Introduction
Soluble dietary fiber (SDF) plays a pivotal role in the formulation of functional foods, offering numerous health benefits. Unlike insoluble fiber, SDF dissolves in water to form a gel-like substance, making it versatile for various food applications. It supports gut health, regulates blood sugar levels, lowers cholesterol, and enhances satiety, aligning with modern dietary goals. This introduction explores the types of SDF, their unique properties, and how they are leveraged to create functional foods that promote overall well-being.
What Is the Use of Soluble Fiber in the Food Industry?
The scientific interest in dietary fiber and its role in modern-day nutrition and the improvement of global health at a community level is one of the key cornerstones in present-day nutrition medicine. The intake of both soluble and insoluble dietary fiber is not only associated with a remarkable number of nutritional and health benefits but is also valued for its potential applications in the food industry. Dietary fiber is integral to the establishment and production of commercial functional foods aimed at enhancing public health on a community level. Indeed, the role of dietary fiber has significantly evolved in nutrition science over the last few decades.
So, what are the main dietary sources of fiber that sustain individual health? These food groups range from fresh or frozen fruits and vegetables to whole grain cereals, legumes, etc. Soluble fiber (SDF) holds an important place in the food industry because, upon hydration, it forms an easy viscous colloidal dispersion or gel matrix. Furthermore, being hydrophilic, non-crystalline, and readily absorbable by gastrointestinal fluids, SDF is frequently utilized in the food sector. These molecular characteristics enable SDF to alter the texture of functional foods and improve their functional properties, making it essential in boosting public health and immunity at a community level.
What about artificial sources of dietary fiber used in functional food production? These include polydextrose, hydroxypropyl methylcellulose, cyclodextrins, etc. In this article, let us particularly focus on the various sources of soluble fiber (also called soluble dietary fiber or SDF), their role in functional foods, and their composition from a nutritional perspective.
What Makes Soluble Dietary Fiber Unique?
It is to be firstly noted that there are various constituents of dietary fiber, ranging from pectins, arabinoxylans, and β-glucans, that have received a lot of nutritional highlighting or endorsements for public functional health food production. However, it is also important for consumers, current-day nutrition experts, and healthcare professionals to be aware of the health benefits of both soluble and insoluble dietary fiber sources.
From a nutritional perspective, foods that comprise a higher soluble fiber content tend to be more fully fermented and also score a higher viscosity content compared to foods with greater amounts of insoluble fibers. It need not, however, be the case that all soluble fibers are viscous. There are exceptions, such as partially hydrolyzed guar gum and acacia gum, for instance. There are also exceptions to these properties in some insoluble fibers that are well fermented. However, as a general rule of thumb, and based on the solubility of the fiber, dietary fiber is categorized mainly into two groups:
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Soluble dietary fiber (SDF), molecularly comprising non-cellulosic polysaccharides for instance, non-digestible oligosaccharides, arabinoxylans (AX), β-glucans, pectins, gums, mucilages, inulin, etc.
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Insoluble dietary fiber (IDF), on the other hand, is found in plant foods that are primarily composed of cell wall components that are hard to break down.
What Are the Different Varieties of SDF Used for Functional Food Production?
Let us look at the different types of SDF-containing foods:
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Guar Gum: This is a soluble fiber most often used as a thickening agent for functional food, primarily derived from guar beans. Numerous research studies have clearly demonstrated the overall benefits associated with guar gum, such as its ability to boost food satiety and improve digestibility. Additionally, the gum is also utilized for thickening and stabilizing various commercial food and industrial products.
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Xanthan Gum: This is a soluble fiber food source mainly added to enhance food texture, particularly benefiting individuals with gluten allergies. It can be used in baking products without gluten. The bacterium Xanthomonas campestris is responsible for producing xanthan gum, a major soluble fiber polysaccharide source for functional foods.
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Beta-Glucans: These are one of the important food sources of soluble fiber, commonly found in oats, barley, and certain medicinal mushrooms, known for their cholesterol-lowering properties and immune-boosting benefits. β-glucan is, in fact, one of the common substances yielded from the cell wall of Saccharomyces cerevisiae, the yeast primarily used for baking purposes. β-glucan, as a polysaccharide, exerts a hypocholesterolemic effect, making it a useful SDF source in functional foods due to its regulated molecular weight and high water solubility.
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Inulin: This is mainly a prebiotic fiber source that offers both physiological benefits and functional advantages in the food industry, particularly for producing commercial products targeted at heart health. Sourced from foods like chicory root, garlic, and onions, which commonly contain inulin, this prebiotic fiber boosts gastrointestinal health by feeding beneficial gut bacteria. These healthy oligosaccharides are extensively studied for their application in producing low-calorie, physiologically beneficial, and cardioprotective functional foods.
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Pectin: Pectin is the primary soluble dietary fiber source commonly found in the primary cell walls and intercellular tissues of most terrestrial plants. It plays dual roles as a hydrating and cementing agent in functional food production. Pectin is extensively studied for its heterogeneous and heteropolysaccharide molecular structure, with various extraction methods and sources for use in functional foods.
Conclusion
According to the Dietary Guidelines for Americans, adults are encouraged to consume approximately 1.5 to 2.5 cups of dietary fiber daily, derived from a variety of food sources. This recommendation includes a combination of at least one cup of fruit and two to four cups of vegetables, with the exact amount depending on factors such as age and sex. Commercially available functional foods containing both soluble and insoluble fiber are considered excellent for promoting overall health.
Whether it is fruits, vegetables, whole grains, nuts, seeds, plant-based proteins, animal proteins, or dairy products, it is crucial to incorporate a diverse range of fiber-rich foods into your diet. Both soluble and insoluble fiber play vital roles in supporting optimal health. Soluble fiber aids in digestion, regulates blood sugar levels, and lowers cholesterol, while insoluble fiber promotes regular bowel movements and maintains gut health. Including a variety of these fibers in your daily meals ensures a balanced and nutritious diet for long-term well-being.
