Food Comp & Behavior: Lipids

Deodorizing duration

Takes 5 min-4 h Typically 2-4 mbar pressure Bar = 1 atmospheric pressure

Common Fatty Acid: Vaccenic Acid

- (from word meaning cow) found in butterfat, has one double bond in there but that is a trans fatty acid and it's naturally occurring and not dangerous, apparently. There is another trans fatty acid which is not naturally occurring and that is called Elaidic has double bonds in a different place

Plasticity Fats normally plastic-like: An ex: ketchup

- (means normally fats will behave like solid until you apply enough stress - will behave like a liquid) - Behave as solid below critical applied stress, liquid above it: Below, weak bonds between crystals are intact Above, bonds break, crystals slide past each other, flow begins Fats normally plastic-like until you apply enough stress until it becomes a liquid An example: ketchup - just stays at one end of bottle, so you need to apply stress (hitting the bottle) breaking these bonds that are holding the "goop" together and so now things start to slide - Applied stress that causes something flow below which it won't flow

Frying Typically at what temp? Pan frying:

- 160-195°C - Food absorbs oil, sometimes at 10-40% by weight - Shorter frying times result in less absorption, but oil will degrade - Provides heat transfer (don't need to heat it as much as water) and interacts with proteins and carbohydrates to induce desirable flavor - Pan-frying: only enough oil to lubricate pan, food must be turned partially through process, steam escapes and keeps oil out

Crystallization in Cocoa Butter 6 out of 6 processes:

- 6th form: hard and melts slowly in the mouth, shows some blooming - cannot be formed from melted chocolate - can only be formed after solid, tempered chocolate has rested for at least 4 months - 6th form melts at 36 - that one is a bit hard and melts too slow - 36.3 degrees C: melts too slowly

Lecithin: Group of _______ compounds that attract _____ and ____. Used for _______ texture, emulsifying, _______, reducing spattering

- Group of phospholipid compounds that attract water and fat - Used for smoothing texture, emulsifying, homogenizing, reducing spattering - Often from soy With soy: need to use a solvent to get it out of there With sunflower there is no need for solvent Both basically the same class of molecules

Fat Substitutes Also called fat...?

- Also called fat mimetics (mimics fat) - Lipase enzyme cannot reach ester bond to release fatty acids - Pass through gut without adding calories - When they make these fat substitutes, it turns out the lipase enzyme in you - the kind that ordinarily breaks down fat can't do it bc it can't reach the bond that it used to release the fatty acids. - Remember again the structure (letter E) - the ester bonds that bonds the fatty acid to the glycerol backbone, if the lipase enzyme cannot reach it then that means that fat substitute will go right through you without being digested and if it is not digested it is not going to add any calories That is why it is desirable

Lipid Basics Composed of: Soluble in:

- C, H, and O; may contain P (ex. phospholipids) Much more H and much less O than carbohydrates - nonpolar solvents Mostly triglycerides (triacylglycerols) in food

Canola Oil

- Canada oil, coined in 1970s - From rapeseed bred for low 22:1 content - Erucic acid bitter tasting and possibly unhealthful - Plant is known as rapeseed - ppl did not like first syllable of that so since a lot of it is made in Canada, they shortened it to Canola 22 carbons: 1 double bond They use rapeseed plant which is bred for its low erucic acid which has 22 carbons and 1 double bond Erucic acid tastes bitter and is possibly unhealthy

cis-oleic and trans-oleic

- Cis-Oleic acid, which is the kind that you normally find in nature. 42 degrees - Trans-Oleic acid, which you really don't find in nature. 6 degrees

Deep-fat frying What temps? Food often coated with? What happens to... proteins - starches - fiber -

- Completely submerging food in oil at 350-375°F (177-191°C) - Food often coated with bread, cornmeal, or flour - Surface dehydrates, undergoes Maillard reactions, creates brown color - Proteins denature, starches gelatinize, fiber softens - Crust forms on outside, prevents further absorption of oil

Conjugated Linoleic Acid

- Conjugated: single and double bonds alternate - Abbreviated CLA At least 28 isomers Anticarcinogenic - CLA (conjugates linoleic acid) - may have heard of this bc there is a possibility that it prevents cancer or some kinds of cancer - So when they say conjugated in chemistry, they mean that they have single and double bonds alternating. - So, with linoleic acid this doesn't alternate - Last two are most common

Soybean and corn oils How do we get corn oil?

