File Name: physical and chemical properties of lipids .zip
Analysis of Lipids. Lipids are one of the major constituents of foods, and are important in our diet for a number of reasons. They are a major source of energy and provide essential lipid nutrients.
Physical properties of structured lipids from lard and soybean oil produced by enzymatic interesterification. The main goal of the present research was to evaluate the physical properties of blends of lard and soybean oil modified by enzymatic interesterification catalyzed by two different commercial microbial lipases, viz.
Pure lard exhibited a softening point of ca. This result was most likely due to the sn -1,3-specificity of M10 lipase. Pure lard displayed a lower SFC after interesterification, and M10 lipase proved to be more effective than AY30 lipase.
The non-interesterified lard had a SFC of The lard and soybean oil blends were affected by the enzymatic interesterification and dilution with soybean oil. Keywords: structured lipids; lipase; lard; soybean oil; interesterification. Structured lipids SLs are defined as triacylglycerols TAGs that have been modified by the incorporation of new fatty acids, restructured to change the positions of fatty acids, or synthesized to yield novel TAGs AKOH, aiming at obtaining some desirable properties, such as reduced caloric value or modified melting point.
They can also present more favorable characteristics, inducing e. SLs can be produced via interesterification reactions of fats, oils, or mixtures thereof, either chemically or enzymatically.
Currently, under the perspective of cost reduction and large scale application, chemical interesterification seems to be the most attractive method. However, under the perspective of producing lipids with very specific compositions aiming at functional and medical applications, enzymatic interesterification is far more interesting WILLIS et al. Among the currently available methods for modifying lipids, lipase-catalyzed reactions are better than conventional chemical methods since lipases mimic natural pathways, which concern mild reaction conditions, high catalytic efficiency, and the inherent selectivity of natural biocatalysts.
Many different types of lipases have been investigated for the enzymatic modification of oils and fats.
Commercial lipases are available from microbial, plant, and animal sources. Regarding the physical characteristics of structured lipids SLs produced via lipase-catalyzed reactions, it is important to know the thermal characteristics, rheology, crystallization patterns, texture, and appearance of a new SL when determining its suitability for the use in certain food applications OSBORN; AKOH, The slip melting point procedure measures the temperature at which a column of fat moves in an open capillary when heated.
Some researchers have used the dropping point method to verify the occurrence of complete interesterification LIST et al. However, this method may not provide an accurate measurement for all SLs.
ROUSSEAU and co-workers have found that a linear increase in the proportion of canola oil did not lead to a linear reduction in the dropping point. SFC is, in this sense, responsible for many product characteristics including general appearance, ease of packing, organoleptic properties, ease of spreading, and oil exudation. Hardness and cohesiveness are important textural parameters for spreadable materials and chocolate products.
Lohman and Hartel clearly demonstrated a link between SFC of fat and hardness in a "chocolate fat". Lard is the only fat that has a structure similar to that of human milk fat. The main goal of this research was to characterize the physical properties of the structured lipids produced by enzymatic interesterification of lard and soybean oil blends catalyzed by commercial lipases from Candida cylindracea and Mucor circinelloides that could be used as SLs resembling human milk fat.
All other reagents and solvents were of analytical or chromatographical grade. Three binary mixtures of lard and soybean oil were prepared. After that, a known amount of crude lipase powder ca. The headspace above the reaction mixture was continuously supplied with anhydrous nitrogen.
Aliquots were withdrawn at regular intervals of time and assayed for fatty acid composition by gas chromatography. Fatty acids in the triacylglycerols of the interesterified mixtures were converted into fatty acid methyl esters FAMES according to the procedure described by Hartman e Lago The qualitative fatty acid composition of the samples was determined by comparing the retention times of the peaks produced after injecting the methylated samples with those of the respective standards of fatty acids.
All samples were analyzed in duplicate and the reported values are the average of the two runs. These analyses were performed in triplicate.
Test parameters were as follows: penetration depth: 1. The measurements were performed in triplicate, and the reported values are the simple average of the three values. Two replicates were performed for every sample, and the reported value is the average of the two values. A multiple regression model was applied to some analytical responses softening point and consistency and solid fat contents HARE, represented by the following Equation The Statistics 7. The fatty acid composition and distribution within the triacylglycerols in infant formulas have recently gained much attention.
The fatty acid composition of lard depends on characteristics such as race, sex, diet, and age of the animal. Therefore, the saturation of lard depends mainly on the amount and composition of the fat supplied to the animal O' BRIEN, An adequate intake of the essential fatty acids viz. In human milk, such ratio is ca. Interesterification does not affect the degree of saturation and does not cause isomerization. Our results suggest that interesterification did not cause a significant alteration in the fatty acid profile of the starting blends.
The iodine value is a valuable parameter in fat analyses which measure the degree of unsaturation without defining the specific fatty acids. The iodine value of the fat blends under study changed as the function of the proportion of soybean oil and were not affected by interesterification.
The results obtained for the softening point of all samples can be found in Figure 1. Pure lard presented a softening point of After interesterification, the softening point of lard was reduced to ca. The addition of soybean oil promoted a decrease in the softening point, and this was probably caused by the incorporation of polyunsaturated fatty acids present in the soybean oil.
Silva and Co-Workers reported the softening point for human milk fat as In the present research, all fat blends exhibited softening points very close to this value, both before and after the enzymatic interesterification reactions. The interesterified blends displayed lower values for the softening points when compared with blends before enzymatic interesterification.
These results are in close agreement with the findings of other researchers, which carried out interesterification of tallow with rapeseed oil catalyzed by a sn -1,3-specific lipase FORSSEL et al.
