They also must be isolated from other varieties of sweet corn, because cross pollination with standard sweet corn will make kernels tough and starchy in both types. Germination in supersweet varieties is also poor. Marketing sweet corn effectively depends on promotion and educating the consumer to differences between varieties. Free samples along with recipes are an excellent way to promote these varieties. Pearl types have smooth, rounded pearl-like crowns, while rice types are pointed.
Popcorns also vary in color.
Popcorn has a hard, flinty endosperm that surrounds a small amount of soft moist starch in the center. Popcorn quality depends on a number of factors. Generally, the more a popcorn variety expands after popping, the better the quality, as a greater volume produces a better texture. Most commercial varieties will expand 30-40 times their volume. Expansion is also affected by moisture content, drying procedure, and amount of damage to the pericarp and endosperm.