Reductive Adaptation
When a child’s intake is insufficient, the needs of the body for energy are met by mobilising tissue reserves of fat and protein from muscle, skin and the gut. Physiological and metabolic changes also take place to conserve energy. These changes take place in an orderly progression called reductive adaptation.
Through reductive adaptation, energy is conserved by:
Reducing physical activity and growth
Reducing basal metabolism by slowing protein turnover, reducing the functional reserve of organs, slowing the sodium and potassium pumps in cell membranes and reducing their number
Reducing inflammatory and immune responses
Consequences of Reductive Adaptation
The changes caused by reductive adaptation have important consequences. The functioning of every cell, organ and system is affected. Here are some of the consequences:
The liver is less able to make glucose and is less able to excrete excess dietary protein and toxins
The kidneys are less able to excrete excess fluid and sodium
The heart is smaller and weaker and has a reduced output
The gut produces less acid, and smaller amounts of enzymes. Villi become flattened and motility is reduced.
Sodium leaks into cells due to fewer and slower pumps and potassium leaks out of the cells and is lost in urine
Iron that is liberated from red blood cells is not stored safely and so promotes the growth of pathogens and harmful free radicals
Muscle mass is reduced, so there is a loss of intracellular nutrients and glucose stores
The immune system does not give the normal responses to infection
lipids biochemistry science PPT for college students and teachersLavanyaVijaykumar2
The document discusses various physical and chemical properties of fatty acids. Physically, saturated fatty acids are solid while unsaturated ones are liquid. Fats are insoluble in water but soluble in organic solvents. Melting point depends on chain length and saturation. Chemically, fats undergo hydrolysis to yield glycerol and fatty acids. Unsaturated fatty acids can undergo hydrogenation, halogenation, and oxidation reactions at double bonds. Rancidity occurs when microbes hydrolyze fats or unsaturated fats oxidize. Saponification value, iodine value, peroxide value, and acid value provide information about fatty acid composition and purity.
Changes occur to fats during food processing and cooking. Heating fats can cause randomization of glyceride structure, dimer formation, cis-trans isomerization, and formation of conjugated fatty acids. Specific processes like hydrogenation, interesterification, and deodorization further impact fat composition. Deep frying is high heat cooking that promotes reactions like oxidation, leading to rancidity over time. Thermal properties like smoke point are important considerations for fat selection in cooking.
Rancidification is the process of complete or incomplete oxidation or hydrolysis of fats and oils when exposed to air, light, or moisture or by bacterial action, resulting in unpleasant taste and odor. Specifically, it is the hydrolysis or autoxidation of fats into short-chain aldehydes and ketones, which are objectionable in taste and odor. When these processes occur in food, undesirable odors and flavors can result.
Lipids can be classified by their structure as simple lipids like fats and oils or complex lipids like phospholipids. They can also be classified based on whether they undergo hydrolysis in alkaline solutions. Lipids are made up of fatty acids and glycerol, forming triglycerides. Fats are usually saturated while oils contain some unsaturated fatty acids. Waxes differ from fats and oils in that they are esters of long-chain alcohols and fatty acids with higher melting points. Lipids serve important functions and have many applications, such as in soaps, foods, and cosmetics.
This document discusses various chemical processes involving oils and fatty acids, including hydrolysis, saponification, hydrogenation, rancidity, and drying oils. Hydrolysis involves the breakdown of triglycerides into free fatty acids and glycerol. Saponification is the hydrolysis of triglycerides with an alkali to produce soaps. Rancidity refers to the deterioration of oils over time resulting in unpleasant tastes and textures. Drying oils such as linseed oil harden when exposed to air through polymerization reactions.
This document provides an overview of lipids, which are one of the four major families of biological molecules. It discusses the different types of lipids including fatty acids, waxes, triglycerides, phospholipids, glycolipids, steroids, and eicosanoids. Key points covered include the structures and properties of these lipid subclasses, how they are synthesized and interact with other molecules, and their various biological functions and roles in membranes and transport.
The document defines and describes various types of lipids. It discusses simple lipids like fats and waxes, as well as complex lipids including phospholipids, glycolipids, and gangliosides. Key points covered include the structures and functions of fatty acids and triglycerides, as well as the roles of lipids in energy storage, insulation, cell membranes, and lipid transport. Steroids such as cholesterol are also introduced.
lipids biochemistry science PPT for college students and teachersLavanyaVijaykumar2
The document discusses various physical and chemical properties of fatty acids. Physically, saturated fatty acids are solid while unsaturated ones are liquid. Fats are insoluble in water but soluble in organic solvents. Melting point depends on chain length and saturation. Chemically, fats undergo hydrolysis to yield glycerol and fatty acids. Unsaturated fatty acids can undergo hydrogenation, halogenation, and oxidation reactions at double bonds. Rancidity occurs when microbes hydrolyze fats or unsaturated fats oxidize. Saponification value, iodine value, peroxide value, and acid value provide information about fatty acid composition and purity.
Changes occur to fats during food processing and cooking. Heating fats can cause randomization of glyceride structure, dimer formation, cis-trans isomerization, and formation of conjugated fatty acids. Specific processes like hydrogenation, interesterification, and deodorization further impact fat composition. Deep frying is high heat cooking that promotes reactions like oxidation, leading to rancidity over time. Thermal properties like smoke point are important considerations for fat selection in cooking.
