Fats and Oils PDF

Fats and Oils RONNA T. SAMILLANO, RM, RN, LPT, MAEd Assistant Professor II Fats and Oil 1. Saturated and Unsaturated Fatty Acids 2. Structures of Fatty Acids 3. Characteristics of Fats and Oils 4. Lipid-related diseases Fatty Acids are key building blocks of lipids, essential for energy storag...

Fats and Oils RONNA T. SAMILLANO, RM, RN, LPT, MAEd Assistant Professor II Fats and Oil 1. Saturated and Unsaturated Fatty Acids 2. Structures of Fatty Acids 3. Characteristics of Fats and Oils 4. Lipid-related diseases Fatty Acids are key building blocks of lipids, essential for energy storage, structural function, and signaling in biological systems are carboxylic acids with long hydrocarbon chains they are classified as saturated or unsaturated based on the presence of double bonds Classification of Fatty Acids Saturated FA Unsaturated FA Contain no double bonds in their Contain one or more double hydrocarbon chain. bonds. They are typically solid at room They are usually liquid at room temperature and are found in temperature and found in plant animal fats and some plant oils oils and fatty fish. (e.g., coconut oil). Monounsaturated Fatty Acids Example: Stearic acid (C18H36O2) (MUFA): One double bond (e.g., Oleic acid).Polyunsaturated Fatty Acids (PUFA): Multiple double bonds (e.g., Linoleic acid, Omega- 3, and Omega-6 fatty acids). Health Implications Saturated FA Unsaturated FA may contribute to increased are considered healthier, LDL cholesterol levels, leading improving HDL cholesterol to cardiovascular diseases. levels and reducing heart disease risks Structures of Fatty Acids Fatty acids have two main parts: Hydrocarbon Chain: Hydrophobic, determines the length and saturation level. Carboxyl Group (-COOH): Hydrophilic, responsible for fatty acid reactivity. Structure Saturated FA Unsaturated FA A straight chain due to single Cis Configuration: Naturally bonds. occurring, kinked structure due to double bonds. Trans Configuration: Found in partially hydrogenated oils, linear and unhealthy. Characteristics of Fats and Oil Physical State ▪ Fats are solid at room temperature, primarily from animal sources. ▪ Oils are liquid at room temperature, mainly from plant sources. Chemical Properties Hydrolysis – Breakdown into glycerol and fatty acids. Oxidation – Unsaturated fats are prone to rancidity due to exposure to oxygen. Hydrogenation – Converts unsaturated oils to saturated fats (e.g., margarine production). Nutritional Role Provide energy (9 kcal/gram). Essential fatty acids (e.g., linoleic acid) are precursors for prostaglandins and play structural roles in cell membranes. Storage Fats are stored as triglycerides in adipose tissue. Oils are commonly used in cooking and as dietary supplements. Lipid Related Diseases Cardiovascular Diseases (CVD) Atherosclerosis – Accumulation of fatty plaques in arterial walls due to high LDL cholesterol Prevention: Consume unsaturated fats and limit saturated and trans fats. Include Omega-3 fatty acids (found in fish) to reduce triglyceride levels and prevent clot formation. Obesity Results from an imbalance between calorie intake and expenditure. High-fat diets are energy- dense, leading to excessive calorie consumption. Diabetes Mellitus Saturated and trans fats may impair insulin sensitivity. Prevention: Opt for unsaturated fats, which improve glucose metabolism. Lipid Metabolism Disorders Hyperlipidemia Fatty Liver Disease  Neurodegenerative Diseases Lack of Omega-3 fatty acids is linked to impaired cognitive function and neurodegenerative conditions like Alzheimer’s disease. Bile Salts RONNA T. SAMILLANO, RM, RN, LPT, MAEd Assistant Professor II Bile Salts Structure are amphipathic molecules derived from cholesterol in the liver and conjugated with glycine or taurine to enhance their solubility in water. Hydrophobic (lipid-soluble) side: Binds to fats. Hydrophilic (water-soluble) side: Interacts with the aqueous environment. Bile Salts Synthesis and Storage Produced in the liver and stored in the gallbladder as part of bile. Released into the duodenum via the bile duct during digestion. Bile Salts Functions Act as detergents to emulsify dietary fats. Form micelles, facilitating the absorption of