RESUMEN
From the leaves of aloe, a succulent plant, a dried exudate commonly called aloe can be obtained, which is used as a natural drug for its cathartic effect and is widely employed as a bittering agent in alcoholic beverages. This investigation provides a tentative characterization of several commercial aloe exudates carried out both by reversed phase HPLC and by headspace GC-MS analysis. By means of HPLC the derivatives were evaluated, and by GC-MS the volatile fraction was investigated. Qualitative and quantitative differences among the constituents in various samples of different origins were found. In particular, these were evident in the HPLC profile of Kenya aloe and an Aloe barbadensis sample, which exuded a high content of isoaloeresin D and aloins, whereas GC-MS analysis showed the presence of anisole exclusively in Kenya aloe samples. Moreover, the results obtained by means of the latter technique suggested a reason for the prevailing use of Mosselbay and Port Elizabeth aloes in bitter spirits formulation.
Asunto(s)
Aloe/química , Cromatografía Líquida de Alta Presión/métodos , Emodina/análogos & derivados , Cromatografía de Gases y Espectrometría de Masas/métodos , Hojas de la Planta/química , Bebidas Alcohólicas/análisis , Cromonas/análisis , Emodina/análisis , Glucósidos/análisis , VolatilizaciónRESUMEN
Characteristic HPLC profiles of fresh and aged aloe solutions, detected at 360 and 220 nm, are presented and compared. Several aloe constituents (aloesin, aloeresin A, hydroxyaloin, aloin A and B and aloinoside A and B) were simultaneously separated and identified. The determination of aloin is described (detection limit 0.15 ppm) and discussed. In aloe-based alcoholic beverages, the aloins could not be detected, owing to their instability and degradation in solution; this is discussed in relation to the EEC Council Directive 88/388, which fixed the values of maximum allowable concentrations for aloin in food and beverages. Instead of aloin, other aloe compounds (e.g., aloeresin A or aloesin) should perhaps be used as an index of the presence of aloe in alcoholic beverages.
Asunto(s)
Bebidas Alcohólicas/normas , Aloe/química , Emodina/análogos & derivados , Plantas Medicinales , Bebidas Alcohólicas/análisis , Cromatografía Líquida de Alta Presión , Cromonas/análisis , Emodina/análisis , Unión Europea , Aromatizantes/análisis , Aromatizantes/normas , Glucósidos/análisis , Cinética , Estructura Molecular , EspectrofotometríaRESUMEN
The matrix of the correlation between the concentrations of 11 trace elements determined in 45 samples of cows' milk was used as a starting matrix for principal component analysis. The space dimension was reduced from 11 variables to 5 principal components, accounting for about 80% of the total variance. After an orthogonal rotation, the first factor (F1) was found to be positively correlated with Cr, Mn, and Fe, F2 positively correlated with Ni and negatively with Cu, F3 positively with Cd and Pb, F4 positively with Zn, Sr, and Mo and F5 positively correlated with A1 and Sr. Element clusters appear to be determined by their origin. Some clusters are confirmed by principal factor analysis. A plot of the principal component scores was also applied to the differentiation of Italian Milk from different geographical origins.