In this study, the effect of extraction processes on the physicochemical characteristics and antioxidant potential of baobab (Adansonia digitata L.) seed oil was evaluated. The oils were extracted, on the one hand, by...In this study, the effect of extraction processes on the physicochemical characteristics and antioxidant potential of baobab (Adansonia digitata L.) seed oil was evaluated. The oils were extracted, on the one hand, by cold pressing, and on the other hand, with three types of organic solvents (acetone, chloroform, n-hexane). The recorded results indicated that the extraction yield of baobab oil was significantly impacted by both the extraction method and the polarity of the solvent used. In addition, chloroform provides the best extraction yield (40.12 ± 0.607). However, extraction by cold pressure preserves at best the physicochemical and bioactive properties of the extracted oils. Indeed, the pressing oil contains a content of phenolic compounds (0.047 ± 0.0024 mgEAG/g of oil) and a very high radical scavenging activity (DPPH) (31.71% ± 0.61%). For the various oils extracted, the minimum and maximum values were 0.50 and 3.17 mEq?kg-1;56.26 and 99.113 mgI2?100 g-1;1.457 and 1.465;205.37 and 233.587 mgKOH/g respectively for the peroxide, iodine, refractive and saponification values. The color parameters (L*, a* and b*) of the oils also differ depending on the nature of the organic solvent used. Principal component analysis (PCA) and correlation analysis were performed on the physicochemical properties and the antioxidant potential of the extracted oils. Therefore, the results suggest the mixed use of acetone and hexane to obtain oil comparable to that extracted by cold pressing.展开更多
The considerable post-harvest losses (5% to 40% depending on storage time) due to the high water content level of the onion varieties in Senegal are the main cause of the problem of access to local onion all year roun...The considerable post-harvest losses (5% to 40% depending on storage time) due to the high water content level of the onion varieties in Senegal are the main cause of the problem of access to local onion all year round. Therefore, drying is one of the techniques that can be used to solve the problem of onion perishability. This study deals with the characterization of naturally convective kinetics drying of four onion varieties in relation to their maturity level. The experiment was carried out using the gravimetric method. The Welch and Turkey statistical tests display a significant difference between the effective diffusivity coefficients depending on the maturity level within each variety and across the four varieties. The effective diffusivity coefficients of the Galmi Violet, Safari, Gandiol F1 and Orient F1varieties range from 2.18 × 10−11 ± 2.69 × 10−12 to 1.32 × 10−10 ± 1.17 × 10−11 m2⋅s−1 at a maturity level less than 80%. When the maturity level is greater than 85%, the effective diffusivity coefficients range from 1.30 × 10−11 ± 1.24 × 10−12 to 8.05 × 10−11 ± 8.94 × 10−13 m2⋅s−1. As far as the activation energy is concerned, the study only reveals a significant difference between the varieties whatever the maturity level is. The Galmi Violet variety stands out with an average activation energy of 66.71 ± 0.12 KJ⋅mol−1 K−1 for the maturity level below 80% and 58.74 ± 0.11 KJ⋅mol−1 for the maturity level above 85%. For the three remaining varieties, the average activation energy ranges from 58.15 ± 0.19 to 59.12 ± 0.13 KJ⋅mol−1 for a maturity level less than 80% whereas the rates go from 47.63 ± 0.28 to 49.96 ± 0.77 KJ⋅mol−1 when the maturity level is greater than 85%. In summary, the higher the maturity level is, the lower the effective diffusivity coefficients will be. The same tendency was observed with the activation energy. The Galmi Violet variety represents the limitative one in case of the drying of the four varieties mix together.展开更多
文摘In this study, the effect of extraction processes on the physicochemical characteristics and antioxidant potential of baobab (Adansonia digitata L.) seed oil was evaluated. The oils were extracted, on the one hand, by cold pressing, and on the other hand, with three types of organic solvents (acetone, chloroform, n-hexane). The recorded results indicated that the extraction yield of baobab oil was significantly impacted by both the extraction method and the polarity of the solvent used. In addition, chloroform provides the best extraction yield (40.12 ± 0.607). However, extraction by cold pressure preserves at best the physicochemical and bioactive properties of the extracted oils. Indeed, the pressing oil contains a content of phenolic compounds (0.047 ± 0.0024 mgEAG/g of oil) and a very high radical scavenging activity (DPPH) (31.71% ± 0.61%). For the various oils extracted, the minimum and maximum values were 0.50 and 3.17 mEq?kg-1;56.26 and 99.113 mgI2?100 g-1;1.457 and 1.465;205.37 and 233.587 mgKOH/g respectively for the peroxide, iodine, refractive and saponification values. The color parameters (L*, a* and b*) of the oils also differ depending on the nature of the organic solvent used. Principal component analysis (PCA) and correlation analysis were performed on the physicochemical properties and the antioxidant potential of the extracted oils. Therefore, the results suggest the mixed use of acetone and hexane to obtain oil comparable to that extracted by cold pressing.
文摘The considerable post-harvest losses (5% to 40% depending on storage time) due to the high water content level of the onion varieties in Senegal are the main cause of the problem of access to local onion all year round. Therefore, drying is one of the techniques that can be used to solve the problem of onion perishability. This study deals with the characterization of naturally convective kinetics drying of four onion varieties in relation to their maturity level. The experiment was carried out using the gravimetric method. The Welch and Turkey statistical tests display a significant difference between the effective diffusivity coefficients depending on the maturity level within each variety and across the four varieties. The effective diffusivity coefficients of the Galmi Violet, Safari, Gandiol F1 and Orient F1varieties range from 2.18 × 10−11 ± 2.69 × 10−12 to 1.32 × 10−10 ± 1.17 × 10−11 m2⋅s−1 at a maturity level less than 80%. When the maturity level is greater than 85%, the effective diffusivity coefficients range from 1.30 × 10−11 ± 1.24 × 10−12 to 8.05 × 10−11 ± 8.94 × 10−13 m2⋅s−1. As far as the activation energy is concerned, the study only reveals a significant difference between the varieties whatever the maturity level is. The Galmi Violet variety stands out with an average activation energy of 66.71 ± 0.12 KJ⋅mol−1 K−1 for the maturity level below 80% and 58.74 ± 0.11 KJ⋅mol−1 for the maturity level above 85%. For the three remaining varieties, the average activation energy ranges from 58.15 ± 0.19 to 59.12 ± 0.13 KJ⋅mol−1 for a maturity level less than 80% whereas the rates go from 47.63 ± 0.28 to 49.96 ± 0.77 KJ⋅mol−1 when the maturity level is greater than 85%. In summary, the higher the maturity level is, the lower the effective diffusivity coefficients will be. The same tendency was observed with the activation energy. The Galmi Violet variety represents the limitative one in case of the drying of the four varieties mix together.