- Corn oil: pressed from corn germ, extracted with hexane (volatile solvent), byproduct of corn starch and corn meal production Corn oil: pressed from corn germ (they press it out - get oil out as part of that), extracted with hexane (volatile solvent), byproduct of corn starch and corn meal production

Rancidity Deterioration in: Hydrolytic:

- Deterioration in quality of fat or oil - Hydrolytic: fatty acids split from glycerol Lipolysis In presence of lipase enzyme or heat Oxidative: uptake of O2 at double bond - Deterioration in quality of fat or oil - could be bc you are getting these fatty acids being broken off in a reaction from the glycerol. - If you are getting a breaking down = glycolysis (lipo - lipid; lysis = killing) basically degrading a lipid, and when that happens you are getting some rancidity forming. Can do that with heat or enzyme known as lipase, which breaks down lipids - Can also get oxidative (taking in oxygen across that double bond in unsaturated fat) rancidity - when that happens you are going to get some interesting compounds forming - none which are any good for you - Degrading a lipid - going to get some rancidity forming

Omega-3 Fatty Acids

- Double bond at third C from end of chain (ω-3 position) - Includes 18:3, 20:4 - Fish oil provides some, especially 20:5, eicosapentaenoic acid (EPA) 22:6, docosahexaenoic acid (DHA) - The fatty acids that are important with omega 3's are EPA and DHA - can take supplements 20:5, eicosapentaenoic acid (EPA) Eicosa - means 20 -penta - means 5 -enoic - means 5 double bonds 22:6, docosahexaenoic acid (DHA) Docosa - means 22 -hexa- means 6 -enoic- 6 double bonds in it - EPA and DHA are the ones your body uses and appears to help you. Fish oil is the one food that supplies a lot of that so they tell you to eat a lot of oily fish - so you get the EPA and DHA when you do so

Olive oil types

- Extra virgin olive oil has a lot of natural antioxidants in it and also has a lot of polyphenols and sterols - The others are refined and do have added preservatives to them; very pale - Pomace - from the solids, extracted with a solvent, have to refine it, and that also lasts less than 6 months

Shortening: Fat melts and flows, leaves cavity where _____ collects and expands _____ What falls apart, locking cavities in ___ position?

- Flakiness: quality of thin layers of pastry that shatter when cut or chewed - Fat melts and flows, leaves cavity where steam collects and expands matrix - Gluten falls apart, locking cavities in extended position - ex: Napoleon - layers of flaky pastry - When cooking w/ this and heating it up, the fat will melt so that flows. - That leaves this cavity, so when you are heating things you get the steam collecting and that expands the matrix and then you have different holes in there with escaping steam...so when that is happening that gluten falls back apart again and that means those cavities stay there - so now you have a small network that is going to stay that way

Crystallization in Cocoa Butter 3 and 4 out of 6 processes:

- Form 3: by cooling at 5-10 degrees C. Form 2 becomes form 3 after storage at low temps above freezing - Form 4: produced by allowing melted chocolate to cool at room temp. Form 3 becomes form 4 after storage at room temp for some time - 25C and 27C - temps for 3rd and 4th forms - those are firm and don't give a good snap like when you bite into chocolate or break off a piece you like to get that snap. You get that a lot with dark chocolate and not as intense as milk chocolate because the milk is there

CLA Study btw pasture raised and commercial raised cows

- Found in meat and milk from grass-fed cattle 85% of CLA in dairy products is cis-9-trans-11 CLA - Also found in eggs from chickens with diets rich in CLA - Pasture raised cows had greater CLA when they were able to eat whatever they desired (what they ate had a lot of CLA) versus cows being fed conventionally in stalls

Soybean and corn oils Most widely produced and least expensive vegetable oils in US

- Frying and baking oils - Don't use soybean and corn in Europe because they have olive oil - We produce those here bc they are least expensive oil here in US

Rendering: Heated with _______ to break down _______ structures and release triglycerides from animal tissue - Can also be done at home

- Heated with steam to break down cellular structures and release triglycerides from animal tissue Other lipids also extracted and need to be removed - you take cheesecloth and put raw fat in it and heat it with steam - will break down the cells - and can do it with fat from a pig or whatever. - Then you will get those triglycerides coming out and basically you have that dripping into a pan (so you have that fraction), and if you can keep doing it by adjusting temp then you are left with cracklings in the cloth In the industry, they also render fat using the same kind of principle, so it is fractionating the fat which are getting diff melting properties depending on when it comes out and how you treat it

Melting Point Trans vs. Cis Fats

- Higher with trans than cis b/c of the kink - harder to pack together. If trying to solidify it will take more energy to do so - Trans fat molecule being straight can be stacked pretty easily, so that is a physical difference

Lard Highest grade? Middle grade? Lowest grade?

- Highest grade: leaf fat, from visceral fat surrounding kidneys and inside loin, melts at 43-48°C - Middle grade: fatback, from layer between muscle and back skin, melts at 30-40°C - Lowest grade: caul fat/crépine, surrounding digestive organs 27% 16:0 11% 18:0 44% 18:1 11% 18:2 - Smoke point: 190°C (not much higher than butter so do not see much frying with lard)

Sterol and sitosterol

- Maintain structural integrity in animal cells, eliminates need for cell walls - Around half of dietary cholesterol not absorbed - your body has to make cholesterol (start in the liver) - cholesterol: not in plants or plant foods - sitosterol: a plant sterol Have to have them because they help our cells maintain structure of the cell membrane. If you do not have cholesterols in you then you will need to have cell walls to hold things together - animals don't have that

Micelle

- Micelle (can dissolve in water) - washes away parts of the soaps that are hydrophilic but the rest of fatty acid doesn't like water so it attaches to grease or dirt, so now you have something with these molecules sticking out - grease molecules secured by lipophilic tails of the soap molecules crowding in center of micelle, away from water