Rancidification is the process of complete or incomplete oxidation or hydrolysis of fats and oils when exposed to air, light, or moisture or by bacterial action, resulting in unpleasant taste and odor. Specifically, it is the hydrolysis or autoxidation of fats into short-chain aldehydes and ketones, which are objectionable in taste and odor. When these processes occur in food, undesirable odors and flavors can result.
Lipids can be classified by their structure as simple lipids like fats and oils or complex lipids like phospholipids. They can also be classified based on whether they undergo hydrolysis in alkaline solutions. Lipids are made up of fatty acids and glycerol, forming triglycerides. Fats are usually saturated while oils contain some unsaturated fatty acids. Waxes differ from fats and oils in that they are esters of long-chain alcohols and fatty acids with higher melting points. Lipids serve important functions and have many applications, such as in soaps, foods, and cosmetics.
This document discusses various chemical processes involving oils and fatty acids, including hydrolysis, saponification, hydrogenation, rancidity, and drying oils. Hydrolysis involves the breakdown of triglycerides into free fatty acids and glycerol. Saponification is the hydrolysis of triglycerides with an alkali to produce soaps. Rancidity refers to the deterioration of oils over time resulting in unpleasant tastes and textures. Drying oils such as linseed oil harden when exposed to air through polymerization reactions.
This document provides an overview of lipids, which are one of the four major families of biological molecules. It discusses the different types of lipids including fatty acids, waxes, triglycerides, phospholipids, glycolipids, steroids, and eicosanoids. Key points covered include the structures and properties of these lipid subclasses, how they are synthesized and interact with other molecules, and their various biological functions and roles in membranes and transport.
The document defines and describes various types of lipids. It discusses simple lipids like fats and waxes, as well as complex lipids including phospholipids, glycolipids, and gangliosides. Key points covered include the structures and functions of fatty acids and triglycerides, as well as the roles of lipids in energy storage, insulation, cell membranes, and lipid transport. Steroids such as cholesterol are also introduced.
This document discusses the chemical and physical properties of oils and fats. It begins by describing the structures of lipids and fatty acids, including saturated and unsaturated varieties. It then covers the chemical and biological synthesis of fatty acids. The physical properties of oils and fats are influenced by their fatty acid compositions. Chemical properties include hydrolysis, saponification, halogenation, and oxidation (rancidity). Preventing rancidity involves controlling exposure to light, oxygen, moisture, and bacteria.
Fats and oils are triglycerides composed of fatty acid chains bonded to a glycerol backbone. They undergo various chemical reactions including hydrolysis, hydrogenation, hydrogenolysis, and saponification. The properties of fats and oils can be analyzed using various values such as acid value, saponification value, iodine value, and Reichert Meissl value. These values provide information about the fatty acid composition and purity of the sample being tested.
Application of biotechnology_in_lipid_processing_and_valueVishnuraj R S
Lipid biotechnology uses enzymes like lipases to modify lipids and produce specialty products. Lipases can hydrolyze or interesterify triglycerides and are used in food processing. Glycerol, a byproduct of biodiesel production, can be converted to high-value chemicals like dihydroxyacetone and 1,3-propanediol using biocatalysts. Supercritical fluids like carbon dioxide are also used to efficiently extract lipids due to their gas-like diffusion properties.
This document discusses the application of biotechnology in lipid processing and value-added products from fats and lipids. It describes how various biocatalysts like lipases can be used to modify lipids and transform oils and fats through processes like interesterification. It also discusses how glycerol, a byproduct of biodiesel production, can be converted to valuable intermediates. Supercritical fluid technology using carbon dioxide is also highlighted as an environmentally friendly method for lipid extraction.
Soaps are made by reacting fats or oils with a strong alkali like sodium hydroxide. Detergents are similar cleansing agents but use synthetic surfactants instead of fats/oils and do not form scum with hard water. The manufacturing process for soaps involves saponification of fats/oils, glycerin removal, purification, and finishing. Detergent production uses petrochemical raw materials and involves slurry making and spray drying. Both have advantages like cleaning ability but can harm aquatic environments if not properly treated in wastewater.
This document provides an overview of lipids, including their structure and subclasses. It discusses the four major classes of biological molecules and focuses on lipids. Lipids are a structurally diverse group of hydrophobic molecules that include fatty acids, triglycerides, phospholipids, and steroids. Fatty acids contain long hydrocarbon chains that give them a nonpolar character. Triglycerides are composed of fatty acid chains esterified to a glycerol backbone and serve as an energy storage molecule. Hydrogenation, oxidation, and saponification are important reactions involving lipids.
Lipids are organic compounds made up of fatty acids and their derivatives. They provide calories and energy and help with the absorption of fat-soluble vitamins. Lipids are classified as simple lipids like fats and waxes, compound lipids containing other molecules, and derived lipids from hydrolysis. They have important functions like insulating the body, storing energy, and carrying fat-soluble vitamins. While essential to the diet, excessive fat intake should be avoided.
soap is a salt of a fatty acid,.
Consumers mainly use soaps as surfactants for washing, bathing, and cleaning, but they are also used in textile spinning and are important components of lubricants.
