Organic oils

Despite their negative publicity over the years, edible oils play an important role in maintaining physical health and wellbeing. Compared to other nutrients, they are particularly high in energy and are routinely stored as a reserve supply. Every cell is surrounded by a lipid layer which helps to maintain the integrity of the intracellular environment. Oils play a key role in transporting fat-soluble nutrients like vitamin E, D, and they are key constituents of the steroidal compounds which regulate metabolism, development and integration of the body’s vital functions.

It wasn’t long ago that health advocates were recommending polyunsaturated vegetable oils like safflower, sunflower, and soybean as the best choices for a healthy diet. The current position is that too many of these can result in oxidation and free radical damage within the body. Monounsaturated vegetable oils and certain types of fish oil are more nutritious and provide higher levels of protection.

Why it’s important to use organic oils

Is it worthwhile seeking organically certified oils for kitchen purposes? The answer is yes, unreservedly, for a number of reasons. When living organisms are exposed to chemical pollutants, they process and eliminate these according to metabolic capacity while the remainder is temporarily stored in fatty tissue. Over time, the fat-soluble metabolites of pesticides, herbicides, and other agricultural agents are subject to accumulation within plant oils.

Choosing organically certified oils is the best way to ensure purity, since the oil yielding plants will have been minimally exposed to these chemicals. Unless there is a clear label to indicate otherwise, cooking oils extracted from intensively produced crops like canola, corn, and soybeans are likely to include material sourced from genetically modified stock. Organic certification provides an accurate assurance that these products contain only natural, unadulterated ingredients. Under organic conditions, well-nurtured soils provide balanced nutrients which support the healthy plant growth required for premium quality oil yields.

With a focus on high volume production, commercial oil crops can rapidly deplete soils by absorbing important trace minerals and organic components. When these are replaced with synthetic fertilisers, the vitality of forthcoming crops will be lowered along with the quality of their oils.

Extraction methodologies

Like most natural foods, vegetable oils must be handled with care to ensure the preservation of their beneficial properties. From a consumer’s perspective, the first aspect to consider is their method of extraction. Hydraulic pressing involves squeezing the oil-bearing produce between heavy metal plates. Traditionally, these were fashioned from combinations of timber and iron, not dissimilar to an antique wine press. Today, modern equipment is highly mechanised and efficient; although the hydraulic method is usually reserved for oil rich produce like olives and tree nuts. Unlike other methods, hydraulic pressing does not require the produce to be heated or treated with chemical solvents. Cold pressing protects the nutrients and prevents the oil from altering its physical composition and becoming unstable.

Another widely used extraction process is known as expeller. This involves a large auger rotating inside a cylindrical metal filter. When the blades of the auger contact the fruit or seeds, the oils are pressed through the pores of the filter while the solid pulp remains inside the cylinder. Expeller processing can be complicated and expensive in terms of the capital investment and periodic maintenance required. Despite claims to the contrary, expeller processing does not ensure a cold pressing. Unless the cylinders are refrigerated, there is potential for mechanical friction to generate levels of heat which will compromise the oil.

High volume oil processing and the use of hexane

Many of the high volume oil crops are now processed with the assistance of extreme heat and industrial solvents like hexane. Pause on that for a moment. Hexane is a highly toxic petroleum derivative.  According to manufacturing technologists, the solvents are evaporated throughout the process and leave no detectable residue within the extracted oils. Despite this assurance, the levels of heat applied must certainly destroy nutrients and lower the stability of the oil.

The best advice is to avoid the cheaper, mass produced vegetable oils. Concentrate as much as possible on the better quality products which should be organically certified and mechanically pressed.

Preserving and heating oils

Providing they are stored in darkened glass containers and kept away from light and heat, most vegetable oils will maintain their integrity for at least several months. In order to achieve consistent results, it is important to understand the basic heating properties of the different types of oil available. This enables an appropriate product to be selected for individual cooking applications.

The no heat oils have very low smoking points and should be used for cold dressings, sauces, and soups. Heating decreases their flavour, and can degrade their beneficial monounsaturated molecules into unhealthy saturated fats. Examples of no heat oils are flaxseed, wheat germ, and evening primrose. While some health conscious individuals may prefer to consume the majority of their oils with minimal or no heat applied, there are numerous exciting dishes which require flavoursome oils to be rapidly heated yet maintained below their smoking point.

Oils which can be used for medium or low heat applications include olive, grapeseed, walnut, and canola oils. Those known to maintain flavour and integrity with vigorous, high temperature applications include sesame, macadamia, almond, apricot kernel, and avocado. 

Nutritional content of oils

In terms of cardiovascular health, medical researchers have focused on the ratio of key essential fatty acids within each type of oil. Many of the monounsaturated vegetable oils are significantly higher in Omega 6 compared to Omega 3 fatty acids. In situations where the dietary intake of Omega 6 becomes too dominant, there is less opportunity for the equally important Omega 3 components to be effective. This can be corrected with dietary supplementation of fish oil capsules which are concentrated sources of Omega 3 fatty acids. Alternatively, some individuals may prefer to focus on eating the monounsaturated vegetable oils which contain a good balance of fatty acids. The best examples are the cold pressed flaxseed and walnut oils.

In terms of overall health benefits combined with practicality, there is no serious rival to a premium quality olive oil. A freshly pressed olive oil contains more antioxidant and polyphenol compounds than other monounsaturated vegetable oils. Freshness and quality can be identified by the level of acidity present in cold pressed oil. Virgin oil may contain up to three percent acidity while extra virgin must contain less than one percent acidity.

The major health benefits of premium grade olive oils appear to include enhanced immune function, supple skin, regulated appetite, and protection against certain types of bowel cancer. Therapeutic benefits aside, olive oil has richly satisfying flavours which can be described in terms of fruit, pepper, spice, and mildly bitter characteristics. There are several varieties of olive which interact with their local growing climates to provide a distinctive foundation for Mediterranean and Nouveau cuisine.