爆米花是怎样“爆”出来的？

Whether popcorn can be successfully “popped” out depends on the firmness of its skin, and whether it can effectively transfer external heat to the starch inside the grain. When the temperature rises, the moisture inside the kernels turns into steam and is gradually pushed toward the husk. When the pressure exceeds 200 degrees Celsius (400 degrees Fahrenheit), the husk bursts, and the starch and steam inside it expand and explode as the pressure inside and outside equalizes.

科学家们还找到了一种方法，使爆开的玉米粒体积增加一倍。如果在加热玉米粒的同时使用真空泵降低泵内空气的压力，玉米粒爆开时，爆开的量就会比平常大。

Today, popcorn also enjoys a healthy reputation. While you may think of popcorn as a sweet, salty, butter-filled snack reserved for special occasions like movies or carnivals, it’s actually a whole grain food, low in fat and salt before it’s seasoned.