Soaps for cleansing are obtained by treating vegetable or animal oils and fats with a strongly alkaline solution
Lipids are a group of naturally occurring, nonpolar and water-insoluble compounds that include fats, oils, waxes and other fatty substances. They serve important biological functions such as energy storage, cell signaling, and as structural components of cell membranes. Lipids can be classified as simple lipids like fatty acids, fats and oils, or compound lipids which contain additional functional groups. Fats are composed of triglycerides containing fatty acid chains that are saturated, while oils contain some unsaturated fatty acid chains, making them liquid at room temperature. Lipids play critical roles in the body and have a variety of industrial applications.
Rancidity is a common problem in rendered animal products. It can have detrimental effects on both the quality and safety of the product.
It is caused by the oxidation of fats and oils, leading to the formation of harmful compounds such as free radicals and hydroperoxides.
The best way to prevent rancidity is through proper storage, packaging, and handling techniques, as well as the use of antioxidants to slow down the oxidation process. It is important for manufacturers and consumers to be aware of the potential for rancidity in rendered animal products and take the necessary precautions to ensure the safety and quality of the product.
Rancidity testing is essential in the feed industry, as a key indicator of product quality and shelf life.
It is conducted to determine the level of oxidation in samples of feed or feed ingredients
Rancidity is a chemical change that results in an unpleasant odour and taste in a fat or oil.
Types of Rancidity
Hydrolytic rancidity
Oxidative rancidityOil becomes rancid due to the decomposition of fats it contains
Milk turns rancid due to not heating it in the humid atmosphere.
Butter changes its smell and taste when it is kept in an open atmosphere for a longer duration.
Hydrolytic rancidity develops due to the presence of moisture and by growth of microorganisms in the fat.
The microorganisms secrete lipases which split the triglycerides into glycerol and fatty acids.
Hydrolytic rancidity of butter releases volatile butyric acid which gives the bad odour and taste.
Oxidative rancidity occurs in oils and fats containing unsaturated fatty acids due to exposure to air.
Unsaturated fatty acids are converted into hydroperoxides, which break down into volatile aldehydes, esters, alcohols, ketones, and hydrocarbons, some of which have disagreeable odours.
Fats contaminated with enzymes like lipase undergo partial hydrolysis and oxidation of unsaturated fatty acids at the double bonds.
This is even brought about by the atmospheric moisture and temperature. Due to this, there is release of hydrogen peroxide giving a bad odour and taste to the fat.
Rancidity can be prevented by antioxidants like vitamin E, vitamin C, phenols, hydroquinone’s, etc.
Rancidity Process: Rancidity happens in food products that have oil and fatty acids in them. Any substance turns rancid in basically three steps:
I. Initiation Reaction: Initiation reaction leads to the formation of radicals on the food substances because of external factors like heat and air that stimulates this reaction. A radical is an atom molecule or ion that has an unpaired electron. These unpaired electrons make radicals very reactive chemical substances.
RH ⇒ R- + H+
Propagation Reaction: In this step, oxygen present in the atmosphere gives rise to peroxides. These peroxides react further with unsaturated fatty acids and then produce new radicals.
Termination Reaction: In the third stage, two radicals combine together to form a new single bond.
Lipids include fats, oils, and waxes. Fats and oils are triglycerides composed of glycerol and three fatty acids. Fats are usually saturated and solid at room temperature, while oils are unsaturated and liquid. Fats and oils are extracted from plants through pressing or solvent extraction. Waxes also contain fatty acids but have higher molecular weight alcohols. Lipids have many applications including soaps, coatings, and supplements.
6.lipids full notes in pdf pharmacognosy and biochemistryDr Muhammad Bilal
Lipids include fats, oils, and waxes. Fats and oils are triglycerides composed of glycerol and three fatty acids. Saturated fats from animal sources are solid at room temperature due to straight hydrocarbon chains that pack closely. Unsaturated plant oils are liquid due to double bonds that cause kinks in the chains and prevent close packing. Fixed oils are obtained from plants by expression or solvent extraction, while animal fats are separated by rendering. Lipids have many uses including soaps, coatings, and supplements.
The document discusses the production of soap and detergents through various chemical processes. It describes the group members presenting on the topic and provides an outline of the contents to be covered, including the chemistry of soap, manufacturing processes like the Colgate Palmolive and Lever Rexona continuous processes as well as batch processes, and the cleansing action of soap. Key steps in the continuous processes involve saponification, lye separation, soap washing, neutralization and drying. The batch process involves heating, purification, mixture heating, saponification, addition of materials like sodium chloride and additives, and moulding. Soap works by forming micelles that emulsify oil and allow dirt to be washed away.
Food as a heterogeneous mixture, types of cooking, types of oils, chemistry of rancidity, uses of cooking , starch gelatinization in cooking rice, Maillard reaction, caramelisation
This document discusses oil and fat processing, specifically refining of oils and fats. It describes the major steps in refining which include lecithin removal, degumming, neutralization, bleaching, and deodorization. The purpose of refining is to remove undesirable components from crude oils and produce an edible oil with desirable characteristics like clear appearance and stability. Key steps include degumming to remove phospholipids, neutralization to remove free fatty acids, bleaching to remove color, and deodorization to remove odors and flavors through steam distillation under vacuum. Proper processing refines crude oils into finished oils suitable for human consumption.
