Cottage Grove Olive Oil

Evaluating the Quality of Cottage Grove Olive Oil

Numerous attributes of olive oil play a role in determining its overall quality. However, two basic ones are its Peroxide Value, PV and the amount of Free Fatty Acid it contains.

Peroxides are primary oxidation products that are formed when oil is exposed to oxygen, producing undesirable flavours and odours. The Peroxide Value will rise and then taper down while oil is in storage. The unit used for PV is milli-equivalents of active oxygen/kg oil. Virgin olive oils should have a PV of <20.

The Free Fatty Acid value is measured as free acidity expressed in g/100g of oleic acid in the oil. Extra Virgin Olive Oil has not more than 0.8g/100g of free acidity.

The following are test results of Peroxides and Free Fatty Acid for samples of the 2016 and 2017 harvest from Cottage Grove (analysis done by the Far North Enviro Lab Ltd, Taipa).

2016 Test Results Result 1 Result 2
Peroxide mEqO2 4.39 4.38
Free fatty acid % 0.11 0.11
2017 Test Results Result 1 Result 2
Peroxide mEqO2 8.42 8.40
Free fatty acid % 0.03 0.03

Clearly, the olive oil from Cottage Grove passes the Peroxide test with flying colours, although it is interesting that the 2017 PV value is considerably higher than that of 2016. This probably reflects the year standing time of the 2016 vintage before we sent samples for analysis. We would expect the 2017 PV value to fall to a similar low level after another year of storage.

The free acid values of both 2016 and 2017 are much less than 0.8g/100g and therefore both Cottage Grove vintages qualify as extra virgin oil.

General Characteristics of Olive Oil

There is a lot of misinformation about the health and other benefits of olive oil compared to other oils used with food.

Firstly, a comment on terminology: what we refer to as fat is a complex mixture of different molecules, known as lipids or fatty acids. The latter two terms are often used interchangeably.

There are only two or three fats which are truly beneficial to humans, and they are known as Essential Fatty Acids (EFAs). These fats are essential because the human body cannot produce them on its own, so they must come from diet. The two primary EFAs are known as linoleic acid or LA (an omega-6 lipid), and alpha-linolenic acid or ALA (an omega-3 lipid).

Some other fatty acids are sometimes classified as conditionally essential, meaning that they can become essential under some developmental or disease conditions; examples include docosahexaenoic acid or DHA (an omega-3 lipid) and gamma-linolenic acid or GLA (an omega-6 lipid).

Arachidonic acid or AA is not one of the essential fatty acids. However, it does become essential if there is a deficiency in linoleic acid or if there is an inability to convert linoleic acid to arachidonic acid, which is required by most mammals.

The main lipids present in a sample of the Cottage Grove olive oil from the 2016 harvest is given below (analysis by Nutrition Laboratory, Massey University).

Lipid Name                   Percent
Oleic                          76.72
Palmitic                        8.96 
Linoleic                        7.33  LA 
Stearic                         2.54 
Vaccenic                        1.17  
cis-9,12,15-Alpha linolenic     0.82  ALA
Arachidic                       0.40 
cis-9-Palmitoleic               0.38 
cis-ll-Eicosenoic               0.27  
Behenic                         0.12  
Margaric                        0.11 
Lignoceric                      0.05 
cis-ll,14-Eicosadienoic         0.04   
Heneicosanoic                   0.02  
Tricosanoic                     0.02  
cis-13-Erucic                   0.01   
Myristic                        0.01  
Vaccenic                        0.01
Total                          98.98
As can be seen in these results, Cottage Grove olive oil from the 2016 harvest contains just over 8% of EFA (7.33% LA, and 0.82% ALA). This is very modest, compared with those listed below.
Percent EFA lipids       ALA      AL
Chia seed oil             64      18
Flax/linseed seed oil     40      31
Hemp oil                  19      56
Walnut oil               0.4      59
Avocado oil              0.8      15
Grapeseed oil            0.1      73
For clarity, the species names of these plants are: chia, Salvia hispanica; common flax or linseed, Linum usitatissimum (not to be confused with NZ flax, Phormium tenax); hemp, Cannabis sativa; walnut, Juglans regia; avocado, Persea americana; grape, Vitis vinifera.

Olive oil as a source of Omega 3 fatty acids
The main Omega 3 fatty acids are: 18:3 Alpha-Linolenic acid (ALA); 20:5 Eicosapentaenoic acid (EPA); and 22:6 Docosahexaenoic acid (DHA).

