Effects of Maillard reaction on physicochemical and functional properties of walnut protein isolate

  • Sahibzada Fahim Ullah
  • Nasir Mehmood KhanEmail author
  • Farman Ali
  • Shujaat Ahmad
  • Zia Ullah Khan
  • Noor Rehman
  • Abdul Khaliq Jan
  • Nawshad Muhammad


In this study, the Maillard reaction (MR) of glucose was applied to improve the physicochemical and functional properties of walnut protein isolate (WNPI). The MR products (MRPs) were prepared with glucose at 0 h (MRP0), 1 h (MRP1), 2 h (MRP2) and 3 h (MRP3) heating at 95 °C. The Infra-Red spectrum showed reduction of amide and S–H functionalities in MRPs with complete intermixing of glucose in MRP3. Scanning electron microscopy indicated changes in the morphology of MRP3 which also exhibited promising antioxidant effect. Significant decrease (P < 0.05) in hydrophobicity values (Ho) and increase (P < 0.05) in emulsifying activity/emulsifying stability indexes values were observed for MRPs. Uniform droplet distribution was observed in microscopy of emulsions while an increase in the interfacial protein concentration (Г) was obtained for MRPs. These results suggest that MR is useful in improving the utilization of this protein in food product development.


Walnut protein isolate Maillard reaction Physicochemical and functional properties FT-IR SEM Antioxidant effect 



No funding was received from any agencies (public and commercial) or not for profit sectors.

Compliance with ethical standards

Conflict of interest

The author declare that they are no conflict of interest


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Copyright information

© The Korean Society of Food Science and Technology 2019

Authors and Affiliations

  1. 1.Department of ChemistryShaheed Benazir Bhutto University, SheringalDir UpperPakistan
  2. 2.Department of AgricultureShaheed Benazir Bhutto University, SheringalDir UpperPakistan
  3. 3.Department of PharmacyShaheed Benazir Bhutto University, SheringalDir UpperPakistan
  4. 4.Department of AgricultureAbdul Wali Khan UniversityMardanPakistan
  5. 5.Interdisciplinary Research Center in Biomedical Materials (IRCBM)COMSATS Institute of Information TechnologyLahorePakistan

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