Thermal Properties

- Most important: amount of heat that has to be supplied or removed from system to change its temperature, along with rate - Easier to heat oil than water - takes a lot of heat to get water to boil but not much with oil Example: it takes 330 J/g to get water from solid to liquid With fats it takes 70 or 80 J/g

Palm and Coconut Oils

- Oil palm tree produces palm oil (pressed from pulp) and palm kernel oil (pressed from seed) - Palm oil: 44% palmitic acid (16:0), semisolid at room temperature, good for making cookies and crackers - Plantations replacing lowland forests - deforestation

Winterizing

- Oils chilled carefully to solidify fractions with high melting points - Fractions removed to prevent interference with flow properties of products containing oil - Olive oil not winterized since flavor compounds would be removed So you don't have this oil freezing when it's cold out Winterizing - they keep the liquid oil at liquid state during cold temperatures - Olive oil does not get winterized bc they will remove the flavor compounds - one reason why ppl like olive oil is bc they like the flavor

Degumming Phospholipids cause _____ and ____ above what temp?

- Phospholipids cause spattering and foaming above 100°C - Add up to 3% water at 60-80°C for 30-60 min Can also be done with acid or enzymes - You add a bit of water, which remember phospholipids are emulsifiers and they do dissolve in water - so you add a little water in there then heat it up and you get the phospholipids coming out with the water; can also be done by using acid or enzymes

Stability ______ formation affects quality of frying oil Also: Accelerates _____ Increases _____ Decreases _____ Stability of oil determined by:

- Polymer formation affects quality of frying oil - Accelerates degradation, increases viscosity, decreases heat transfer, induces foaming, develops undesirable color in food, increases oil absorption in food - Stability of oil determined by relating to its stability to oxidation - Relative reaction rates of unsaturated fatty acids with O2 - Frying quality of oil with high unsaturated fatty acids and free fatty acids not as good as oil with low levels of these When you are forming these polymers, these chains in molecule are going to affect how oil behaves and quality, so when they cause oil to degrade they get more viscous (less heat transfer, less efficient). May start to get bad colors in the food and so forth. The stability depends on how well it holds up to being oxidized, so you have a lot of unsaturated fatty acids and free fatty acids - it is not as good as oil that doesn't have as much of those Those are qualities that get looked at

Flavor _____ triglycerides have _____ flavor since they have low ______ What products impart some flavor? Most volatile compounds in food are?

- Pure triglycerides have little flavor since they have low volatility - Natural impurities and oxidation products impart some flavor - soluble in lipids - Triglycerides that are pure don't usually have much flavor that's bc triglycerides have medium or long chains and those are not very volatile - If it is not volatile you will not be able to detect any kind of flavor there. - Flavor composed of taste part (acid, bitter taste on tongue) other part is what you detect up in your nose when you inhale it - need to have volatile compounds in order to do that. - If you have some natural impurities and it starts to oxidize then you are going to get some flavor, but these lipids are responsible for flavor in food, not bc of their flavor but bc flavor compounds dissolve in them. One reason why these low-fat foods do not taste as well as regular fat foods. The fat is a carrier of flavor molecules - remove fat and you will remove a lot of flavor molecules

plant sterols (phytosterols) FDA approval:

- Reduce cholesterol and LDL in humans by blocking their absorption in small intestine - Stanols: unsaturated versions Sterol: is saturated Stanol: unsaturated - Reason they work: instead of you absorbing cholesterol and low-density lipoprotein in your intestines, it tries to absorb these plant sterols instead. And by doing that you are not getting cholesterol, you will be getting plant sterols which apparently isn't harmful - FDA approval to see health benefits in order to be able to brand a product as something beneficial - proven to lower cholesterol

Fractionating Winterization of cottonseed oil:

- Separation into different portions of different melting properties - Winterization of cottonseed oil: cool to 0°C, filter out crystalline material - Produces "olein" and "stearin" - Dry fractionation of tropical oil (coconut oil/ palm oil): melt and slowly cool with stirring for 24 h - you get fractions out that way - Repeat to obtain fractions - When you get fat they can get different fractions/ different portions with diff melting properties, so you can for example (WINTERIZATION) pull cottonseed oil to 0 degrees and some of it will crystallize out - so you filter that out, and then you take the rest. So now you have olein which is the lipid (liquid?) part of stearin which is the solid part

Shortening

- Shortens preparation time - Used for crumbly pastry - Crisco: crystallized (hydrogenated) cottonseed oil, starting in 1911 Lard also used - Crisco is from cottonseed and it is partially hydrogenated

Appearance Solid fats usually: Liquid oils usually:

- Solid fats usually opaque - Light scattered by crystals - Liquid oils usually clear (could be yellow color) - Emulsions cloudy - Dispersed droplets Whole milk whiter than skim milk - If you have an emulsion - you have something partially dissolved in something else - going to be cloudy because of the droplets that are dispersed. - An example is milk; whole milk is whiter than skim milk - skim milk does not have as much fat in there so that is going to appear differently than whole milk which does have fat

Hydrogenation of Lipids Stabilizes what, and increases what at room temp? What happens if there is no reaction?