Liposomes are small artificial vesicles created from cholesterol and phospholipids that resemble cell membranes. They are promising for drug delivery due to their biocompatibility and ability to encapsulate both hydrophilic and hydrophobic drugs. Liposomes are classified based on size, number of bilayers, composition, and preparation method. They can be prepared using techniques like film hydration, extrusion, sonication, and solvent injection. Coating liposomes with polymers like PEG creates stealth liposomes that have longer circulation times in the body.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
This document discusses the chemical and physical properties of oils and fats. It begins by describing the structures of lipids and fatty acids, including saturated and unsaturated varieties. It then covers the chemical and biological synthesis of fatty acids. The physical properties of oils and fats are influenced by their fatty acid compositions. Chemical properties include hydrolysis, saponification, halogenation, and oxidation (rancidity). Preventing rancidity involves controlling exposure to light, oxygen, moisture, and bacteria.
Fats and oils are triglycerides composed of fatty acid chains bonded to a glycerol backbone. They undergo various chemical reactions including hydrolysis, hydrogenation, hydrogenolysis, and saponification. The properties of fats and oils can be analyzed using various values such as acid value, saponification value, iodine value, and Reichert Meissl value. These values provide information about the fatty acid composition and purity of the sample being tested.
Application of biotechnology_in_lipid_processing_and_valueVishnuraj R S
Lipid biotechnology uses enzymes like lipases to modify lipids and produce specialty products. Lipases can hydrolyze or interesterify triglycerides and are used in food processing. Glycerol, a byproduct of biodiesel production, can be converted to high-value chemicals like dihydroxyacetone and 1,3-propanediol using biocatalysts. Supercritical fluids like carbon dioxide are also used to efficiently extract lipids due to their gas-like diffusion properties.
This document discusses the application of biotechnology in lipid processing and value-added products from fats and lipids. It describes how various biocatalysts like lipases can be used to modify lipids and transform oils and fats through processes like interesterification. It also discusses how glycerol, a byproduct of biodiesel production, can be converted to valuable intermediates. Supercritical fluid technology using carbon dioxide is also highlighted as an environmentally friendly method for lipid extraction.
Soaps are made by reacting fats or oils with a strong alkali like sodium hydroxide. Detergents are similar cleansing agents but use synthetic surfactants instead of fats/oils and do not form scum with hard water. The manufacturing process for soaps involves saponification of fats/oils, glycerin removal, purification, and finishing. Detergent production uses petrochemical raw materials and involves slurry making and spray drying. Both have advantages like cleaning ability but can harm aquatic environments if not properly treated in wastewater.
This document provides an overview of lipids, including their structure and subclasses. It discusses the four major classes of biological molecules and focuses on lipids. Lipids are a structurally diverse group of hydrophobic molecules that include fatty acids, triglycerides, phospholipids, and steroids. Fatty acids contain long hydrocarbon chains that give them a nonpolar character. Triglycerides are composed of fatty acid chains esterified to a glycerol backbone and serve as an energy storage molecule. Hydrogenation, oxidation, and saponification are important reactions involving lipids.
Lipids are organic compounds made up of fatty acids and their derivatives. They provide calories and energy and help with the absorption of fat-soluble vitamins. Lipids are classified as simple lipids like fats and waxes, compound lipids containing other molecules, and derived lipids from hydrolysis. They have important functions like insulating the body, storing energy, and carrying fat-soluble vitamins. While essential to the diet, excessive fat intake should be avoided.
soap is a salt of a fatty acid,.
Consumers mainly use soaps as surfactants for washing, bathing, and cleaning, but they are also used in textile spinning and are important components of lubricants.
Soaps for cleansing are obtained by treating vegetable or animal oils and fats with a strongly alkaline solution
Lipids are a group of naturally occurring, nonpolar and water-insoluble compounds that include fats, oils, waxes and other fatty substances. They serve important biological functions such as energy storage, cell signaling, and as structural components of cell membranes. Lipids can be classified as simple lipids like fatty acids, fats and oils, or compound lipids which contain additional functional groups. Fats are composed of triglycerides containing fatty acid chains that are saturated, while oils contain some unsaturated fatty acid chains, making them liquid at room temperature. Lipids play critical roles in the body and have a variety of industrial applications.
Rancidity is a common problem in rendered animal products. It can have detrimental effects on both the quality and safety of the product.
It is caused by the oxidation of fats and oils, leading to the formation of harmful compounds such as free radicals and hydroperoxides.
The best way to prevent rancidity is through proper storage, packaging, and handling techniques, as well as the use of antioxidants to slow down the oxidation process. It is important for manufacturers and consumers to be aware of the potential for rancidity in rendered animal products and take the necessary precautions to ensure the safety and quality of the product.
Rancidity testing is essential in the feed industry, as a key indicator of product quality and shelf life.
It is conducted to determine the level of oxidation in samples of feed or feed ingredients
Rancidity is a chemical change that results in an unpleasant odour and taste in a fat or oil.
Types of Rancidity
Hydrolytic rancidity
Oxidative rancidityOil becomes rancid due to the decomposition of fats it contains
Milk turns rancid due to not heating it in the humid atmosphere.
Butter changes its smell and taste when it is kept in an open atmosphere for a longer duration.
Hydrolytic rancidity develops due to the presence of moisture and by growth of microorganisms in the fat.
