Chapter 10 Flashcards
Fats and Oils
which food contains trans Fat
beef, lamb, dairy product
which food contain linoleic acid (omega 6)
vegetables oils (safflower,corn), meat, nuts, seeds
which food contain linolenic acid (omega 3)
vegetable oils (canola), eggs, chia seeds, flax seeds, leafy greens, walnuts, soy products
which food contain EPA and DHA
fatty fish
role of phospholipids
emulsifying agent
which food contain phospholipids
mustard, egg yolk, soybean, liver, wheat germ
where do we found phytosterols
many plants (fruits, vegetables, seeds, nuts, legumes,cereals)
Why industries put waxes on fruits + vegetables (3 reasons)
increase shelf life, prevent moisture loss, protect them during shipping)
which fats are recommend for frying (high smokin point + neutral flavor)
peanut, safflower, sunflower, cottonseed, canola,
what is refined oils
physically and chemically processed to remove undesirable components from the oil
what is the problem with refined oils
some of the nutrients are loss when we take out the impuretes
storage of most oils
at room temperatire, away from light, tighlty covered (will be keep longer in the fridge)
storage of butter and margarine
refrigerator
what is rancidity
chemical deterioration of fat ( fatty acids break down in smaller units) that cause off flavor and rancid odours
what accelerate rancidity
heat, light and exposure to oxygen
what is hydrolytic rancidity
exposure to water, catalyse by heat and lipase enzyme
example of hydrolytic rancidity
butter at room temperature, deep-frying
what is oxydative rancidity + more susceptible fat
exposure to oxygen, unsaturated fatty acids
first step of oxydative rancidity + what happened
initiation, free radical are formed
what triggered the formation of free radical in the first step of oxydative rancidity
metal (Fe, Cu, Ni), heat, light, sugar, food particules in frying oils
second step of oxydative rancidity + what it does
propagation, oxygen link with the free radical and formed peroxide free radical
when does the progagation (second step) stop
when all of the double bonds have been used
last step of oxydative rancidity + what happened
termination, no more hydrogens at double bond to react with oxygen
examples of antioxydant
vit C, vit E (found in vegetable oils), beta-carotene, flavonoids,sulfites, BHA, BHT
amount of unsaturated fat to consume every day
30-45 ml
fats that we have to limit
hard margarine, lard, shortening, butter
oil extraction: advantages of chemical (using solvents)
affordable, better yield so highest profit
oil extraction- disadvantages of chemical
lost of many nutrients because of the heat, 25 ppm of the solvent rest in the final product, less quality oil
oil extraction- advantages of cold-pressed
highest quality of oils, maintin integrity of oil + compunds in it
oil extraction- disadvantages cold-pressed
more expensive, lower yield
oil extraction- what is expelled-pressed
higher pressure, therefore more heat generated
why waxes are unrefined
because can not support a high heat (very sensitive), so remain pure
why it is preferable to cook at high temperature with refined oils
because has higher smoking point
advantage of interesterification
modify the physical properties of the fatty acids without production of trans fatty acid
difference between fractionation + winterization
the goal of the 2 is to cool down the oil and separated the liquid from the solid (different melting point) but the fractionation is very more sophisticated than the winterization (use flitration)
functions of fat
emulsifier, satiety, flavors, texture, heat transfer, shortening, nutrients
tips for low fat cooking (4)
choice of equipment, of ingredients, of cooking methods and the preparation
replacing fat in baking (5)
applesauce, silken tofu, bananas, beans, shredded zucchini
type of fatty acid in coconut oil
lauric (C12) (45%), Decanoic (8%) (C10), Caprylic (C8) (7%), Myrisitic (16%) (C14), Palmitic (16%) (C16)
monounsaturated : (C18) Oleic (6,5%)
how antioxydant prevent oxydation
- being oxydize themselves
- donating their hydrogen to FA
- sequestring the metals (chelating agent)
what do hydrogenation
harden vegetable oils (unsaturated fat become semi-solid or solid oil)
explains 2 choices of equipment to lower fat
- non-stick frying pan
2. parchement paper: eliminate need for greasing
explains 2 choices of cooking methods
- steaming
2. grilling, baking, or poaching instead of frying
explains 5 choices of ingredients methods
- low-fat versions
- leans cut of meat
- healthier versions (unsaturated oils)
- versions requiring less
- low-fat replacement
explains 2 preparation to lower fat
- trim the visible fat off the meat
2. bake pies with only a bottom crust or top crust
which food replace applesauce for fat
in place of oil in cakes, cupcakes and some cookie recipe
which food replace mashed bananas for fat
muffins and cookies
which food replace shredded zucchinis for fat
lock in moisture in muffins + breads
which food replace beans for fat
brownies + other items with a fudge-like texture
which food replace silken tofu for fat
cream in recipes
4 examples that are unrefined
pigments, odor and flavors, waxes, can also contains heavy metals and pesticides residues
5 basic process in refined oils
- degumming (removal of phosphatides ex lecithin)
neutralization (removal of free fatty acids)
bleaching (removal of colours)
deodorization (removal of odors, flavors and free FFA)
winterization (removal of waxes)
what is health claim + roles
plant sterols + lowering cholesterol in adults
in coconut oil, what is good about lauric acid
good antimicrobial