- Stabilizes lipids, increases solid fat index at room temperature - If no reaction, double bond forms again into cis or trans configuration - You can add hydrogen to the oil, across that double bond to change from double bond to a single bond - When that is done then you have a solid fat and not as much of a liquid fat; an unsaturated fat going into a saturated fat - Problem is that unless this is a 100% efficient (and it never is) then the double bond can go form again - ---- would be cis or trans; trans formation that is the problem. - Some companies would sell - saturated fats - hydrogenated fats or partially hydrogenated fats and because of that you were getting trans-fat forming - those trans fat are dangerous for you because they do not occur in nature for the most part. - That is why companies are cutting back and why you are seeing more labels of how much trans fat there is

Stopping Rancidity

- Storage in tightly closed container in cool, dark place - Use antioxidant Provides H from own molecule to react with free radical or peroxide - Resulting compound (original fatty acid or hydrogen peroxide) fairly stable - Can also scavenge O2 or metal - What you can do is store in a cool, dark place so you do not have this starting - Can also use an antioxidant: will supply H from itself instead of allowing another fatty acid to supply it - So, it will stop that reaction from perpetuating itself

Interesterification Switching of what? Usually done to modify what? What is used?

- Switching of fatty acid groups between triglyceride molecules or within one molecule - Usually done to modify melting - Sodium methoxide used Enzymes also used, more specific When you take the fat and fatty acids and combine w/ glycerols, you are esterifying it bc those are ester linkages between the glycerol and fatty acids - Interesterification means that you can take the different fatty acids and rearrange them, so it can be rearranged on a particular molecule or w/in number of molecules and they usually do that to change the way it melts. - You can use enzymes to do that - enzymes will look for particular sites and lengths, and they can switch things around - what you wind up with are diff fats and oils that you started with and everything gets rearranged

Melting Points: short versus long chains? trend seen with double bonds?

- The shorter they are the lower the melting point, so these short-chain fatty acids here are liquid at room temperature - Then as chains get longer, the melting point goes up - Another trend: once these start getting unsaturated (getting double bonds) that drops the melting point considerably. So, palmitic melts at 64 but if you throw a double bond in there it melts at zero -that changes the properties - Stearic melts at 70 but oleic melts at 14, trans-18:1 (Elaidic) melts at 44 degrees because of the difference in structure

USDA Standards for Grades

- US extra virgin olive oil: free fatty content does not exceed 0.8% (if going for flavor) - US virgin olive oil: free fatty content does not exceed 2.0% - US olive oil: mixture of two - Refined olive oil: color, odor, flavor removed - use that where ppl do not want to impart any kind of flavor from the olive oil

Lipids also include - ? - used in food industry to get specific coating or appearance on food - Fat-soluble vitamins: - Phospholipids

- Waxes (beeswax, lanolin - comes from sheep; sheep oil from wool): esters of long-chain fatty acids and alcohols, used as candy glaze and fruit coating - Fat-soluble vitamins (A, D, E, K) - Used in food industry (shiny) to get that glaze on candy or coating on fruit - You have your fatty acid and then as you move up you have the glycerol backbone, and above that is the phosphate group (there is phosphorous and oxygen attached to it) and then there is choline attached to that. The fatty acid is hydrophobic - meaning it does not like water. The rest on top is hydrophilic, will dissolve - the glycerol, phosphate, and choline on top are all hydrophilic so you have a molecule that will dissolve in either water or oil - known as an emulsifier Water and oil can come together - do not have them separating out

Fat Substitutes Sucrose fatty acid ester (Olean/Olestra) in 1996

- Wow chips was a thing in 1996 bc it contained olestra which was developed around that time - Meant you could eat the chips without digesting any of the fat bc you would not be obtaining those calories - Had issues with anal leakage - Olestra/ Olean = used as fat mimetic in chips to be able to enjoy the chips without gaining calories - However: the warning sign deterred a lot of customers from purchasing the chips

Deodorizing Crude lipids contain? Arise during? Can deodorize if you do not want...? What is the temp to strip out free fatty acids?

- alcohols, aldehydes, ketones, etc. - extraction and refining - Steam distill under low pressure at < 200°C for heat-sensitive oils Avoid too much degradation of omega-3 fatty acids (fish oil) and negative effects on crystallization characteristics (cocoa butter) - 260°C for stripping out free fatty acids - an odor imparting by the fat When you take lipids out from a plant or an animal, you want to have things other than lipids dissolved in there - other classes or compounds (alcohols, aldehydes, ketones), all those can produce some kind of off-aroma or off-flavor and they also come up as you are doing the refining. So, they get those out of there - they use low pressure and temp under 200 degrees so they boil it without burning it By doing that they do not degrade those omega-3 fatty acids Then you want to strip out the free fatty acids - 260 degrees C to strip those out

Oxidative Rancidity H removed from:

