【油酸，亚油酸，亚麻酸】

油酸，Oleic acid

What is Oleic Acid?

• One of the most common fats in human breast milk
• Makes up 25% of fat in cow's milk
• Monounsaturated
• Omega-9 fatty acid
• Chemical formula is C₁₈H₃₄O₂
• Hangs out with triglycerides
• Is used in high priced cosmetics as a very effective moisturizer
• Found in milk fat, cheese, olive oil, grapeseed oil, nuts, avocados, eggs and meat
• May be responsible for most of the health benefits of olive oil!

 

 

Oleic acid reduces blood pressure, increases fat burning to help with weight loss, protects cells from free radical damage, may prevent type 2 diabetes, prevents ulcerative colitis and generates brain myelin.

Milk fat contains 25% oleic acid. Oleic acid is an monounsaturated omega-9 fatty acid with many health benefits.

 

Five Reasons to Enjoy Foods Rich in Oleic Acid

1) Oleic acid reduces blood pressure.

Oleic acid regulates the activity of adrenoreceptor signaling pathways which direct the adrenergic receptors (α- and β-adrenoceptors) that help regulate blood pressure (Teres et al. 2008). Eating a diet high in oleic acid for 4 weeks reduced blood pressure while increasing good HDL cholesterol in women (Ruiz-Gutiérrez et al. 1996).

2) Oleic acid may help you burn fat.

Oleic acid normalizes or increases fat oxidation (burning). Lim et al. (2013) found that oleic acid increases the expression of genes involved in fat burning. This means that your body is more efficient at using fat as fuel. In addition oleic acid accelerated rates of complete fat oxidation in muscle cells.

3) Diets rich in oleic acid prevent ulcerative colitis.

People consuming the highest amounts of oleic acid were 89% less likely to have ulcerative colitis than those consuming the least amount of oleic acid (de Silva et al. 2014).

4) Oleic acid alleviates type 2 diabetes.

Oleic acid reverses the symptoms caused by type 2 diabetes in mice (Vassilious et al. 2009). Consuming oleic acid inhibited the inflammatory cytokine TNF-α which is produced by fat cells in obese people and contributes to metabolic syndrome (Yudkin 2007, Vassilious et al. 2009). A diet high in oleic acid may reduce the inflammation seen in obesity and non-insulin dependant obesity (Vassilious et al. 2009).

5) Oleic acid protects cell membranes from free radicals.

When you consume oleic acid, it replaces other omega fatty acids in cell membranes. Since oleic acid is less susceptible to oxidation damage than omega-6 and omega-3 fatty acids, replacing these fatty acids with oleic acid protects your cell membranes from free radicals and other oxidative stressors (Haug et al. 2007).

Oleic acid is a common monounsaturated fat in human diet. Monounsaturated fat consumption has been associated with decreased low-density lipoprotein (LDL) cholesterol, and possibly increased high-density lipoprotein (HDL) cholesterol.^[22]However, its ability to raise HDL is still debated.

Oleic acid may be responsible for the hypotensive (blood pressure reducing) effects of olive oil.^[23] Adverse effects also have been documented, however, since both oleic and monounsaturated fatty acid levels in the membranes of red blood cells have been associated with increased risk of breast cancer,^[24] although the consumption of oleate in olive oil has been associated with a decreased risk of breast cancer.^[25]

 

Oleic acid is the most abundant fatty acid in human adipose tissue,^[9] and second in abundance in human tissues overall only to palmitic acid.^[10]

 

亚油酸 Linoleic acid

 

Linoleic acid is a doubly unsaturated fatty acid, also known as an omega-6 fatty acid, occurring widely in plant glycosides. In this particular polyunsaturated fatty acid (PUFA), the first double bond is located between the sixth and seventh carbon atom from the methyl end of the fatty acid (n-6). Linoleic acid is an essential fatty acid in human nutrition because it cannot be synthesized by humans. It is used in the biosynthesis of prostaglandins (via arachidonic acid) and cell membranes. (From Stedman, 26th ed).

