Vegetable oils are a source of energy, essential fatty acids, antioxidants and fat-soluble vitamins useful for human health care and development. These oils also contribute to organoleptic quality of their products’ ...Vegetable oils are a source of energy, essential fatty acids, antioxidants and fat-soluble vitamins useful for human health care and development. These oils also contribute to organoleptic quality of their products’ derivatives. However, their chemical and physical properties can be modified by the mode of their extraction, storage and distribution. These modifications might negatively affect the nutritional quality of the oils. The goals of this study were to: sample different vegetable oils for cosmetic or dietary use marketed in Cameroon, and verify purity and oxidation states of each kind of oil through determination of its acidity, iodine, peroxide, saponification, refractive indexes and the conformity of the labeling. The carotene content, the level of polar components and specific absorbance were also determined. As the result, six oils namely palm, palm kernel, coconut, black cumin, peanut and shea butter were collected. Apart from labeling, chemicals and physicals parameters analyzed were generally in accordance with the Cameroonian and Codex Alimentarius standard. This study suggests that vegetable oils sampled in the Cameroonian market may not expose consumers to lipid oxidation products generating pathological oxidative stress and inflammation. However, efforts in application of existing standard need to be done as far as labeling are concerned.展开更多
The objective of this work is to extract walnut oil using various processes in order to compare the influence on the nature of the components extracted, and thus identify the areas of potential use. We carried out the...The objective of this work is to extract walnut oil using various processes in order to compare the influence on the nature of the components extracted, and thus identify the areas of potential use. We carried out the extractions by mechanical process, thanks to a press in reduced model provided with a worm. We obtained cold extracted oil whose characteristics slightly diverge from extra virgin oil found in shops in Romania, but its composition is similar. We were also able to extract by chemical process using two methods, Folch and Soxhlet. Commercially available table walnut oils are only cold extracted to avoid the presence of solvents. Those are difficult to remove and strongly oxidize the oil. Currently, consumers appreciate walnut oil for its taste and nutritional qualities. In nutrition, this oil is put forward for its composition rich in polyunsaturated fatty acids, which are needed for human body. Food supplements made from walnut oil are available today. For the moment, this is the only use of walnut oil. Indeed, there are some studies on other fields of application, but they remain in the field of research and nothing has yet been commercialized. In this present study, we compared the chemical and physical properties of cold-extracted oil with the solvent extraction of walnut kernel originating from the mountain region of Rumania. The cold extracted oil has a high content of polyunsaturated fatty acids (63%) and monounsaturated fatty acids (30%), a very low level of saturated fatty acid (7%) and no content of linolenic acid. The Soxhlet and Folch methods produced slightly different oils with increased amounts of minor components, which changes their characteristic. Even when solvent-extracted oils do not meet the standard criteria imposed by the Codex Alimentarius, they offer a possible use in the fields of food, cosmetics industries and biomedicine.展开更多
Seven Colletotrichum acutatum strains isolated from strawberries were cultivated on various culture media and tested in vitro and in vivo on Fragaria x ananassa for anthracnose symptoms. PDA caused an optimum growth o...Seven Colletotrichum acutatum strains isolated from strawberries were cultivated on various culture media and tested in vitro and in vivo on Fragaria x ananassa for anthracnose symptoms. PDA caused an optimum growth of all isolates, MEA, ML and Strawberry allowed a good but not optimal growth. Czapeck, Sabouraud and the organic medium from potato gave the lowest growth rate of all isolates. PDA allowed a good sporulation of isolates follow-up by strawberry, MEA;in contrast, ML, Czapeck and Sabouraud gave a low sporulation. The fungal development is maximal at 25°C and 27°C for all the isolates studied. No growth was observed at 5°C and 37°C. The studied strains developed at all pH values. They didn’t develop at 0.6, 0.65 and 0.7 aw but mycelial growth was perfect at 1 and 0.95 aw. The in vitro test of the pathogenicity caused by C. acutatum strains on strawberry’s leaves showed an increasing percentage of infection with time and different infection rates among C. acutatum strains, strain Ca6 having a pathogenic power very high compared to the other isolates. After in vivo inoculation and incubation of the seedlings, all isolates caused severe symptoms related to anthracnose on leaflets and petioles of the studied strawberry plants.展开更多