- another unsaturated fatty acid to form hydroperoxide -O-O-H - Other fatty acid now a free radical, process perpetuates - Autocatalytic (acceleration of free radical formation) - Wide range of compounds form - Sped up by presence of certain metals (Cu, Fe) and light or warm temperatures - Pulling H from another fatty acid so you now have that as free radical - now this perpetuates; autocatalytic: meaning acceleration of free radical formation, and getting lots of different compounds forming. - If in presence of copper or iron it is going to accelerate even more, as well as light or warm temperatures - Going to experience lots of rancidity bc you have all these free radicals forming and it's not going to stop unless you do something about it

Selecting Oil Depends on:

- appearance and fat retention - Oils sometimes blended - Light color, bland flavor Low levels of metals (< 1 ppm P, < 0.1 ppm Fe, < 0.02 ppm Cu) Low levels of free fatty acids (< 0.05%) and 18:3 (< 2%) - When you select an oil, you look at appearance, how much fat is retained when you fry it - Look for low levels of metal, again because you get rancidity forming - Low levels of free fatty acids and lower levels of linolenic acid (18:3) - can result in a lot of rancidity forming - Linolenic is one free fatty acid that can result in a lot of rancidity forming

Triglyceride structure Glycerol: Fatty Acids: Structures linked by what kind of bond?

- backbone is a water-soluble alcohol - chains of carbon atoms with a methyl (-CH3) group at one end and carboxylic acid (-COOH) group at the other - ester bonds (R-COOR') and water is released

Bleaching Removal of undesired pigments such as? Heat to 80-110°C with?

- carotenoids or chlorophyll (too much of a yellow or orange color) - activated carbon, clay, silicates, etc. Remove absorbent under vacuum to prevent lipid oxidation

Crystals: Solid fats consist of: There are three/ four crystal forms, normally, which are called:

- crystals of fat in oil - Fat molecules link upon cooling to form crystals Four crystal forms: α, β′, intermediate, and β - Solid fats are not entirely solid - basically crystals, solid crystals suspended in oil. - So when you heat it up, everything is liquid, and then you just let it cool down - you get these crystals forming. - alpha, beta, and intermediate, and beta prime - all have different crystal shapes depending on the type of crystal - They can affect the texture

Crystallization in Cocoa Butter 5 out of 6 processes:

- form 5: shiny, smooth texture, good 'snap', and melts in the mouth; formed by tempering chocolate slowly at room temp. - most desirable! - 5th form: melts at 33.8 C - gives you texture and snap, and melt in your mouth feel, plus that chocolate gloss everyone likes.

Crystal forms: β crystals:

- form when fat melts completely and recrystallizes without being disturbed, extremely stable, coarsest texture - For creating flakiness in baking (lard) and cocoa butter stability - Crystals force starch granules apart, slow formation of elastic gluten, pastry becomes short (inelastic)

Crystal forms: Intermediate crystals:

- form when β′ melt and recrystallize, undesirable grainy appearance - Difference between grainy and smooth in a persons mouth - crystal size is around 30 microns - if it is below that then humans can detect a rater smooth texture, but above that and we feel grainy

Neutralizing Removal of what? What does that cause? You then mix what in to form soaps?

- free fatty acids, which cause off-flavors - Mix in base to form soaps Soap stock recovered and used - Removal of free fatty acids (FA that are not part of a triglyceride) and a lot of those, if they are floating free, can cause these off-flavors, especially if they are unsaturated. - - - then you get oxidation and you get bad odors and bad flavors. So, since these are acids you can neutralize them by adding a base. So you mix in a base and you have fatty acids (FA) plus a base = soap - They then extract the soap and they use that

Phospholipids and water coalesce to form?

- gum Soybean oil: gum sold as lecithin - two different forms of Lecithin - can be solid granule or liquid - They degum these fats and then coalesce that and that forms the gum and then you sell it off as lecithin once you have used the solvent to extract it

General Hydrogenation Process

- hydrogen gas is aded under pressure in the form of tiny bubbles at the base of agitator - oil temps increase once hydrogenation process begins You take a container with liquid oil in there and you pump in hydrogen gas and a bit of nickel (acts as a catalysts) and as it bubbles in there you are hydrogenating

ω-3 and ω-6 Fatty Acids Necessary for: May play role in: Ratio btw 6's and 3's should be 1:1 but in Western diets (US) ratio is:

- metabolism - preventing cognitive decline, dementia, inflammation ω-6 fatty acids (includes linoleic acid, 18:2) also necessary ω-6 to ω-3 ratio should be 1:1, but over 16:1 in Western diets because of vegetable oils - Should be consuming more omega-3 than omega-6 but Western diets have been mainly consisting of vegetable oils - You need omega 3's and omega 6's when you are metabolizing things and can play a role in preventing cognitive decline, dementia, and even inflammation Omega-6's are linoleic acid (18 carbons: 2 double bonds) Omega-3's are linolenic (18 carbons: 3 double bonds) - 16:1 bc of the oils we are consuming. We should be consuming both kinds of those fatty acids but we should be consuming a lot more of the omega-3's and less of the 6's but we consume a lot of soybean and corn oil which throws the ratio out of whack

Overuse and Overheating Results in? May also get formation of acrylamide?