fat-soluble vitamins (A, D, E, K) and fatty acids. Aid in the elimination of cholesterol by excreting it in bile. Role of Bile in Digestion Bile Bile is a yellow-green fluid composed of bile salts, bile pigments (e.g., bilirubin), cholesterol, phospholipids (e.g., lecithin), water, and electrolytes. Regulation: The release of bile is triggered by the hormone cholecystokinin (CCK), secreted in response to fat presence in the small intestine. Bile Function in Fat Digestion Emulsification – Breaks large fat globules into smaller droplets, increasing the surface area for lipase action. Micelle Formation – Encapsulates fatty acids, monoglycerides, and cholesterol, allowing them to cross the intestinal mucosa. Waste Removal – Excretes excess cholesterol, bilirubin (a breakdown product of hemoglobin), and other waste products. Enzymes in Digestion Lingual Lipase Secreted by glands in the tongue. Begins fat digestion in the mouth and stomach (minor role). Gastric Lipase Secreted by the chief cells of the stomach. Functions in acidic environments (pH 3–6) to break down short- and medium-chain triglycerides. Pancreatic Lipase Secreted by the pancreas into the small intestine (major role in fat digestion). Requires bile salts and colipase (a coenzyme) for activation. Hydrolyzes triglycerides into monoglycerides and free fatty acids. Phospholipase A2 Acts on phospholipids (e.g., lecithin) to release fatty acids and lysophospholipids. Cholesterol Esterase Hydrolyzes cholesterol esters into free cholesterol and fatty acids for absorption. Emulsification of Fats Emulsification Emulsification is the process of breaking large fat globules into smaller, stable droplets to increase their surface area for enzyme action. Emulsification Mechanism 1. Bile Salts Action 2. Mechanical Action 3. Formation of Emulsion 4. Micelle Formation 5. Absorption Emulsification Mechanism Bile Salts Action Bile salts bind to fat globules with their hydrophobic side while their hydrophilic side interacts with water, stabilizing smaller droplets. Emulsification Mechanism Mechanical Action Peristalsis in the intestine aids in physically breaking down fat globules. Emulsification Mechanism Formation of Emulsion The combination of bile salts and intestinal motility creates a fine suspension of fat droplets. Emulsification Mechanism Micelle Formation After enzymatic digestion by lipases, bile salts and phospholipids form micelles that encapsulate monoglycerides, free fatty acids, and fat-soluble vitamins. Emulsification Mechanism Absorption Micelles deliver their contents to the intestinal epithelium for absorption, leaving bile salts behind in the lumen to be recycled via enterohepatic circulation.  Key Processes in Fat Digestion and Absorption 3. Cholesterol and 1. Fat Digestion 2. Absorption Fat-Soluble Vitamins Begins in the stomach Micelles transport digested Incorporated into with gastric lipase. fats to the brush border of micelles for efficient Most digestion occurs enterocytes. absorption. in the small intestine Inside the enterocytes: with pancreatic lipase, Fatty acids and aided by bile. monoglycerides are re- esterified into triglycerides. Triglycerides are packaged into chylomicrons and transported via the lymphatic system into the bloodstream. Clinical Relevance Cholelithiasis Imbalance in bile composition (e.g., excess cholesterol) can form stones, impairing bile flow and fat digestion. Pancreatic Insufficiency Reduced secretion of pancreatic lipase leads to fat malabsorption (steatorrhea). Bile Salt Deficirncy Can result from liver disease or intestinal disorders, causing poor fat emulsification and absorption. References Gropper, S. S., Smith, J. L., & Carr, T. P. (2018). Advanced Nutrition and Human Metabolism. Cengage Learning. Nelson, D. L., & Cox, M. M. (2017). Lehninger Principles of Biochemistry. W. H. Freeman. Martin, C. A., & Schmid, H. (2021). Fats and Fatty Acids: Chemistry and Function. Springer. American Heart Association. (2023). "Fats and Heart Health." heart.org World Health Organization (WHO). (2022). "Lipid-related Diseases and Prevention Strategies.” Google photos Bring the following tomorrow: Bile salt (from fish gal bladder) Margarine Vegetable oil Salt solution