The Coconut Pearl
Posted: Mon Dec 17, 2007 3:34 pm
Sprouting fruit of a coconut Cocos nucifera. The hard inner layer (endocarp) contains the actual seed composed of a minute embryo and food storage tissue (endosperm). The seed is surrounded by an outer brown layer called the seed coat or testa. This is the brown material that adheres to the white "meat" or endosperm when it is removed from the endocarp shell. Pieces of the woody endocarp are polished and made into earrings and necklaces. The base of the embryo (cotyledon) swells into an absorbing organ that fills the entire cavity of the seed as it digests the endosperm. The endocarp has three germination pores, one functional pore and two plugged pores. [In "blind coconuts" all three pores are plugged.] The three pores represent three carpels, typical of the palm family (Arecaceae). Just inside the functional germination pore is a minute embryo embedded in the endosperm tissue. During germination, a spongy mass develps from the base of the embryo and fills the seed cavity. This mass of tissue is called the "coconut apple" and is essentially the functional cotyledon of the seed. In some older references this cotyledon mass is referred to as a haustorium, the organ of absorption in parasitic flowering plants. [The white color in photo has been altered in order to clearly differentiate it from the endosperm.] It dissolves and absorbs the nutrient-rich endosperm tissue to supply the developing shoot with sugars and minerals. Eventualy, the developing palm becomes self sufficient, as its leaves produce sugars through photosynthesis and its roots absorb minerals from the soil. The coconut "apple" is rich in sugars and is a sweet delicacy in tropical countries. The endosperm is the coconut "meat" which is dried and sold as "copra." The coconut "water" is multinucleate liquid endosperm inside green coconuts that has not developed into solid tissue composed of cells. It is incorrectly called "coconut milk" in some references. Before the liquid endosperm forms a solid "meat" it is jellylike and may be eaten with a spoon. This stage of the endosperm development is called "spoon meat." The "coconut milk" used in many Asian recipes is made by soaking grated coconut meat in water and squeezing out the oil-rich liquid. "Coir" fibers are derived from the fibrous mesocarp. The saturated fat called "coconut oil" is derived from the meaty endosperm
http://www.pearls.com/news2/pp21/coconut_pearls.htm