The microorganisms secrete lipases which split the triglycerides into glycerol and fatty acids.
Hydrolytic rancidity of butter releases volatile butyric acid which gives the bad odour and taste.
Oxidative rancidity occurs in oils and fats containing unsaturated fatty acids due to exposure to air.
Unsaturated fatty acids are converted into hydroperoxides, which break down into volatile aldehydes, esters, alcohols, ketones, and hydrocarbons, some of which have disagreeable odours.
Fats contaminated with enzymes like lipase undergo partial hydrolysis and oxidation of unsaturated fatty acids at the double bonds.
This is even brought about by the atmospheric moisture and temperature. Due to this, there is release of hydrogen peroxide giving a bad odour and taste to the fat.
Rancidity can be prevented by antioxidants like vitamin E, vitamin C, phenols, hydroquinone’s, etc.
Rancidity Process: Rancidity happens in food products that have oil and fatty acids in them. Any substance turns rancid in basically three steps:
I. Initiation Reaction: Initiation reaction leads to the formation of radicals on the food substances because of external factors like heat and air that stimulates this reaction. A radical is an atom molecule or ion that has an unpaired electron. These unpaired electrons make radicals very reactive chemical substances.
RH ⇒ R- + H+
Propagation Reaction: In this step, oxygen present in the atmosphere gives rise to peroxides. These peroxides react further with unsaturated fatty acids and then produce new radicals.
Termination Reaction: In the third stage, two radicals combine together to form a new single bond.
Lipids include fats, oils, and waxes. Fats and oils are triglycerides composed of glycerol and three fatty acids. Fats are usually saturated and solid at room temperature, while oils are unsaturated and liquid. Fats and oils are extracted from plants through pressing or solvent extraction. Waxes also contain fatty acids but have higher molecular weight alcohols. Lipids have many applications including soaps, coatings, and supplements.
6.lipids full notes in pdf pharmacognosy and biochemistryDr Muhammad Bilal
Lipids include fats, oils, and waxes. Fats and oils are triglycerides composed of glycerol and three fatty acids. Saturated fats from animal sources are solid at room temperature due to straight hydrocarbon chains that pack closely. Unsaturated plant oils are liquid due to double bonds that cause kinks in the chains and prevent close packing. Fixed oils are obtained from plants by expression or solvent extraction, while animal fats are separated by rendering. Lipids have many uses including soaps, coatings, and supplements.
The document discusses the production of soap and detergents through various chemical processes. It describes the group members presenting on the topic and provides an outline of the contents to be covered, including the chemistry of soap, manufacturing processes like the Colgate Palmolive and Lever Rexona continuous processes as well as batch processes, and the cleansing action of soap. Key steps in the continuous processes involve saponification, lye separation, soap washing, neutralization and drying. The batch process involves heating, purification, mixture heating, saponification, addition of materials like sodium chloride and additives, and moulding. Soap works by forming micelles that emulsify oil and allow dirt to be washed away.
Food as a heterogeneous mixture, types of cooking, types of oils, chemistry of rancidity, uses of cooking , starch gelatinization in cooking rice, Maillard reaction, caramelisation
This document discusses oil and fat processing, specifically refining of oils and fats. It describes the major steps in refining which include lecithin removal, degumming, neutralization, bleaching, and deodorization. The purpose of refining is to remove undesirable components from crude oils and produce an edible oil with desirable characteristics like clear appearance and stability. Key steps include degumming to remove phospholipids, neutralization to remove free fatty acids, bleaching to remove color, and deodorization to remove odors and flavors through steam distillation under vacuum. Proper processing refines crude oils into finished oils suitable for human consumption.
Liposomes are small artificial vesicles created from cholesterol and phospholipids that resemble cell membranes. They are promising for drug delivery due to their biocompatibility and ability to encapsulate both hydrophilic and hydrophobic drugs. Liposomes are classified based on size, number of bilayers, composition, and preparation method. They can be prepared using techniques like film hydration, extrusion, sonication, and solvent injection. Coating liposomes with polymers like PEG creates stealth liposomes that have longer circulation times in the body.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
PPT on Alternate Wetting and Drying presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
(June 12, 2024) Webinar: Development of PET theranostics targeting the molecu...Scintica Instrumentation
Targeting Hsp90 and its pathogen Orthologs with Tethered Inhibitors as a Diagnostic and Therapeutic Strategy for cancer and infectious diseases with Dr. Timothy Haystead.
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...Advanced-Concepts-Team
Presentation in the Science Coffee of the Advanced Concepts Team of the European Space Agency on the 07.06.2024.
Speaker: Diego Blas (IFAE/ICREA)
Title: Gravitational wave detection with orbital motion of Moon and artificial
Abstract:
In this talk I will describe some recent ideas to find gravitational waves from supermassive black holes or of primordial origin by studying their secular effect on the orbital motion of the Moon or satellites that are laser ranged.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
Anti-Universe And Emergent Gravity and the Dark UniverseSérgio Sacani
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a0 = cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
Mending Clothing to Support Sustainable Fashion_CIMaR 2024.pdfSelcen Ozturkcan
Ozturkcan, S., Berndt, A., & Angelakis, A. (2024). Mending clothing to support sustainable fashion. Presented at the 31st Annual Conference by the Consortium for International Marketing Research (CIMaR), 10-13 Jun 2024, University of Gävle, Sweden.
