ding much of the lard sold in supermarkets, is rendered from a mixture of high and low quality fat sources from throughout the pig.[9] To improve stability at room temperature, lard is often hydrogenated. Hydrogenated lard sold to consumers typically contains fewer than 0.5g of transfats per 13g serving.[10] Lard is also often treated with bleaching and deodorizing agents, emulsifiers, and antioxidants, such as BHT.[4][11] These treatments make lard more consistent and prevent spoilage. (Untreated lard must be refrigerated or frozen to prevent rancidity.)[12][13] Consumers seeking a higher-quality

rd is obtained from fatback, the hard subcutaneous fat between the back skin and muscle of the pig. The lowest grade (for purposes of rendering into lard) is obtained from the soft caul fat surrounding digestive organs, such as small intestines, though caul fat is often used directly as a wrapping for roasting lean meats or in the manufacture of pâtés.[3][4][5]
Lard may be rendered by either of two processes: wet or dry. In wet rendering, pig fat is boiled in water or steamed at a high temperature and the lard, which is insoluble in water, is skimmed off of the surface of the mixture, or it is separated in an industrial centrifuge. In dry rendering, the fat is exposed to high heat in a pan or oven without the presence of water (a process similar to frying bacon). The two processes yield somewhat differing products. Wet-rendered lard has a more neutral flavor, a lighter color, and a high smoke point. Dry-rendered lard is somewhat more browned in color and flavor and has lower smoke point.[6][7] Rendered lard produces an unpleasant smell when mixed with oxygen.[8]
Industrially-produced lard, including much of the lard sold in supermarkets, is rendered from a mixture of high and low quality fat sources from throughout the pig.[9] To improve stability at room temperature, lard is often hydrogenated. Hydrogenated lard sold to consumers typically contains fewer than 0.5g of transfats per 13g serving.[10] Lard is also often treated with bleaching and deodorizing agents, emulsifiers, and antioxidants, such as BHT.[4][11] These treatments make lard more consistent and prevent spoilage. (Untreated lard must be refrigerated or frozen to prevent rancidity.)[12][13]
Consumers seeking a higher-quality source of lard typically seek out artisanal producers of rendered lard, or render it themselves from leaf lard or fatback.[9][13][14][15][16]
A by-product of dry-rendering lard is deep-fried meat, skin and membrane tissue known as cracklings.[4]
Chemistry of lard



A triglyceride molecule, the main constituent of lard.
Lard is mainly fats, which, in the language of chemistry are known as triglycerides. These triglycerides are composed of three fatty acids and the distribution of fatty acids varies from oil to oil. In general, lard is similar to tallow in its composition.[17] Pigs that have been fed different diets will have lard with a significantly different fatty acid content and iodine value. Peanut-fed hogs or the acorn-fed pigs raised for Jamón ibérico therefore produce a somewhat different kind of lard compared to pigs raised in North American farms that are fed corn.[2][18]
History and cultural use



Raw fatback being diced to prepare tourtière.
Lard has always been an important cooking and baking staple in cultures where pork is an important dietary item, the fat of pigs often being as valuable a product as their meat.[4]
During the 19th century, lard was used in a similar fashion as butter in North America and many European nations. Lard was also held at the same level of popularity as butter in

Canola (rapeseed) 7.365 63.276 28.142 9-11 19-21 - 400 °F (204 °C)[92] Coconut 91.00 6.000 3.000 - 2 6 350 °F (177 °C)[92] Corn 12.948 27.576 54.677 1 58 28 450 °F (232 °C)[93] Cottonseed 25.900 17.800 51.900 1 5

