Physicists at Temple University in Philadelphia have come up with a novel approach to manufacturing chocolate that could allow for a lower fat content. Current techniques rely on a relatively high fat percentage — as much as 40 percent — to keep chocolate in liquid form during production, but the new method detailed in a study published today suggests that can be circumvented with the clever application of an electric field.
Electrorheology, as this field of research is called, is concerned with the deformation and flow of matter when affected by electricity. What the Temple researchers found was that an electric field applied in the flow direction of a liquid stream of chocolate helped to reduce its viscosity along that direction. Because this field polarizes the cocoa particles, they were able to essentially reorient and aggregate the particles inside the chocolate, turning them into short chains that flow more easily. The liquid’s viscosity was made anisotropic, which is to say that it was reduced only in the flow direction, the one that matters.
A less viscous chocolate mixture means a lower minimum required fat content, and the Temple team claim their approach can reduce that figure from 40 percent down to 32 percent. Their argument is that chocolate containing less fat would be healthier to consume, owing primarily to the associated reduction in calories. High-fat chocolate leads to obesity, they contend, although they do also concede that the majority of fat in chocolate is cocoa butter, which actually has quite a few health benefits in and of itself.
一個黏性較低的巧克力混合物，意味著最低脂肪含量的需要可以較低 (就是可以降低脂肪含量)，天普大學的團隊聲稱他們的方法可以從40％下降到32％ (看似不多，但這卻在巧克力製成上卻有很大的突破!)。他們的論據是含脂肪較少可以使消費者更健康，在熱量上也可以相對減少。雖然他們抱怨說高脂肪的巧克力導致肥胖，但他們也承認大多數巧克力的脂肪是用可可脂，而這實際上對健康有相當的益處。