Applications of Slowly Digestible Starch (SDS)

As a new functional component or ingredient in novel product development, Slowly Digestible Starch (SDS) can be widely used in solid or liquid processed food products, nutritional supplements, and drug preparations (tablets, emulsions, and suspensions). The amount of SDS added is selected to confer the desired functional properties, digestibility, and glucose release rate or some desirable balance of these parameters.

Applications in Foods

A wide range of techniques is used by the food industry to process various food materials. Processing changes the food structure and also influences the nutritional characteristics of the food, including its starch digestibility. Slowly Digestible Starch (SDS) can be added to many food products in the form of a powdered ingredient to help control energy release, including in cakes, bread, cookies, pastries, pasta, pizza, cereals, chips, fries, candy, muesli, dressings, fillings, icing, sauces, syrups, soups, gravies, puddings, custards, cheese, yogurts, creams, beverages, dietary supplements, and diabetic products.

Oral glucose can be taken before prolonged vigorous exercise to increase endurance and to avoid the exhaustion associated with endurance sporting activities. SDS products, which can extend glucose release, may therefore provide athletes with necessary energy.

High-fat foods contain more calories than low-fat foods, and in light of the epidemiological link between fat intake and health, they increase health risks. The caloric content of fat is higher than that of carbohydrates, and the replacement of fats in typical foods with carbohydrates should reduce the calorie-associated health hazards. Several essential requirements must be considered when carbohydrates are used as fat replacements in food, such as their unique flavors, mouthfeel, viscosity, and other functional and organoleptic properties.

Most SDSs that contain linear short chains are fat-like carbohydrates and may effectively replace one or more fats in foods. These starches are either partially or totally undigested and therefore contribute zero calories to food. Some SDSs provide a variety of fat-like textures in aqueous dispersions, ranging from oily to creamy to waxy. These fat replacements offer significant advantages in food applications, including the high-strength gels or thermo-reversible gels provided by SDS dispersions.

Microencapsulation is often used to preserve food components that are volatile or sensitive to oxidation, light, or temperature. Park et al. used this method to preserve some heat-sensitive SDSs and RSs. They encapsulated native and amylosucrase-treated waxy cornstarches with three different concentrations of sodium alginate: 0.5%, 0.7%, or 1.0%. The SDS and RS fractions constituted 57.5% and 97.7% of the encapsulated starch, respectively. After cooking, the proportions of these fractions still ranged from 55.7% to 96.1%, depending on the type of starch and the concentration of sodium alginate added, whereas the unencapsulated starch contained between 2.9% and 48.3% SDS and RS after cooking. Therefore, replacing amylosucrase-treated waxy cornstarch with an encapsulated form allowed the development of new products with high SDS levels and different functional properties.

Functional Foods

A new slow-digesting rice starch (Ricemic) has been developed at the US Department of Agriculture (USDA) Southern Regional Research Center and is used to maintain stable blood sugar levels in diabetics and to provide athletes with a steady energy supply to maintain their endurance.

Starch-based cereal foods and whole kernel foods have been developed with low GIs and high Slowly Digestible Starch (SDS) loads. For example, EDP® (“energy delivered progressively”) can be found in both European and Chinese markets.

Slow-Release Energy Beverages

The satiating power of foods is related to their energy and volume and might also be related to their fiber content. The Institute of Medicine (Kathmandu, Nepal) defined dietary fiber as those indigestible or weakly digestible carbohydrates that occur naturally in plants, so Slowly Digestible Starch (SDS) can be considered a kind of dietary fiber. The addition of fiber to foods and beverages can provide volume and reduce the energy density of the food and can increase the viscosity of liquid or semiliquid foods. Both dietary and functional fibers have been shown to promote physiological processes that are associated with satiety. For example, fiber can slow gastric emptying, reduce the GI of foods, modify the release of gastrointestinal hormones, and alter the absorption of other nutrients.

Jolly-Zarrouk et al. investigated extended energy beverages containing a high level of SDS (1.5%) prepared with a hydrothermal treatment (35% moisture, 100°C for 60 min), such as Milo®, Nesquik®, and Migros®.

Applications in Medicine

Starch, a natural carbohydrate polymer, is cheap, abundant, and renewable, and its biodegradability, biocompatibility, and bio absorbability make it suitable for pharmaceutical applications. Starch can be thoroughly absorbed by the human body without any allergic or toxic effects. The interactions between the functional groups in the starch matrix and those in other compounds strengthen the capacity of starch to bind and entrap wide ranges of hydrophilic and hydrophobic compounds. In contrast to lipid- or protein-based carriers, starch-based delivery systems provide a better protective shell for bioactive compounds at high processing temperatures because they are thermally stable. These advantages of starch materials, together with the diversity of starch modifications, make starch and its derivatives ideal candidates for use in drug delivery, tissue engineering, and wound dressing.

Recent studies have focused on the modification of starch for its use in drug delivery systems. For instance, starch nanoparticles synthesized from cornstarch (modified and unmodified) have been used to formulate two different types of nanoparticles used in drug delivery systems.

Given the characteristics of the enzymatic digestion that occurs in the upper gastrointestinal tract, Slowly Digestible Starch (SDS) can be used in medicines as a novel, starch-based biodegradable carrier, which may prove useful in oral drug delivery systems that specifically target the small intestine. For example, SDS can be used as a biomacromolecular film to coat pharmaceuticals to ensure that the medicines are released in the small intestine. SDS can also be used for the treatment of certain medical modalities. Wolf and Bauer reported its utility in treating glycogen storage disease and diabetes mellitus.

Application to Fodder

Starch is the main source of energy in poultry diets, comprising approximately 40% of the diet and contributing more than half of the metabolizable energy intake. Therefore, variations in starch digestibility strongly affect the energy value of poultry diets. Despite this, starch digestion in poultry has received little attention until recently because it is seldom a problem in poultry fed a corn-based diet. Several studies have indicated that the starch in corn is almost completely digested by broiler chickens. The secretion of pancreatic amylase by chickens also increases as their ingestion of starch increases. However, accumulating evidence suggests that starch is not fully digested by poultry and that its digestibility varies considerably among cereal species and cultivars within those species. Therefore, the factors that reduce starch digestibility in the total gastrointestinal tract or the ileum in poultry are critically relevant to the development of practical feed formulations.

Perhaps the most important factor affecting starch digestibility in poultry, at the total gastrointestinal tract or ileal level, is the accessibility to the starch fraction by digestive enzymes. This accessibility is determined by several factors, including granule size, shape, and surface area and the amylose-to-amylopectin ratio. Briefly, the lower susceptibility of large granule starches to enzymatic hydrolysis has been attributed to their smaller granule-specific surface area, which may reduce the extent of enzyme binding and ultimately result in less hydrolysis than small granules.

Its excellent properties make Slowly Digestible Starch (SDS) a suitable feedstuff or fodder material. Based on a patent of Winowiski, feed for ruminants that is rich in SDS may reduce the rate of digestion by rumen microbes, thereby reducing the effect that the rapid consumption of fermentable grains can have on the rumen pH and the digestion of fiber. This may provide a more even flow of fermentable starch to support microbial metabolism and may increase the proportion of starch from cereal grain consumption that ultimately arrives in the small intestine.

The consumption of SDS improves protein and energy utilization in broiler chickens, including superior feed conversion at the amino acid level. The results of Weurding et al. suggest that the starch digestion rate is an important feed characteristic in broiler chickens. Broiler chickens grew faster and more efficiently on a diet containing SDS than on a diet containing RDS.

Leave a Reply

Your email address will not be published. Required fields are marked *