Dietary fibre is widely distributed in plants and consumed as food which are not fully or rapidly digested or absorbed in upper gastrointestinal tract (Schultz, 2011).
They are chemically consisting of cellulose, noncellulosic polysaccharides, and lignin. Cellulose is a non-soluble crystalline linear polymer with up to 10,000 of 1-4 β glucose units (Kay, 1982) and it serves as functional fibre when added to food (Gropper, Smith & Groff, 2009). Foods contain high cellulose include bran, nuts, apples, root vegetables and cabbages (Gropper, Smith & Groff, 2009). Figure # 1 shows chemical compositions of cellulose.
(Image from Advanced nutrition and human metabolism)
Noncellulosic polysaccharides are the mixture of pentoses, hexoses, and uronic acids (Kay, 1982). The major noncellulosic polysaccharides are hemicellulose and pectic substances. Hemicellulose (Figure # 2) is made of backbone of numbers of different β-1, 4 linked sugars, for instance xylose, mannose, and galactose, and side chain and usually appears in branched form (Gropper, Smith & Groff, 2009). Hemicellulose is normally smaller than cellulose and more soluble in water (Kay, 1982). Food sources for hemicellulose are bran, whole grains, nuts and legumes (Gropper, Smith & Groff, 2009).
(Image from Advanced nutrition and human metabolism)
Pectic substances are generally water-soluble plant cell wall components and comprised of un-branched axial-axiala-(1→4)-linked D-galacturonic acid units (Kay, 1982). Apples, strawberries, citrus fruits, nuts and legumes are considered as good sources for pectin (Gropper, Smith & Groff, 2009).
(Image from Advanced nutrition and human metabolism)
Lignin is a random 3-demensional polymer containing about 40 oxygenated phenylpropane units (Kay, 1982; Gropper, Smith & Groff, 2009). Lignin is composed of coniferyl, p-coumaryl, and sinapyl alcohols in varying ratios in different plant species (Mora et al, n.d.). Strong intramolecular bonding provides lignin great resistance against digestion. Mature root vegetables, for instance carrot, strawberries, wheat consist of high lignin (Gropper, Smith & Groff, 2009).
Human enzymes, like amylase, maltose, sucrose, and lactase, are designed to breakdown carbohydrates into monosaccharaides. Only D-isomeric saccharides with α-1:4 glycosidic bonds can be digested in upper gastrointestinal tract. Whereas, saccharides with β-glycosidic, α-1:2 and α-1:6 bonds and L-glucose isomers, which are considered as inactive saccharides, will not be broken down into monosaccharaides in human bodies (Shultz, 2011). According to Schultz (2011), dietary fibres are categorized into five types based on different chemical structures, which are resistant and slowly-digested starch, non-starch polysaccharides, non-digestible oligo-saccharides, sugar alcohols, non-digestible carbohydrate compounds chemically bound to noncarbohydrate molecules (Schultz, 2011).
== Amylase is an enzyme found in our bodies, which digest starch into
Starch, cellulose, glycogen, and chitin are all examples of polysaccharides. According to the BIO 1510 Lab Manual (2016) polysaccharides are not very soluble in water but can be made to go into solution through heating or agitation. Polysaccharides are excellent energy storage molecules because they are easily built and broken down by enzymes. Forming fairly compact structures, polysaccharides allow energy storage without the space required by a pool of free glucose monomers. Other polysaccharides form strong fibers that provide protection and structural support in both plants and animals. (Carbohydrates.” Home,
All monosaccharides are reducing sugars because they all aldehydes. Different monosaccharides contain different number of carbon atoms. There are three types of monosaccharides, trioses, pentose and hexose. They generally contain three (trioses), five (pentoses) or six (hexoses) carbon atoms. Triose is used as a product in biochemical pathways of respiration and photosynthesis.
Gut microbiota plays an important role in human metabolism. The important sources of energy for human and microbial cells are carbohydrates. Most complex carbohydrates and plant polysaccharides, such as cellulose, xylans, resistance starch and inulin cannot be digested by the human enzymes. The gut micro...
