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Food Classification 2 Good Day, Without further ado, let's continue with the process of digestion. Digestive speed & efficiency vary with individuals and circumstances. However, certain general statements can be made. Fruits pass through the stomach quickly; low protein and low starch vegetables also pass through the stomach rapidly, with little change; vegetables containing much starch must be retained in the stomach longer, for more thorough digestion; and proteins require a still longer time for gastric digestion. Fruits may remain in the stomach for 30 to 60 minutes, low proteins and low starch vegetables a little longer, concentrated starches about 2 hours and concentrated proteins approximately 4 hours. Some foods may take 5 to 6 hours or more to leave the stomach. Some examples are combination starch/protein foods like legumes, beans, grains, cooked cabbage and flesh foods. Most digestion occurs in the stomach and small intestine. Digestion, especially starch digestion, actually begins in the mouth, with mastication and insalivation of the food. This sends the proper signals for the release for the release of the digestive juices suited to the character of the food eaten. Digestive juices are present in the saliva and in the gastric secretions of about 5 million microscopic glands in the wall of the stomach. The digestive glands supply different enzymes and juices of varied strength and character and with specific timing, depending on the different foods ingested. After food is masticated, insalivated and swallowed, gastric digestion is initiated. Involuntary movements of the stomach slowly mix the food with gastric juices secreted by the glands in the walls of the stomach. Pepsin, a protein-splitting enzyme, and hydrochloric acid are separated, as well as lipase, a fat-splitting enzyme, mucus, and diluting juice, along with other factors needed in the digestive process. An alkaline secretion protects the walls of the stomach from the acids. Mucus is a natural lubricant that is secreted by the cells of the mucus membranes lining all the hollow organs of the body. It keeps the body tissues moist and prevents them from drying and cracking. Gastric secretion is continuous (except during fevers, gastric inflammation, pain and strong emotions and therefore fasting is indicated). Hunger and the sight, smell taste or thought of food stimulate gastric secretion. Usually about 1.5 liter of gastric juices is secreted every 24 hours and about half this amount is needed to digest a hearty meal. If you eat more than 2 hearty meals daily, your account will be overdrawn. As the process of digestion continues in the stomach and the food is mixed with the gastric juices, water (from the body's reserve supply) is added to the mixture in a process known called hydrolysis. During hydrolysis, digestive enzymes separate carbohydrates into simple sugars, and proteins into their constituent amino acids. Since digestion is a mechanical as well as chemical process, some cellulose is an important part of the diet. Although humans cannot digest cellulose, it serves as bulk in the propulsion of food through the digestive tract. Cellulose also provides the bulk needed in the efficient elimination of food residues. Juices and refined foods contain little cellulose. Food residues, fibrous materials and particles not thoroughly masticated proceed on to the colon. Peristalsis (wave-like muscular contractions) propels the food mixture back and forth in the stomach. Periodically, the most liquid portion of the mixture is discharged into the duodenum where it meets a very acid fluid. The resulting semi-liquid mixture, known as chyme, then proceeds further -into the small intestine- where it meets a very alkaline mixture consisting of pancreatic juice, additional digestive enzymes and bile ( for the emulsifying of fats ). The intestinal glands secrete a juice containing enzymes similar to pancreatic enzymes. Virtually all absorption should occur by the time the food passes through the small intestine, and the residue proceeds into the large intestine ( the colon ). Digestion is governed by physiological chemistry, and this must be considered in the planning of meals that are compatible with the physiological limitations of the digestive glands and their secretions. Until then, stay well and take care, The Crazy Nut Team