The decrease observed in the softening point of interesterified lard and soybean oil blends was most likely caused by a change in the structure of triacylglycerols.
Due to the exchange of fatty acids on glycerol backbone and between triacylglycerols, new triacylglycerols are formed and new interrelations among them can appear. The observed decrease in the softening point was higher after the interesterification reaction catalyzed by M10 lipase, when compared to that catalyzed by the AY30 lipase.
In the case of enzymatic interesterification, small changes in the fatty acids esterified at the sn -2 position may stem from acyl migration in the triacylglycerol species during prolonged interesterification times, as reported by Xu et al. Texture is a critical factor in determining the functionality and consumer acceptability of table spreads WRIGHT et al. In Figure 2 the results obtained for the consistency of the blends of lard and soybean oil can be seen.
For the binary blends, the consistency of non-interesterified samples was higher than those of the interesterified ones for all temperatures studied. A zero value for the consistency physically represents a product with a very low consistency, and so the analytical equipment is not able to detect it.
These products generally present themselves as high viscosity fluids. Crystal patterns both polymorphism and morphology of interesterified lard substantially differed from those of native lard. Significant reductions in the SFC occurred as a consequence of enzymatic interesterification. The SFC profile of lard is displayed in Figure 3.
The SFC of lard substantially decreased by the end of the lipase-catalyzed enzymatic interesterification reaction. Non-interesterified lard exhibited a SFC of It can also be observed that the addition of soybean oil caused a significant decrease in SFC since soybean oil is liquid oil.
For the binary blends, the interesterification reaction did not promote significant differences between the lipases utilized. An increase in the temperature caused a reduction in the SFC in all blends due to the melting profile of the crystals. In their studies, Marangoni and Rousseau found the same behavior for blends between lard and canola oil. Lard and soybean oil blends were affected by both enzymatic interesterification and dilution with soybean oil.
Considerable changes in the SFC induced by lipase-catalyzed interesterification occurred, and these were lower for the reactions catalyzed by AY30 lipase. Interesterified samples presented the same behavior. The addition of soybean oil promoted a generalized decrease in the physical properties of lard, such as softening point, consistency, and solid fat content.
The lard and soybean oil blends produced were affected by enzymatic interesterification with a marked decrease in the softening point, consistency, and solid fat content.
These reductions were greater for the interesterification reactions catalyzed by the sn -1,3-specific M10 lipase. Novel triglyceride and composition comprising the same. Europen Patent A1, AKOH, C. Structured lipids. Food Lipids. New York: Marcel Dekker, Lipase-catalysed modification of borage oil: incorporation of capric and eicosapentanoic acids to form a strutured lipid. Journal of the American Oil Chemists'Society , v. Official Method Ce fatty acid composition by gas chromatography.
USA, a. Official Method Cd iodine value calculated by fatty acid composition. USA, b. Official Method Cc softening point. USA, c. Official Method Cd 16b solid fat content. USA, Bioreactors with immobilized lipases: State-of-the-art. Enzyme and Microbial Technology, v.
The analysis of the physical properties of oils and fats allows us to understand the behavior and characteristics of these elements, as well as their differences. For this, the crystallization, the melting point, the viscosity, the refractive index, the density, the solubility, the plasticity and the emulsifying capacity will be analyzed. Here we provide more detail on each of these. Fats differ from oils in their degree of solidification at room temperature, since in these conditions the oils are in a liquid state not crystallized while the fats are in the solid crystallized state. The proportion of crystals in fats have great importance in determining the physical properties of a product. The fat crystals have a size between 0.
Once production of your article has started, you can track the status of your article via Track Your Accepted Article. Help expand a public dataset of research that support the SDGs. Chemistry and Physics of Lipids publishes research papers and review articles on chemical and physical aspects of lipids with primary emphasis on the relationship of these properties to biological functions and to biomedical applications.
Dilini N. Perera, Geeth G.
Hamdy A. Tawfeuk 2. Received: 20 August Accepted: 28 March Peanuts Arachis hypogaea L. Peanut seeds are a rich source of oil content The physicochemical properties of extracted oil were investigated in this study.
Physical properties of structured lipids from lard and soybean oil produced by enzymatic interesterification. The main goal of the present research was to evaluate the physical properties of blends of lard and soybean oil modified by enzymatic interesterification catalyzed by two different commercial microbial lipases, viz. Pure lard exhibited a softening point of ca. This result was most likely due to the sn -1,3-specificity of M10 lipase. Pure lard displayed a lower SFC after interesterification, and M10 lipase proved to be more effective than AY30 lipase. The non-interesterified lard had a SFC of
Most people think "lipid" is just another term for "fat," but lipids are actually an entire class of molecules.
Fats in Food Products pp Cite as. Milkfat has a more variable triglyceride composition than vegetable and other animal fats. Butyric acid is a key fatty acid which influences the physical properties of the fat. Palm kernel and coconut fat are the vegetable fats most similar to milkfat in properties. The basic principles of polymorphism and phase behaviour of fats are described. Fats occur mainly in alpha, beta prime and beta polymorphic forms and two packing modes for each are possible. Phase behaviour describes how the many triglyceride components in fats and blends are related to physical properties such as melting range and solid content.
Lipid , any of a diverse group of organic compounds including fats , oils , hormones , and certain components of membranes that are grouped together because they do not interact appreciably with water. One type of lipid, the triglycerides , is sequestered as fat in adipose cells , which serve as the energy-storage depot for organisms and also provide thermal insulation. Some lipids such as steroid hormones serve as chemical messengers between cells , tissues , and organs , and others communicate signals between biochemical systems within a single cell.
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