The objective of this study is to determine the factors responsible for the acidification of Burundi palm oils. The investigation of the duration of fermentation of palm fruits performed among artisanal producers foun...The objective of this study is to determine the factors responsible for the acidification of Burundi palm oils. The investigation of the duration of fermentation of palm fruits performed among artisanal producers found that more than 89% of producers from commune of Rumonge ferment for more than 5 days while more than 61% of those from commune of Mutimbuzi ferment for 4 days. The determination of acid value using the method of ISO 660:2009 showed that Dura and Tenera varieties fermented for 4 days had respectively 5.9 ± 2.3 and 5.8 ± 1.8 mg of KOH/g of oil for clustered fruits, 7.03 ± 3.4 and 7.02 ± 3.2 mg of KOH/g for destemmed fruits. After 8 days, the acid values of Dura and Tenera varieties obtained were respectively 10.9 ± 4.7 and 12.5 ± 5.4 mg KOH/g for clustered fruits, 12.5 ± 5.4 and 12.5 ± 4.1 mg KOH/g for destemmed fruits. No significant difference was recorded between varieties. On the other hand, a highly significant difference at p < 0.05 was obtained between fruits fermented in the open air (e.g. around the foot of the oil palm, FFOA), in a shed when the fruits were not covered (SFNC) and in a shed when the fruits were covered by branches or straw (SFC). At 8 days of fermentation, the acid values of FFOA, SFNC and SFC were 9.1 ± 0.7 < 12.6 ± 0.8 < 17.7 ± 1.4 for destemmed fruit and 9.1 ± 0.7 < 13.2 ± 1.3 < 13.2 ± 3.2 for clustered fruit, respectively. In light of these results, the acidity of Rumonge palm oil is probably due to the long fermentation time and the technique of covering the fruits during fermentation. These results will allow producers to extract good quality oil and consequently improve the health of consumers.展开更多
[ Objective] This study was to improve the biomass of Navicula tenera, and thus to provide reference for achieving the industrial production of Navicula tenera. [Method] The feasibility of using sewage to cultivate Na...[ Objective] This study was to improve the biomass of Navicula tenera, and thus to provide reference for achieving the industrial production of Navicula tenera. [Method] The feasibility of using sewage to cultivate Navicula tenera was preliminarily investigated based on the consideration of regional characteristics; and a series of culture conditions including the nutrient source of nitrogen（N）, phosphorus（P）, iron（Fe）, silicon（ Si ） and the salinity in medium for culturing Navicula tenera, were optimized by single factor test and orthogonal design.[Result] The optimized conditions for cultivating Navicula tenera using sewage are as follows： the water from Xiaoerlou Artificial Lake of Nanjing University of Technology as basic solvent; 360 mg/L urea; 150 mg/L N2HPO4 · 12H2O; 50 mg/L ferric citrate; 2 000 mg/L Na2SiO3 · 9H2O; 2.0 mol/L salinity. Navicula tenera was strongly adaptive to sewage and could well uptake the nutrient sources in the sewage. Under the optimized conditions, the culture cost decreased, and meanwhile the biomass of Navicula tenera reached 4. 766 g/L which is 3.57 multiples over original medium and 1.9 multiples over optimized medium No. 1.[ Conclusion] This study laid a foundation for the combination of culturing Navicula tenera in large scale and sewage treatment.展开更多
文摘The objective of this study is to determine the factors responsible for the acidification of Burundi palm oils. The investigation of the duration of fermentation of palm fruits performed among artisanal producers found that more than 89% of producers from commune of Rumonge ferment for more than 5 days while more than 61% of those from commune of Mutimbuzi ferment for 4 days. The determination of acid value using the method of ISO 660:2009 showed that Dura and Tenera varieties fermented for 4 days had respectively 5.9 ± 2.3 and 5.8 ± 1.8 mg of KOH/g of oil for clustered fruits, 7.03 ± 3.4 and 7.02 ± 3.2 mg of KOH/g for destemmed fruits. After 8 days, the acid values of Dura and Tenera varieties obtained were respectively 10.9 ± 4.7 and 12.5 ± 5.4 mg KOH/g for clustered fruits, 12.5 ± 5.4 and 12.5 ± 4.1 mg KOH/g for destemmed fruits. No significant difference was recorded between varieties. On the other hand, a highly significant difference at p < 0.05 was obtained between fruits fermented in the open air (e.g. around the foot of the oil palm, FFOA), in a shed when the fruits were not covered (SFNC) and in a shed when the fruits were covered by branches or straw (SFC). At 8 days of fermentation, the acid values of FFOA, SFNC and SFC were 9.1 ± 0.7 < 12.6 ± 0.8 < 17.7 ± 1.4 for destemmed fruit and 9.1 ± 0.7 < 13.2 ± 1.3 < 13.2 ± 3.2 for clustered fruit, respectively. In light of these results, the acidity of Rumonge palm oil is probably due to the long fermentation time and the technique of covering the fruits during fermentation. These results will allow producers to extract good quality oil and consequently improve the health of consumers.
基金Supported by National Basic Research Program of China(973 Pro-gram)(2003CB71600)~~
文摘[ Objective] This study was to improve the biomass of Navicula tenera, and thus to provide reference for achieving the industrial production of Navicula tenera. [Method] The feasibility of using sewage to cultivate Navicula tenera was preliminarily investigated based on the consideration of regional characteristics; and a series of culture conditions including the nutrient source of nitrogen（N）, phosphorus（P）, iron（Fe）, silicon（ Si ） and the salinity in medium for culturing Navicula tenera, were optimized by single factor test and orthogonal design.[Result] The optimized conditions for cultivating Navicula tenera using sewage are as follows： the water from Xiaoerlou Artificial Lake of Nanjing University of Technology as basic solvent; 360 mg/L urea; 150 mg/L N2HPO4 · 12H2O; 50 mg/L ferric citrate; 2 000 mg/L Na2SiO3 · 9H2O; 2.0 mol/L salinity. Navicula tenera was strongly adaptive to sewage and could well uptake the nutrient sources in the sewage. Under the optimized conditions, the culture cost decreased, and meanwhile the biomass of Navicula tenera reached 4. 766 g/L which is 3.57 multiples over original medium and 1.9 multiples over optimized medium No. 1.[ Conclusion] This study laid a foundation for the combination of culturing Navicula tenera in large scale and sewage treatment.
