Functionalization of whey protein isolate fortified with blackcurrant concentrate by spray-drying and freeze-drying strategies

Gang Wu; Xiaodan Hui; Jianlou Mu; Margaret A Brennan; Charles S Brennan

doi:10.1016/j.foodres.2020.110025

Functionalization of whey protein isolate fortified with blackcurrant concentrate by spray-drying and freeze-drying strategies

Food Res Int. 2021 Mar:141:110025. doi: 10.1016/j.foodres.2020.110025. Epub 2021 Jan 7.

Authors

Gang Wu¹, Xiaodan Hui¹, Jianlou Mu², Margaret A Brennan³, Charles S Brennan⁴

Affiliations

¹ Department of Wine, Food and Molecular Biosciences, Faculty of Agriculture & Life Sciences, Lincoln University, Christchurch, New Zealand; Riddet Institute, Palmerston North, New Zealand.
² College of Food Science and Technology, Hebei Agricultural University, Baoding 071001, China.
³ Department of Wine, Food and Molecular Biosciences, Faculty of Agriculture & Life Sciences, Lincoln University, Christchurch, New Zealand.
⁴ Department of Wine, Food and Molecular Biosciences, Faculty of Agriculture & Life Sciences, Lincoln University, Christchurch, New Zealand; Riddet Institute, Palmerston North, New Zealand. Electronic address: Charles.Brennan@lincoln.ac.nz.

PMID: 33641954
DOI: 10.1016/j.foodres.2020.110025

Abstract

A solution of whey protein isolate was combined with blackcurrant concentrate via spray-drying and freeze-drying techniques separately to develop novel protein ingredients, (SWB and FWB). Chemical compositions, colour profiles, total anthocyanin content and encapsulation efficacy of the protein ingredients were evaluated. An in vitro digestion process was employed to observe the changes in total phenolic content, antioxidant activity, and predictive in vitro glycaemic response of the protein ingredients. The half maximal inhibitory concentration (IC₅₀) towards α-Amylase, and a molecular docking study on the interactions of α-Amylase with anthocyanins, were both performed to investigate the potential mechanisms of hypoglycaemic properties of these protein ingredients. The protein contents of SWB and FWB were 67.94 ± 0.47% and 68.16 ± 0.77%, respectively. Blackcurrant concentrate significantly (p < 0.001) changed the colour profiles of whey protein isolate. SWB obtained a higher total phenol content (3711.28 ± 4.36 μg/g), total anthocyanin content (85390.80 ± 162.81 μg/100 g), and greater encapsulation efficacy (99.64 ± 0.16%) than those of FWB (3413.03 ± 20.60 μg/g, 64230.24 ± 441.08 μg/100 g, and 95.43 ± 0.14%, respectively). Total phenolic content and antioxidant activities of SWB and FWB decreased after the in vitro digestion. The reducing sugar released during the in vitro digestion from SWB and FWB decreased compared with their corresponding controls (SWC and FWC). FWB (IC₅₀ = 73.46 μg/mL) exhibited stronger α-Amylase inhibitory activity than SWB (IC₅₀ = 81.46 μg/mL). Different anthocyanins differed from binding affinities to bind with the active sites of α-Amylase via formation of hydrogen bonds. This study suggested whey protein encapsulated-blackcurrant concentrate might be an innovative food product with improved nutritional profiles. Both spray- and freeze-drying are potential options to this encapsulation.

Keywords: Anthocyanins; Antioxidant activity; Encapsulation efficiency; Glycaemic response; Molecular docking; α-Amylase inhibition.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anthocyanins
Freeze Drying
Molecular Docking Simulation
Ribes*
Whey Proteins

Substances

Anthocyanins
Whey Proteins