Chemical Properties of Food Chapter

A process that converts liquid oils into semi-solid fats, used to create spreads.

A type of unsaturated fatty acid with a specific structure. They are more stable and increase the melting point of fats.

The ability of a fat to spread easily at room temperature.

The process of changing the arrangement of fatty acids within a fat molecule.

The process of breaking down fats into simpler molecules, leading to rancidity.

A type of fat that is solid at room temperature, often found in animal products.

A type of fat that is liquid at room temperature, often found in plant products.

Fats that are essential for our bodies but cannot be produced by our bodies, and must be obtained from diet.

The process of converting a liquid oil into a solid fat by adding hydrogen atoms to its unsaturated fatty acids.

A type of unsaturated fatty acid with a hydrogen atom on the same side of the double bond. These are typically found in natural fats and oils.

The process of breaking down a complex fat (triglyceride) into simpler molecules (glycerol and fatty acids) by adding water molecules.

A measure of the degree of unsaturation in a fat or oil. It is determined by the amount of iodine that can be absorbed by the fat.

The conversion of unsaturated fatty acids into saturated fatty acids by adding hydrogen atoms, which eliminates double bonds. This process can also create trans fats.

A type of fat that is created during the hydrogenation process. Trans fats are considered unhealthy and can increase the risk of heart disease.

Substances that protect oils and fats from oxidation, which can make them rancid.

The process of oxygen reacting with fats or oils, leading to rancidity.

A group of natural compounds found in oils that act as antioxidants.

Compounds that can speed up oxidation in certain situations, potentially counteracting the effects of antioxidants.

The period during which an oil is stable and doesn't readily oxidize.

Compounds that can inhibit or slow down the oxidation process.

The process of removing impurities from oils, which can sometimes reduce their natural antioxidant content.

The distribution of antioxidants and pro-oxidants between the oil and water phases in an emulsion.

Hydroperoxides are formed when unsaturated fatty acids, like oleate, linoleate, and linolenic acid, undergo oxidation. The specific structure of these hydroperoxides influences the formation of volatile short-chain compounds, each having its own unique flavor and odor.

Linolenic esters, which contain three double bonds (trienes), oxidize faster than dienes (two double bonds). The volatile aldehydes produced from linolenic acid have lower odor thresholds, meaning they are more noticeable at lower concentrations.

The oxidation of fatty molecules can lead to the formation of volatile compounds. One fragment, called the core aldehyde, remains attached to glycerol. The other fragment, at the methyl end of the molecule, is released as a volatile component. This volatile component can often cause undesirable flavors and aromas in oils.

In the oxidation process, the volatile component of a broken fatty molecule can be removed during refining. However, the core aldehyde that remains attached to glycerol will likely persist in the oil.

Autoxidation is a radical chain process that involves three stages: initiation, propagation, and termination. In initiation, free radicals are formed. During propagation, these radicals react with molecules, leading to the formation of more radicals. Termination occurs when two radicals combine to form a stable molecule.

The rate of autoxidation and photo-oxidation varies depending on the type of fatty acid. Linolenate oxidizes much faster than linoleate and oleate, indicating a higher susceptibility to oxidation.

During autoxidation, the presence of oxygen is crucial. Autoxidation rates are significantly higher in the presence of oxygen. Additionally, the type of oxygen, triplet or singlet, also influences the rate of oxidation.

The ratio of reaction rates between photo-oxidation and autoxidation highlights the sensitivity of different fatty acids to light and oxygen. Linolenate is significantly more susceptible to photo-oxidation compared to oleate and linoleate, indicating a strong sensitivity to light.

The most abundant form of vitamin E found naturally in foods - it has the highest biological activity compared to other forms of vitamin E.

A class of vitamin E molecules that contribute to its antioxidant properties; they have different structures and biological activities compared to tocopherols.

The total amount of vitamin E in a food or supplement, calculated according to the biological activity of each different form of vitamin E.

A specific type of vitamin E that has been extensively studied for its potential health benefits, especially in promoting heart health.

An antioxidant found in oats, known for its potential benefits in reducing inflammation and cholesterol levels.

A compound found in sesame seeds and oil, known for its potential to lower blood pressure and cholesterol.

A group of compounds found in rice bran oil, known for their antioxidant and potentially anti-inflammatory properties.

A group of compounds found in oats, known for their potential to reduce inflammation and improve blood sugar control.

The process of breaking down fats into simpler molecules by adding water, often resulting in fatty acids and glycerol.

The process of removing undesirable substances from fats and oils, such as free fatty acids, by using steam under pressure.

The breakdown of fats into smaller molecules, often triggered by heat or oxidation, leading to changes in the chemical composition of the fat.

The process of changing the shape or arrangement of fatty acids, often resulting in the formation of cyclic structures or trans isomers, influencing the properties of the fat.