as well. For example, it is also a natural and safe lubricant, and can be used to lubricate machinery that is used within the kitchen (grinders, blenders, cookware, etc.) It can also be used for illumination (oil lamps) or as the base for soaps and detergents.[89] Some cosmetics also use olive oil as their base.[90]
Vegetable oils
Type    Saturated
fatty acids[91]    Mono-
unsaturated
fatty acids[91]    Polyunsaturated fatty acids    Oleic acid
(ω-9)    Smoke point
Total poly[91]    linolenic acid
(ω-3)    Linoleic acid
(ω-6)
Not hydrogenated
Canola (rapeseed)    7.365    63.276    28.142    9-11    19-21    -    400 °F (204 °C)[92]
Coconut    91.00    6.000    3.000    -    2    6    350 °F (177 °C)[92]
Corn    12.948    27.576    54.677    1    58    28    450 °F (232 °C)[93]
Cottonseed    25.900    17.800    51.900    1    54    19    420 °F (216 °C)[93]
Flaxseed/Linseed (European)[94]    6 - 9    10 - 22    68 - 89    56 - 71    12 - 18    10 - 22    225 °F (107 °C)
Olive    14.00    72.00    14.00    <1.5    9–20    -    380 °F (193 °C)[92]
Palm    49.300    37.000    9.300    -    10    40    455 °F (235 °C)[95]
Peanut    16.900    46.200    32.000    -    32    48    437 °F (225 °C)[93]
Safflower
(>70% linoleic)    8.00    15.00    75.00    -    -    -    410 °F (210 °C)[92]
Safflower
(high oleic)    7.541    75.221    12.820    -    -    -    410 °F (210 °C)[92]
Soybean    15.650    22.783    57.740    7    54    24    460 °F (238 °C)[93]
Sunflower
(<60% linoleic)    10.100    45.400    40.100    0.200    39.800    45.300    440 °F (227 °C)[93]
Sunflower
(>70% oleic)    9.859    83.689    3.798    -    -    -    440 °F (227 °C)[93]
Fully hydrogenated
Cottonseed (hydrog.)    93.600    1.529    .587        .287[91]       
Palm (hydrogenated)    47.500    40.600    7.500               
Soybean (hydrogen.)    21.100    73.700    .400    .096[91]           
Values as percent (%) by weight of total fat.
Religious use[edit]

Fatty acid Percentage ref. Oleic acid 55 to 83% [52][53]

first press", sometimes found on bottle labels, is today meaningless, as there is no "second" press; it comes from ancient times of stone presses, when virgin oil was the one produced by battering the olives.
The label term "cold-extraction" on extra virgin olive oils indicates that the olive grinding and stirring was done at a temperature of maximum 25 °C (77 °F), as treatment in higher temperatures risks decreasing the olive oils' quality (texture, taste and aroma).[51]
Constituents[edit]



General chemical structure of olive oil (triglyceride). R1, R2 and R3 are alkyl groups (approx. 20%) or alkenyl groups (approx. 80%).
Olive oil is composed mainly of the mixed triglyceride esters of oleic acid and palmitic acid and of other fatty acids, along with traces of squalene (up to 0.7%) and sterols (about 0.2% phytosterol and tocosterols). The composition varies by cultivar, region, altitude, time of harvest, and extraction process.
Fatty acid    Percentage    ref.
Oleic acid    55 to 83%    [52][53]
Linoleic acid    3.5 to 21%    [52][53]
Palmitic acid    7.5 to 20%    [52]
Stearic acid    0.5 to 5%    [52]
α-Linolenic acid    0 to 1.5%    [52]
Phenolic composition[edit]
Olive oil contains polyphenols such as esters of tyrosol and hydroxytyrosol, including oleocanthal and oleuropein,[54] having acidic properties that give extra-virgin unprocessed olive oil its bitter and pungent taste. Olive oil is a source of at least 30 phenolic compounds.[55]
Other phenolic constituents include aldehydic secoiridoids, flavonoids and lignans (acetoxypinoresinol, pinoresinol).[56] The latter two compounds are only present in extra virgin oil.[57]
Hydroxytyrosol (2-(3,4-Di-hydroxyphenyl)-ethanol or DHPE) is a phenolic component of extra-virgin olive oil. An olive oil fraction containing DHPE was shown to inhibit platelet aggregation and eicosanoid (thromboxane B2) formation in vitro.[58] Both hydroxytyrosol and its precursor oleuropein exist in the fruit at levels on the order of 100 times that of shelf extra virgin olive oil. Phenolics are considerably higher in fresh cloudy olive oil than extra virgin that has been separated and aged.
Oleocanthal from olive oil is a non-selective inhibitor of cyclooxygenase (COX) similar to classical NSAIDs like ibuprofen. It has been suggested that long-term consumption of small quantities of this compound from olive oil may be responsible in part for the low incidence of heart disease associated with a Mediterranean diet.[59]
Nutrition[edit]

Olive oil