Abstract
Extracts rich in pectins were isolated by aqueous extraction at pH. 4.0 (OE4) and 6.0 (OE6) from okra (Abelmoschus esculentus) pods. They were examined in terms of their composition and emulsion stabilizing capacity in model acidic emulsions (hexadecane-in-water at pH. 3.0). Extracted polysaccharides were assessed using size exclusion chromatography (SEC) and FTIR spectroscopy. The properties and stability of the resulting emulsions were examined by means of droplet size distribution and ζ-potential measurements, viscometry, fluorescence microscopy and protein interface concentration. As emulsifiers, both extracts produce emulsions of initially monomodal size distribution and of similar average droplet size, while ζ-potential was negative for both. The emulsions prepared using OE6 are relatively stable in terms of droplet size distribution and average droplet size after 30. days of storage, while emulsions prepared with OE4 increase in droplet size, in part attributable to Ostwald ripening. Determination of the protein interface coverage Γsuggests that the increased stability of the OE6 emulsions should be attributed to the higher protein load of the interfaces prepared using this extract, resulting to increased rigidity of the interface. Viscosity of emulsions containing OE6 was two times greater than OE4 while aging increases the viscosity of both emulsions. The present work suggests that okra extracts can be strong candidates for emulsification in acidic environments.
Original language | English |
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Title of host publication | Gums and Stabilisers for the Food Industry 17 - The Changing Face of Food Manufacture: The Role of Hydrocolloids |
Publisher | Royal Society of Chemistry |
Pages | 238-244 |
Number of pages | 7 |
Publication status | Published - 2014 |
Event | 17th International Gums and Stabilisers for the Food Industry Conference - Glyndwr University, Wrexham, United Kingdom Duration: 25 Jun 2013 → 28 Jun 2013 Conference number: 17 |
Publication series
Name | Food Research International |
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Number | 2 |
Volume | 54 |
ISSN (Electronic) | 0963-9969 |
Conference
Conference | 17th International Gums and Stabilisers for the Food Industry Conference |
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Country/Territory | United Kingdom |
City | Wrexham |
Period | 25/06/13 → 28/06/13 |