The only Omega 3 lipid found in the Cottage Grove olive oil was ALA at a mere 0.82%, which is a typical result for olive oils (see the United States Department of Agriculture Composition Database USDA). Fish oils are the most common source which is rich in Omega 3 lipids. Some examples are outlined below:

Fish Oils %    EPA     DHA    ALA
Salmon oil     13      18    <1
Sardine oil    10      11    <1
Cod liver       7      11    <1

Olive oil is not recommended as a cooking oil

This is because of the low smoke point of olive oil (see Table below). Other oils which have high smoke points (above 200C/400F) include avocado oil, almond oil, corn oil, canola oil, grapeseed oil, peanut oil, safflower oil, sesame oil and sunflower oil. These oils are better suited for cooking at higher temperatures.

Avocado oil                     271C
Ghee (clarified Butter)         252C
Soybean oil (refined)           238C
Peanut oil                      232C
Coconut oil (refined)           232C
Corn oil                        227C
Grapeseed oil 			216C
Canola oil (refined)		204C
Olive oil (virgin)              199C
Olive oil (extra virgin)        191C
Lard                            188C
Vegetable shortening            182C
Coconut oil (extra virgin)      177C
Sesame oil (unrefined)          177C
Butter                          120-150C
Flax seed oil                   107C

Saturated and Unsaturated Fats

Saturated fats have no double bond between molecules (the fat is saturated with hydrogen molecules), and they are generally solid at room temperature.

Unsaturated fats have one (monounsaturated) or more (polyunsaturated) double bonds in their molecules and are liquid at room temperature.

The American Heart Association recommends that 25-35% of human total daily calories should consist of fat, and that most of this intake should be from unsaturated fat. However, accumulating scientific research now suggests that unsaturated fats alone may not be as heart healthy, and consuming saturated fats may not be as dangerous as once thought.

The most common sources of saturated fats include:
    Animal meat including beef, poultry, pork
    Certain plant oils such as palm kernel or coconut oil
    Dairy products including cheese, butter, and milk
The most common sources of unsaturated fats include:
    Monounsaturated fats canola oil and olive oil
    Polyunsaturated fats safflower oil, sunflower oil, and corn oil
As can be seen from the above, olive oil is a monounsaturated fat, and as a result is considered by many to be a more healthy source of dietary fat than many others available. However, the scientific literature relating to the hazards and benefits of consuming different types of fats in diet is far too complex (and in some places contradictory) to be summarised here. One suggestion is that whatever modest health benefits that might be associated with consuming olive oil could be largely due to the beneficial plant chemicals, such as polyphenols and plant sterols, found in the extra virgin olive oils. In addition, these plant chemicals are largely lost in the more processed light cheaper olive oils available in supermarkets. Clearly, Cottage Grove extra virgin oil might therefore have a lot to recommend it.

The following Table presents the complete lipid analysis carried out on the 2016 vintage from Cottage Grove. ND = Not detected.

Cottage Grove olive oil, 2016 harvest Fatty acid profile. g/100g

Lipid Number Fatty Acid Name Percent
C6:0 Caproic ND
C8:0 Caprylic ND
Cl0:0 Capric ND
Cll:0 Undecanoic ND
C12:0 Lauric ND
C13:0 Tridecanoic ND
C14:0 Myristic 0.01
C14:1n5 cis-9-Myristoleic ND
C15:1n5 cis-l0-Pentadecenoic ND
C16:0 Palmitic 8.96
C16:1n7 cis-9-Palmitoleic 0.38
C17:0 Margaric 0.11
C17:1n7 cis-l0-Heptadecenoic ND
C18:0 Stearic 2.54
C18:1n9t Elaidic ND
C18:1n7t Vaccenic 0.01
C18:1n9c Oleic 76.72
C18:1n7c Vaccenic 1.17
C18:2n6t Linolelaidic ND
C18:2n6c Linoleic 7.33
C20:0 Arachidic 0.40
C18:3n6 cis-6,9,12-Gamma Linolenic ND
C20:1n9 cis-ll-Eicosenoic 0.27
C18:3n3 cis-9,12,15-Alpha Linolenic 0.82
C21:0 Heneicosanoic 0.02
C20:2n6 cis-ll,14-Eicosadienoic 0.04
C22:0 Behenic 0.12
C20:3n6 cis-8,ll,14-Eicosatrienoic ND
C22:1n9 cis-13-Erucic 0.01
C20:3n3 cis-ll,14,17-Eicosatrienoic ND
C20:4n6 cis-5,8,ll,14-Arachidonic ND
C23:0 Tricosanoic 0.02
C22:2n6 cis-13,16-Docosadienoic ND
C24:0 Lignoceric 0.05
C20:5n3 cis-5,8,ll,14,17-Epa ND
C24:1n9 cis-15Nervonic ND
C22:5n3 cis-7,10,13,16,19-DPA ND
C22:6n3 cis-4,7,10,13,16,19-DHA ND