Cellulases are o- glycosyl hydrolases (GHs) that hydrolyse β-1,4 glucosidic bonds in cellulose. Cellulase system is grouped into “glycoside hydrolases (GH) family” classified by different means, according to their substrate specifities, reaction, mechanisms or structural similarities. The cellulase complex is found to contain three basic components which may be present either as single polypeptide or can be grouped together into multienzyme complex known as cellulosome. Cellulase system is composed of three main classes based on their activity toward a wide range of substrates. This is rather difficult, since the enzymes have overlapping specificities toward substrates which themselves are poorly defined. The three main classes are:
Fructose- is also a monosaccharide and also the sweetest natural sugar. It’s found in fruits and honey.
arg.gov.sk.ca - arg.gov.sk.ca - arg.gov.sk.ca - arg.gov.sk.ca - arg.gov Carbohydrates supply 80-90% of dietary energy. Sugars, starch, cellulose and related substances are carbohydrates. Starch is more easily digested than cellulose. Grains are easy to digest as they are 60-80% starch. A recent study conducted by Sharon R. Bullimore et al.
The beginning process of digestion starts as pizza enters the gastrointestinal tract through the mouth, where the oral cavities begin mechanically breaking down pizza by the cutting, ripping, and grinding actions of the teeth. As the pizza breaks down it is mixed with saliva; salvia contains salivary amylase, this converts the starches in carbohydrates into simple sugars. Therefore, as your saliva and rolling motion of the tongue turns the pizza into a soft, pliable ball called a bolus. As the bolus slides down into your throat (pharynx), this allows for you to swallow. Within the occurrence through the breakdown of complex molecules into a simpler one just took place, which is the chemical digestion accomplished by enzymes.
Enzymes are proteins that help speed up chemical reactions. Some enzymes associated with carbohydrate breakdown are sucrose, lactose, maltase, and amylase. They aid in turning carbohydrate into glucose. The body uses glucose for energy, especially within the cells. Lipids or fats must be emulsified by bile found in the liver, and will be broken down into fatty acids and glycerol, and the body is able to absorb them. The enzyme associated with lipid breakdown is lipase. Protein that is ingested use the enzymes proteases and peptidases to help break up the protein and make amino acids in the
Provide muscle energy, fuel for the nerve system, the fat metabolism and protect the protein to been used as energy
Janick. J. (2011). Center for New Crops & Plant Products - Department of Horticulture and
Glucose, fructose, and galactose are examples of single or simple sugar molecules or monosaccharides. Maltose, sucrose, and lactose are examples of two sugar molecules linked, also known as disaccharides. Starch, glycogen, and cellulose are examples of many sugar molecules linked. They are also called polysaccharides. If you wanted to test if there were carbohydrates in something, you could do the sugar or the starch test.
Tannins, a natural compound produced by many plants, have become a common topic when discussing various beverages and fruits, yet the truth is that tannins are compounds that can be found in most all plants and have a much more involved significance than astringent taste. Tannins are a type of plant product that is classified as a polyphenol (Cornell University 2014). Polyphenols, also referred to as phenolic compounds, can have a high molecular weight due to the attachment of one or many hydroxyl groups to an aromatic ring structure (Balasundram 2006). Phenolic compounds can commonly be found connected to single and complex sugars within plants (Balasundram 2006). There is a vast diversity within the plant polyphenols as related to composition, yet polyphenols are categorized into 12 different classes based on structure (Balasundram 2006). Tannins along with
Milk and milk products are the only foods derived from animals that contain a significant amount of carbohydrates. Carbohydrates are divided into two groups, simple carbohydrates and complex carbohydrates. Simple carbohydrates, sometimes called simple sugars, include fructose (fruit sugar), sucrose (table sugar), and lactose (milk sugar), as well as several other sugars. Fruits are one of the richest natural sources of simple carbohydrates. Complex carbohydrates are also made up of sugars, but the sugar molecules are strung together to form longer, more complex chains.
Carbohydrate is a molecule that is made up of carbon, hydrogen, and oxygen. Carbohydrates are sugar molecules and are classified by how many sugar molecules they contain. In this article, it talks about two main carbs, Simple carbs, and Complex carbs. Simple carbs are referred to as sugars which are single sugar molecules called monosaccharides or two monosaccharides joined together called disaccharides. Two common monosaccharides are glucose and fructose. While sucrose and lactose are two common disaccharides. Complex carbs contain two or more sugar molecules chains that are called oligosaccharides. Chains of more than ten monosaccharides linked together are called polysaccharides.