Components of medicinal plants have many pharmacological activities, including antioxidant activity, playing an important role in limiting oxidative stress that can cause several damages. This paper characterizes polyphenols of Retama monosperma L., Berberis vulgaris L. and Ricinus communis L. plant extracts and evaluates their antioxidant activity by DPPH, conjugated diene and TBARS assay. To ensure the quality of analytical results, this paper presents performance criteria of the validated method using UHPLC/DAD/ESI-MS. Regarding method validation, the results confirm different used tests and evaluate detection and quantification limits. Concerning the characterization and study of antioxidant activity, realized testing showed that R. monosperma is rich in isoflavone, flavone and flavonol. For R. communis, we notice the presence of rutin as a major compound. Meanwhile, B. vulgaris contains significant amounts of gallic acid and p-coumaric acid. These plant extracts have high antioxidant activity due to the presence of phenolic compounds.

The attractiveness of pomegranate (Punica granatum L.) is increasing worldwide among producers and consumers. Depending on its characteristics, the pomegranate may be intended for fresh consumption, for industrial processing, or for medical purposes. This study aims to assess the variability in terms of mineral content and biochemical properties of ten selected pomegranate cultivars grown in the center of Morocco to better know their fruit potential. Mineral composition, organic acids, total polyphenols, anthocyanins content, individual phenolic compounds, and antioxidant activity were determined in pomegranate juices. Results showed significant differences between cultivars. The sour cultivar Lhamdha is rich in organic acids, gallagyl esters, and ellagitannins and showed high antioxidant activity. It could therefore be used as a source for nutraceutical substances. The cultivar Sefri of Lalla Takerkoust showed important content of mineral elements, especially iodine (I), calcium (Ca), magnesium (Mg), iron (Fe), and silver (Ag). The cultivars Sefri of Ouled Abdellah, Sefri of Beni Meskine, Lahmer, and Marrakchia are suitable for production of fresh pomegranate juice with high potential of health benefits. In fact, they are rich in anthocyanins, polyphenols, and oxalic and ascorbic acids and they presented high antioxidant activity. While the cultivars Sefri of Sour Laaz, Sefri of Tmassine, Sefri of Sidi Abdellah, and Bzeq Tir could be intended for fresh fruit consumption. Cluster analysis has revealed the divergence of cultivars with the same appellation Sefri confirming the problem of homonymy or synonymy in the pomegranate cultivars appellation. This study clearly demonstrates the nutritional and functional potential of the studied cultivars and the importance of their valorisation, especially for food and pharmaceutical industries.

Several factors have increased the use of reference materials in laboratories. This can be explained by the fact that the reference materials have several roles, namely: the confirmation of the identity of unknown materials and/or the determination of their properties; the calibration of measuring equipment; the validation of methods; the realization of proficiency tests; etc. To be able to produce and use them, a set of standards and guidelines concerning the subject of reference materials has been established. There are several producers of reference materials in many fields, but finding the right choice is sometimes considered difficult given the multitude of materials to be analyzed that do not correspond perfectly to the reference material, especially in the case of matrices. This makes the market always seek new materials. To develop them, five steps are essential: material preparation, homogeneity study, stability study, characterization, and evaluation of measurement uncertainties. These steps are equally important; the fact of highlighting less than one of them will imply a significant decrease in the quality of the reference material developed. This review seeks to furnish the scientific community with a paper elucidating the functions of these materials in research laboratories, the normative references devised to standardize their production and utilization, the factors influencing their production, and the essential steps for their development.