Module 9-fat biochemistry Flashcards
what re edible fats and oils made of
Edible fats and oils are mixtures of triacylglycerols (TG), also called triglycerides, consisting of a glycerol subunit linked or esterified to three fatty acid (FA) molecules
what is the distinction between fats and oils
The distinction between fats and oils is made on their state of matter at room temperature, fats are solid at room temperatures whereas oils are liquid at room temperature
where can fats and oils be derived from
Fats and oils may be derived from animal or vegetable sources
what are the principal animal fats
The principal animal fats are tallow, lard and butterfat which include many saturated fatty acids that can be a health concern. On the other hand, marine oils with high levels of long chain, polyunsaturated fatty acids including omega-3 fatty acids, are recommended for their health benefits
what is glycerol
Glycerol, the backbone of a trigylceride is an organic trihydroxy sugar alcohol with three carbon atoms and three hydroxyl (-OH) groups
what are fatty acids
Fatty acids are long chains of carbon atoms with an attached carboxyl group
what a triglyceride form
The triglyceride forms when three fatty acid molecules undergo esterification with the three hydroxyl groups of the glycerol molecule producing a large triester molecule
what would a simple triglyceride look like
Simple triglycerides have three identical fatty acids attached to the glycerol backbone
what would a mixed triglyceride look like
in mixed triglycerides, the glycerol is combined with two or three different types of fatty acids
what determines the physical and chemical property of a fat or oil
The physical and chemical properties of a fat or oil are determined by its fatty acid and triglyceride profile
what are the properties at most concern
The properties of most concern are melting point, crystal form and stability
what does the melting point determine
The melting point determines the hardness and spreadability of solid fats like margarine and shortening and the susceptibility of liquid oils to cloudiness when refrigerated
what does the nature of the crystals influence
The nature of the crystals in solid fats influences texture sensation when the product is consumed
what does the stability influence
Stability refers to susceptibility to oxidation or rancidity (spoilage).
how many different types of fatty acids are there and what makes them different
Hundreds of different types of fatty acids, distinguished by number of carbons, degree of branching, and level of saturation, exist in nature
how many of fatty acids are found in vegetable oil
A dozen of these fatty acids are important in vegetable oils and five are predominant in most vegetable oils.
what is the amount carbon range that can be found in fatty acids and what is the most common range
Fatty acids can be 4 to 28 carbons in length but the most common are between 12 and 24 carbons long
what is the melting point of fatty acids dependent on
The melting point of fatty acids increases as the number of carbons in the chain increases
what kind of bonds does a saturated fatty acid have
Saturated fatty acids contain no double bonds between the carbon atoms
what kind of bond does a monounsaturated fatty acid contain
monounsaturated fatty acids contain a single double bond between the constituent carbon atoms of the fatty acid molecule
what kind of bond would a polyunsaturated fatty acid contain
polyunsaturated fatty acids contain more than one double bond between the constituent carbon atoms of the fatty acid molecule
why are saturated fatty acids called saturated fatty acids
Saturated fatty acids are called saturated because they contain the maximum number of hydrogen atoms possible with the given number of carbon atoms
how do double bonds impact melting points
The melting point of a fatty acid decreases as the degree of unsaturation or the number of double bonds increases
what affects the melting point the most? double bonds or chain length
The effect of the number of double bonds on melting point is more dramatic than the effect of the chain length
what effects oxidation stability
The oxidative stability of fatty acids decreases as the number of double bonds increases, saturated fats are less prone to spoilage than unsaturated fats
what are the ways the melting point of a fatty acid decreases
The melting point of a fatty acid decreases as the degree of unsaturation or the number of double bonds increases
How does oxidative stability of fatty acids correlate to number of double bonds
The oxidative stability of fatty acids decreases as the number of double bonds increases
are saturated or unsaturated fats more prone to spoilage
saturated fats are less prone to spoilage than unsaturated fats
is most of the fatty acids in liquid saturated or unsaturated
A high proportion of the fatty acids in liquid oils are unsaturated
in most of the fatty acids in solid fats saturated or unsaturated
the fatty acids in solid fats are mostly saturated or a mixture of unsaturated and saturated
what are polyunsaturated fatty acids
Polyunsaturated fatty acids can be conjugated, with adjacent double bonds, or non-conjugated (also called unconjugated) with double bonds separated by one or more methylene groups
what are the most naturally occurring polyunsaturated fatty acids
Most naturally occurring polyunsaturated fatty acids have non-conjugated double bonds
what is the different physiological effects of conjugated and non-conjugated polyunsatureated fatty acids
Conjugated and non-conjugated polyunsaturated fatty acids have different physiological effects; conjugation of double bonds may increase anti-carcinogenic effects of fatty acids and fatty acids with conjugated double bonds may have more beneficial effects on moderating cardiovascular tension
what configuration can a conjugated fatty acids be in
Conjugated fatty acids can be in a cis or a trans configuration
what is the configuration of polyunsaturated fatty acids in a trans vs cis
polyunsaturated fatty acids in a trans configuration are straight whereas those in a cis configuration are bent
what does the cis and trans configuration refer to
The cis and trans configurations refer to the orientations of the hydrogen atoms flanking a double bond
do trans fats occur in nature
Trans fats occur only in small amounts in nature
why are most dietary trans fats produced
most dietary trans fats are produced when fats are partially hydrogenated to extend shelf life and increase the melting point of the fat
are trans fats a dietary requirement
Trans fats are not a dietary requirement
why arent trans fats good for the inclusion of human diet
the inclusion of trans fats in the human diet is associated with an increased risk of cardiovascular disease
what actions are now taken to reduce trans fats
Health Canada banned the use of partially hydrogenated oils in food service establishments in 2018.
what doe we need to indicate when describing a fatty acid
In describing a fatty acid, we need to indicate the number of carbon atoms, the degree of saturation and the position(s) of double bond(s)
what does the omega nomenclature for fatty acids describe
The omega nomenclature for fatty acids describes the fatty acid in terms of the number of carbons in the fatty acid chain, the number of double bonds and the position of the double bond(s). Cis and trans configurations may also be included.
what are the nutritional benefits of fats
Nutritionally, fats and oils are highly digestible sources of energy and essential fatty acids such as linoleic and linolenic acid. They also act as carriers for fat soluble vitamins
how much of daily caloric intake should fat make up the diet
Fat should constitute no more than 30% of daily caloric intake in the human diet. Both saturated and trans fats should be limited
what of fatty acids determines the effect on health
The characteristics of fatty acids determine their effect on health
ideally what fatty acids do we and to increase and what ones do we want to decrease
Ideally, we want to increase high-density lipoproteins (HDL) which are considered to be beneficial cholesterols and lower low-density lipoproteins (LDL), considered to be detrimental cholesterols
what source does most fats come from in human and livestock diets
The oilseeds provide a major source of fats in both human and livestock feeds
why are fats important
Fats are nutrient dense sources of energy and include essential fatty acids that must be supplied in the diet.
what is oleic acid and trans isomer
The trans isomer of oleic acid, a monounsaturated fatty acid with eighteen carbons (C18:1 cis), is commonly called elaidic acid (C18:1 trans); the melting point of oleic acid is 16oC whereas the melting point of the trans isomer, elaidic acid, is 45oC
