Chapter 11-Vegetable Oils and Waxes Fats and Oils Stored by Plants Fats and oils occur in all parts of plants, but they are present in only a few plant organs. Most vegetable oils are obtained from seeds. The oils are stored in cells: -endosperm --coconut oil --castor bean oil -cotyledon --cottonseed oil --peanut oil --soybean oil In all of these examples, the vegetable oils are food for the germinating embryo. Oils require more energy for production than starch, but contain more calories. In a few examples, oils are pressed from the fruit pulp. --olives --palm fruits

REVIEW Fats

Dietary fats consist of the molecule triglyceride. The triglyceride is made of a molecule of glycerol joined with 3 molecules of fatty acids. Saturated” fats versus “unsaturated” fats The fatty acid is said to be unsaturated because it has less than the maximum number of hydrogens at the location of the double bond. Fatty acids are saturated because they are bonded to the maximum number of hydrogen atoms. Saturated fats - Solid at room temperature - Most animal fats, such as lard or butter, have a high proportion of saturated fatty acids.

Saturated fat and fatty acid.

Stearic acid

Unsaturated fats

- Usually liquid at room temperature

- Vegetable oils (corn, canola)

Unsaturated fat and fatty acid.

Oleic acid

cis double bond causes bending

A given fatty acid can have one, several or no double bonds. monosaturated = 1 double bond polyunsaturated = more than 1 double bond Because all vegetable oils are mixtures of triglycerides and some free fatty acids, saturated, monounsaturated and polyunsaturated refer to the total mix of saturated and unsaturated fatty acid that make up any type of oil. The four fatty acids that are most commonly found in vegetable oils: -oleic -palmitic -linoleic -stearic

Selection in Vegetable Oils and Fats Most modern modifications in seed oils have been the result of classical breeding and selecting for the following qualities: -low saturation for health purposes -low linoleic acid content for flavor stability -high oleic acid content for health and oxidative stability -in some cases, high levels of saturation to replace formerly hydrogenated oils Polyunsaturated Oils Linseed Oil Linseed is probably the oldest domesticated oilseed crop. It forms part of the ancient complex of wheat, barley, peas, lentils, and chickpeas in the Middle East. Fossil linseeds from 6000 B.C. show evidence of human selection. Linseed, Linum usitatissimum (Linaceae), produces linseed oil and flax. Oil seed extraction predated fiber use by several thousand years. Linseed oil is highly unsaturated and a drying oil: Today, linseed oil is: -incorporated into paints -used as a protectant for wood surfaces such as decking and fences

Unsaturated Oils Safflower Oil Safflower oil, Carthamus tinctorius (Asteraceae), was originally domesticated in the Middle East for more than 4000 years ago. Oils from the seeds were traditionally used only for medicinal purposes. -carthamin Until recently, the major use of safflower oil in developed countries: -paint -varnish -resin production Safflower received attention in the U.S. in the 1970’s because it is the most unsaturated of the edible oils. Safflower oil tolerates cold temperatures and it is used for: -salad dressings -margarines Soybean Oil Soybeans, Glycine max (Fabaceae), were pressed for oil and meal in the 1700’s. Today, soybean oil is produced in higher quantities than any other vegetable oil. The U.S. accounts for 40% of the global production. Soybeans oil is always highly processed because it has a highpercentage of linoleic and linolenic acids. Linoleic acid and linolenic acid produce taste problems and cause the oil to foam during frying.

Unsaturated Oils Soybean Oil Manufacturers of soybean oil have overcome this problem by partially hydrogenating the oil to reduce the linolenic content. Most soybean oil is used for: -salad and cooking oils -artificially fluffy or creamy products --whipped toppings --mixes for icing --instant cheesecakes Unsaturated Oils Sunflower Oil Among all the plants used for seed oils, only the sunflower originated in North America. Wild plants of Helianthes annuus (Asteraceae) were branched and had numerous small heads. Modern domestication has produced a plant with one large head. Sunflower cultivation began in Europe in the mid-16th century. In 1830, Russia began commercial extraction of sunflower oil. The selection of a large-head, large-seeded sunflower plants (1000 seeds per head), occurred first in Russia. The Russian Orthodox Church forbade the consumption of common edible oils during Lent. Sunflowers were not on the list of forbidden oils.

