The Irvingia gabonensis kernels, which have been extensively studied for their numerous virtues, including the ability to act against the accumulation of fats in the body[1], contain an oil. The aging of this oil unde...The Irvingia gabonensis kernels, which have been extensively studied for their numerous virtues, including the ability to act against the accumulation of fats in the body[1], contain an oil. The aging of this oil under two different conditions of conservation was the subject of our work. One of the results was an increase in the content of long-chain carbonaceous fatty acids during aging for 11 months of storage at low temperature (6℃) and at 30℃. This behavior does not find a concordant explanation by the comparative analysis of the chemical indices. Hence, there is the need to use the Medium Infra-Red spectroscopy (MIR) which allowed to clarify the information of the saponification index, to justify the weakness of the formation of peroxides in the case of the conservation at 30℃ and to confirm the information given by the peroxide index. It also allowed to understand the formation of the long carbon chains by the “cis-trans” isomerization and the homolytic cuts which intervene within the matrix of the fat by the analysis of the number of -CH<sub>2</sub> and -CH<sub>3</sub> groups in the two conditions of conservation. This study reveals that the rapid solidification of Irvingia gabonensis oil at room temperature[2] is an advantage for its preservation at room temperature but a great weakness when the fat is stored at low temperature.展开更多
The main purpose of this study is to improve the energy efficiency of a refrigerated facility by means of exergetic analysis. In order to achieve this goal, we have evaluated the input exergy flows of the whole system...The main purpose of this study is to improve the energy efficiency of a refrigerated facility by means of exergetic analysis. In order to achieve this goal, we have evaluated the input exergy flows of the whole system to deduce the exergetic yields, which are compared to the degree of irreversibility in order to have a qualitative measurement of energy losses. The concept of exergy is the part of energy that is virtually converted into work. The exergetic analysis </span><span style="font-size:12px;font-family:Verdana;">was performed on a refrigeration unit ZR22K3E Copeland Scroll. The results of this analysis are consistent with the condition, that the exergetic performance, which is: 36.57% and it is approximately equal to the degree of irreversibility which is 37.50%. This approach provides a comprehensive, standard and rigorous framework for the analysis of energy systems, and thus for </span><span style="font-size:12px;font-family:Verdana;">the understanding and systemic management of the energy challenge.展开更多
The study of the polymerization of a vegetable oil has a double interest;industrial but especially food. Industrial because polymers based on vegetable oil are in line with sustainable development;food because an oil ...The study of the polymerization of a vegetable oil has a double interest;industrial but especially food. Industrial because polymers based on vegetable oil are in line with sustainable development;food because an oil which polymerizes easily is a danger for human consumption. Three situations of <em>Cucurbita pepo</em> oil polymerization are carried out in the course of time, the factor retained being temperature. A monitoring of the evolution of the enthalpy by temperature variation by the DSC method allows to report the polymerization of this oil. It happens that a polymerization is triggered in the oil matrix but it seems to fade very quickly, this behavior is general because after sweeping a temperature range of 80<span style="white-space:nowrap;">°</span>C;100<span style="white-space:nowrap;">°</span>C and 150<span style="white-space:nowrap;">°</span>C adding different amounts of Irgacure: the<em> Cucurbita pepo</em> oil resists polymerization through its antioxidant compounds. However, a photolysis of this oil carried out over 8 days shows that it effectively polymerizes after 144 hours, which proves the great capacity of antioxidant compounds to protect this oil. The analyses carried out at 25<span style="white-space:nowrap;">°</span>C aim to simulate the behavior of the oil at room temperature. The results reveal good resistance to both thermochemical and photochemical polymerization, which opens up great prospects for its development in the food industry and in nutrition.展开更多
文摘The Irvingia gabonensis kernels, which have been extensively studied for their numerous virtues, including the ability to act against the accumulation of fats in the body[1], contain an oil. The aging of this oil under two different conditions of conservation was the subject of our work. One of the results was an increase in the content of long-chain carbonaceous fatty acids during aging for 11 months of storage at low temperature (6℃) and at 30℃. This behavior does not find a concordant explanation by the comparative analysis of the chemical indices. Hence, there is the need to use the Medium Infra-Red spectroscopy (MIR) which allowed to clarify the information of the saponification index, to justify the weakness of the formation of peroxides in the case of the conservation at 30℃ and to confirm the information given by the peroxide index. It also allowed to understand the formation of the long carbon chains by the “cis-trans” isomerization and the homolytic cuts which intervene within the matrix of the fat by the analysis of the number of -CH<sub>2</sub> and -CH<sub>3</sub> groups in the two conditions of conservation. This study reveals that the rapid solidification of Irvingia gabonensis oil at room temperature[2] is an advantage for its preservation at room temperature but a great weakness when the fat is stored at low temperature.
文摘The main purpose of this study is to improve the energy efficiency of a refrigerated facility by means of exergetic analysis. In order to achieve this goal, we have evaluated the input exergy flows of the whole system to deduce the exergetic yields, which are compared to the degree of irreversibility in order to have a qualitative measurement of energy losses. The concept of exergy is the part of energy that is virtually converted into work. The exergetic analysis </span><span style="font-size:12px;font-family:Verdana;">was performed on a refrigeration unit ZR22K3E Copeland Scroll. The results of this analysis are consistent with the condition, that the exergetic performance, which is: 36.57% and it is approximately equal to the degree of irreversibility which is 37.50%. This approach provides a comprehensive, standard and rigorous framework for the analysis of energy systems, and thus for </span><span style="font-size:12px;font-family:Verdana;">the understanding and systemic management of the energy challenge.
文摘The study of the polymerization of a vegetable oil has a double interest;industrial but especially food. Industrial because polymers based on vegetable oil are in line with sustainable development;food because an oil which polymerizes easily is a danger for human consumption. Three situations of <em>Cucurbita pepo</em> oil polymerization are carried out in the course of time, the factor retained being temperature. A monitoring of the evolution of the enthalpy by temperature variation by the DSC method allows to report the polymerization of this oil. It happens that a polymerization is triggered in the oil matrix but it seems to fade very quickly, this behavior is general because after sweeping a temperature range of 80<span style="white-space:nowrap;">°</span>C;100<span style="white-space:nowrap;">°</span>C and 150<span style="white-space:nowrap;">°</span>C adding different amounts of Irgacure: the<em> Cucurbita pepo</em> oil resists polymerization through its antioxidant compounds. However, a photolysis of this oil carried out over 8 days shows that it effectively polymerizes after 144 hours, which proves the great capacity of antioxidant compounds to protect this oil. The analyses carried out at 25<span style="white-space:nowrap;">°</span>C aim to simulate the behavior of the oil at room temperature. The results reveal good resistance to both thermochemical and photochemical polymerization, which opens up great prospects for its development in the food industry and in nutrition.
