Health Concerns
Saturated and Unsaturated Fatty Acids
The fatty acids components of triglycerides can either be saturated, (fully hydrogenated) or they may contain double bonds (unsaturated). Saturated fatty acids have higher melting points than unsaturated fatty acids with a similar size, and are often considered better for deep frying. Polyunsaturated fatty acids (PUFAs), including the 18-carbon atom linoleic and linolenic acids, contain more than one carbon-carbon double bond, are present in significant quantities in many vegetable oils. Vegetable oils high in monounsaturated fatty acids - including safflower, sunflower and high oleic soy and Canola oils – are considered healthier and degrade more slowly.Fry Life
As one of the more costly kitchen commodities, frying oil is typically used for several days before being discarded. Multiple frying cycles result in more extensive degradation; the rate of degradation (and number of times a batch of oil can be reused) is dependent on the oil type, the temperature, and the type of food being fried. Regardless of the initial composition of the oil, multiple scientific studies have concluded that when the accumulated TPCs comprise over 25% of the oil it is no longer healthy and the fried foods are less appealing. This point, is often referred to as the Fry Life of an oil.The Science of Frying Oil
Oxidation of Frying Oil
Deep Frying Byproducts
The high temperatures used for frying, combined with oxygen, light, salts, and water from the food being fried significantly accelerate the degradation of frying oils. In the presence of high heat and water, triglycerides hydrolyze to form free fatty acids and glycerol. The fatty acids, especially those present in polyunsaturated oils, further degrade to form an array of oxygenated products including epoxides, carboxylic acids, hydroperoxides, alcohols, aldehydes and ketones. These oxygenated byproducts are collectively referred to as Total Polar Materials (TPM). After decades of research, measurements of TPM are now accepted as the most reliable measure of oil quality. Measuring the concentration of TPM is the best indicator for determining oil degradation.International Regulations
Oil Quality Guidelines
Although there is not one specific worldwide regulation for frying oil quality, many countries have guidelines or regulations restricting how much frying oil can be repeatedly used. These rules are based on extensive studies of frying oil stability during cooking and the generation of byproducts with deleterious effects in human health. Even in countries such as the USA and Australia, where TPC is not regulated, it is increasingly being used by foodservice operators as a benchmark for determining when to dispose of frying oil.
Chemical Composition
Frying oils are most commonly derived from the seeds or fruits of vegetables (e.g. soybeans, palm, sunflowers) and are primarily composed of triglycerides. Triglycerides consist of three fatty acid molecules esterified to a glycerol unit. The differences among vegetable oils prepared from different sources involve the length and number of double bonds in the fatty acid components.
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Health Concerns
Saturated and Unsaturated Fatty
Acids
The fatty acids components of triglycerides can either be saturated, (fully hydrogenated) or they may contain double bonds (unsaturated). Saturated fatty acids have higher melting points than unsaturated fatty acids with a similar size, and are often considered better for deep frying. Polyunsaturated fatty acids (PUFAs), including the 18-carbon atom linoleic and linolenic acids, contain more than one carbon-carbon double bond, are present in significant quantities in many vegetable oils. Vegetable oils high in monounsaturated fatty acids - including safflower, sunflower and high oleic soy and Canola oils – are considered healthier and degrade more slowly.Fry Life
As one of the more costly kitchen commodities, frying oil is typically used for several days before being discarded. Multiple frying cycles result in more extensive degradation; the rate of degradation (and number of times a batch of oil can be reused) is dependent on the oil type, the temperature, and the type of food being fried. Regardless of the initial composition of the oil, multiple scientific studies have concluded that when the accumulated TPCs comprise over 25% of the oil it is no longer healthy and the fried foods are less appealing. This point, is often referred to as the Fry Life of an oil.The Science of
Frying Oil
Oxidation of Frying
Oil
Deep Frying Byproducts
The high temperatures used for frying, combined with oxygen, light, salts, and water from the food being fried significantly accelerate the degradation of frying oils. In the presence of high heat and water, triglycerides hydrolyze to form free fatty acids and glycerol. The fatty acids, especially those present in polyunsaturated oils, further degrade to form an array of oxygenated products including epoxides, carboxylic acids, hydroperoxides, alcohols, aldehydes and ketones. These oxygenated byproducts are collectively referred to as Total Polar Materials (TPM). After decades of research, measurements of TPM are now accepted as the most reliable measure of oil quality. Measuring the concentration of TPM is the best indicator for determining oil degradation.International
Regulations
Oil Quality Guidelines
Although there is not one specific worldwide regulation for frying oil quality, many countries have guidelines or regulations restricting how much frying oil can be repeatedly used. These rules are based on extensive studies of frying oil stability during cooking and the generation of byproducts with deleterious effects in human health. Even in countries such as the USA and Australia, where TPC is not regulated, it is increasingly being used by foodservice operators as a benchmark for determining when to dispose of frying oil.
Chemical Composition
Frying oils are most commonly derived from the seeds or fruits of vegetables (e.g. soybeans, palm, sunflowers) and are primarily composed of triglycerides. Triglycerides consist of three fatty acid molecules esterified to a glycerol unit. The differences among vegetable oils prepared from different sources involve the length and number of double bonds in the fatty acid components.
© Copyright 20xx Company | Made with Xara