Unsaturated Oils Sunflower Oil The achene coat of sunflowers varies in color, but there are two predominate types: -black -gray with brown or black stripes These colors generally indicate whether the seeds are used for snacks or oils. Refined sunflower oil is used as a salad, cooking and commercial oil in prepared foods. Corn Oil Corn oil is produced as a by-product of the corn-milling industry. The oil-rich germs are removed during the milling process, dried, and extracted with solvents. Corn oil is high in linoleic acid and oleic acid, and one of the mostadaptable of all the vegetable oils. Today, most of the refined corn oil is used for salad dressing and margarines.

Unsaturated Oils Sesame Oil Although less important than the other edible oils, sesame oil, Sesamum indicum (Pedaliaceae), has historical importance. Current archeological and molecular data show that the original area of domestication was India Sesame plants were cultivated in the Middle East by 5000 B.C. Sesame seeds are pressed with or without removal of the seed coats. Most sesame oil is extracted with a cold press method that leave the characteristic nutty flavor. The seeds can be eaten toasted or crushed and sweetened to make tahini. Cottonseed Oil Gossypium spp. (Malvaceae) The ancient Hindus extracted cottonseed oil from Asian cottonseed. The oil was skimmed from the surfaces of the water and used for: -medicine -lamp oil Until 1900, cottonseed oil was considered inedible because it contained gossypol. Gossypol is a bitter, toxic pigment that is produced in glands located throughout the cotyledons.

Unsaturated Oils Cottonseed Oil In 1899, David Wesson used caustic soda to purify the seed oils and remove the toxic compounds. By 1900, this purification process was perfected and produced the first edible cottonseed oil- Wesson Oil. In 1911, Procter and Gamble improved the British technique for hydrogenation and introduced the first U.S. vegetable shortening, Crisco. Canola oil Canola, colza or rapeseed oil is the third most important edible oil in the U.S. after soybean oil and cottonseed oil. The oil is extracted from Brassica napus or Brassica campestris (Brassicaceae). Historically, the oil was used for both cooking and as a lubricant. The use of canola oil for cooking was limited because it contained: -erucic acid --long chain fatty acid with a bitter taste -high percentage of linoleic acid --oxidative instability Erucic acid is harmful to humans because it causes heart muscle lesions. Extensive breeding programs in Canada led to the development of varieties with reduced erucic acid and glucosinolates. Commercial varieties of both species that were low in erucic acid and glucosinolates were named canola oil, a trademark of Canola Council of Canada.

Unsaturated Oils Canola Oil -low level of saturated fatty acids -level of monounsaturated fatty acids shown to lower plasma levels of cholesterol -intermediate level of polyunsaturated fatty acids -good ratio (2:1) between linoleic and linolenic acids Moderately Saturated Oils Peanut Oil Peanuts, Arachis hypogaea (Fabaceae), were not used for oil until about 135 years ago. In the U.S., one-fourth of the peanut crop goes into oil production. Peanut Oil Shelled peanuts are carefully dried. The seed coats are removed. The oil is pressed by crushing and solvent extraction. Peanut oil is considered a premium cooking oil because: -it does not smoke when heated to high temperatures -does not retain odors Olive Oil Olives, Olea europa (Oleaceae) have sustained cultures since ancient times. Wild olives were used during the Neolithic period 10,000-7,000 years ago. Molecular evidence suggests independent domestications . The first archeological evidence of olive cultivation dates from 3500 B.C. The Egyptians and the Greeks used olive oil: -to anoint bodies -lamp oil -food -medicine -religion

