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Components of Cells
The Macromolecules
Sweetness

Sweet


The human tongue has on its surface specialized receptors for a very limited number of tastes. If food containing certain "flavors" lands on one of these receptors, the molecules trigger the receptor, fire off the nerves and our brains receive the message "this tastes good" or "this is horrible - spit it out!".

Getting the most nutritious and high value food into our mouths and thus into our bodies is clearly advantageous to our survival. One of the most valued type of organic molecule in food is carbohydrate, so it is not surprising that our tongues contain specialized receptors that fire off signals of pleasure when we put sweet, carbohydrate containing foods into our mouths.

Sweet foods give us pleasure and so we search out and consume more of them than almost any other kind. Carbohydrates, with their high energy content, give us the fuel we need to drive our bodies.

In order to taste "sweet" the organic molecule falling on these particular receptors must meet certain criteria; it must have two electronegative atoms (atoms that pull electrons towards them) separated by 2.5 to 4 Angstroms; one of these electronegative atoms must have a hydrogen atom attached to it; it must be able to bind to the fat loving part of the receptor molecule. One particular carbohydrate, sucrose, meets all these criteria and therefore stimulates the "sweetest" response in our mouths.

Honey


Probably for as long as humans and bees have known one another each has had an uneasy relationship with the other. Spanish cave paintings, at least 7,000 years old, show illustrations of what could be bee keeping, but fossil bees in amber are at least 150 millions years old, so our even older ancestors probably knew about honey long before the caves were painted.

Four thousand years ago the Egyptians recorded the use of honey in food as both a sweetener and as a cure for illness. It was fed to mothers about to give birth, and then again at the time of mummification, indicating its importance to Egyptian society.

About 2,000 years later, the Pharaohs kept bees in hives, and honey was a common form of payment for debts or as offerings to the Gods, animal or humanoid.

Greeks and Romans liked their honey. It was an important ingredient in Greek medicine (Hippocrates and Aristotle both recommended its use), in their food, and also in their drink. Mead, and alcoholic drink made from fermented honey was considered the "nectar of the gods".

Greek and Romans Gods, such as Eros (the God of Love) used honey to cause people to fall in love by firing honey tipped darts into them. Romans extended and practiced apiculture (bee keeping) across their empire and could never produce enough to meet the demand.

All the civilizations that followed the Greeks and Romans had the same problem. No matter how many bees and hives were kept, the amount of sweetening honey they produced was never enough. A different source of sweetener was definitely needed. But the answer was not found until the 17th century.

Sugarcane


Far away from Rome, in the Pacific Islands, there grew a very large grass with huge, cane-like stalks. The Polynesians knew that cutting the stalks of this grass and licking the thin juice that ran out, was very pleasurable, and sweet! So when they went of long voyages, such as when they migrated to the shores of India between 1,000 and 5,000 years ago, they took sugarcane with them to their new homes.

That is where the Persians found it in 510 BC when they conquered that part of the sub-continent and described a "reed that gives honey without bees". About 2000 years later the voyage of sugarcane continued when Alexander the Great took it with him to Persia and other parts of Asia.

Sugarcane traveled with warriors wherever they went. Arab invaders of Persia in the 7th century A.D. took it to Syria, Palestine, Egypt and along the Mediterranean coast as far as Spain, and it was not long before the climate of Egypt made it a major sugar grower and exporter. At one time there were 450 miles of sugarcane fields stretched along the banks of the Nile.

The Crusades

Knights from Europe and Britain fighting in the Crusades in Syria first tasted the sweet juice from sugarcane in 1099, and were very impressed. Henry III of England bought three pounds of sugar in 1226 at a kingly price, and 100 years later it was still selling for a kings ransom of "two shillings a pound"; the equivalent of about $50 per pound in today's prices!

But even at these prices the sugar produced in the Mediterranean reached is peak in the 15th century and then began to decline as other, cheaper, sources were exploited. For, in 1493 Christopher Columbus sailed to the shores of what was eventually to become America, and one of the things he took with him was sugar cane.

The fertile soils and climate of the island of San Domingo was the perfect home for the "sweet reed" and it grew faster there than anywhere else in the world. A new industry had been formed and the island soon became the dominant sugar producer in the world. In 1530 there were already 28 sugar mills.

Long before George Washington participated in the American revolution, there were over 120 sugar producing refineries in England with a combined output of about 30,000 tons a year of this luxury product most people called "white gold". Naturally government after government taxed the sale of sugar, and added a lot to the exchequer until 1874 when the taxes were finally abolished and the price of sugar came within reach of the average citizen.

Sugar beet


Honey and the "sweet reed", sugarcane, remained, however the only sources of sweetness until a German chemist, Andreas Sigismund Marggraf published an account in 1747 of his researches into root vegetables. Pure sugar, he said, could be boiled out of a carrot-like root vegetable that quickly became called "sugar beet". When he boiled the dried roots in alcohol the sweetener was extracted and then deposited as pure crystals the moment the liquid cooled.

Sugarcane growers and refiners did not like this discovery one bit, and were fairly successful at suppressing the growth of sugar beet in Europe until Britain cut off the sugar supplies to France during the Napoleonic wars. In 1811 the Emperor of France not only allowed his citizens to grow sugar beet, he encouraged it by giving subsidies to farmers and grants to scientists. A European based sugar industry, based on this source of supply, quickly developed.

It only took two years before France was growing 160,000 acres of the root, and had 330 "mom and pop" sugar refineries that had a combined output of about 3,000 - 4,000 tons of sugar. This was so successful that eventually the excess was exported to - England!

Today, the largest producer of sugar from cane is Asia, followed by South and North American and Hawaii, where more than 6,000,000 tons of sugar are produced every year for an estimated value of $7-8,000,000. It has been estimated that nearly 43 pounds of sugar are consumed, one way or another, by every American every year! This makes it one of the more important single foods we eat.


BIOdotEDU
© 2004, Professor John Blamire