Wednesday, March 7, 2012


Food industry and the Pharmaceutical companies are continuously looking for newer non-calorie sweeteners with least harmful side effects and off taste. There are already half a dozen such sweeteners popular with weight watchers and diabetic people though each one of them cannot be considered as perfect in all respects. Latest to arrive is Tagatose a natural sugar obtained by isomerization of galactose under alkaline condition or through use of isomerase enzymes derived from yeast. It appears Tagatose occurs in small quantities in most dairy products though its presence is not felt by the consumer. As its sweetness index is 92 compared to 100 for cane sugar and its calories content is only 1.5 kC per gm lot of attention is being focused on this new sweetener. Though Tagatose is not produced commercially as of now, its emergence in future as a major player in low calorie foods cannot be ruled out. Here is a report on this natural sugar substitute.

"It's not quite as sweet as table sugar, but it's very close. It works well in baked goods and beverages for sweetening, but it hasn't become common yet. Besides the food industry, tagatose has caught the interest of medical researchers for a couple of reasons. One is that we don't absorb it very well. That means that we don't get as many calories from tagatose as we do from fructose or glucose — only about half as many. And if we don't absorb it, it doesn't have as much effect on our blood sugar. So it has been getting some interest for use in weight-control foods and for people with diabetes. The other effect of not being absorbed is that when it gets farther down in our gut, the friendly bacteria can use it. So some producers are trying to promote it as a prebiotic, something to help the good gut bacteria grow better. The flip side of that is that bacteria produce gas when they grow. Some people have found that eating foods sweetened with tagatose gives them gas, bloating, stomach rumbles and even diarrhea. As with many dietary fibers that are also prebiotics, the effects depend on the dose. Eat a lot and you're more likely to feel an effect than eating just a little bit. Yogurt doesn't bother most people, and neither does tagatose. It's not commonly used yet, but don't be surprised if it starts to appear in more and more foods".

Tagatose is not absorbed across the intestinal wall and hence passes into large intestine with no calorie effect in the blood. But it has been pointed out that the Tagatose molecules can be physically transported across the intestine, eventually getting into the blood though in relatively small concentrations. Without adequate safety studies and enough understanding of its metabolism once it enters the blood stream, its universal use should not be permitted. As its sweetness is only 92% that of sugar, large amounts are needed to perceive the sweetness effect and with average consumption of 75 gm of sugar by an individual Tagatose can never be an alternate sugar substitute unless its consumption at high levels is proved safe. Of course cost is another factor which may come in the way of commercializing this new sweetener. Since it has been approved as a GRAS ingredient in the US in 2001, food industry may still try it out for special applications. Probably use of Tagatose as a base for carrying other sweeteners like Aspartame, Sucralose, Stevia etc may be more feasible.  


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