Emulsifying properties of Ghanaian grewia gum
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Date
2020
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International Journal of Food Science and Technology
Abstract
Grewia gums were extracted with phosphate (PB) and sodium metabisulphite buffers (SMB) and their emulsification properties in acidic oil-in-water emulsions on ageing were studied by means of droplet size distribution, f-potential measurements, interfacial composition analysis and viscometry. PB extracts showed smaller droplet sizes (~10 lm) than SMB isolates (>35 lm) and greater long-term stability. PB stabilised emulsions also demonstrated the least polysaccharide (~0.6 mg m 2 ) and protein (~0.2 mg m 2) interfacial coverage compared with SMB counterparts (~1.5 mg m 2 for polysaccharide and ~ 1 mg m 2
for protein). f-Potential measurements revealed negative interfacial charge for all emulsions confirming the presence of polysaccharide-laden interfaces. Droplet size distribution also varied among emulsions during ageing indicating a complex relationship between interfacial composition and stability. The present work shows that different emulsifying properties may be obtained depending on the extraction technique employed that could be exploited in preparation of emulsions for flavour or bioactive-delivery applications.
Description
This is an article published in International Journal of Food Science and Technology 2020, 55, 1909–1915; doi:10.1111/ijfs.14389
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Citation
Grewia gums were extracted with phosphate (PB) and sodium metabisulphite buffers (SMB) and their emulsification properties in acidic oil-in-water emulsions on ageing were studied by means of droplet size distribution, f-potential measurements, interfacial composition analysis and viscometry. PB extracts showed smaller droplet sizes (~10 lm) than SMB isolates (>35 lm) and greater long-term stability. PB stabilised emulsions also demonstrated the least polysaccharide (~0.6 mg m 2 ) and protein (~0.2 mg m 2 ) interfacial coverage compared with SMB counterparts (~1.5 mg m 2 for polysaccharide and ~ 1 mg m 2 for protein). f-Potential measurements revealed negative interfacial charge for all emulsions confirming the presence of polysaccharide-laden interfaces. Droplet size distribution also varied among emulsions during ageing indicating a complex relationship between interfacial composition and stability. The present work shows that different emulsifying properties may be obtained depending on the extraction technique employed that could be exploited in preparation of emulsions for flavour or bioactive-delivery applica tions.