- oxidation, polymerization, acrylamide formation Want to change the oil every so often bc if you do not then not only are you going to get the rancidity forming, you are going to get that polymerization and more viscous. - acrylamide: possible carcinogens that can be formed through a variety of different reactions - some are from when you are heating up oil too much (ie frying same oil too much)

Crystallization in Cocoa Butter - Cocoa butter has 6 different crystal forms - all depends on how you temper it 1 and 2 out of 6 processes:

- produced by cooling melted chocolate rapidly (freezer) - produced by cooling melted chocolate at 2 degrees C per minute - form 1 crystals gradually become form 2 after short time of freezing temperature storage - first and 2nd form - they melt at 17 - 23C and both are soft and crumbly and they have bloom - don't like

Crystal forms: β′ crystals:

- stable, smooth surface, most desired form - For smooth spreads and cake mixes - Fat spreads evenly throughout flour, lubricates surfaces of starch and gluten particles, enables them to slide past each other

Mono- and Diglycerides Slow down rate of? Mono- and diglycerides can occupy what which slows down what?

- staling - straight chains occupy centers of amylose and amylopectin helices, slowing down retrogradation - Emulsifiers - center of helix and that slows that retrogradation - they make mono- and diglycerides by stripping off these fatty acids and they do that to slow down how things get stale

Emulsifiers Surfactants: Most important food emulsifier?

- surface active agents, reduce surface tension of water - Egg yolk: most important food emulsifier One third lipid, consisting of 67% triglyceride, 28% phospholipid, (mostly lecithin), 3% cholesterol Why you add eggs to a recipe - as a binder

Thermal Stability: Smoke point:

- temperature at which smoke appears

Thermal Stability: Flash point:

- temperature at which volatiles can be temporarily ignited - so once it starts getting volatile you hit a particular temp and then it is going to flash

Thermal Stability: Fire point:

- temperature of continuous combustion - where the combustion is going to stay Triglycerides more thermally stable than (separate) fatty acids

Blooming in chocolate happens when? Chocolate manufacturers want to avoid that, so they use?

- that happens when there was temperature abuse - temperature went up and down (fluctuated) and the fat comes up to the surface and crystallizes there. - Bc of that you have a chocolate that does not look desirable and the texture is all wrong (crumbly). - tempering (?) on the fat - means you heat and cool it to specific temps so you can get the right crystal formation. Wrong temp means you will wind up with a bloom or undesirable texture

Packaged Cake 4th line: palm kernel oil and hydrogenated palm oil, palm oil shortening - ?

- tropical oils that they add in there in order to reduce the properties that they want Soy lecithin - an emulsifier

Common Fatty Acid: Palmitoleic Acid

- unsaturated fat, 16 carbons and one double bond, found in animal fat

Oxidative Rancidity Free radical:

- unstable compound containing unpaired electron - Often initiated with 18:2 at carbons 9, 12, or 13 Free radical combines with O2 to form a peroxide - So you have these oxygen atoms reacting and you get free radicals - one reason why you have antioxidants: to stop these free radicals from forming/ combining - Have linoleic acid (18:2) which has this oxidative rancidity a lot of times, and you have this free radical forming and you end up with this peroxide. When that happens you have an off-flavor and odor

Crystal forms: α crystals:

- very fine, unstable, quickly melt and recrystallize into β′

Texture In oils, depends on: In water/ oil emulsions w/ partially crystalline fats depends on: In oil/ water emulsions (butter and margarine), much depends on:

- viscosity (how thick it is) (resistance to flow) - solid fat index and concentration, shape and interactions of fat crystals - crystal form In water/oil emulsions with partially crystalline fats, (texture) depends on (how much of it is solid fat) solid fat index and concentration, shape and interactions of fat crystals In oil/water emulsion (like butter) - mostly oil and some water - a lot depends on crystal forms, so butter is 80% fat and 16% water and the rest is protein

Beta When baking, for instance, the best kind of fat to use is____because it has that beta crystal structure. - Reasons it works: you have these crystals that are?

- when fat melts completely and recrystallizes - really stable and coarse texture but you do want that in some applications. - Lard - When you make pastries you are going to get a lot of flakiness because of that, also one of the forms in cocoa butter - you have these crystals that are bigger which means that the starch granules get forced apart and then gluten (elastic) does not form very fast. And that means that you do not have an elastic pastry, you have a short pastry - which means you only have to pull a short distance before it breaks apart

Ascorbic acid (vitamin C), ascorbyl palmitate

- when using vitamin C to act as antioxidant in something that has fat they add ascorbyl palmitate to allow it to dissolve Photo is ascorbyl palmitate w/ out ascorbyl palmitate

Saponification

- you have triglyceride and you add sodium hydroxide to it - you wind up with glycerol again

Stearic Acid Structure

18:0 - saturated long-chain fatty acid with an 18-carbon backbone - Stearic acid is found in various animal and plant fats

