail: ylxiong@uky.edu. ORCID Youling L. Xiong: 0000-0002-2164-4783 Funding This work was supported by the United States Department of Agriculture (USDA) National Institute of Food and Agriculture (Hatch Project 2351267000) and an Oversea Study Fellowship from the China Scholarship Council (to Qingling Wang), approved for publication as journal article number 18-07-072 by the Director of the Kentucky Agricultural Experiment Station. Notes The authors declare no competing financial interest.

Publisher Copyright:
© Copyright 2018 American Chemical Society.


  • amino acids
  • emulsifying activity
  • hemp seed protein isolate
  • lysinoalanine
  • solubility

ASJC Scopus subject areas

  • Chemistry (all)
  • Agricultural and Biological Sciences (all)


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