Comparative study of GC-MS characterization, antioxidant activity and hyaluronidase inhibition of different species of Lavandula and Thymus essential oils

The chemical compositions of essential oils of Lavandula angustifolia, Lavandula latifolia, Lavandula hybrida cultivar Grosso and cultivar Super, Thymus zygis with high proportions of thymol and linalool and Thymus hyemalis, from Murcia country (Spain), were studied in relative (%), absolute (mM) and chiral concentrations by GC/MS. Hyaluronidase inhibition and antioxidant activities of the essential oils were evaluated using ABTS(center dot+), DPPH center dot, ORAC, chelating power, hydroxyl radical, nitric oxide, TBARS and reducing power assays. Linalool and linalyl acetate were the most abundant components in the Lavandula genus whereas thymol, linalool and 1,8-cineole were the most abundant molecules in the respective Thymus species. Chiral determination of the main components showed (+)-enantiomers like terpinen-4-ol, beta-pinene, borneol and a-terpineol and (-)-enantiomers like linalool, linalyl acetate and camphene in Lavandula sp. In the case of Thymus sp. (+)-enantiomers like a-pinene, limonene, terpinen-4-ol and a-terpineol and (-)-enantiomers like borneol were found. Essential oils containing thymol were found especially powerful in all assays but chelating power, ORAC and hydroxyl radical scavenging assays. The capacity for inhibiting hyaluronidase showed that T. zygis with a high proportion of thymol was the most effective inhibitor. Essential oils containing thymol and linalool/linalyl acetate have a potential use as antioxidant agents. Thymol shows strong inhibition of hyaluronidase. Copyright (C) 2015 John Wiley & Sons, Ltd

A fruit firmness QTL identified on linkage group 4 in sweet cherry (<em>Prunus avium</em> L.) is associated with domesticated and bred germplasm.

Fruit firmness is an important market driven trait in sweet cherry (Prunus avium L.) where the desirable increase in fruit firmness is associated with landrace and bred cultivars. The aim of this work was to investigate the genetic basis of fruit firmness using plant materials that include wild cherry (syn. mazzard), landrace and bred sweet cherry germplasm. A major QTL for fruit firmness, named qP-FF4.1, that had not previously been reported, was identified in three sweet cherry populations. Thirteen haplotypes (alleles) associated with either soft or firm fruit were identified for qP-FF4.1 in the sweet cherry germplasm, and the "soft" alleles were dominant over the "firm" alleles. The finding that sweet cherry individuals that are homozygous for the "soft" alleles for qP-FF4.1 are exclusively mazzards and that the vast majority of the bred cultivars are homozygous for "firm" alleles suggests that this locus is a signature of selection. Candidate genes related to plant cell wall modification and various plant hormone signaling pathways were identified, with an expansin gene being the most promising candidate. These results advance our understanding of the genetic basis of fruit firmness and will help to enable the use of DNA informed breeding for this trait in sweet cherry breeding programs

Effect of melatonin treatments on biochemical quality and postharvest life of nectarines

The study investigated the effects of melatonin on the postharvest quality of nectarine fruit (cv. Fantasia). Fruits were dipped in melatonin concentrations (control, 250, 500 and 1000 µmol l? 1) and stored for 40 days at 0–1 °C and 85–90% relative humidity. Changes in weight loss, respiration rate, fruit firmness, total soluble solids, titratable acidity, chilling injury, ascorbic acid, total flavonoids, total phenolics and total antioxidants were evaluated during 0, 10, 20, 30 and 40 day. According to the results, melatonin treatments effectively slowed process of senescence, as indicated by reduced fruit softening, chilling injury and respiration rate. Moreover, this effect is concentration-dependent, with 1000 µmol l? 1 melatonin treatment more effective than other doses during the 40 days of storage. Melatonin treated nectarines exhibited higher total antioxidant activity than controls, which was correlated primarily to the high levels of total phenolics and to lesser loss to ascorbic acid and flavonoids contents. These results demonstrated that melatonin treatment could be a good practice for extending postharvest life of nectarine fruits, maintaining the appearance and nutrient value, and reducing the loss of health-promoting compounds. © 2020, Springer Science+Business Media, LLC, part of Springer Nature