Tuesday, April 24, 2012


Sugar, that historic source of sweetness is traditionally used for preparing almost all foods that need sweet taste. It is derived from Sugar cane in many countries while a few producing countries use Sugar beets as a source. Chemically both are same, viz Sucrose, a disacharide containing the monomers Glucose and Fructose. Sugar cane cultivation was mentioned in history as early as 8000 BC as being grown in Africa, According to some reports India was the first nation to make crytal sugar in 350 A.D though regular production started only in 500 A.D. The major competitor for sugar cane as a source of sugar,viz Sugar Beets made its appearance relatively late in 19th century in Europe and to day this accounts for 30% of global sugar production.

Is there any difference between sugar from the above two sources? Theoretically both are sucrose and taste wise there ought not to be ant difference. One major difference in to day's modern world is that R & D on sugar beets has been substantial while sugar cane production continues without much of a new development either in cultivation or in processing except for use of stainless machinery for most of the unit operations in newly set up factories. Another positive development has been in the area of utilization of Bagasse, the left over residue during crushing, with most modern sugar mills having co-generating facilities using it as a fuel. Besides the molasses left over after recovery of crystal sugar became the major source of alcohol for chemical industry, beverage industry and Gasohol industry. Brazil one of the major growers of sugar cane produces huge quantity of alcohol used in automobile industry.

Not till 1975 any one heard about high fructose corn syrup (HFCS) which is made from corn through hydrolysis of starch extracted from it and conversion to a product containing glucose and fructose by chemical or enzymatic isomerization process. As the American corn is dirt cheap, being priced low because of heavy subsidization of corn production by the government there, food industry adopted this sweetener immediately to improve their bottom line. On sweetness scale sucrose and HFCS score equally with practically no difference in their taste perception. While HFCS was hailed as a harbinger of good things to come for the industry as well as the consumer, there was a sour note a few years ago that threatened to mar the explosive growth of HFCS industry. With the rabid spread of obesity in the US, threatening the health security of the country seriously, HFCS became the "whipping boy" and serious questions were raised regarding the role of HFCS in making people obese.

It is to be conceded that Sucrose and HFCS are almost same in terms of chemistry, the only difference being that gluose and fructose are in free form in HFCS whereas they are chemically bound in sucrose. Theoretically when sucrose is digested in GI by sucrase enzyme within a few minutes of ingestion, the result is a mixture of glucose and fructose, almost in the same proportion as in HFCS. If this is so the logical question is why should HFCS behave differently than sucrose as being claimed by some credible scientific studies? It is by now well established that fructose metabolism in human body differs sharply compared to that of glucose but whether ingesting both together as with HFCS intake will make a difference is the subject matter of current day controversy.  

Further confusion is created by a recent finding by a group of scientists that there are two forms of enzymes that metabolize fructose. This is being touted as a reason for the behavior of fructose differently compared to other sugars. It is suggested that human body is not designed to handle fructose in high quantities unlike glucose which is fast metabolized into energy through Citric Acid Cycle. It seems that the two isoforms of the enzyme Fructokinase-C and A have different functions in the body. While one form causes fatty liver, obesity and insulin resistance the other one protects the body from on set of these disorders. What triggers this switch between these two forms is still not clear. There is also the suggestion that fructose, in presence of glucose behaves differently while high load of fructose can behave differently. These findings still do not answer the question as to why HFCS is more obesogenic than sucrose alone. For centuries humans have been consuming sugar and no adverse findings have been recorded in history due to this. Probably there may be other factors not currently understood as to why Sugar and HFCS do cause health disorders to day as diet and living styles have undergone sea change during the last 100 years.      

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