2. Importance
• Fuel
• Insulation & protection
• Constituent of cell-wall
• Absorption of fat soluble
vitamins.
Food:
Palatability
Satiety
Flavour etc.
3. Source
Edible fats traditionally classified according to food source.
1. Milk fats : Derived from the milk of ruminants and in particular dairy
cows. Major fatty acids in milk fat are palmitic, oleic and stearic, milk fats.
Also appreciable amounts of the shorter chain acids C4 to C12, small
amounts of branched and odd-numbered acids.
2. Lauric acids :Derived from species of palm, e.g. coconut. Characterized by
their high content of lauric acid (40-50%), moderate amounts of C6, C8 and
C10 fatty acids, low content of unsaturated acids and low melting
points.
•
4. Edible Fat classification
3. Vegetable Butters :Derived from the seeds of various tropical plants and
are distinguished by their narrow melting range which is due to mainly to
the arrangement of fatty acids in the tri-acyl glycerol molecules.
4. Animal fats: Fats from animals. Contains large amounts of C16 and C18
fatty acids, medium amounts of unsaturated acid, e.g. oleic and linoleic
& small amounts of odd-numbered acids.
5. Marine Oils; Typically contain large amounts of long chain omega-3-
polyunsatured fatty acids, with up to six double bonds, & are usually rich in
vitamins A and D. Less resistant to oxidation than other animal or vegetable
oils due to their high degree of unsaturation.
5. Physical Properties
• Colorless, odorless and tasteless. Any color or taste is due to
association with other substances eg. yellow color of animal fat is due
to carotenoids.
• Have specific gravity of <1 (float on H2O)
• Insoluble in water but soluble in organic solvents (benzene, ether)
• Low melting points but higher than solidification points
6. Chemical Reactions
1.Hydrolysis (Lipolysis); Hydrolysed to constituents (glycerol & FAs) due to
action of heat and moisture, acids, alkali or enzymes.
In deep-fat frying hydrolysis ocuurs due to large amounts of water released
from food and the relatively high temperature used.
FFA released during frying causes decrease in surface tension of the oil &
the reduction in quality of fried food (FFA more susceptible to oxidation)
• Hydrolytic rancidity is responsible for the development of an undesirable
rancid flavor in raw milk .
• certain typical cheese flavours are produced by deliberate addition of
mild lipases.
• Controlled and selective lipolysis is used in manufacture of yogurt and
bread.
• Phospholipid hydrolysis in most species of fish during frozen storage is
associated with deterioration in quality.
7. Saponification
• Hydrolysis is by the action of alkali usually KOH or NaOH to glycerol
and corresponding salts of fatty acids(soaps)
8. Halogenation
• The addition of halogens (hydrogen & iodine) at the point of
unsaturation in fat. Important in determining the degree of
unsaturation of a fat hence its biological value
9. Hydrogenation
• A subset of halogenation: addition of H-atoms at point of
unsaturation in fat to harden and stabilize the fat.
• Done under high pressure of hydrogen & catalyzed by finely divided
nickel/copper and heat.
• Mainly used to make margarines .
10. Auto-Oxidation (Rancidity)
• Physico-chemical change in the natural properties of fat leading to
devt of off-odor, taste or color esp, during exposure to atmospheric
oxygen, light, moisture, bacteria or fungal contamination and/or heat
known as rancidity
• Saturated fats are more resistant to rancidity than unsaturated .
• Auto-oxidation follows 3 major steps
• Initiation where free radicals are formed
• Propagation : Free radicle chain reactions occur
• Termination: Formation of non-radical products.
11. Steps
• Initiation
• RH+02→R.+.OH
• R.+O2→+ROO.
• Propagation
• ROO.+RH→R.+ROOH
• ROOH→RO.+.OH
• Termination
• R.+R.→RR
• R.+ROO.→ROOR
• ROO.+ROO.→ROOR+O2
• RH is the unsaturated fatty acid
• R. is the free radical formed by removal of
hydrogen from the carbon atom adjacent
to the double bond in the Fatty acid.
• ROOH is hydrogen peroxide. ROOH
decomposes to form products such as
hexanal, monoaldehyde and pentanal
which are responsible for the off-flavours
and odours during rancidity)
• ROO. is a peroxyradical. These radicals may
attract hydrogen atoms to form more
hydrogen peroxide and the chain reaction
continues or react together to form
nonradicals hence termination of oxidation.
12. • The reaction RH+O2 to form free radicals is thermodynamically
difficult. Production of the first few radicals in the initiation stage
must occur by some catalytic means such as
1. Hydrogen peroxide decomposition
2. By metal catalysis (e.g. CU+)
3. By exposure to light
4. Enzymatic action
13. Factors Affecting Rate of Oxidation
• Fatty Acid Composition: The number, position and geometry of double bonds
affect rate of oxidation. Cis acids oxidize more readily than trans isomers and
conjugated double bonds are more reactive than non- conjugated.
• FFA Vs corresponding acyl glycerols: FFA oxidize at faster than when esterified to
glycerol.
• Oxygen Concetration:. When oxygen is abundant the rate of oxidation is
independent of oxygen concentration, but at very low oxygen concentration the
rate is approximately proportional to O2 concentration.
