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.

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Tecnología de Alimentos

Se evaluó la influencia de dos concentraciones de aceite esencial de orégano: 0,1 % y 0,3 %, aplicados a un aceite de oliva extravirgen con un % de acidez y de índice de peróxido inicial de 0,168 y 9,5 miliequivalente de peróxido/kg, respectivamente. Para la estimación de la vida en anaquel, las muestras de aceite de oliva fueron almacenadas a tres temperaturas: 50 °C, 60 °C y 70 °C, y se evaluó los cambios producidos en el % de ácidos grasos libres e índice de peróxido como factores de calidad durante el almacenaje. Los análisis demostraron que el aceite de oliva se oxida en menor proporción cuando la concentración del aceite esencial es mayor.

Thermal regulation and ultrasound affect the physical, chemical, and antioxidant properties of essential oils and hydrosols extracted by microwaves from the leaves of Tagetes elliptica S. (chincho). The leaves were conditioned by dehydration or freezing, then pre-treated with ultrasound for 15 or 30 minutes at 40 Hz to finally obtain the essential oil (AECH) and hydrolat (HCH) through microwave extraction (500 W and 30 minutes). Yields, phenolic content, antioxidant capacity, leaf structure by optical microscopy, and chemical composition by gas chromatography and mass spectrometry (GC-MS) were evaluated. The conditioning of the leaves by freezing and sonication for 30 minutes obtained the best performance, 8.86±0.1% and 67.40 ± 4.8%, phenolic content of 39.4±0.1 mg EAG/mL and 346.2 ± 13.6 mg EAG/mL, and antioxidant capacity of 35.7 μmol EqT/mg and 0.25 μmol EqT/mg equivalent, for A...

Se evaluó la influencia de dos concentraciones de aceite esencial de orégano: 0,1 % y 0,3 %, aplicados a un aceite de oliva extravirgen con un % de acidez y de índice de peróxido inicial de 0,168 y 9,5 miliequivalente de peróxido/kg, respectivamente. Para la estimación de la vida en anaquel, las muestras de aceite de oliva fueron almacenadas a tres temperaturas: 50 °C, 60 °C y 70 °C, y se evaluó los cambios producidos en el % de ácidos grasos libres e índice de peróxido como factores de calidad durante el almacenaje. Los análisis demostraron que el aceite de oliva se oxida en menor proporción cuando la concentración del aceite esencial es mayor.

The solvent-free microwave extraction and the ultrasound-assisted extraction, as emerging technologies, offer advantages in the essential oil extraction, being the research about the effect on the yield and chemical composition of the essential oil important. The influence of leaves moisture and extraction power on the yield of solvent-free microwave eucalyptus essential oil, and a comparison with the ultrasound-assisted extraction was evaluated. The extraction was done by microwaves at 300 and 600 watts, 70, 80 and 90% humidity in the leaves, selecting the power that shows the highest yield of the essential oil. Afterwards, the effect of ultrasound at 180 watts, 40 kHz per 15 minutes on the yield and chemical composition was evaluated. The analytes obtained by both extraction methods were identified, by gas chromatography coupled to a mass spectrometer (GC-MS). The highest yield (0,55%)...

The solvent-free microwave extraction and the ultrasound-assisted extraction, as emerging technologies, offer advantages in the essential oil extraction, being the research about the effect on the yield and chemical composition of the essential oil important. The influence of leaves moisture and extraction power on the yield of solvent-free microwave eucalyptus essential oil, and a comparison with the ultrasound-assisted extraction was evaluated. The extraction was done by microwaves at 300 and 600 watts, 70, 80 and 90% humidity in the leaves, selecting the power that shows the highest yield of the essential oil. Afterwards, the effect of ultrasound at 180 watts, 40 kHz per 15 minutes on the yield and chemical composition was evaluated. The analytes obtained by both extraction methods were identified, by gas chromatography coupled to a mass spectrometer (GC-MS). The highest yield (0,55%)...

The objective of this research was to identify the functional groups that are responsible for the adsorption of Pb (II) on the treated hair residues of the enzymatic unhairing process of the tanneries. For this purpose was made the preparation of adsorbent, which consisted in washing hair residues in order to deliming and lower the pH of 12 to neutral, after which they were dried and was applied these the treatment of acid hydrolysis, at the end of which these were washed, dried and ground. Then the hairs treated with the Pb (II) solution were placed in agitation in a range of time and pH, for the study of adsorption isotherms and the kinetic study. At the end of which a chemical characterization was carried out through the FTIR analysis and the XRD analysis. Thus also a physical characterization with a SEM analysis, by means of two detectors of the equipment. These analyses were carried...

The solvent-free microwave extraction and the ultrasound-assisted extraction, as emerging technologies, offer advantages in the essential oil extraction, being the research about the effect on the yield and chemical composition of the essential oil important. The influence of leaves moisture and extraction power on the yield of solvent-free microwave eucalyptus essential oil, and a comparison with the ultrasound-assisted extraction was evaluated. The extraction was done by microwaves at 300 and 600 watts, 70, 80 and 90% humidity in the leaves, selecting the power that shows the highest yield of the essential oil. Afterwards, the effect of ultrasound at 180 watts, 40 kHz per 15 minutes on the yield and chemical composition was evaluated. The analytes obtained by both extraction methods were identified, by gas chromatography coupled to a mass spectrometer (GC-MS). The highest yield (0,55%)...

The solvent-free microwave extraction and the ultrasound-assisted extraction, as emerging technologies, offer advantages in the essential oil extraction, being the research about the effect on the yield and chemical composition of the essential oil important. The influence of leaves moisture and extraction power on the yield of solvent-free microwave eucalyptus essential oil, and a comparison with the ultrasound-assisted extraction was evaluated. The extraction was done by microwaves at 300 and 600 watts, 70, 80 and 90% humidity in the leaves, selecting the power that shows the highest yield of the essential oil. Afterwards, the effect of ultrasound at 180 watts, 40 kHz per 15 minutes on the yield and chemical composition was evaluated. The analytes obtained by both extraction methods were identified, by gas chromatography coupled to a mass spectrometer (GC-MS). The highest yield (0,55%)...