Metabolite Description from Human Metabolome Database (HMDB)

Linoleic acid is a doubly unsaturated fatty acid, occurring widely in plant glycosides. It is an essential fatty acid in mammalian nutrition and is used in the biosynthesis of prostaglandins and cell membranes. (From Stedman, 26th ed)

from MeSH

Linoleic Acid is a polyunsaturated essential fatty acid found mostly in plant oils. It is used in the biosynthesis of prostaglandins and cell membranes.

Pharmacology from NCIt

 

 

 

Linoleic acid, or omega-6 fatty acid, and linolenic acid, or omega-3 fatty acid, are the two essential fatty acids. They are termed as essential because the body cannot synthesize them and needs to obtain them from the diet. A lack of either of the two leads to ill health and causes deficiency symptoms to develop.

Functions of Linolenic Acid

As reported in the “Manual of Dietetic Practice,” linolenic acid is essential for normal growth and development. In the body, linolenic acid is used to make substances called eicosanoids, which regulate inflammation. Linolenic acid is also a component of cell membranes and is converted to the longer chain omega-3 fatty acids eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA. The omega-3 fatty acids deliver numerous health benefits, according to the National Institutes of Health Office of Dietary Supplements.

Special Roles of EPA and DHA

EPA and DHA, the long chain derivatives of linolenic acid, have been associated with a number of health benefits. For example, in regard to cardiac health, these omega-3 fatty acids have been shown to protect against coronary heart disease, sudden cardiac death and heart failure, possibly through anti-arrhythmic, anti-thrombotic, anti-atherosclerotic and anti-inflammatory mechanisms, as reported in the 2009 issue of “Current Pharmaceutical Design.” Other benefits that the “Oxford Handbook of Clinical Medicine” attributes to these omega-3 fatty acids include control of inflammation in arthritic conditions and protection against neurodegenerative diseases.

Functions of Linoleic Acid

Linoleic acid is part of cell components, and is used to manufacture signaling molecules in the body. However, it now appears Western diets contain too much linoleic acid relative to linolenic acid. The March-April 2011 issue of “Nutricion Hospitalaria” reported that current diets have an omega-6:omega-3 ratio of about 20:1, while optimal ratios should probably be closer to 1.5:1. It is recommended that you focus more on increasing your omega-3 fat intake than your omega-6 intake.

Sources

Omega-6 fatty acids are found in many plant oils, including palm oil, sunflower oil, flaxseed oil, corn oil and evening primrose oil. Other good sources include nuts, avocados and pumpkin seeds. On the other hand, the best sources of omega-3 fatty acids are oily fish and seaweed, because these contain omega-3 in the form of EPA and DHA. Sources of the parent linolenic acid include flax, purslane, hemp, nuts and organic eggs. Supplements of both linoleic and linolenic acids are readily available. Check with your doctor, however, before adding supplements to your diet, especially if you have health problems or take other medicines.

 

 

 

亚麻酸 linolenic acid

a polyunsaturated fatty acid (with one more double bond than linoleic acid) present as a glyceride in linseed and other oils and essential in the human diet.

Sources of the essential fatty acid linolenic acid are soybean oil, canola oil, walnuts and flaxseed.

 

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胡麻油生产分为浸出法和压榨法

浸出法是将原料利用油脂和有机溶剂相互溶解的性质，将胡麻籽破碎压成胚片或者膨化后，用正己烷等有机溶剂和胡麻籽胚片在名叫浸出器的设备内接触，将胡麻籽中的油脂萃取溶解出来，然后通过加热汽提的方法，脱除油脂中溶剂。这样得到的毛油再经过进脱胶、脱水、脱味、脱蜡等一系列的精炼处理，就成为最终的胡麻油。

热榨胡麻油图册

浸出法的优点是：出油率高，成本低
缺点是：对油质营养成份破坏大

压榨法又分为热榨法和冷榨法

热榨是将胡麻籽除杂后进行烘炒，将炒熟的胡麻籽再进行物理压榨，用热榨法压榨而得的胡麻油含有浓郁的胡麻籽香味而微苦，呈褐红色；

冷榨是将除杂后的胡麻籽直接进行物理压榨，冷榨法压榨的胡麻籽闻起来有淡淡的胡麻籽香味，品尝微苦，加热后有浓郁鱼香味，色泽金黄。

压榨法的优点是：最大程度的保留的胡麻籽的营养成份

冷榨胡麻油图册

缺点是：出油率低，成本高