Fats and Oils Structure Structure  Triglyceride—3 fatty acids attached to a glycerol backbone  Various fatty acids within the TG

Fats and Oils Types Types  Solid fats  Straight chain fatty acids  Saturated or trans fatty acids  Fat crystals suspended in oil  Liquid fats (oils)  Contain kinked chain fatty acids  Mono- or polyunsaturated fatty acids  No fat crystals

Fats and Oils Melting temperature is directly proportional to degree of saturation Melting temperature is directly proportional to degree of saturation   saturation (less double bonds) = higher melting point   saturation (more double bonds) = lower melting point

Fats and Oils Essential fatty acids Essential fatty acids  Linolenic and Linoleic acids  Excellent source of vitamin E  Combats rancidity (free radical scavenger)  Varies in amounts by: Type of plant used for pressingType of plant used for pressing Refining processRefining process  Preserved by storing in cool, dark place  Degraded by overheating

Fats and Oils Influences on texture (mouth-feel) and flavor Influences on texture (mouth-feel) and flavor  Types of fatty acids present and their corresponding chain lengths  Degree of saturation (thus melting temp.)  Degree of refinement (flavor components removed)

Fats and Oils Smokepoint Smokepoint  Involves chemical degradation of glycerol molecule  Induced by overheating  Breaks down into acrolein  Irritating to eyes and nose

Fats and Oils Reduction of smoke point by avoiding: Reduction of smoke point by avoiding:  Prolonged or repeated heating of fat  Collected food particles  Exposure of fat to air  Oxidation occurs  Deep fryers are better than shallow pans  Presence of emulsifiers in fats  Use of iron and/or copper pans which contributes to oxidative rancidity

Fats and Oils Shelf life of fat can be extended: Shelf life of fat can be extended:  Frying below smokepoint  Cooling quickly Fat absorption leads to greasy products: Fat absorption leads to greasy products:  Oil is not hot enough (too far below smokepoint)  Cold foods  Too much food added at once

Fats and Oils Ingredients that increase fat absorption of food Ingredients that increase fat absorption of food  Sugar  Leavening  Aqueous liquid  Fat Crispiness (favorable attribute) Crispiness (favorable attribute)  Dehydrating outer portion of food  Exchanging fat for lost moisture

Fats and Oils Fat in cheese Fat in cheese  Butterfat  Highly saturated Types of cheese and relative fat content Types of cheese and relative fat content  Dessert cheese (comparable to butter fat)  Hard cheese (1/3 fat by weight)  Low fat cheese (about 7% fat by weight)  Fat replacers WaterWater Vegetable gumsVegetable gums

Fats and Oils Other types Other types  Cheese spread (Velveeta, which uses emulsifier to aid in ease of melting)  Cream cheese (soft cheese)  More water than cheddar  Fat free cream cheese utilizes: