Extra Virgin Olive Oil is able to withstand high frying temperatures due to its high stability making it the perfect companion for conventional cooking methods.
Functions of oil and fat in food
Fats and oils are not only a source of calories, but they also serve many chemical, physical, and nutritional functions in the body.
Some of the most important functions that fats and oils serve in food are:
– Appearance and texture: Fats and oils can alter a food’s appearance by creating a glossy or moist visual texture, making foods such as salads and vegetables appear more desirable.
– Flavour: Fats and oils have the unique ability to absorb and preserve flavours, increasing the palatability of certain foods (such as vegetable and salads).
– Nutrition: Fats and oils are the most calorie dense component of food and are also important for delivering fat soluble vitamins such as vitamins A, D, E and K.
– Satiety: Fats and oils play an important role in achieving satiety after a meal.
– Solubility: While fats and oils are not soluble in water, there are other chemical compounds that are only soluble in fats. Many of these fat-soluble compounds are responsible for the flavour in food and vitamin content. Including fat in food allows for maximum flavpopour and a wider range of nutritional content to transfer from the food to your body.
– Heat transfer: Fats and oils provide one of the most efficient modes of heat transfer during cooking. (1)
What happens to oil during the cooking process?
When cooking oils are exposed to high temperatures a variety of chemical changes can occur, such as hydrolysis, oxidation and other thermal reactions. (2,3) Heating oils too high, or for too long, can result in oil decomposition and the production of byproducts, including free fatty acids (FFAs), alcohol, cyclic compounds, dimers and polymers. (3) These chemical reactions which take place are governed by factors such as; the type and quality of oil used in cooking, the properties of the food being cooked, temperature and time of exposure and the food/oil ratio. (2)
The end result of these chemical changes which occur through heating oil are twofold, potentially affecting both the organoleptic properties of the oil and the nutritional value. (4) In addition, some of the products formed through oil decomposition may have adverse effects on human health. (3)
The total deterioration of oil when frying can be measured by both sensory (i.e. changes in colour, smell and taste) and laboratory values (i.e. measuring FFAs and the formation of total polar compounds (TPC)). (3) Overall, there are two major properties of cooking oils which dictate the behavior of that oil, and subsequent safety when exposed to high cooking temperatures – Smoke Point and, most importantly, Oxidative Stability.
POP OUT / FACT – Contrary to unsubstantiated popular myths, Cobram Estate Extra Virgin olive Oil (EVOO) is an excellent choice for cooking. Cobram Estate EVOO has a smoke point well above the standard temperatures required for cooking, and its resistance to oxidation is higher than most cooking oils due to the antioxidant and mono-unsaturated fat content. Therefore, it is ideal for both hot and cold cooking and there is less chance that harmful substances will be formed upon the application of heat, through cooking. Furthermore, although the heating process will reduce the natural antioxidant content of EVOO, there is scientific evidence to demonstrate that a substantial amount of antioxidants can still be found in the prepared meal. (5,6)
The smoke point of an oil or fat is the temperature at which, under defined conditions, sufficient volatile compounds emerge from the oil and a bluish smoke becomes clearly visible. At this temperature, volatile compounds, such as water, FFAs, and short-chain degradation products of oxidation evaporate from the oil. The smoke point is the temperature at which the oil is decomposed and where possible toxicologically relevant compounds are formed.
The smoke point of an oil generally increases as the FFA content decreases, and the degree of refinement increases. (7)
When cooking foods, they are exposed to a variety of temperatures:
High quality Cobram Estate EVOO has a reasonably high smoke point ranging between 200°C and 215°C, which is well above the standard temperatures required for cooking. This is due to the low FFA content that results from the fresh, healthy olive fruit grown on Cobram Estate’s farms and care taken when handling and milling the fruit to minimise deterioration of the fruit (deteriorated fruit delivers oils with higher FFA and thus lower smoke point). (8) High quality Cobram Estate EVOO is able to withstand high cooking temperatures due to the high stability of the oil, and subsequently high smoke point, making it a suitable oil for use for hot and cold cooking via conventional methods including pan frying (sauté), stir frying, deep frying, BBQ’s and oven baking.
When heating oils, the process of fat oxidation is accelerated. Fat oxidation is where the fat molecules interact with oxygen, leading to the potential formation of harmful compounds. Oxidative stability is the best predictor of the behaviour of oil during cooking (9,10,11).
EVOO has a high level of oxidative stability (when compared to other types of cooking oil), and is less likely to undergo oxidation. (4) This is primarily attributed to two factors:
(antioxidants) which are naturally found in EVOO, improve the oil’s resistance to oxidative deterioration. (12) These minor components of EVOO not only add to the health profile of the oil, but also improve heat stability, due to a reduction in oxidative processes in heated oil. (3)
– the high level of oleic acid (a MUFA), and low levels of linoleic acid and linolenic acid (PUFAs) in EVOO contributes to the resultant high oxidative stability and resistance to the formation of harmful compounds when heated (such as polar compounds).
The combination of a high content of MUFA (and low PUFA content), together with the antioxidant components found in EVOO, make it highly resistant to oxidation, and therefore there is less chance that harmful substances will be formed upon the application of heat, through cooking. This also means that EVOO will last longer in storage.*
* Based on analysis performed on standard supermarket products by ISO 17025 accredited laboratory
The interaction between oil and food while cooking
Cooking with EVOO can improve the nutritional properties of the food
During any cooking process, when oil is the heating medium (i.e. deep frying), two phases typically occur. The first phase is where water evaporates from the food being cooked, and this commences once the oil reaches 100ºC, and continues until most of the food moisture has evaporated. The second phase is that during which the food absorbs and releases (in the case of fatty foods) fat. This second process determines the changes in fatty acid composition of the food which occurs during the cooking process. It has been well documented that the fatty acid profile of the food after deep frying is closer to that of the oil used to fry the food than that of the raw food itself. (13,14)
Furthermore, despite the impact that heating has in reducing the antioxidant content in EVOO, a significant amount of polyphenols, tocopherols, sterols and squalene still remain in EVOO after heating, and they are absorbed by the cooked food.
When fatty foods (i.e. meat) are cooked in EVOO there is an increase in the food’s MUFA content and a reduction in the saturated fatty acid (SFA) and PUFA content. The resultant cooked food will also have a higher content of powerful bio-active substances such as polyphenols (i.e. hydroxytyrosol and oleuropein), tocopherols, squalene and phytosterols.
When vegetables are cooked in EVOO there are additional health benefits – carotenoids (give colour to vegetables) require dietary fat (i.e. EVOO) for absorption, and glucosinolates (found in broccoli, cauliflower, kale, cabbage, Brussels sprouts) are absorbed better with fat (i.e. EVOO).
When food is cooked with EVOO it is healthier than if cooked with other oils that have a different fatty acid profile, or contain lower amounts natural bioactive substances. (5,6,13,14)
How does olive oil compare?
Insert final version of chart from approved training guides
Polyphenols (phenolic compounds) and a-tocopherol are antioxidants, which are found in high quantities in premium EVOO. These compounds have multiple activities in the body, including scavenging free radicals, increasing HDLs and inhibiting LDL oxidation (which contributes to atherosclerosis). EVOO has a substantially higher naturally occurring antioxidant content than any other cooking oil.
The concentration of phenols in EVOO depends on a variety of factors, such as growing conditions, production method, olive cultivars and storage conditions. Cobram Estate EVOO has substantially higher levels of antioxidants (polyphenols) than most other brands of EVOO, refined olive oil, rice bran oil, vegetable oil, seed oils, canola oil and virgin coconut oil. This is primarily due to the freshness of Cobram Estate EVOO – the fresher the oil, the higher the antioxidants. Cobram Estate EVOO is cold pressed within 6 hours of harvest, and reaches Australian consumers much more quickly than other imported brands of olive oil.
EVOO does not contain trans fats
Unlike refined oils, EVOO is naturally produced and it does not contain any trans fats.
Trans fats are a type of unsaturated fat which have the potential to increase LDL cholesterol, and lower levels of HDL cholesterol, which can be detrimental to health.
The Cobram Estate Promise
Cobram estate extra virgin olive oil is made exclusively from premium quality olives grown on our own Australian estates, picked at optimum ripeness, and cold pressed within six hours of harvest using our proprietary technology, to ensure we consistently deliver high quality and optimal composition.
Cooking with EVOO reduces the nutrient value of foods
Applying heat to food in any form of cooking (frying, steaming baking, boiling etc.) will change the properties of the food. The added benefit of cooking with EVOO, is that fats are required to absorb carotenoids and glucosinolates (phytonutrients) found in some foods. (8) By cooking foods that contain these elements (such as cabbage, broccoli, cauliflower and kale) in EVOO, a high percentage of the phytonutrients will be absorbed, and this is more nutritious that with steaming or boiling the vegetables. Furthermore, EVOO’s oleic acid, sterols and squalene exhibit a high stability against oxidation. Although not as stable under heat, a large amount of polyphenols and tocopherols remain in EVOO after cooking. Therefore, despite the heating conditions during cooking, EVOO maintains most of its minor compounds and, therefore, most of its nutritional properties. (5,6,13–16)
Heating EVOO converts the mono-unsaturated fats to trans fats
Trans fats form when any edible oil is subjected to an industrial process such as refining or hydrogenation (which is designed to turn liquid oil into an edible fat that is solid at room temperature (i.e. margarine)). Trans fats are not formed during the cooking process in a kitchen. The vast majority of trans fats in the average person’s diet arise from fast foods, inexpensive margarines, or more commonly commercially baked products and crackers. EVOO is naturally trans-fat free; cooking with EVOO will ensure that undesirable trans fats are not added to the diet.