Dept. of Food Science, Univ. of Guelph, Guelph, Ontario, Canada, N1G 2W1.
J Food Sci. 2013 Sep;78(9):C1334-9. doi: 10.1111/1750-3841.12175.
The development of structure in ice cream, characterized by its smooth texture and resistance to collapse during melting, depends, in part, on the presence of solid fat during the whipping and freezing steps. The objective of this study was to investigate the potential application of 10% rice bran wax (RBW) oleogel, comprised 90% high-oleic sunflower oil and 10% RBW, to replace solid fat in ice cream. A commercial blend of 80% saturated mono- and diglycerides and 20% polysorbate 80 was used as the emulsifier. Standard ice cream measurements, cryo-scanning electron microscopy (cryo-SEM), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM) were used to evaluate the formation of structure in ice cream. RBW oleogel produced higher levels of overrun when compared to a liquid oil ice cream sample, creating a lighter sample with good texture and appearance. However, those results were not associated with higher meltdown resistance. Microscopy revealed larger aggregation of RBW oleogel fat droplets at the air cell interface and distortion of the shape of air cells and fat droplets. Although the RBW oleogel did not develop sufficient structure in ice cream to maintain shape during meltdown when a mono- and diglycerides and polysorbate 80 blend was used as the emulsifier, micro- and ultrastructure investigations suggested that RBW oleogel did induce formation of a fat globule network in ice cream, suggesting that further optimization could lead to an alternative to saturated fat sources for ice cream applications.
冰淇淋结构的发展，其特点是质地光滑，在融化过程中不易坍塌，部分取决于搅打和冷冻过程中固体脂肪的存在。本研究的目的是研究 10%米糠蜡（RBW）油凝胶在冰淇淋中替代固体脂肪的潜在应用，该油凝胶由 90%高油酸葵花籽油和 10% RBW 组成。使用商业混合的 80%饱和单甘酯和双甘酯以及 20%聚山梨醇酯 80 作为乳化剂。标准冰淇淋测量、低温扫描电子显微镜（cryo-SEM）、差示扫描量热法（DSC）和透射电子显微镜（TEM）用于评估冰淇淋结构的形成。与液态油冰淇淋样品相比，RBW 油凝胶产生了更高的膨胀率，形成了更轻、质地和外观更好的样品。然而，这些结果与更高的抗融性无关。显微镜显示，在空气细胞界面处，RBW 油凝胶脂肪滴的聚集更大，空气细胞和脂肪滴的形状发生了扭曲。尽管 RBW 油凝胶在使用单甘酯和聚山梨醇酯 80 混合物作为乳化剂的冰淇淋中没有形成足够的结构来保持融化过程中的形状，但微观和超微结构研究表明，RBW 油凝胶确实在冰淇淋中诱导了脂肪球网络的形成，这表明进一步优化可能会为冰淇淋应用提供替代饱和脂肪源的方法。
