www.ijraset.com Volume 2 Issue XII, December 2014 ISSN: 2321-9653 International Journal for Research in Applied Science & Engineering Technology (IJRASET) ©IJRASET 2014: All Rights are Reserved 120 Cholesterol Content and Free Fatty Acids in Edible Oils and Health Effects: A review Alemayehu Gashaw 1 , Tewodros Getachew 2 1,2 Department of Chemistry, Faculty of Natural and Computational Sciences, Bule Hora University, Bule Hora, Ethiopia Abstract: Cholesterol plays a major role in human heart health and high cholesterol is a leading risk factor for human cardiovascular diseases such as coronary heart disease and stroke. Not only cholesterol content but also cholesterol oxidation (favoured during thermal-processing of food) can be potentially harmful to human health. A person with the level of 240 mg/dl or above has more than twice the risk of heart disease as someone whose cholesterol is below 200 mg/dl. Most literatures showed that there is no cholesterol free oil in the market as shown on the vegetable oil brand labels and companies producing and advertising vegetable oils are enjoined to desist from misleading the public by labeling their products as “cholesterol free”. Hence this review explains the way of determining the cholesterol content in edible oils and call attention to write or label the amount of cholesterol present in the oil, no matter how small quantity may be. In addition, this review describes acid value, iodine value, and saponification value and oil rancidity. Key words: Lipoprotein; Cholesterol; Rancidity; Liebermann-Burchard reaction I. INTRODUCTION Many vegetable oils are consumed directly or used as ingredients in food. Reports show that approximately 75% of the World’s production of oils and fats come from plant sources. Although many plant parts yield oil, in actual marketable practices, oil is extracted primarily from seeds of oilseed plants such as soybean, cotton, palm, rape and groundnut (Okpuzor et al., 2009). Oils have always been an integral part of human foods, being fundamental for health. Industrially, they play an important role in the development of different areas of chemical products, pharmaceutical, cosmetics, paints and most importantly, food. Oils are naturally occurring esters of long straight-chain carboxylic acids. They belong to the saponifiable group (contain an ester groups) of lipids. Lipids are biologically produced materials that are relatively insoluble in water but soluble in polar and non- polar organic solvents. Edible oils are constituted of triacylglycerol molecules, mainly formed by unsaturated (oleic, linoleic, linolenic acids etc.) and saturated fatty acids (myristic, palmitic, stearic acids etc.) esterified to glycerol units (Andersson et al., 2010). They can be formed from a single fatty acid that could be esterified up to three times into glycerol backbone, or at least by three different ones. Almost every adult at present times develops some degrees of atherosclerosis, commonly known as “hardening of the arteries”. Atherosclerosis leads to strokes, heart attacks and other serious health problems. High cholesterol, smoking and high blood pressure are the principal risk factors linked to heart disease (Dimberu and Belete, 2011). Cholesterol is a waxy substance made by animal liver and also supplied in diet through animal products such as meats, poultry, fish and dairy products. It is needed in the body to insulate nerves, make cell membranes and produce certain steroid hormones, and for the biosynthesis of bile and bile acid salts. Bile is the major excretion route of cholesterol from the body, predominantly as unesterified cholesterol. In the adult human, approximately 400 mg of cholesterol per day are converted to bile acids and only approximately 50 mg are converted to hormones (Valenzuela et al., 2003). Sterol plays also an important role in embryonic development and an important lipid in some membranes. However, the body makes enough cholesterol, so any dietary cholesterol isn't needed (Ma, 2006). Cholesterol plays a major role in human heart health. Cholesterol can be both good and bad. High-density lipoprotein (HDL) is good cholesterol and low-density lipoprotein (LDL) is bad cholesterol. LDL cholesterol is considered as “bad cholesterol” responsible for allowing fatty plaques to develop in the lumen of arteries, leading to their narrowing. If this narrowing develops in coronary arteries (supplying blood to the heart), the person can develop coronary artery disease (CAD) and can lead to heart attacks (Mishra and Manchanda, 2012). HDL cholesterol is desirable as it is a means of transporting cholesterol from parts of the body where there is too much of it to the liver where it can be disposed of. High cholesterol in serum is a leading risk factor for human cardiovascular disease such as coronary heart disease and stroke - America's number one killer. Excess cholesterol in the bloodstream can form plaque (a thick, hard deposit) in artery walls. The cholesterol or plaque build-up causes arteries to become thicker, harder and less flexible, slowing down and sometimes blocking blood flow to the heart. When blood flow is restricted, angina (chest pain) can result. A heart attack will result when blood flow to the heart is severely impaired and a clot stops blood flow completely. When there is too much LDL cholesterol in the blood, it is deposited inside the blood vessels, where it can build up to hard deposits and causes