Oleic Acid Structure

18:1 - a mono-unsaturated fatty acid due to presence of a single double bond

Shorthand abbreviations: Example: Butyric

4 (carbons): 0 (zero double bonds) 4:0

Common Fatty Acid: Butyric Acid

4 carbon bonds, 0 double bonds Sources: butterfat Short chain fatty acid Butyric comes from word for butter

Butter

4% 4:0-12:0 -> 4% (of short chain fatty acids) 4:0-12:0 = they provide the flavor 12% 14:0 26% 16:0 11% 18:0 28% 18:1 - Short-chain fatty acids produced from anaerobic fermentation = meaning without oxygen/ air, the bacteria that are in the cow stomach work on the food that it gets and it generates the short chian fatty acids - that is where they come from - Smoke point: 150°C (will start to smoke after a little while, which is why we do not fry using butter)

Goose Liver Pate

A lot of ppl will not eat this due to cruelty to the animal This is a fatty food Saturated fat: 14.5/ 100g Unsaturated fat: 26.5/ 100g

Pot Pie

A lot of the fat coming from the chicken that is inside as well as the crust 1 cup = 200g 25g of fat; 10g of that is saturated fat, so if you have one serving you already have half your sat fat for the day Container says that pot pie in the box is two servings, so if you eat the whole thing you consume your sat fat for the day

Fatty Acid Structure

Ordinarily even number of C atoms May have at least one C=C double bond in middle

Antioxidants

Alpha tocopherol - vitamin E Ethylenediaminetetraacetate (EDTA) Citric acid Ascorbic acid (vitamin C), ascorbyl palmitate

trans Fatty Acids

Apparently increase LDL cholesterol and decrease HDL cholesterol Elaidic acid major culprit Must be declared on nutritional label if ≥ 0.5 g/serving Vaccenic acid naturally occurring and appears to be OK (don't classify as trans for purpose of labeling) One thing that is pretty bad are trans fatty acids - it looks as though they increase your LDL cholesterol (low density lipoprotein - bad cholesterol) and decreases the HDL (high-density lipoprotein - the good cholesterol) Elaidic acid is the major culprit: the double bond is in a position which makes it dangerous. Not the same position as the oleic acid - in different position and two spots over And if you have more than half a gram per serving of trans fatty acid you have to declare it on the label Vaccenic: because double bond seems to be in an ok position unlike Elaidic acid

Changes during frying Agent: high temp Change? New Compounds?

Change: Polymerization New Compounds: cyclic monomers, dimers, nonpolar polymers, trans fats

Capric Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 10 Double bonds: 0 Scientific Name: decanoic Sources: coconut oil

Lauric Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 12 Double bonds: 0 Scientific Name: dodecanoic acid Sources: coconut oil

Myistic Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 14 Double bonds: 0 Scientific Name: tetradecanoic Sources: palm kernel oil

Palmitic Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 16 Double bonds: 0 Scientific Name: hexadecanoic Sources: palm oil

Palmitoleic Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 16 Double bonds: 1 Scientific Name: 9-hexadecanoic Sources: animal fats

Stearic Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 18 Double bonds: 0 Scientific Name: octadecanoic acid Sources: animal fats

Vaccenic Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 18 Double bonds: 1 Scientific Name: 11-octadecanoic Sources: butterfat

Oleic Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 18 Double bonds: 1 Scientific Name: 9-octadecanoic Sources: olive oil

Ricinoleic Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 18 Double bonds: 1 Scientific Name:12-hyroxy-9-octadenoic Sources: castor oil

Linoleic Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 18 Double bonds: 2 Scientific Name: 9, 12-octadecadienoic Sources: grape seed oil

Alpha-Linoleic Acid (ALA) Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 18 Double bonds: 3 Scientific Name: 9, 12, 15-octadecatrienoic Sources: flaxseed (linseed) oil

Butyric acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 4 Double bonds: 0 Scientific Name: butanoic acid Sources: butterfat

Caproic Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 6 Double bonds: 0 Scientific Name: hexanoic acid Sources: butterfat

Caprylic Acid Carbon atoms: Double bonds: Scientific Name: Sources:

Carbon atoms: 8 Double bonds: 0 Scientific Name: octanoic Sources: coconut oil

Changes during frying Agent: moisture Change? New Compounds?

Change: Hydrolysis New Compounds: free fatty acids, mono- and diglycerides

Changes during frying Agent: air and materials Change? New Compounds?