Moderately Saturated Oils Olive Oil Olive oil is one of the few oils that is obtained from fruit pulp rather than seeds. Because only the pulp is used, the procedure for extraction differs from most oils: -fruits are macerated -seeds are removed -pulp is pressed The oil is separated from water and bits of particulate matter by decanting, centrifuging and filtering. The first press yield “virgin” olive oil which is graded on the basis of taste and acid content. Subsequent pressings, usually with heat, yield oils of lower grades. Extra virgin olive oil is best for salads and fresh use, but should not be used for cooking due to its low smoke point.

Moderately Saturated Oils Castor Oil Castor oil, Ricinus communis, (Euphorbiaceae), was forced down the throats of many children in the past century by well-intentioned parent. The laxative action of the oil was caused by ricinoleic acid. The seeds, hulls and unrefined oil are toxic to humans if taken in large quantity. Four compounds are responsible for these effects: ricinine --mildly toxic alkaloid -ricin --highly poisonous protein that leads to hemorrhaging -Ricinus communis agglutinin (RCA) --agglutinates red blood cells -protein polysaccharide mixture (castor bean allergen) (CBA) --causes violent allergic reaction Botanists do not agree about the original area of distribution of Ricinus communis. It was probably domesticated in tropical Africa with the oldest records of use in Egypt, approximately 6000 ybp. Ancient uses of the oil included: -lamp oil -medicine -religious ceremonies

Moderately Saturated Oils Castor Oil Castor plants are monoecious perennials with male flowers at the bottom and female flowers at the top. If the oil is used for medicinal purposes, then the seeds are pressed at temperatures lower than 50°C (122°F), so the ricin is not removed with the oil. Today, castor oil is used in: -paints -varnishes -synthetic polymers -resins -cosmetics

Waxes Waxes are made by joining simple alcohols and fatty acids. All flowering plants produce waxes that cover epidermal surfaces to prevent water loss. Species that produce a substantial amount of wax have been exploited as sources of wax. Only four types of waxes are used in the U.S. today: -jojoba -carnauba wax -candelilla wax -bayberry Jojoba Jojoba, Simmondsia chinensis, (Simmondsiaceae) is a shrub that grows in the Sonoran Desert of North America. Jojoba -crop that can be grown on land that is unsuitable for other purposes -oil is chemically similar to sperm whale oil -potential replacement for sperm whale oil as a lubricant for machinery Jojoba is effective in penetrating the outer layers of human skin. This property has led to its use primarily in cosmetics.

Waxes Carnauba Wax Copernica cerifera- palm from NE Brazil Source of carnauba wax which is used in waxes and shoe polish Candelilla Wax Candelilla wax is obtained from the succulent stems of Euphorbiaantisyphilitica (Euphorbiaceae) and is often substituted for carnauba wax. Candelilla plants are native to the Chihuahuan Desert along the U.S.-Mexican border. Plants collected for wax extraction are wild. In the U.S., collection of the plant is forbidden because the species is endangered. Bayberry Early settlers in the northeastern United States collected the fruits of the bayberry, Myrica pensylvanica (Myricaceae). The fruits were boiled to melt off the wax. The wax was cooled and re-melted to make candles.

