Chemical Composition of Hips Essential Oils of Some Rosa L. Species December 13, 2004

The chemical composition of the hips essential oils of 9 taxa of Rosa L. was analyzed and compared using the standardized analytical GC and GC/MS methods. The volatile hips oil compositions for these species are presented. All oil samples were dominated by following components: vitispiran (isomer), α-E-acaridial, dodecanoic acid, hexadecanoic acid, docosane (C22), β-ionone, 6-methyl-5-hepten-2-one, 2-heptanone, heptanal, myristic acid and linolic acid. Statistical analyses of 97 GC peaks of these oils were used to distinguish compositional patterns. There appeared to be correlation between the essential oil patterns and the classification within Rosa L. Cluster analysis of the composition of main components clearly showed two groups, one constituted by R. rugosa Thunb. from the Cinnamomea section, and the other constituted by the remaining taxa from the Caninae section.

CHANGES IN THE PHYSICAL PROPERTIES OF GLUTEN WITH AGING OF FLOUR

The physical properties of gluten, as determined by the hydration of the gluten between pH 4 and 7, are deleteriously affected by aging of flour. Similar effects are obtained by adding linolic acid, whereas some of the effects of aging can be removed by extraction of the flour with ether. The original quality of the gluten is not restored by such extraction. Gluten from aged deteriorated flour swells enormously in 0.1 N acetic acid; such hydration is not an indication of good quality but rather of resistance to dispersion. Some freshly milled flours produce gluten possessing the physical characteristics of gluten from aged deteriorated flour.It is concluded that the quality of gluten depends to a considerable extent on the nature of the adsorbed lipoids. Many of the characteristics of gluten are determined by relatively insoluble (unidentified) lipoid substances, whereas the absence of such lipoids and the formation of fatty acids during aging are deleterious to gluten quality.