Sarkar, A, Kamaruddin, H, Bentley, A et al. (1 more author) (2016) Emulsion stabilization by tomato seed protein isolate: Influence of pH, ionic strength and thermal treatment. Food Hydrocolloids, 57. pp. 160-168. ISSN 0268-005X
Abstract
There is a burgeoning interest for plant protein-based emulsifiers owing to their economic benefits and lower environmental impacts. This study investigated the stability of 10.0 wt% oil-in-water emulsions stabilized by 1.0 wt% protein extracted from tomato seeds, a by-product of tomato processing industries. Both water-soluble albumin and salt-soluble globulin fractions of tomato seed protein in the molecular weight range of 48-10 kDa were adsorbed at the oil-water interface, as confirmed by sodium dodecyl sulfate polyacryl amide gel electrophoresis (SDS-PAGE). Tomato seed protein isolate-stabilized emulsions were subjected to environmental stresses such as pH (2-9), ionic strength (0-250 mM NaCl or CaCl2) and thermal treatment (30-90°C, 30 min). Droplet size, droplet charge, microstructure and creaming stability were assessed. Emulsions were stable to droplet aggregation except at pH 2-4, owing to their proximity to isoelectric point. Emulsions showed excellent stability to high NaCl concentrations (250 mM) at pH 6-8 with surface charges above -40 mV. However, extensive droplet flocculation with aggregated optical microstructure and creaming indices was observed in presence of ≥ 50 mM CaCl2, which was attributed to ion binding and charge screening effects. Droplet aggregation above 80 °C was due to the denaturation of the globular protein fractions adsorbed at the interface. These results might have implications for the utilization of tomato seed protein as potential emulsifier for food and beverage applications.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2016, Elsevier. This is an author produced version of a paper published in Food Hydrocolloids. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Tomato seed protein; salt stability; SDS-PAGE; thermal denaturation; creaming; charge screening |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Food Science and Nutrition (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 04 Feb 2016 13:05 |
Last Modified: | 06 Nov 2017 10:26 |
Published Version: | http://dx.doi.org/10.1016/j.foodhyd.2016.01.014 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.foodhyd.2016.01.014 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:94603 |