Chemical profile of Juniperus excelsa M. Bieb. essential oil within and between populations and its weed seed suppression effect.

The aims of this study were to (1) establish the intrapopulation and seasonal variation of Juniperus excelsа essential oil (EO); (2) compare the J. excelsa concrete and resinoid composition with its EO composition; and (3) investigate the potential herbicidal activity of J. excelsa EO against seeds of Papaver rhoeas L., Consolida orientalis (J.Gay) Schrödinger, Anthemis arvensis L., Avena fatua L., and Agrostemma githago L. Four independent studies were performed to meet these objectives. Twenty-eight individual trees were analyzed from two populations to establish intrapopulation and interpopulation variability of EOs yield and composition. In the seasonal dynamic study of leaf EO, samples from the same three trees and in the same population were collected in January, March, May, July, October, and December and their EO yield and composition determined. The EOs (intrapopulation and seasonal) were extracted by hydrodistillation, while the EO for the herbicidal test was obtained by steam distillation in a semi-commercial (SCom) apparatus. Overall, the EO yield varied significantly from 0.93% to 2.57%. α-Pinene (8.85-35.94%), limonene (11.81-50.08%), and cedrol (3.41-34.29%) were the predominant EO compounds in all samples (intrapopulation variability); however, trans-2,4-decadienol and ß-caryophyllene were predominant in some individual trees. Four chemical groups were identified in the samples collected from two natural populations (intrapopulation). This is the first report on the compositions of J. excelsa concrete and resinoid. Cedrol (15.39%), 7-hydroxy-4-methyl-coumarin (17.63%), 1-octacosanol (36.85%), tritriacontane (16.08%), and tiacontanoic acid were the main compounds in the concrete and resinoid. Juniperus excelsa EO suppressed seed germination and seedling growth of P. rhoeas, C. orientalis, A. arvensis, A. fatua, and A. githago, demonstrating its potential to be used for the development of new biopesticides. The highest EO yield with high content of limonene and cedrol was obtained from samples harvested during the winter months (December, January, and March).

Evaluation of chemical composition, antioxidant potential and functional properties of carob (Ceratonia siliqua L.) seeds.

The interest in carob pod as an ingredient of functional foods is constantly increasing due to its beneficial health effect and functional properties. The aim of this study was to evaluate the chemical composition and antioxidant potential of carob seeds, as well as the functional properties of its isolated galactomannan fraction. The lipid, protein, carbohydrate and phenolic composition were analysed. The obtained results demonstrated that the main detected fatty acids were oleic (45.0%), linoleic (32.4%), and palmitic (16.6%) acid. The primary tocopherol in the tested tocopherol fraction was γ-tocopherol (53.1%). It was established that ß-sitosterol (74.2%) and stigmasterol (12.8%) predominated in the sterol fraction. Carob seed was characterized by high protein (25.7%) content, while mannose and galactose were the dominating monosaccharides. Moreover, the isolated galactomannan from carob seed demonstrated good swelling properties-30.1 ml per g sample and oil-holding capacity (27.9 g/g sample). The total polyphenolic and flavonoids content of carob seeds was 1.76 mg Gallic acid equivalent/g dry weight and 0.30 mg quercetin equivalents/g dry weight, respectively. The carob seeds showed the highest antioxidant potential by cupper reduction assay-15.71 mM Trolox® equivalent/g dry weight. The mineral composition was also defined as the macroelements Ca and Mg were the predominant minerals in the seed. The obtained results showed that carob seeds were a valuable source not only of phenolic compounds and antioxidants, but also of proteins, lipids, galactomannan with functional properties that could improve the nutritional value of foods in which are incorporated.