蛋之機能性一般以其蛋白之起泡性 (foaming property) 與蛋黃之乳化性 (emulsifying property) 被研究的最多。本研究則係以探討蛋黃之起泡性為主，期就不同蛋白質濃度、pH值以及添加食鹽、砂糖和食用油時對其起泡性之影響，並與蛋白做比較。結果顯示，於相同蛋白質濃度下，蛋黃之起泡力 (foaming ability) 反較蛋白為高；而純蛋黃於稀釋50%，並於pH 8時，具最佳之起泡力，惟其泡沫安定性 (foaming stability) 皆較蛋白低。添加食鹽後，相較於蛋白，其對蛋黃起泡性之影響較大，而蛋黃於0.4 M食鹽濃度時有最佳起泡力。
相同攪打時間，蛋黃於添加10-20%砂糖後之起泡力不受影響，而泡沫之安定性則隨添加之砂糖濃度增加而提高。另外，雖然油之添加顯著降低蛋白之起泡力，然於蛋黃而言，油之存在對其起泡性並無負面之影響。
由新鮮蛋白及上述最佳條件調配之蛋黃作不同比例之混合後，顯示蛋白與蛋黃比例為30：20時有最佳之起泡性。綜上所述，蛋黃於適當稀釋濃度下除具良好之乳化性外，亦兼具油性環境之起泡能力，並可預期於特定條件下使用蛋黃在配方食品中，且同時發揮其起泡及原有之乳化特性。e

The mostly discussed functional properties of eggs were foaming properties of egg white (EW) and emulsifying properties of egg yolk (EY). The purpose of this study was to compare the effects of different protein concentration, pH, salt, sugar, and oil content on foaming properties between EY and EW. The results indicated that EY had higher foaming ability but lower foaming stability when compared to EW at the same
protein concentration. When diluted to 50% and processed at pH 8, egg yolk had the best foaming ability but lower foaming stability than egg white. Salt had more collision effect on foaming properties to EY than
EW, and egg yolk had the best foaming ability when 0.4 M of salt was added. EW with 10-20% sugar had no significant effect on foaming ability but foaming stability would increase with increasing sugar concentration
at same whipping time. Furthermore, on oil factor, it decreased foaming ability of EW but there was no significant difference on EY in oily environment. Fresh EW mixed with EY under the best condition tested at
30 : 20 ratio gave rise to the best foaming properties. In conclusion, egg yolk not only had better emulsifying properties but also possessed foaming ability in oily environment. Therefore, at specific conditions, egg yolk could develop foaming properties and original emulsifying properties at the same time in the formulated food.cel