Saunf (Fennel Seeds) in size and shape they resemble cumin or zeera, but Saunf is a different spice altogether. From regulating blood pressure to water retention, fennel seeds pack many nutrients that make it a must have in your kitchen. Dried fennel or saunf is a storehouse of vital nutrients, low on calories and abundant in vitamin C fennel seeds bolsters the immune system, stimulates the collagen production and works as a potent antioxidant that scavenges the free radicals.