• Temperature: In general, the rate of oxidation increases as the temperature is
raised.
14. • Moisture: rate of oxidation depends strongly on water activity. In
dried foods with very low moisture contents, oxidation proceeds
very rapidly. Increase the aw to about 0.3 retards lipid oxidation and
produces a minimum rate.
• This protective effect of small amounts, water is believed to occur by
reducing the catalytic activity of metallic catalysts by quenching free
radicals and by impeding access of oxygen to the lipid. At higher
water activities (aw = 0.55 – 0.85) the rate oxidation increases again
as result of increased mobilization catalysts and oxygen
15. • Pro oxidants : Transition metals particularly those possessing two or
more valency states and a suitable oxidation –reduction potential
between them e.g : cobalt, copper, iron, manganese and nickel) are
effective pro oxidants and catalyse oxidation of lipids
• Light: Visible, U.V and gamma radiation are effective promoters of
oxidation.
• Surface area: The rate of oxidation increases in direct proportion to
the surface area of the lipid exposed to air
16. TECHNOLOGY OF FATS: Extraction.
• Three principle methods are used for extraction of edible fats and oils from the
animal or vegetable tissues in which they occur i.e. Rendering, Pressing & Solvent
extraction.
Rendering :
• Process of fat removal from a tissue by heat. The tissue containing a high
percentage of fat is carefully removed from the animal and chopped and minced
and heated.
• Heat allows the lipid to escape from the cells. If the heat is high the cells
are completely ruptured, a cooked flavor develops and the oil is left floating on
top. Rendering can be carried out either in the presence of water as in wet
rendering or in its absence as in dry Rendering
17. Rendering
Wet Rendering:
• fat is separate by gentle heat in an open kettle or in autoclave in the presence of steam.
The well chopped tissue is introduced into an open kettle along with a charge of water,
stirred gently and heated to about 500C. The fat floats to the top and is carefully
skimmed off.
• It has a bland flavor and requires little deodorization but the process does not remove
all of the fat from the tissue. Nowadays autoclaves and steam in digesters at high
temperature and pressures of 40 to 60 psi is used. In this way the tissue is quite well
disintegrated and separation of fat is efficient.
Dry Rendering :
• The tissue is heated and the fat separates as the protein is denatured and
water is evaporated. Commercially the process is carried out under vacuum steam
jacketed cookers. process used in cooking bacon.
18. Pressing
• It is application of high pressures to the oil bearing tissue to squeeze
out the fat. The oil is removed by pressure from an expeller or screw
press. In some cases, such as pressing olives, virgin oil is the first
pressing of the fruit and is partially bland in flavor. The fruit is then
subjected to subsequent pressing to give other grades of oil.
19. Solvent extraction:
• In this method the oil is removed from tissues which have relatively low
percentage of oil.
• Some times a tissue is subjected to pressing and then the press cake with
its low fat concetration is extracted with a solvent. The solvent must
be removed from oil after extraction of oil.
• The method is quite efficient but is expensive because of the inevitable loss
of the solvent through evaporation. Common solvents are petroleum
ether, Benzene, chlorinated hydrocarbon and carbon disulfide. The
residue obtained after pressing or extraction is high in protein and is
valuable feed for cattle.
20. Soxhlet Extraction
• Method of isolating compounds,
such as lipids, from a large amount
of solid material with a relatively
small volume of solvent.
• The solid to be extracted is placed
in a thimble in the central chamber
of the apparatus. The extraction is
aided by the addition of energy in
the form of heat, known as
refluxing.
A typical assembly uses a
round-bottomed flask, a cold
water condenser, and the
Soxhlet apparatus.
21. • The solvent vapor rises through the distillation path in the Soxhlet
apparatus to the condenser.
• Upon condensing, the solvent collects in the chamber, dissolving
some of the organic material in the thimble.
• As the chamber fills, the siphon fills as well. When the siphon is full,
the solution flows back into the flask. The solution level never
exceeds the top of the thimble, so no solid enters the flask.
22. • The lipid extract continually collects in the flask, whereas the solvent becomes part of
the next extraction cycle. Thus, the cycle can repeat indefinitely without loss of solvent.
• After extraction solvent is removed by use a rotary evaporator leaving the extracted
compound.
• Non soluble portion of extracted solid remains in the thimble and is usually discarded.
Advantages.
• The conservation of the solvent, the continuous nature of the extraction, and the ability
to accommodate large sample sizes makes Soxhlet extraction ideal for isolating organic
compounds from large portions of insoluble material.
• State the Characteristics of a good Solvent
23. Technology of fats: Hydrogenation and inter
esterification.
Refining:
• After extraction, the crude oils extracted from the tissue often contains
materials that must be removed. Including;
1. Cellular material derivatives like protein and CHO’s
2. Free fatty acids and phospholipids
3. Pigments
4. Odour compounds such as aldehydes, ketones and essential oils
5. Glycerides with high melting point.
• The first step in refining most oils and fats is the removal of cell debris.
• Free fatty acids present in some crude oils can be fairly completely removed by
steam refining.
24. Steam refining:
• Process is used for the deodorization of fats & consists of blowing steam through hot
oil through a vacuum.
• Oil with high concentration of free fatty acids is usually first subjected to steam
refining which is then followed by alkali refining.
