Why ordinary corn does not pop like popcorn?

Ordinary corn, also known as field corn or dent corn, does not pop like popcorn because it has a different structure and moisture content. Here's why:

1. Hardness of the Kernel: Popcorn kernels have a hard outer shell made of cellulose, which is a tough plant fiber. This hard shell is what allows the kernel to build up pressure when heated. Ordinary corn kernels, on the other hand, have a softer outer shell, which does not provide enough resistance to build up pressure.

2. Moisture Content: Popcorn kernels have a higher moisture content compared to ordinary corn. This moisture gets converted into steam when heated, further increasing the pressure inside the kernel. As the pressure builds, the kernel eventually bursts, causing the starch inside to expand and creating the fluffy popcorn. Ordinary corn kernels have a lower moisture content, so they don't generate enough steam to cause the popping effect.

3. Starch Structure: The starch granules in popcorn kernels are smaller and more densely packed than in ordinary corn. When heated, the smaller starch granules in popcorn gelatinize quickly, creating a rapid expansion of the starch. This expansion, combined with the pressure built up inside the kernel, leads to the characteristic popping action. Ordinary corn has larger and looser starch granules, which don't expand as dramatically when heated.

4. Kernel Size and Shape: Popcorn kernels are typically smaller and rounder than ordinary corn kernels. This shape helps distribute heat more evenly, allowing for uniform expansion and popping. The larger size and irregular shape of ordinary corn kernels make it more difficult to achieve consistent popping.

Due to these differences in structure, moisture content, starch composition, and kernel size, ordinary corn does not pop like popcorn when heated.