Studies on the quantitative and qualitative content of protein in samples of corn (Zea mays L.)

O presente trabalho constitui estudo quantitativo e qualitativo da proteína de 49 amostras de milho. Os trabalhos de análises foram conduzidos separadamente para o germe e o endosperma. Descrevem-se, também, os métodos de análise química utilizados dando especial ênfase ao método para determinação do triptofano que tem dado bons resultados. Foram as seguintes as principais observações feitas: 1. É bastante elevado o teor médio em proteína bruta das amostras examinadas (10,65%) 2. Os milhos duros apresentaram superioridade significativa aos milhos dentados quanto ao teor de proteína bruta (11,09% e 10,09%) 3. Não há diferença significativa entre milhos dentados e duros quanto à relação triptofano/proteína. 4. A proteína dos grãos ricos em proteína contém aproximadamente 1,10% de triptofano; a proteína dos grãos pobres em proteína contém, em média, 1,20% do triptofano. A diferença é pouco significativa. 5. A proteína do germe contém mais triptofano que a maioria das proteínas animais e vegetais de elevado valor biológico 6. A seleção no sentido de aumentar a percentagem de germe no grão é eficiente para aumentar não só a quantidade como principalmente a qualidade da proteína do milho.The paper studies the quantitative and qualitative content of protein in 49 samples of com (Zea mays L.). Independent chemical analysis were made on the protein of germ and endosperm. The description of the method of the chemical analysis in presented, giving special emphasis to the method with good result, for the determination of tryptophan. The following observations were made: 1. The average total protein content is fairly high in the studied samples (10,65%). 2. Flint corn samples showed significant higher total protein content than the dent corn samples (11,09% and 10,09%). 3. Between flint and dent corns the difference is not significant in the proportion of tryptophan over total protein. 4. The protein of the samples rich in protein, contains approximately 1,10% tryptophan; the protein of low protein samples contains, in the average, 1,20% tryptophan. The difference is poorly significant. 5. The protein of the germ has more tryptophan than the most high biological value animal or vegetal proteins. 6. Selection for a larger percentage of germ in the corn Kernel is efficient to increase not only the quantity but also the quality of the protein in corn

Essential Oil of Betula pendula Roth. Buds

The essential oil of Betula pendula Roth. buds was obtained using both hydrodistillation and microdistillation techniques and their chemical compositions were analyzed using both gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS). Overall, more than 50 compounds were identified representing 80% and 92% for hydrodistillation and microdistillation, respectively. The main components (by hydrodistillation and microdistillation, respectively) found were α-copaene (12% and 10%), germacrene D (11% and 18%) and δ-cadinene (11% and 15%) in the analyzed essential oils. The microdistillation technique proved to be a useful tool and compliant alternative when compared to hydrodistillation

Modelling the Influence of Different Soot Types on the Radio-Frequency-Based Load Detection of Gasoline Particulate Filters

Gasoline particulate filters (GPFs) are an appropriate means to meet today’s emission standards. As for diesel applications, GPFs can be monitored via differential pressure sensors or using a radio-frequency approach (RF sensor). Due to largely differing soot properties and engine operating modes of gasoline compared to diesel engines (e.g., the possibility of incomplete regenerations), the behavior of both sensor systems must be investigated in detail. For this purpose, extensive measurements on engine test benches are usually required. To simplify the sensor development, a simulation model was developed using COMSOL Multiphysics® that not only allowed for calculating the loading and regeneration process of GPFs under different engine operating conditions but also determined the impact on both sensor systems. To simulate the regeneration behavior of gasoline soot accurately, an oxidation model was developed. To identify the influence of different engine operating points on the sensor behavior, various samples generated at an engine test bench were examined regarding their kinetic parameters using thermogravimetric analysis. Thus, this compared the accuracy of soot mass determination using the RF sensor with the differential pressure method. By simulating a typical driving condition with incomplete regenerations, the effects of the soot kinetics on sensor accuracy was demonstrated exemplarily. Thereby, the RF sensor showed an overall smaller mass determination error, as well as a lower dependence on the soot kinetics