Sustaining Energy

After decades of public education about nutrition and its importance to one’s health, many consumers could distinguish good carbohydrates such as dietary fi ber from the bad ones like sucrose. Coupled with the general trend towards healthier eating habits and how carbohydrate metabolism works in the body, more informed consumers are looking for good carbohydrates in the food and beverages today.

As a result, manufacturers are offering products with a range of alternative carbohydrate ingredients that claim to improve one’s metabolic balance. With alternative food ingredients such as inulin and oligofructose, many “smarter choices” products are driving consumer interest while still providing traditional expectations of taste, texture and mouthfeel.

Lasting energy
Isomaltulose, a multi-functional carbohydrate ingredient, can be used in products to enhance carbohydrate metabolism in the body. It is a low glycemic carbohydrate that provides longer lasting energy in the form of glucose.

Isomaltulose occurs naturally in small amounts in honey and sugar cane juice. It is obtained from sucrose using enzymatic rearrangement and marketed for use as a next generation carbohydrate in food and beverage applications under the brand name Palatinose.

Like sucrose, isomaltulose is a disaccharide composed of glucose and fructose. While isomaltulose has an alpha -1,6 glucosidic linkage, sucrose has an alpha-1,2 glucosidic linkage.

The different linkage gives isomaltulose characteristic physiological properties that differ largely from those of sucrose and other common sugars. It resists oral bacteria and is kind to teeth, unlike traditional sugars. It is more stable under acidic conditions, such as in the stomach or in food and beverage applications. It is also slowly hydrolyzed by intestinal enzymes, allowing a slow glucose release resulting in a low effect on blood glucose and insulin levels.

Isomaltulose has been shown to exert a positive infl uence on fat metabolism and energy release over time. It provides the human body with full carbohydrate energy over a signifi cantly longer period of time while having a low effect on the blood glucose level. Offering balanced and sustained energy, it can be regarded as a carbohydrate providing “slow calories”.

Blood glucose response
Following a meal containing carbohydrates, released monosaccharide constituents are absorbed into the blood and glucose is distributed throughout the body. This results in an increase in blood glucose concentrations after a meal with the highest level at about 30 minutes after intake, extending over one to two hours until – with the help of the hormone insulin – the blood glucose level returns to the baseline. The various digestion and absorption properties of carbohydrates are also refl ected in their blood glucose responses.

Readily available carbohydrates, such as glucose, sucrose, maltodextrins, and processed starch in white bread or boiled potatoes, have a fast and high blood glucose response. Slowly available carbohydrates like isomaltulose have a low blood glucose response. Lowdigestible and partially available carbohydrates such as polyols have a very low blood glucose response in the body. Non-digestible carbohydrates like dietary fi ber however have no blood glucose response.

Glycemic Index
Even among those that are fully available, carbohydrates can differ largely in their supply of glucose to the body, with consequences for insulin release and energy management. The Glycemic Index (GI) is a means of comparing and classifying available carbohydrates according to their blood glucose response.

According to a FAO/WHO report in 1998, GI is defi ned as the area under the blood glucose response curve of a 50g carbohydrate portion, expressed as percentage of the response of the same amount of a reference carbohydrate (typically glucose or white bread) taken by a subject. The GI of a carbohydrate is deemed to be high if it is 70 and above, medium if it is in the range of between 56 and 69, and low if it is 55 or under.

Figure 1 provides the GI values of various sugars and sweetening carbohydrates, showing that the vast majority of traditional carbohydrates are in the medium to high GI range. There are a number of factors affecting the blood glucose response in food applications and more complex food matrices of solid foods (see Table 1).

The slow release properties of isomaltulose in the small intestine are refl ected in its blood glucose response. Several blood glucose response studies showed that its intake is followed by a signifi cantly lower rise in blood glucose levels over a longer period of time in comparison to sucrose. Corresponding blood glucose fl uctuations after isomaltulose intake have lower amplitude than those from readily-available carbohydrates. In other words, glucose is supplied in a more balanced way.

Expressing the overall lower blood glucose response in numerical terms, isomaltulose has a GI of 32, as determined by Jenny Brand-Miller and her team at Sydney University in 2002, which was based on their internationally recognized methodology that uses glucose as a standard.

Isomaltulose is a low-glycemic carbohydrate under the GI classifi cation of carbohydrates. The resultant low blood glucose response is associated with a lower insulin release and less subsequent metabolic changes than readily-available, highglycemic carbohydrates.

The blood glucose response and fi ndings from other studies illustrate that isomaltulose is completely, yet very slowly, digested and absorbed in the small intestine leading to a prolonged delivery of blood glucose to the body. It is also considered as the fi rst disaccharide carbohydrate with low glycemic characteristics and delivers blood glucose over a long period of time.