• Oils with low fatty acids may directly undergo alkali refining.
• In alkali refining hot oil is treated with a solution of alkali usually sodium hydroxide.
Sometimes with sodium carbonate.
• The free fatty acids react with alkali and forms soaps which are dispensable in water.
The process is called saponification. The oil is then mixed with hot water and passed
through a centrifuge that discharges it out.
•
25. Bleaching
• Bleaching involves removal of pigments by adsorption through the addition of small
amount of charcoal (activated). The oil is heated to 220– 240oF and then agitated and
filtered until the color of filtered oil is sufficiently light. Chemical agents like oxidizing or
reducing agents are not used for bleaching of edible oils, but used for waxes.
• Steam deodorization: The last step of the refining process of oils and fats to remove
unwanted odours and taste. This is achieved by applying low pressures and small
quantities of steam. The fat is heated as steam is injected into the bottom of the vessel.
The oils are rapidly deodorized at 425 to 475oF. If lower temperatures are used longer
periods are required then oil is rapidly cooled.
• By steam deodorization fats and oils are rendered, so bland that it is difficult to detect
their origin by taste or smell.
26. Hydrogenation :
• Hydrogenation of fats involves the addition of hydrogen double to bonds in the
fatty acid chains. The process is of major importance in the fats and oils
industry & accomplishes two major objectives.
- First it allows the conversion of liquid oils into semisolid or plastic fats more
suitable for specific applications, such as in shortenings and margarine
- second, it improves the oxidative stability of the oil.
• In practice, the oil is first mixed with a suitable catalyst heated to a desired
temperature (140-2250C), then exposed, while stirring to hydrogen at pressures
up to 60 psi.
• Agitation is necessary to aid dissolving the hydrogen to achieve uniform mixing.
27. Inter-esterification & Intra-esterification
• Processes used to improve the consistency of lipids
to improve their usefulness. This process involves
rearranging the fatty acids within a triglyceride
molecule. Generally done to modify the melting
point, slow down rancidity or making the oil more
suitable for deep frying.
• Note: This is not the same as hydrogenation.
Principle :
• If a lipid contains two fatty acids A & B, 8 possible
TAG species are possible according to rule of
chance.
A A A A B B B B
A A B B A A B B
B A A B A B A B
28. • Regardless of the distribution of the two acids
in the original fat (eg:
• AAA & BBB or ABB,ABA,BBA), intra-
esterification results in the “shuffling” of fatty
acids within a single molecule and among TAG
molecules until an equilibrium is achieved in
which all possible combinations are formed.
• Inter-esterification follows the same principle
but this time rearrangement is between
molecules and not within molecules.
29. Chemistry of Frying
• Foods fried in fat make significant contributions to the calories in the
average global population diet. In the course of deep fat frying, food
contacts oil at about 1800C and is partially exposed to air for various
periods of time.
• Thus frying more than any other standard food process and handling
method, has the great potential for causing chemical changes in fat,
and sizeable amount of this fat are carried with food.
30. Behavior of the frying oil:
• The following classes of compounds are produced from the oil during
frying.
1. Volatiles:
• During frying, oxidative reactions involving the formation and
decomposition of hydroperoxides lead to formation of compounds such as
saturated and unsaturated aldehydes, ketones, hydrocarbons, alcohols,
acids and esters.
• After oil is heated for 30 min at 1800c in the presence of air, the primary
volatile oxidation products can be detected by gas chromatography.
Although the amounts of volatiles produced vary widely, depending on oil
type, food type and the heat treatment.
31. 2. Non polymeric polar compounds of moderate volatility. The
compounds are produced according to the various oxidative
pathways involving the radicals.
3. Dimeric and polymeric acids, and dimeric and polymeric
glyceride. These compounds occur as a result of thermal and oxidative
combinations of free radicals. Polymerization results in a substantial
increase in the viscosity of the frying oil.
4. Free fatty acids :
• These compounds arise from hydrolysis of triacylglycerols in the
presence of heat and water.
32. What Happens During Frying
• During frying, water is continuously released from the food into the
hot oil. This produces a steam distillation effect, sweeping volatile
oxidative products from the oil.
• The released moisture also agitates the oil and hastens hydrolysis.
The blanket of steam formed above the surface of the oil tends to
reduce the amount of oxygen available for oxidation.
• Volatiles may develop in the food itself or from the interactions
between the food and oil.
33. • Food absorbs varying amounts of oil during deep fat frying, resulting
in the need for frequent or continuous addition of fresh oil.
• In continuous fryers, this result in rapid attainment of a steady state
condition for oil properties. The food itself can release some of its
endogenous lipids into the frying fat and consequently the oxidative
stability of the new mixture may be different from that of the original
fat. The presence of food causes the oil to darken at an accelerated
rate.
34. • The changes that occur in the oil and food during frying should not be automatically
construed as undesirable or harmful. Infact some of these changes are necessary
to provide the sensory qualities typical of fried food. On the other hand,
extensive decomposition, resulting from lack of adequate control of the frying
operation, can be potential source of damage not only to sensory quality of the fried
food but also to nutritional value.
• The chemical and physical changes in the frying fat are influenced by a number of
frying parameters. Obviously, the compounds formed depend on the composition of
both the oil and the food being fried. High temperature, long frying times, and
metal contaminants favour volume ratios.