Cambios en aceites de oliva usados como coberturas en la conservación de berenjenas (Solanum Melongena) en relación con el tiempo y las condiciones de almacenamiento

The use of the extra virgin olive oil as covering in food preserves presents some problems and still today object of study. With this research it was investigate the changes of some analytical parameters that occur during the storage in the olive oils used as covering in eggplant preserves. It was ascertained that in the oils in presence of the eggplants a drastic decrease of the total phenols was verified immediately after the thermal treatment affecting the oxidative processes. Besides it was observed that in all the oils stored under light the values of the K270. ΔK, the total chlorophylls and the 1,2-DG36/1,3-DG36 ratio were significantly changed.El uso de aceite de oliva virgen extra como cobertura en conservas alimentarias presenta una serie de problemas que son todavía hoy objeto de estudio. El objetivo de este estudio fue investigar los cambios de algunos parámetros analíticos producidos durante el almacenamiento en aceite de oliva usado como cobertura en la conservación de berenjenas. Se encontró que el aceite que ha estado en contacto con las berenjenas, sufrió una disminución de los fenoles totales inmediatamente después del tratamiento térmico, afectando a los procesos oxidativos. Se observó asimismo, que en todos los aceites almacenados a la luz variaron significativamente los valores del K270, del ΔK, de la clorofila y de la proporción de 1,2-DG36/1,3- DG36

A Fluorescent Probe for Diacetyl Detection

A water-soluble fluorescent probe, rhodamine B hydrazide (RBH), was prepared and its properties for recognition of diacetyl were studied. The method employs the reaction of diacetyl with RBH, a colorless and non-fluorescent rhodamine B spiro form derivative to give a pink-colored fluorescent substance. In weakly acidic media, RBH reacts more selectively with diacetyl than with other carbonyls, causing a large increase in fluorescence intensity and thereby providing an easy assay for the determination of diacetyl

Possible Utilization of Two-Phase Olive Pomace (TPOP) to Formulate Potential Functional Beverages: A Preliminary Study

The demand for functional beverages is expanding over the world. In this work, a rapid, easy and low-cost procedure was followed to prepare a functional beverage (FB) by directly using two-phase olive pomace (TPOP). Liquid ingredients (water and 6% citric acid), extraction systems (heat and ultrasonic treatment), treatment time (30, 60, 90 min) and drying techniques (freeze and air-dried) were studied. Experimented TPOP had a total phenol content of 7.5 mg/g CAE (caffeic acid equivalent), composed majorly of o-diphenols. Air drying of TPOP caused a 50% depletion of total phenols compared to freeze drying. Conversely, no substantial differences were found in the FB, neither for liquid ingredients nor treatment/time adopted. Both 6% citric acid and water were revealed to be profitable liquid ingredients. A 30-min heating treatment was enough to produce a satisfactory beverage, whereas ultrasound treatment caused a loss of total phenols, especially in the water FB. All FBs appeared just limpid after a simple filtration; the citric acid beverage showed reddish color, while water ones were brownish. Finally, the prepared FBs had an average total phenol of about 600 mg/L CAE (by using 300 g/L fresh pomace), with hydroxytyrosol and related compounds being well represented, which confirmed their potential functionality