Identification of Polyphenolic Compounds Responsible for Antioxidant, Anti-Candida Activities and Nutritional Properties in Different Pistachio (Pistacia vera L.) Hull Cultivars.

The use of by-products from the agri-food industry is a promising approach for production of value-added, polyphenol-rich dietary supplements or natural pharmaceutical preparations. During pistachio nut processing, a great amount of husk is removed, leaving large biomass for potential re-use. The present study compares antiglycative, antioxidant, and antifungal activities as well as nutritional values of 12 genotypes belonging to four pistachio cultivars. Antioxidant activity was measured using DPPH and ABTS assays. Antiglycative activity was evaluated as inhibition of advanced glycation end product (AGE) formation in the bovine serum albumin/methylglyoxal model. HPLC analysis was performed to determine the major phenolic compounds. Cyanidin-3-O-galactoside (120.81-181.94 mg/100 g DW), gallic acid (27.89-45.25), catechin (7.2-11.01), and eriodictyol-7-O-glucoside (7.23-16.02) were the major components. Among genotypes, the highest total flavonol content (14.8 mg quercetin equivalents/g DW) and total phenolic content (262 mg tannic acid equivalent/g DW) were in KAL1 (Kaleghouchi) and FAN2 (Fandoghi), respectively. The highest antioxidant (EC50 = 375 µg/mL) and anti-glycative activities were obtained for Fan1. Furthermore, potent inhibitory activity against Candida species was recorded with MIC values of 3.12-12.5 µg/mL. The oil content ranged from 5.4% in Fan2 to 7.6% in Akb1. The nutritional parameters of the tested cultivars were highly variable: crude protein (9.8-15.8%), ADF (acid detergent fiber 11.9-18.2%), NDF (neutral detergent fiber, 14.8-25.6%), and condensed tannins (1.74-2.86%). Finally, cyanidin-3-O-galactoside was considered an effective compound responsible for antioxidant and anti-glycative activities.

Essential Oil Composition and Antioxidant Activity of Oregano and Marjoram as Affected by Different Light-Emitting Diodes.

Oregano and marjoram are important aromatic spices in the food industry, as well as medicinal plants with remarkable antioxidant properties. Despite their popularity, little is known about treatments that would influence the antioxidant capacity of essential oils. In this study, different spectra of LED light, namely blue, red, white, blue-red, and natural ambient light as a control, were applied to assess the essential oil content, composition, flavonoid, phenolic, and antioxidant capacity of oregano and marjoram. GC-MS analysis revealed thymol, terpinen-4-ol, sabinene, linalool, p-cymene, and γ-terpinene as the main compounds. In oregano, the thymol content ranged from 11.91% to 48.26%, while in marjoram it varied from 17.47% to 35.06% in different samples. In oregano and marjoram, the highest phenolic contents were in blue (61.26 mg of tannic acid E/g of DW) and in white (65.18 mg of TAE/g of DW) light, respectively, while blue-red illumination caused the highest increase in total flavonoids. The antioxidant activity of oregano and marjoram extract was evaluated using two food model systems, including DPPH and ß-carotene bleaching. The highest antioxidant capacity was obtained in control light in oregano and blue-red light in marjoram. The results provide information on how to improve the desired essential oil profile and antioxidant capacity of extracts for industrial producers.

Polyphenolic and molecular variation in Thymus species using HPLC and SRAP analyses.

In the present research, inter and intra genetic variability of 77 accessions belonging to 11 Thymus species were assessed using eight SRAP primer combinations. High polymorphism (98.3%) was observed in the studied species. The cluster analysis classified Thymus species into five main groups. According to molecular variance (AMOVA) analysis, 63.14% of total genetic variation was obtained within the species, while 36.86% of variation was observed among species. STRUCTURE analysis was also performed to estimate the admixture of species. For instance, T. carmanicus and T. transcaspicus revealed high admixtures. HPLC analysis also demonstrated the presence of rosmarinic acid (32.3-150.7 mg/100 g DW), salvianolic acid (8-90 mg/100 g DW), and cinnamic acid (1.7-32.3 mg/100 g DW) as major phenolic acids, as well as apigenin, epicatechin, and naringenin as the major flavonoids. The highest phenolic and flavonoid contents were detected in T. transcaspicus (37.62 mg gallic acid equivalents (GAE) g-1 DW) and T. vulgaris (8.72 mg quercetin equivalents (QE) g-1 DW), respectively. The antioxidant properties and total phenolic of Thymus species were examined using DPPH and ß-carotene-linoleic acid model systems and consequently T. vulgaris and T. pubescens were detected with the highest and the lowest antioxidant activities respectively. Cluster and principal Components Analysis (PCA) of the components classified the species in to three groups. Finally, similarity within some species was observed comparing molecular and phytochemical markers. For instance, T. vulgaris separated from other species according to major polyphenolic profiles and molecular analyses, as well as T. transcaspicus, T. carmanicus, and T. fedtschenkoi that were clustered in the same groups.

Genetic relations among and within wild and cultivated Thymus species based on morphological and molecular markers.

In the present study, the diversity of 11 Thymus species was assessed using molecular and morphological markers. Essential oil content and morphological traits were also investigated during two agronomic years. The result of the analysis of variance showed considerable differences among morphological traits. In the first and second years, the essential oil content of the species varied from 0.63 to 1.94% and 0.86 to 2.34%, respectively. T. vulgaris and T. migricus showed the highest essential oil content in two agronomic years. In this research, nine ISSR primers were also used to amplify 151 polymorphic bands in 77 accessions belonging to 11 Thymus species. Cluster and principal component (PCA) analyses classified the species in three major groups. Among the species, T. vulgaris and T. fedtschenkoi presented relatively higher genetic distance in comparison with other species. Analysis of molecular variance (AMOVA) revealed that 72.34% of the total variation was belonged to within-species variation, while 27.66% was associated among the species. High gene flow (Nm = 1.11) and genetic differentiation (Gst = 0.31) were also observed among the species. T. transcaspicus exhibited the highest genetic variation (0.19), polymorphism % (57.69%), and Shannon index (0.29). The STRUCTURE analysis also showed a high admixture of Thymus species that might be originated from a high rate of natural hybridization. Finally, based on molecular and morphological information, T. vulgaris and T. carmanicus can be suggested as good candidate species for further breeding programs in Thymus species.