Un estudio de los patrones de ácidos grasos y tococromanoles de algunas plantas Fabaceae (Leguminosae) de Turquía

In this study, the fatty acid, tocopherol, tocotrienol and plastochromanol-8 contents of some selected Fabaceae (Leguminosae) species belonging to different genera (Colutea, Vicia, Lathyrus, Gonocytisus, Lupinus, Hedysarum, Onobrychis, Trigonella) from Turkey were determined by using GLC and HPLC techniques. Some of the studied species are endemic to Turkey. The seed oils of different Leguminous taxa contained linoleic, oleic and linolenic acids as their major components. The ratios of these fatty acids in the Leguminous genera were found to be highly variable. Palmitic and stearic acids are the major saturated fatty acids in the seed oils. Vicia and Onobrychis patterns showed high similarity in means of qualitative fatty acid concentration. The tocopherol and tocochromanol patterns of the seed oils were also found to be highly variable among the genera investigated here. The total tocopherols was higher than the total tocotrienols. Alpha and gamma tocopherols were also the highest tocopherols present in the whole species. Beta, gamma and delta-tocotrienols were not found in most of the studied leguminous patterns. The results are discussed in view of renewable sources and chemotaxonomy.En este estudio, los contenidos en ácidos grasos, tocoferoles, tocotrienoles y plastocromanol-8 de algunas especies seleccionadas de Fabaceae (Leguminosae), pertenecientes a diferentes géneros (Colutea, Vicia, Lathyrus, Gonocytisus, Lupinus, Hedysarum, Onobrychis, Trigonella) de Turquía, fueron determinadas usando técnicas de GLC y HPLC. Algunas de las especies estudiadas son endémicas de Turquía. Los aceites de semillas de los diferentes taxones de leguminosas contenían los ácidos linoleico, oleico y linolénico como principales componentes. Las proporciones de estos ácidos grasos fueron muy variables entre los géneros de leguminosas. Los ácidos palmítico y esteárico son los principales ácidos grasos saturados en los aceites de semillas. Los patrones de Vicia y Onobrychis mostraron una alta similitud en las medias de las concentraciones de ácidos grasos cualitativos. Los patrones de tocoferoles y tococromanoles en los aceites de semillas resultaron también ser altamente variables entre los géneros investigados aquí. El total de tocoferoles fue superior al de tocotrienoles. Los tocoferoles alfa y gamma fueron los principales tocoferoles encontrados en el conjunto de especies. Los tocotrienoles beta, gamma y delta no se encontraron en la mayoría de los patrones estudiados de leguminosas. Los resultados son discutidos con vistas a los recursos renovables y a la quimiotaxonomía.

Micro-organisms growing on rapeseed during storage affect the profile of volatile compounds of virgin rapeseed oil

Wagner C, Bonte A, Bruehl L, Niehaus K, Bednarz H, Matthaeus B. Micro-organisms growing on rapeseed during storage affect the profile of volatile compounds of virgin rapeseed oil. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE. 2018;98(6):2147-2155.BACKGROUNDMicro-organisms populate on rapeseed after harvest during storage depending on the growing conditions. The composition of the bacterial colonization is unknown, although its contribution to the profile of volatile aroma-active compounds determines the sensory quality of virgin cold-pressed rapeseed oil. RESULTSFrom four rapeseed samples, 46 bacterial strains were isolated. By DNA-sequencing, the identification of four bacteria species and 17 bacteria genera was possible. In total, 22 strains were selected, based on their typical off-flavors resembling those of virgin sensory bad cold-pressed rapeseed oils. The cultivation of these strains on rapeseed meal agar and examination of volatile compounds by solid phase microextraction-gas chromatography-mass spectrometry allowed the identification of 29 different compounds, mainly degradation products of fatty acids such as alkanes, alkenes, aldehydes, ketones and alcohols and, in addition, sulfur-containing compounds, including one terpene and three pyrazines. From these compounds, 19 are described as aroma-active in the literature. CONCLUSIONMicro-organisms populating on rapeseed during storage may strongly influence the sensory quality of virgin rapeseed oil as a result of the development of volatile aroma-active metabolic products. It can be assumed that occurrence of off-flavor of virgin rapeseed oils on the market are the result of metabolic degradation products produced by micro-organisms populating on rapeseed during storage. (c) 2017 Society of Chemical Industr