Most carbohydrates provide glucose as a form of energy to the body. The way glucose is received by the body will affect the supply of energy. Glucose from carbohydrate intake is often used in preference over that from internal sources such as the mobilization of glycogen stores and via the formation from other macronutrient sources. Blood glucose can also be regarded as a biomarker for energy supply.

According to the typical blood glucose response of isomaltulose shown in Chart 1, isomaltulose provides carbohydrate energy in a slower, more gradual and balanced way, and over a longer period of time. The sustained energy release is a unique property of isomaltulose as a result of its slow yet complete intestinal release.

Formulating with isomaltulose
Studies have shown isomaltulose to be well suited for use in energy and sports beverages and nutrition, as well as in tea, beer and confectionery. With its low hygroscopicity, it is also suitable for powder products such as instant drinks.

Besides supplying energy to the body in the form of glucose, isomaltulose offers signifi cant formulating advantages such as its stability under high heat, acidity and enzymes. Unlike sucrose, isomaltulose is not easily hydrolyzed by acids, thus it is ideal for iso- and hypotonic-beverage applications.

It can also help maintain the osmolality of the fi nal product. It is stable against fermentation by most yeasts and bacteria, which can increase fi nal extract in beer production, resulting in better palatability, body and an optimized true-to-type sensorial profi le. Isomaltulose also offers antioxidative characteristics to enhance the stability of products that are sensitive to oxygen, resulting in improved shelf life.

With its unique slow energy-release properties, low effect on the blood glucose level and tooth-friendly nature, isomaltulose is a naturally derived carbohydrate that offers health-conscious consumers a low-glycaemic diet. It also offers manufacturers new formulating options for new product development.

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Crystalline Fructose Factor

A partial replacement of sucrose with crystalline fructose during formulation reduces the amount of calories and sugar in a product.

BY V V LEE, INDUSTRY MANAGER, FOOD AND DRINKS BUSINESS, DANISCO SINGAPORE

Beverage manufacturers traditionally use sucrose as the major sweetening agent in their products and as the gold standard for flavor delivery and mouthfeel. Sucrose provides sweetness, body and flavor characteristics that are not easily imitated by substitutes. However, there are now many alternative sweetener ingredients manufacturers can use to reduce sugar and maintain cost in use. These ingredients can also improve the nutritional profile of the products by reducing the amount of calories or sugar in formulations.

Fructose, a naturally occurring sugar, is sometimes referred to as fruit sugar. It is 1.4 to 1.8 times as sweet as sucrose with desirable sweetening and flavor enhancing properties. Fruit, chocolate and coffee flavors are commonly enhanced by the addition of fructose. Figure 1 illustrates the flavor enhancement effect of crystalline fructose, and sucrose/crystalline fructose combination in a cherry-flavored beverage.

Due to global supply imbalances, the prices of sucrose have been increasing steadily over the years. Although crystalline fructose is typically more expensive than sucrose on a per kilogram basis, due to its sweetness enhancing abilities, manufacturers can maintain overall cost in product formulation by substituting some of the sucrose with crystalline fructose.

Scientific evidence
A partial replacement of sucrose with crystalline fructose in a formulation is a straightforward and effective way to reduce the amount of calories and sugar in the product whilst maintaining flavor and cost in use. Recent work by Leatherhead Food research, UK, as shown in Figure 1, confirmed that crystalline fructose offers desirable sweetness synergic effects with sucrose in a beverage. The greatest synergistic effect was seen at 30% reduction of sucrose and replaced by fructose, with an increase in sweetness intensity of 45.5%.

Table 2 shows how crystalline fructose can be used at 2% with 2% sucrose in a control and 6% sucrose beverage. Through this formulation, manufacturers can achieve a similar sweetness level with, depending on local prices of sucrose, lower or at least matching cost in use, as well as lower total calories.

Crystalline fructose provides one with sustainable energy throughout the day. It is metabolized independently of insulin, which does not cause large rises or drops in blood glucose levels, according to a Journal of the American Medical Association report in 1986.

Fructose has a low glycaemic response of 19 (+/-2) compared to sucrose at 65, making it instrumental in the development of low Glycemic Index (GI) products that are suitable for diabetics. Its natural ingredient image enhances that of healthy, natural beverages such as waters, juice drinks, nectars and natural extracts like green tea. Its solubility and clarity in solution makes it ideal for clear beverage systems and powder systems. Fructose is also stable throughout production, although it partakes in the Maillard reaction when in the presence of proteins.

A careful selection of ingredients and an understanding of the nutritional benefits and technological properties of these ingredients could therefore contribute to the success of new product development.

By replacing part of the sucrose with fructose in the formulation as illustrated in this article, manufacturers can reduced the overall sugar content in their products, thereby satisfying the growing demanding for reduced calorie, low sugar and sugarfree products by health-conscious consumers in the years to come.