Vegetable Oil - Cooking Oil
Alcohol plant
Cooking Oil:
Origin Satu
rated
Mono
unsatu
rated
Poly
unsatu
rated
Smo
king
temp.
oC

Almond

8%

66%

26%

221

Avocado

12%

74%

14%

271

Canola

6%

62%

32%

242

Coconut

92%

6%

2%

177

Rice bran

20%

47%

33%

254

Corn

13%

25%

62%

236

Cottonseed

24%

26%

50%

216

Grape seed

12%

17%

71%

204

Hemp

9%

12%

79%

165

Mustard

13%

60%

21%

254

Olive  (virgin)

14%

73%

11%

215

Olive  (refined)

14%

73%

11%

225

Palm

52%

38%

10%

230

Peanut

18%

49%

33%

231

Safflower

10%

13%

77%

265

Sesame

14%

43%

43%

232

Soybean

15%

24%

61%

241

Sunflower 

11%

20%

69%

246

Vegetable oil are lipid materials derived from plants like soy beans. Vegetable oils are composed of triglycerides and is extracted from oil seeds and cooking oils preferably from olives, soybeans, rape- and sunflower seeds.

Extraction Today vegetable oil processing is preferably made by chemical extraction, using solvent extracts like hexane, which produces better yields at a lower cost than by mechanically expelling the oil.

Refining. The crude oil from expellers or solvent extraction plant contains impurities to be removed making the oil edible, palatable and stable against rancidity during storage. The impurities are:
  • Gums: The hydratable gums (phospholipids) are removed during "Degumming" - a treatment with phosphoric acid and centrifugal separation.
  • Hydrolysis Products: Diglycerides and monoglycerides and free fatty acids are removed during "Neutralisation" - a treatment with caustic forming soap with the fatty acids, followed by centrifugal separation.
  • Protein, Carbohydrates, Resins: These are also removed during "Neutralisation".
  • Colour: Chlorophyll (green) carotene (red), anthophyll (yellow) and gossypol (orange) impart distinct colour to the oil and are removed during "Neutralisation" and "Bleaching" - treatment with active carbon and pressure filtration.
  • Odour is present in small amounts but imparts strong objectionable odour to the oil. Odour is volatile constituents and is removed by "Deodorisation". The oil is heated and de-airated under high vacuum and steam injection. The deodorised oil is cooled and filtrated.
  • Wax:  In particular sunflower oil and rice bran oil contains appreciable amounts of waxes. Waxes are high melting esters of fatty alcohol of long chain fatty acids. Wax is removed by "Dewaxing" - chilling and filtration.

TransesterificationMargarine and Bakery Shortening. Fats with higher meleting point may be produced from liquid oils by hydrogenation or transesterification (Inter-Esterification). Lipase-catalyzed transesterification has been used to obtain more natural products more accepted by consumers.