Whole grains provide satisfaction from the beginning to the end of the digestion process. See Table 3. Sweetness is a pleasurable sensation and some people enjoy the taste more than others. Whole grains take longer to chew and get sweeter the more you chew them. Additionally, once in the stomach, whole-grain foods take longer to digest and keep you full longer.
Remember too that they contain fiber which makes elimination much smoother. Source: Carter, J. Stein Carter. All rights reserved.
The mechanical and chemical digestion of carbohydrates begins in the mouth. Chewing, also known as mastication, crumbles the carbohydrate foods into smaller and smaller pieces. The salivary glands in the oral cavity secrete saliva that coats the food particles.
Saliva contains the enzyme, salivary amylase. This enzyme breaks the bonds between the monomeric sugar units of disaccharides, oligosaccharides, and starches. The salivary amylase breaks down amylose and amylopectin into smaller chains of glucose, called dextrins and maltose. The increased concentration of maltose in the mouth that results from the mechanical and chemical breakdown of starches in whole grains is what enhances their sweetness.
Only about five percent of starches are broken down in the mouth. This is a good thing as more glucose in the mouth would lead to more tooth decay. When carbohydrates reach the stomach no further chemical breakdown occurs because the amylase enzyme does not function in the acidic conditions of the stomach. But the mechanical breakdown is ongoing—the strong peristaltic contractions of the stomach mix the carbohydrates into the more uniform mixture of chyme. The chyme is gradually expelled into the upper part of the small intestine.
Upon entry of the chyme into the small intestine, the pancreas releases pancreatic juice through a duct. This pancreatic juice contains the enzyme, pancreatic amylase, which starts again the breakdown of dextrins into shorter and shorter carbohydrate chains.
Additionally, enzymes are secreted by the intestinal cells that line the villi. These enzymes, known collectively as disaccharides, are sucrase, maltase, and lactase. Sucrase breaks sucrose into glucose and fructose molecules. Maltase breaks the bond between the two glucose units of maltose, and lactase breaks the bond between galactose and glucose.
Once carbohydrates are chemically broken down into single sugar units they are then transported into the inside of intestinal cells. When people do not have enough of the enzyme lactase, lactose is not sufficiently broken down resulting in a condition called lactose intolerance. The undigested lactose moves to the large intestine where bacteria are able to digest it. The bacterial digestion of lactose produces gases leading to symptoms of diarrhea, bloating, and abdominal cramps.
Lactose intolerance usually occurs in adults and is associated with race. Most people with lactose intolerance can tolerate some amount of dairy products in their diet. Saliva contains the enzyme, salivary amylase. This enzyme breaks the bonds between the monomeric sugar units of disaccharides, oligosaccharides, and starches.
The salivary amylase breaks down amylose and amylopectin into smaller chains of glucose, called dextrins and maltose. The increased concentration of maltose in the mouth that results from the mechanical and chemical breakdown of starches in whole grains is what enhances their sweetness.
Only about five percent of starches are broken down in the mouth. This is a good thing as more glucose in the mouth would lead to more tooth decay. When carbohydrates reach the stomach no further chemical breakdown occurs because the amylase enzyme does not function in the acidic conditions of the stomach.
But mechanical breakdown is ongoing—the strong peristaltic contractions of the stomach mix the carbohydrates into the more uniform mixture of chyme. The chyme is gradually expelled into the upper part of the small intestine. Upon entry of the chyme into the small intestine, the pancreas releases pancreatic juice through a duct.
This pancreatic juice contains the enzyme, pancreatic amylase, which starts again the breakdown of dextrins into shorter and shorter carbohydrate chains.
Additionally, enzymes are secreted by the intestinal cells that line the villi. These enzymes, known collectively as disaccharidase, are sucrase, maltase, and lactase. Sucrase breaks sucrose into glucose and fructose molecules. Maltase breaks the bond between the two glucose units of maltose, and lactase breaks the bond between galactose and glucose. Once carbohydrates are chemically broken down into single sugar units they are then transported into the inside of intestinal cells.
When people do not have enough of the enzyme lactase, lactose is not sufficiently broken down resulting in a condition called lactose intolerance. The undigested lactose moves to the large intestine where bacteria are able to digest it. The bacterial digestion of lactose produces gases leading to symptoms of diarrhea, bloating, and abdominal cramps. Lactose intolerance usually occurs in adults and is associated with race. The severity of the symptoms depends on how much lactose is consumed and the degree of lactase deficiency.
Carbohydrates that were not digested and absorbed by the small intestine reach the colon where they are partly broken down by intestinal bacteria. Fiber, which cannot be digested like other carbohydrates, is excreted with feces or partly digested by the intestinal bacteria.
She works to help others find happiness in health in her career as a health coach and yoga instructor. What Are the Steps to Digestion for Carbohydrates? Healthy Eating Diet Digestion. Use of Dietary Carbohydrates as Energy. Glucose is the primary energy source of the body.
Major dietary sources of glucose include starches and sugars. Digestion of Carbohydrates. The digestion and absorption of dietary carbohydrates can be influenced by many factors. Absorption of Carbohydrates. Absorbed carbohydrate molecules are used immediately for energy or stored in various forms in the muscles, liver or adipose tissue for future use.
Use of Dietary Carbohydrates as Energy Dietary carbohydrates include starches, sugars and fibre that are mostly found in grain products, vegetables and fruit, milk products, and meat alternatives such as nuts, seeds, and legumes 1, 2.
Muscles use glucose for energy, especially during high-intensity exercise. Absorption of Carbohydrates The end products of sugars and starches digestion are the monosaccharides glucose, fructose, and galactose.
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