Interactions between lecithin and yolk granule and their influence on the emulsifying properties

Egg yolk granule phosvitin (45 kDa) is a phosphoprotein known for its emulsifying properties. Recently, high hydrostatic pressure (HHP) treatment of granule induced the transfer of phosvitin to the soluble plasma fraction. This project evaluated the performance of the ultrafiltration (UF) used to concentrate phosvitin from the plasma fraction to produce a natural emulsifier. Phosvitin was characterized in plasma from a pressure-treated granule (1.73 ± 0.07% w/w) and in its UF retentate (26.00 ± 4.12% w/w). The emulsifying properties of both retentates were evaluated. The emulsion prepared with phosvitin-enriched retentate was more resistant to flocculation and creaming. Confocal laser scanning microscopy showed a network of aggregated protein similar to a gel, which encapsulated oil droplets in emulsions made with UF-retentate of plasma from pressure-treated granule. However, although sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that β-phosvitin is recovered in the cream, it is difficult to attribute the improved emulsifying properties of the UF-retentate of plasma from pressure-treated granules only to phosvitin.

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Functional and Antioxidant Properties of Angelwing Clam (Phplas orientalis) Hydrolysate Produced using Alcalase

Scientific Research Journal ◽

10.24191/srj.v11i1.9399 ◽

2014 ◽

Vol 11 (1) ◽

pp. 29

Author(s):

Nonnah Ismail ◽

Juliana Mahmod ◽

Awatif Khairul Fatihin Mustafa Kamal

Keyword(s):

Antioxidant Properties ◽

Enzyme Concentration ◽

Degree Of Hydrolysis ◽

Emulsifying Properties ◽

Hydrolysis Time ◽

Chelating Activity ◽

Metal Chelating ◽

Metal Chelating Activity ◽

Intermediate Concentration ◽

As Solubility

In this study, Hydrolysate from angelwing clam (Pholas orientalis) was produced at 0, 1, 2 and 3 hrs and E/S ratio of0.5 and 3%using alcalase where the pH and temperature were kept constant at pH 8.5 and 60°C, respectively. The hydrolysates were analysed for antioxidant and functional properties such as solubility, emulsifying properties and water and oil holding capacity. Degree of hydrolysis (DH), yield, functional and antioxidant properties were influenced by the hydrolysis time and E/S ratio. Higher enzyme concentration (E/S 3%) and longer hydrolysis time increased the DH. Yield was higher at E/S 3% but reduced with hydrolysis time. Longer hydrolysis time produced more soluble hydrolysate and higher metal chelating activity but lower in emulsifying properties and DPPH activity. Higher enzyme concentration resulted in increase only in solubility and metal chelating activity. This study revealed that enzymatic hydrolysis using alcalase should be performed at shorter hydrolysis time using intermediate concentration of enzyme (E/S between 0.5 to 3%) in order to produce angelwing clam hydrolysate with collectively good functional and antioxidant properties.

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