Ch 11-Vegetable Oils and Waxes What part of the plant are most vegetable oils from? Give examples from the endosperm; Give examples from the cotyledons In a few examples, oils are pressed from the fruit pulp. Give examples REVIEW: structure of a fatty acid; unsaturated vs. saturated What are the 4 fatty acids most commonly found in vegetable oils? What qualities in vegetable oils and fats have been the result of classical breeding and selection? Polyunsaturated oil Linseed, Linum usitatissimum (Linaceae) Know origin/history and information about cultivation/domestication and uses. Unsaturated Oils Safflower, Carthamus tinctorius (Asteraceae) Know origin/history and information about cultivation/domestication and uses. Soybean, Glycine max (Fabaceae) Know origin/history and information about cultivation/domestication and uses. Sunflower, Helianthes annuus (Asteraceae) Know origin/history and information about cultivation/domestication and uses. Corn, Zea mays (Poaceae) Know origin/history and information about cultivation/domestication and uses. Sesame, Sesamum indicum (Pedaliaceae), Know origin/history and information about cultivation/domestication and uses. Cottonseed, Gossypium spp. (Malvaceae) Know origin/history and information about cultivation/domestication and uses. Canola, colza or rapeseed , Brassica napus or Brassica campestris, (Brassicaceae). Know origin/history and information about cultivation/domestication and uses. Moderately Saturated Oils Peanut, Arachis hypogaea (Fabaceae) Know origin/history and information about cultivation/domestication and uses. Olive, Olea europa (Oleaceae) Know origin/history and information about cultivation/domestication and uses. Castor oil, Ricinus communis, (Euphorbiaceae) Know origin/history and information about cultivation/domestication and uses. Waxes Know the general structure of a wax What are the 4 types of waxes used in the U.S. today? Jojoba, Simmondsia chinensis, (Simmondsiaceae) Know information about cultivation/domestication and uses. Carnauba wax, Copernica cerifera, (Arecaceae) Know information about cultivation/domestication and uses. Candelilla wax, Euphorbia antisyphilitica (Euphorbiaceae) Know information about cultivation/domestication and uses. Bayberry, Myrica pensylvanica (Myricaceae) Know information about cultivation/domestication and uses.

Chapter 11-Fats, Oils and Waxes

Polyunaturated/Unsaturated Oils ___ Linum usitassiumum A. canola oil ___ Brassica napus/B. campestris B. sesame oil ___ Glycine max C. sunflower oil ___ Gossypium spp. D. safflower oil ___ Helianthus annuus E. soybean oil ___ Sesamum indicum F. linseed oil ___ Zea mays G. cottonseed oil ___ Carthamus tinctorius H. corn oil

Definitions fats oils glycerol backbone unsaturated saturated cis bond trans bond monosaturated polyunsaturated partially-hydrogenated linseed oil linoleic acid linolenic acid safflower oil soybean oil sunflower oil corn oil oleic acid sesame oil tahini cottonseed oil gossypol

David Wesson Wesson oil Crisco canola erucic acid glucosinolates peanut oil olive oil “virgin” “extra virgin” castor oil ricinoleic acid ricinine ricin RCA CBA wax jojoba carnauba wax candelilla wax bayberry

Moderately Saturated Oils ___ Arachis hypogaea A. olive oil ___ Ricinus communis B. peanut oil ___ Olea europa C. castor oil

Waxes ___ Myrica pensylvanica A. candelilla wax ___ Simmondsia chinensis B. carnauba wax ___ Euphorbia antisyphilitica C. bayberry ___ Copernica cerifera D. jojoba

What part of the plant are most vegetable oils from? Give examples from the endosperm; Give examples from the cotyledons In a few examples, oils are pressed from the fruit pulp. Give examples Explain the difference between saturated and unsaturated fatty acids. Linseed oil Know origin/history and information about cultivation/domestication and uses. Pick one of the following: soybean oil; safflower oil ; corn oil or sesame oil. Know family, origin/history and information about cultivation/domestication and uses. Sunflower oil Know family, origin/history and information about cultivation/domestication and uses. Cottonseed oil Know origin/history and information about cultivation/domestication and uses. Canola, colza or rapeseed oil Know family, origin/history and information about cultivation/domestication and uses. Pick one of the following: peanut oil or castor oil. Know origin/history and information about cultivation/domestication and uses. Olive oil Know origin/history and information about cultivation/domestication and uses. Pick one of the following: jojoba; candelilla wax; carnauba wax; or bayberry. Know origin/history and information about cultivation/domestication and uses.