Se determinó la influencia del peso, temperatura y tiempo de inyección de vapor saturado en el Sistema de Esterilización Orgánica (OSS por sus siglas en inglés) sobre la carga microbiana, análisis proximal y contenido de capsaicina en el ají mirasol y el ají panca. Se trabajó con 3 y 4 kg de ají, 100 y 105 °C (20 y 25 kPa), por 2 y 3 min. Los análisis pre y pos-OSS fueron los siguientes: recuento de aerobios mesófilos viables, coliformes totales, E. Coli, Salmonella, mohos y levaduras, proximal y contenido de capsaicina. Las muestras de 3 kg del ají mirasol, sometidas a 105 °C por 3 min, y las de 3 y 4 kg del ají panca, sometidas a 105 °C por 3 min, lograron mayor reducción de aerobios mesófilos y mohos. En la evaluación estadística se encontraron interacciones entre las variables peso y temperatura en ají mirasol; entre peso, temperatura y tiempo en el ají panca, sobre la reducción de aerobios mesófilos y mohos; esto influye en la composición proximal y reducción del contenido de capsaicina de 863.2 a 751.9 ppm (ají mirasol) y 405.6 a 315.1 ppm (ají panca); evidenciando que el tratamiento OSS es un método eficiente en procesos de descontaminación microbiana.

The chemical composition, antioxidant, and antibacterial properties of the essential oil from the leaves of Tagetes elliptica Sm., grown in Peru, were studied. The EO was extracted using steam distillation, and its chemical composition was analyzed using GC-MS, while the antioxidant activity was evaluated using the radical, scavenging capacity (DPPH and ABTS assays), and ferric reducing antioxidant power (FRAP) assays, ferrous ion chelating (FIC) activity, and the Rancimat test. The antibacterial activity against Staphylococcus aureus, Escherichia coli, and Salmonella infantis was studied using the agar well diffusion method. Twenty-seven compounds were identified in the essential oil, and the major components were cis-tagetenone (37.27%), trans-tagetenone (18.84%), dihydrotagetone (14.38%), and trans-tagetone (5.15%). With regard to antioxidant properties, the IC50 values obtained for the DPPH, ABTS, and FIC assays were 53.37, 46.38, and 22.65 mg/mL, respectively. These values were lower than those obtained for standard butylated hydroxytoluene and ascorbic acid. In the Rancimat test, antioxidant activity was achieved only at high concentration. T. elliptica essential oil showed a marked antibacterial activity against all bacterial strains at all concentrations assayed. This study demonstrated that T. elliptica essential oil could be considered as an alternative to synthetic antioxidants and antimicrobial agents in the food industry.

The aim of this work was to obtain chitosan nanoparticles (<1000 nm) with chincho (Tagetes elliptica Sp.) essential oil (CEO-CSNPs) using the ionic gelation method. A Box–Behnken design (BBD) was applied, using chitosan solution (CS) pH (4.0, 4.4, 4.8); the mass ratio of CS/CEO (1:0.7, 1:0.85, 1:1.0) and the mass ratio of CS/CS-tripolyphosphate (1:0.46, 1:0.58, 1:0.7) as independent variables. The formulation-dependent variables, encapsulation efficiency (EE) and loading capacity (LC) of the CEO-CSNPs were evaluated. BBD determined that optimal conditions for CEO-CSNPs were pH: 4.4, CS/CEO mass ratio 1:0.7 and CS/TPP mass ratio 1:0.46. Once the optimization was defined, particle size (PS), zeta potential (ZP), polydispersity index (PDI), CEO-CSNPs morphological studies, in vitro CEO release, and antibacterial activity were determined. The CEO-CSNPs showed an EE of 52.64% and a LC of 11.56%, with a diameter of 458.5 nm, with a ZP of 23.30mV, and a PDI of 0.418. The SEM studies showed that the nanoparticles were rounded and had uniform shapes. In addition, CEO-CSNPs showed a minimum inhibitory concentration against Staphylococcus aureus, Salmonella infantis and Escherichia coli of 5.29, 10.57 and 10.57 µg/mL, respectively. These results could be very useful for the stabilization of chincho essential oil for food industry purposes. However, several studies about the release, as well as interaction with food matrices, will be necessary.

Extracción y caracterización química del aceite esencial de Eucalipto obtenido por microondas y ultrasonido Extraction and chemical characterization of essential oil from Eucalyptus obtained by microwave and ultrasound

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 AECH and HCH, respectively in every case. Structural damage of the leaves was observed due to the effect of the conditioning-ultrasound-microwave treatments, achieving a more significant release of bioactive compounds. The main compounds of the essential oil were tagetenones (49.2%), followed by cis-miroxide (14.5%), dihydrotagetone (13.9%), tagetone (9.8%) and ocimene (2.4%); the main compounds in the hydrolate were cis-myroxide (44.66%), followed by cis- tagetone (23.84%), trans-tagetone (12.24%), linalool oxide (5.48%) and dihydrotagetone (4.04%). The significant contribution of the present study is the extraction techniques and chemical profile of tagetes elliptica extracts.