lecture 13 fat for nutrition class
DESCRIPTION
TRANSCRIPT
The Lipids: Fats and Oils
Identify two physical states of lipids
Define the following terms associated with fat
triglyceride mono, and poly unsaturated fatty acids saturated fat hydrogenation winterized oil
Fatty acids and Triglycerides
Differ in chain length, which affects solubility
Differ in saturation– Saturated fatty acid– Monounsaturated fatty acid– Polyunsaturated fatty acid
Saturated Fatty Acids
A fatty acid carrying the maximum possible number of hydrogen atoms (having no points of unsaturation). A saturated fat is one that is made up primarily of saturated fatty acids.
Monounsaturated Fatty Acid
(Sometimes abbreviated MUFA or mono) a fatty acid containing one point of unsaturation.
Polunsaturated Fatty Acid
(Sometimes abbreviated PUFA, or poly) a fatty acid in which two or more points of unsaturation occur.
The Essential Fatty Acids
The body can make all fatty acids except linoleic and linolenic acids (essential fatty acids)– Linoleic acid is an omega-6 fatty acid– Linolenic acid is an omega-3 fatty acid
Characteristics of Fats in Foods Hydrogenation of Fats
– Hydrogenation is a chemical change that retards fat spoilage and causes fatty acid to lose unsaturated character (along with health benefits).
Unsaturated fatty acids are vulnerable to attack by oxygen which leads to rancidity.– Refrigeration helps keep oils from spoilage.
Hydrogenation of Fats continued
Antioxidants are additives that compete for oxygen.
The more unsaturated a fat, the more liquid it is at room temperature.
The more polyunsaturated the fat is, the sooner it melts.
American Heart Association offers recommendations
Not more than 30% calories from fat (1/3 saturated, 1/3 monounsaturated, 1/3 polyunsaturated).
Dietary cholesterol intake to be no more than 300 mg per day.
Benefits from a high-fiber diet.
Fish and the health of the heart
– Study of Eskimos: High fat intake from fish oils Low heart disease rate
– Benefits of Omega-3 fatty acids and fish oils
Foods High in Saturated Fats
Butter Cheese Chocolate Coconut Coconut Oil Cream
Foods High in Saturated Fats continued ...
Meat Milk Palm Oil
Foods High in Monounsaturated Fats
Avocados Canola Oil Cashews Lard Olive Oil Olives
High in Monounsaturated Fats continued ...
Peanut Butter Peanut Oil Peanuts Poultry Vegetable Shortening
Foods High in Polyunsaturated Fats
Almonds Corn Oil Cottonseed Oil Filberts Fish Margarine (soft)
High in Polunsaturated Fats continued ...
Mayonnaise Pecans Safflower Oil Soybean Oil Sunflower Oil Walnuts
Fat in the Diet
The Fat in Foods– Fats and oils.– Meat, poultry, and fish.– Dairy products.
Shopping for Fats– Not all vegetable oils are polyunsaturated.– How to shop for spreads.
List five out of seven characteristics associated with fat Flavor Smoke Point Clarity Cost Solid versus Liquid Amount of Processing Artificial Fat
List eight uses of fat in food preparation adds flavor
adds nutritive value helps to prevent sticking used as a cooking medium adds shortening qualities tenderizes holds air, leavening forms emulsions
Be Fat Wise
Tips for Reducing Fat in the Diet:– Dietary goal for fat intake is not more than
30% of calories.– Learn to read labels– Cooking tips (bake, braise, steam, poach,
sauté, etc...)
Using the Food Label
As a consumer, you need to remember two important points when reading food labels:– the type of fat– the amount of fat
Considerations for Modifing a Recipe
1.Identify the type of meat in the recipe
Try to use lean cuts of meat, trim visible fat, and add very little fat during preparation.
Determine if a different type of meat could be used in the recipe.
1.Identify the type of meat in the recipe, cont.
beef, do not use prime, look for low level of marbling
fish, use white fleshed poultry, use the chicken breast or turkey
tenderloin
2.Identify the food preparation technique
Dry heat examples: Bake, Broil, Roast, Grill, Smoke
Moist heat examples: Simmer/Boil, Steam, Poach, or Stew
Stir-fry, dry saute
3.After cooking the meat, drain it before adding the meat to a soup,
casserole, chili, or spaghetti sauce.
4.Try to incorporate beans whenever possible to the menu.
5.Use a fat spray to help reduce the total amount of fat.
6.Use more fresh herbs and spices to flavor your food.
7.The portion size can be adjusted.
8.Ingredient Substitutions
evaporated skim milk or drained low fat, plain yogurt for heavy cream
blend a low fat cottage cheese with a low fat plain yogurt for cream cheese or heavy fat in a recipe. (Cornstarch added to this mixture helps to prevent curdling when you heat this mixture.)
Ingredient Substitutions
thickening can be accomplished by using the drained yogurt or a modified starch
2/3 low fat cottage cheese and 1/3 low fat plain yogurt can also substitute for mayonnaise or sour cream
egg substitutes or lower the egg yolk and increase the egg white
Ingredient Substitutions
when butter, lard, shortening, or margarine are suggested try an oil
dressings are typically 2/3 oil and 1/3 acid, change the ratio
use a vegetable puree to thicken a cooked sauce
Ingredient Substitutions
mashed or pureed potatoes aid in thickening
use low fat milk instead of coffee whiteners in coffee
substitute low fat cheese, such as part-skim mozzarella and ricotta for full-cream varieties
Ingredient Substitutions
look at labels of substitute cheese products
when a crisp product is needed, coat food with with whole wheat bread crumbs after dipping it in skim milk mixed with an egg white
avoid adding oil to a marinade, brush the food with oil just before grilling it
Modify Beef Stroganoff
Identify what you did to improve the recipe to make it a healthy item.
Nutrient Action: Let Them Eat Cake (Fat-Free, That Is)
The food industry boom in both low-fat and fat-free products is expected to soar through the next decade.– Fat-free cakes and cookies– Reduced-fat burger patties.– Fat-free salad dressings and nonfat dairy
desserts.– Artificial fats/fat substitutes
Using the Food Label
As a consumer, you need to remember two important points when reading food labels:– the type of fat– the amount of fat
Be Fat Wise
Tips for Reducing Fat in the Diet:– Dietary goal for fat intake is not more than
30% of calories.– Learn to read labels– Cooking tips (bake, braise, steam, poach,
sauté, etc.)
Where do you see fat in food?
preparation of products example: muffin tin, sauté pan
Where do you see fat in food?
cooking medium adds shortening qualities to products tenderizes
Where do you see fat in food?
leavening, holds air forms emulsions