文摘Vegetable oils are a source of energy, essential fatty acids, antioxidants and fat-soluble vitamins useful for human health care and development. These oils also contribute to organoleptic quality of their products’ derivatives. However, their chemical and physical properties can be modified by the mode of their extraction, storage and distribution. These modifications might negatively affect the nutritional quality of the oils. The goals of this study were to: sample different vegetable oils for cosmetic or dietary use marketed in Cameroon, and verify purity and oxidation states of each kind of oil through determination of its acidity, iodine, peroxide, saponification, refractive indexes and the conformity of the labeling. The carotene content, the level of polar components and specific absorbance were also determined. As the result, six oils namely palm, palm kernel, coconut, black cumin, peanut and shea butter were collected. Apart from labeling, chemicals and physicals parameters analyzed were generally in accordance with the Cameroonian and Codex Alimentarius standard. This study suggests that vegetable oils sampled in the Cameroonian market may not expose consumers to lipid oxidation products generating pathological oxidative stress and inflammation. However, efforts in application of existing standard need to be done as far as labeling are concerned.
文摘The objective of this work is to extract walnut oil using various processes in order to compare the influence on the nature of the components extracted, and thus identify the areas of potential use. We carried out the extractions by mechanical process, thanks to a press in reduced model provided with a worm. We obtained cold extracted oil whose characteristics slightly diverge from extra virgin oil found in shops in Romania, but its composition is similar. We were also able to extract by chemical process using two methods, Folch and Soxhlet. Commercially available table walnut oils are only cold extracted to avoid the presence of solvents. Those are difficult to remove and strongly oxidize the oil. Currently, consumers appreciate walnut oil for its taste and nutritional qualities. In nutrition, this oil is put forward for its composition rich in polyunsaturated fatty acids, which are needed for human body. Food supplements made from walnut oil are available today. For the moment, this is the only use of walnut oil. Indeed, there are some studies on other fields of application, but they remain in the field of research and nothing has yet been commercialized. In this present study, we compared the chemical and physical properties of cold-extracted oil with the solvent extraction of walnut kernel originating from the mountain region of Rumania. The cold extracted oil has a high content of polyunsaturated fatty acids (63%) and monounsaturated fatty acids (30%), a very low level of saturated fatty acid (7%) and no content of linolenic acid. The Soxhlet and Folch methods produced slightly different oils with increased amounts of minor components, which changes their characteristic. Even when solvent-extracted oils do not meet the standard criteria imposed by the Codex Alimentarius, they offer a possible use in the fields of food, cosmetics industries and biomedicine.
文摘Seven Colletotrichum acutatum strains isolated from strawberries were cultivated on various culture media and tested in vitro and in vivo on Fragaria x ananassa for anthracnose symptoms. PDA caused an optimum growth of all isolates, MEA, ML and Strawberry allowed a good but not optimal growth. Czapeck, Sabouraud and the organic medium from potato gave the lowest growth rate of all isolates. PDA allowed a good sporulation of isolates follow-up by strawberry, MEA;in contrast, ML, Czapeck and Sabouraud gave a low sporulation. The fungal development is maximal at 25°C and 27°C for all the isolates studied. No growth was observed at 5°C and 37°C. The studied strains developed at all pH values. They didn’t develop at 0.6, 0.65 and 0.7 aw but mycelial growth was perfect at 1 and 0.95 aw. The in vitro test of the pathogenicity caused by C. acutatum strains on strawberry’s leaves showed an increasing percentage of infection with time and different infection rates among C. acutatum strains, strain Ca6 having a pathogenic power very high compared to the other isolates. After in vivo inoculation and incubation of the seedlings, all isolates caused severe symptoms related to anthracnose on leaflets and petioles of the studied strawberry plants.
