The oregano essential oil (Origanum vulgare spp.) cultivated in the city of Tacna, Peru, has been chemically analyzed. The physicochemical analysis determined the following characteristics: color (L * 60,51, a * –2,83, b * 14,31), refractive index: 1,475; specific density: 0,9132 and solubility in alcohol: 75 ml. Also, the chemical composition was evaluated by gas chromatography coupled to mass spectrometry. The chromatogram showed the following percentages: l-4 terpineol with 26,56; thymol with 18,80; g-terpinene, 11,77; 2-carene, 6,53; Terpineol, 4,08; M-cymene, 3,27 and carvacrol 2,24, among others present in smaller proportion.

In the present study, the stabilization of horse manure (mixture of rice husk, manure and horse urine) was evaluated through an aerobic process similar to composting. The stabilization process was evaluated in two piles of horse manure for 16 weeks, taking samples every week. A decrease in temperature from 66,7 to 41,0 °C, the reduction of the density from 394,0 to 370,4 kg/m3, the reduction of the water retention capacity from 220,7 to 125,6% and the reduction of the respiratory activity of 9.8 to less than 2 mgO2/g ms/d, were indicators of the stabilization of the horse manure, the easily degradable material of manure and urine were removed by aerobic degradation and washed with irrigation, leaving only the rice husk with a minimum fraction of other materials. On the other hand, the increase in total nitrogen and a decrease in the C/N ratio at the end of the week 16 were indicative of...

The oregano essential oil (Origanum vulgare spp.) cultivated in the city of Tacna, Peru, has been chemically analyzed. The physicochemical analysis determined the following characteristics: color (L * 60,51, a * –2,83, b * 14,31), refractive index: 1,475; specific density: 0,9132 and solubility in alcohol: 75 ml. Also, the chemical composition was evaluated by gas chromatography coupled to mass spectrometry. The chromatogram showed the following percentages: l-4 terpineol with 26,56; thymol with 18,80; g-terpinene, 11,77; 2-carene, 6,53; Terpineol, 4,08; M-cymene, 3,27 and carvacrol 2,24, among others present in smaller proportion.