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Complexation of anthocyanin-bound blackcurrant pectin and whey protein: Effect of pH and heat treatment

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posted on 2023-07-24, 01:53 authored by Nurhazwani Salleh, Kelvin KT Goh, Mark R. Waterland, Lee M. Huffman, Mike WeeksMike Weeks, Lara Matia-Merino

A complexation study between blackcurrant pectin (BCP) and whey protein (WP) was carried out to investigate the impact of bound anthocyanins on pectin–protein interactions. The effects of pH (3.5 and 4.5), heating (85 °C, 15 min), and heating sequence (mixed-heated or heated-mixed) were studied. The pH influenced the color, turbidity, particle size, and zeta-potential of the mixtures, but its impact was mainly significant when heating was introduced. Heating increased the amount of BCP in the complexes—especially at pH 3.5, where 88% w/w of the initial pectin was found in the sedimented (insoluble) fraction. Based on phase-separation measurements, the mixed-heated system at pH 4.5 displayed greater stability than at pH 3.5. Heating sequence was essential in preventing destabilization of the systems; mixing of components before heating produced a more stable system with small complexes (<300 nm) and relatively low polydispersity. However, heating WP before mixing with BCP prompted protein aggregation—producing large complexes (>400 nm) and worsening the destabilization. Peak shifts and emergence (800–1200 cm−1) in infrared spectra confirmed that BCP and WP functional groups were altered after mixing and heating via electrostatic, hydrophobic, and hydrogen bonding interactions. This study demonstrated that appropriate processing conditions can positively impact anthocyanin-bound pectin–protein interactions.

Funding

MBIE: Innovative NZ Hybrid UHT Food Products programme C10X1502

History

Rights statement

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

Publication date

2023-06-29

Project number

  • 14482

Language

  • English

Does this contain Māori information or data?

  • No

Publisher

MDPI

Journal title

Molecules

ISSN

1420-3049

Volume/issue number

27(13)

Page numbers

4202

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