Characterization of diacylglycerol oil mayonnaise emulsified using phospholipase A2-treated egg yolk

摘要

Mayonnaise samples were prepared using DAG oil as the oil phase; the properties and stability were compared with mayonnaise samples prepared from TAG oil. Normal (nontreated) egg yolk and phospholipase A2 (PLA2)-treated egg yolk were used as emulsifiers. The DAG oil mayonnaise prepared with nontreated egg yolk (DAG-M) was unstable, with cracks forming within 4 wk at 40°C. This type of fracture was not observed for TAG oil mayonnaise prepared with nontreated egg yolk (TAG-M). 31P NMR and quantitative analyses of phospholipids suggested that the phospholipids of egg yolk lipoprotein were dissolved in DAG-M oil droplets, which might result in the coalescence and fracture of the DAG-M. Phospholipids were not dissolved in TAG-M oil droplets. No crack formation was observed for DAG oil mayonnaise prepared with PLA2-treated egg yolk (DAG-PLM) after storage for more than 4 wk at 40°C. 31P NMR spectroscopy and quantitative analyses of phospholipids indicated that the dissolution of phospholipid molecules into the oil droplets was almost prevented in DAG-PLM. The stability of DAG-PLM is improved probably because the PLA2 treatment changes the molecular polarity of egg yolk phospholipids and prevents them from dissolution into the DAG oil droplets from oil/water interface.