Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above...Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above 42°C. Protein solubility was also studied. The addition of dissociating reagents allowed concluding that solubility was decreased during oven drying due to thermo denaturation including hydrogen bonds. The volatile compounds of the different powders were extracted by solid phase micro-extraction and identified by mass spectrometry. Volatile compounds were related to lipid oxidation and Maillard reactions occurring during the preparation of the powders. High drying temperatures led to more volatile compounds resulting from Maillard reactions. In the protein powder preparation process, a fractionation step led to a “pulp fraction” and a “juice fraction” of earthworms. The “pulp fraction” contained less odorant volatile compounds resulting from Maillard reactions than the “juice fraction” did.展开更多
Earthworms as test animats,were exposed in different concentrations of two pesticides:1 (6 chloro 3 pyridinylmthyl) N nitromidazoliding 2 ylideneamin and 2′benzoyi 1′ tert butylbenzoylhydrazinc.The acute toxicity of...Earthworms as test animats,were exposed in different concentrations of two pesticides:1 (6 chloro 3 pyridinylmthyl) N nitromidazoliding 2 ylideneamin and 2′benzoyi 1′ tert butylbenzoylhydrazinc.The acute toxicity of these two pesticides was measured as median lethal concentration values(LC 50 ) of earth worms.Tests of three different exposure systems were performed:the comact filter paper bioassay,the immersion bioassay and the artificial soil bioassay.The results indicated that the two new type pesticides showed vaious toxic effects through different exposure paths .The LC 50 of 1 (6 chloro 3 pyridinymethyl) N nitromidazolidin 2 ylideneamine was 0.034 ug·cm 2 for 48hr filter paper test,0.77mg·ml -1 for 48hr inmersion test and 2.3mg·kg -1 for 14d artiflcial soil test,respectively; while the 2′ benzoy 1′tert butylbenzoylhydrazine was>480 μg·cm -2 for 48hr filter paper test. 2655 mg·ml -1 for 48hr immersion test,and>10000mg·kg -1 for 14d artificial soil test,respectively.These outcome led to a conelusion that 1 (6 chloro 3 pyridinylmethyl) N nitromidazolidin 2 ylideneamine was far more toxic than 2′ benzoyl 1′tert butylbenzoylhydrazine with regard to acute toxicity to earthworm.However,the comprehensive assessment of the influence of both the two pesticides to soil ecosystem could not be made only by acute toxic tests because we were not aware of the mechanism acted on organisms.展开更多
文摘Protein powders from Eisenia foetida were prepared using different drying processes and fractionation. Differential scanning calorimetry was used to show that heat denaturation occurred during the drying process above 42°C. Protein solubility was also studied. The addition of dissociating reagents allowed concluding that solubility was decreased during oven drying due to thermo denaturation including hydrogen bonds. The volatile compounds of the different powders were extracted by solid phase micro-extraction and identified by mass spectrometry. Volatile compounds were related to lipid oxidation and Maillard reactions occurring during the preparation of the powders. High drying temperatures led to more volatile compounds resulting from Maillard reactions. In the protein powder preparation process, a fractionation step led to a “pulp fraction” and a “juice fraction” of earthworms. The “pulp fraction” contained less odorant volatile compounds resulting from Maillard reactions than the “juice fraction” did.
文摘Earthworms as test animats,were exposed in different concentrations of two pesticides:1 (6 chloro 3 pyridinylmthyl) N nitromidazoliding 2 ylideneamin and 2′benzoyi 1′ tert butylbenzoylhydrazinc.The acute toxicity of these two pesticides was measured as median lethal concentration values(LC 50 ) of earth worms.Tests of three different exposure systems were performed:the comact filter paper bioassay,the immersion bioassay and the artificial soil bioassay.The results indicated that the two new type pesticides showed vaious toxic effects through different exposure paths .The LC 50 of 1 (6 chloro 3 pyridinymethyl) N nitromidazolidin 2 ylideneamine was 0.034 ug·cm 2 for 48hr filter paper test,0.77mg·ml -1 for 48hr inmersion test and 2.3mg·kg -1 for 14d artiflcial soil test,respectively; while the 2′ benzoy 1′tert butylbenzoylhydrazine was>480 μg·cm -2 for 48hr filter paper test. 2655 mg·ml -1 for 48hr immersion test,and>10000mg·kg -1 for 14d artificial soil test,respectively.These outcome led to a conelusion that 1 (6 chloro 3 pyridinylmethyl) N nitromidazolidin 2 ylideneamine was far more toxic than 2′ benzoyl 1′tert butylbenzoylhydrazine with regard to acute toxicity to earthworm.However,the comprehensive assessment of the influence of both the two pesticides to soil ecosystem could not be made only by acute toxic tests because we were not aware of the mechanism acted on organisms.
