Improving functional properties of pea protein isolate for microencapsulation of flaxseed oil

Abstract

Unhydrolysed pea protein (UN) forms very viscous emulsions when used at higher concentrations. To overcome this, UN was hydrolysed using enzymes alcalase, flavourzyme, neutrase, alcalase–flavourzyme, and neutrase–flavourzyme at 50 °C for 0 min, 30 min, 60 min, and 120 min to form hydrolysed proteins A, F, N, AF, and NF, respectively. All hydrolysed proteins had lower apparent viscosity and higher solubility than UN. Foaming capacity of A was the highest, followed by NF, N, and AF. Hydrolysed proteins N60, A60, NF60, and AF60 were prepared by hydrolysing UN for 60 min and used further for microencapsulation. At 20% oil loading (on a total solid basis), the encapsulated powder N60 had the highest microencapsulation efficiency (ME = 56.2). A decrease in ME occurred as oil loading increased to 40%. To improve the ME of N60, >90%, UN and maltodextrin were added. Flowability and particle size distribution of microencapsulated powders with >90% microencapsulation efficiency and morphology of all powders were investigated. This study identified a new way to improve pea protein functionality in emulsions, as well as a new application of hydrolysed pea protein as wall material for microencapsulation.

Keywords:

• Hydrolysed pea protein isolate
• functional properties
• microencapsulation efficiency
• flowability
• morphology

Acknowledgements

This research was funded, in part, with the U.S. Dry Pea and Lentil Council Grant and with an Emerging Research Issues for Washington Agriculture Grant from Agriculture Research Center, College of Agricultural, Human, and Natural Resource Science. The authors also would like to thank Frank Younce for his technical assistance with spray drying. In addition, we are grateful to Andrew Smith (Western U.S. and Inline Manager, Sympatec Inc.) for his assistance with particle size measurements.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Additional information

Funding

This research was funded, in part, with the U.S. Dry Pea and Lentil Council Grant and with an Emerging Research Issues for Washington Agriculture Grant from Agriculture Research Center, College of Agricultural, Human, and Natural Resource Science.