1. What are lipids?

   Lipids are complex organic substances that do not dissolve in water but dissolve in organic solvents. They include oils and fats, with the distinction that oils are liquid at room temperature, while fats are solid at room temperature. However, they share very similar physical, chemical, and structural properties. Recently, the complexity of oils and fats has been discovered, leading to the categorization into neutral fats, polar fats, nonpolar fats, and others. Lipids are of significant nutritional, health, and economic importance.

2. How are they extracted from various sources?

   Lipids are extracted from different sources, including:

   – Animal Sources: Derived from the fatty tissues of animals such as sheep, camels, and others (wild or domestic), or marine sources like whales and fish.

   – Plant Sources: Obtained from oilseeds or oil-producing crops like soybeans, peanuts, sesame, or from fruits such as olives and date palms.

3. Are they consumed directly, or do they undergo subsequent manufacturing stages?

   The consumption varies based on impurity levels. Some, like animal fats after dry rendering or wet rendering, can be consumed directly. However, vegetable oils extracted from oilseeds, whether mechanically or chemically, produce a raw oil unsuitable for human consumption. It undergoes purification processes involving several stages, resulting in edible liquid oil. Subsequently, it may undergo further processing in secondary industries to produce items like margarine, mayonnaise, salad oils, and cooking oils.

4. What are the legislative regulations for the production, manufacturing, and use of different oil and fat products?

   Each type of oil or fat, whether crude, refined, or secondary product, has standard specifications at the Saudi, Gulf, Arab, and international levels. These specifications define the product, its nature of use, requirements, usage guidelines, and product name. All products have legislative specifications that outline legal aspects and the mandatory nutritional information for factories.

5. What is the difference between cooking oils and frying oils?

   There is significant confusion between cooking oils and frying oils, each with different specifications. Cooking oils are used in small quantities suitable for preparing meals, while frying oils are engineered to withstand harsh frying conditions of high heat and time. Frying oils, being more processed, pose greater risks if not used appropriately, as they may deteriorate and produce harmful compounds due to prolonged exposure to high temperatures.

6. What are the quality grades of olive oil and their various uses?

   Olive oil has specific quality grades outlined in Saudi, Gulf, or international standards, ranging from first-grade to fifth-grade, determined by the level of free fatty acids or acidity in the oil. The first-grade oil, known as extra virgin olive oil, is highly valued for its therapeutic benefits, as it is extracted through cold pressing without the use of chemicals. Lower-grade oils may include residues and are less beneficial. The use of olive oil for frying should be limited, as its nutritional and therapeutic value diminishes after repeated use.

Prof. Hassan Al-Qahtani.