Change: Oxidation New Compounds: oxidized monomers, dimers, polymers, volatile compounds (aldehydes, hydrocarbons, ketones)

Flavor Enhancers Next to last line: inter-esterified soybean oil (esterification = mixes up the fatty acids btw the diff triglycerides) -

Disodium guanylate Disodium inosinate - Next to last line: inter-esterified soybean oil (esterification = mixes up the fatty acids btw the diff triglycerides) - well, they have done that with the pot pie above. They did that so you have melting at particular temperatures - Most of those ingredients are from the crust and some from the filling

Pate de Foie Gras

Duck or goose liver pate (similar to chopped liver) ¾ from France Ducks or geese force fed with corn using feeding tube Ducks twice a day for 2 wk, geese three times a day for 2½ wk Liver becomes 10 times normal size

Ethylenediaminetetraacetate (EDTA)

EDTA used as a preservative in a lot of things

Tenderness

Interactions with development of gluten Structural protein in wheat flour products Gluten complex develops as flour proteins become moistened and then stirred or beaten, resulting in elastic network Fats and oils coat proteins, physically inhibit contact between them and water Shortening - A lot of tenderness has to do with fat - Interactions with how gluten forms, so gluten is protein that you find in wheat flour (some people cannot tolerate) - Complex of forms when you have protein in flour get moisten - start to stir or beat it, have network flowing/ forming. - So, if you have the oil or fat in there the contact btw network and water gets inhibited because it gets in the way. - That is known as shortening - that is why you add shortening to something, to inhibit that contact

Emulsification

Lecithin, others stabilize emulsions Hydrophobic end, avoids water Hydrophilic end, attracted to water Mixing fats and water together - can do that w/ lecithin where you have stabilization, a hydrophobic end which avoids water, hydrophilic (loves water), and so that way you can get water soluble and water insoluble compounds together

Butter characteristics

Made by churning fresh milk Water in oil emulsion, protein acts as emulsifier Melts at 32-35°C You have a water in oil emulsion and so the protein that is in the milk, the casein, acts as an emulsifier (kind of) Butter melts at a low temp - cannot use that for frying very well

Mouthfeel

Oils coat tongue, leading to oily mouthfeel Large fat crystals lead to gritty or grainy mouthfeel (smaller than 30 microns/ micrometers - feel smooth) Small fat crystals lead to smooth texture Melting crystals cause cooling sensation (will draw in heat from your tongue) Mouthfeel - how something feels in your mouth When crystals melt they can give you this cooling sensation bc melting will draw in heat from your tongue bc you need heat in order to go from solid to liquid

Emulsifying Capacity Oleic acid: Monooleate: Soy lecithin: Diacetyl tartaric acid ester of mono- and diglycerides (DATEM): Polyoxyethylene sorbitan monopalmitate (Tween 40):

Oleic acid: 1 (meaning it doesn't do it at all) Monooleate: 3.4 Soy lecithin: 8 Diacetyl tartaric acid ester of mono- and diglycerides (DATEM):8 Polyoxyethylene sorbitan monopalmitate (Tween 40): 15.6 We see more lecithin and now DATEM DATEM - now seen more on labels; has same capabilities as lecithin

Olive oil

Olives crushed or pressed Cold-pressed: maximum 27°C Paste churned or mixed 20-40 min - Oil separated by press or centrifugation (spin it around and oil separates from solid parts) - Solids subjected to solvent extraction to obtain olive pomace oil Virgin olive oil unheated Labor-intensive harvesting and pressing - that is why it is not nearly as cheap as corn oil or soybean oil We do not have too much olive oil being produced here in the US - we get it from Europe

Similar Oils

Peanut, safflower, sesame seed, sunflower oils with low (palmitic acid) 16:0 and high (unsaturated fats) 18:1 and 18:2 - Linseed (flaxseed) oil contains 50% 18:3, susceptible to oxidation, strong odor and flavor

Fractionating process:

Relatively slow process Complex oils could take 3 d - worth it if you want to get particular fats and oils with particular melting properties

Sautéing

Same as pan-frying, but food bounced in pan

Shallow frying

Shallow frying: partially submerging portion-sized cuts in hot oil, must be turned partially through process

Measuring Melting Solid fat index (SFI):

Solid fat index: % solid at particular temperature - Solid fat index (SFI) is a measure of the percentage of fat in crystalline (solid) phase to total fat (the remainder being in liquid phase) across a temperature gradient.

Soybean and corn oils How do we get soybean oil?

Soybean oil: extracted with hexane; composition similar to corn oil but has 8% 18:3 (linolenic acid) - omega 3

Trans and cis fatty acids In a trans fatty acid the structure is: Cis:

Trans fatty acid: where H are in relation to double bond. - pretty straight, there is an angle that is created by the double bond but the angle is only 6 degrees, so that means it is a pretty straight molecule. - hydrogen on the same side of the double bond and that introduces this kink of 42 degrees - can refer to cis as kinky fatty acids By doing this it changes the properties quite a bit

Lipids also include:

Triglyceride, diglyceride, monoglyceride and sterols - Diglyceride - with only two sites on the glycerol backbone - Monoglyceride - with only one site - Sterols: cholesterol (seen on slide). Sterols are counted as lipids - they have OH group. An example is cholesterol

Crystallization in Cocoa Butter

Variations in packing of triglycerides lead to different melting points Fat tempered by heating and cooling to specific temperatures Wrong structure or temperature fluctuations lead to bloom on chocolate

Shorthand abbreviations: Example: Oleic & Elaidic

cis-18:1 trans-18:1 (the dangerous one)

Triglyceride _________ reaction

condensation reaction Glycerol + 3 fatty acids --> condensation reaction --> triglyceride + 3 water molecules