http://naturalingredient.org/wp/wp-content/uploads/Burt_Essential_Oils_A_Review_2004.pdf

Essential oils: their antibacterial properties and potential applications in foods--a review.

Biological effects of essential oils - A review

This review summarizes the multifaceted aspects of antioxidants and the basic kinetic models of inhibited autoxidation and analyzes the chemical principles of antioxidant capacity assays. Depending upon the reactions involved, these assays can roughly be classified into two types:  assays based on hydrogen atom transfer (HAT) reactions and assays based on electron transfer (ET). The majority of HAT-based assays apply a competitive reaction scheme, in which antioxidant and substrate compete for thermally generated peroxyl radicals through the decomposition of azo compounds. These assays include inhibition of induced low-density lipoprotein autoxidation, oxygen radical absorbance capacity (ORAC), total radical trapping antioxidant parameter (TRAP), and crocin bleaching assays. ET-based assays measure the capacity of an antioxidant in the reduction of an oxidant, which changes color when reduced. The degree of color change is correlated with the sample's antioxidant concentrations. ET-based assays include th...

The Chemistry behind Antioxidant Capacity Assays

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

The volatile oils of black pepper [Piper nigrum L. (Piperaceae)], clove [Syzygium aromaticum (L.) Merr. & Perry (Myrtaceae)], geranium [Pelargonium graveolens L'Herit (Geraniaceae)], nutmeg [Myristica fragrans Houtt. (Myristicaceae), oregano [Origanum vulgare ssp. hirtum (Link) Letsw. (Lamiaceae)] and thyme [Thymus vulgaris L. (Lamiaceae)] were assessed for antibacterial activity against 25 different genera of bacteria. These included animal and plant pathogens, food poisoning and spoilage bacteria. The volatile oils exhibited considerable inhibitory effects against all the organisms under test while their major components demonstrated various degrees of growth inhibition.

https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2672.2000.00969.x

Antimicrobial agents from plants: antibacterial activity of plant volatile oils.

Antioxidant activity of selected essential oil components in two lipid model systems

The essential oil composition of Cananga odorata, Boswellia thurifera, Cymbopogon citratus, Marjorana hortensis, Ocimum basilicum, Rosmarinus officinalis, Cinnamomum zeylanicum and Citrus limon was analysed by GC and GC–MS, and their antimicrobial and antioxidant activity tested. Twenty-five different genera of bacteria and one fungal species were used in this study as test organisms. These included animal and plant pathogens, food poisoning and spoilage bacteria and the spoilage fungus Aspergillus niger. The volatile oils exhibited considerable inhibitory effect against all the tested organisms. The oils also demonstrated antioxidant capacities, comparable with α-tocopherol and butylated hydroxytoluene (BHT). The method adopted in this study was the modified thiobarbituric acid reactive species (TBARS) assay. The antioxidant activity was carried out under different conditions by using egg yolk and rat liver in the absence and presence of the radical inducer 2,2′-azobis (2-amidinopropane) dihydrochloride (ABAP). © 1998 John Wiley & Sons, Ltd.

Antimicrobial and antioxidant properties of some commercial essential oils

The essential oils obtained from Crithmum maritimum L. (marine fennel) and two samples of Foeniculum vulgare Miller (common fennel) were analysed by GC and GC-MS and assayed for their antioxidant and antibacterial activities. The antioxidant activity of the oils was evaluated by two lipid model systems: a modified thiobarbituric acid reactive species (TBARS) assay and a spectrophotometric detection of hydroperoxydienes from linoleic acid in a micellar system. The oils demonstrated antioxidant capacities, comparable in some cases to that of alpha-tocopherol and butylated hydroxytoluene (BHT), used as reference antioxidants. Concerning the antimicrobial tests the essential oils were assayed against twenty-five genera of bacteria, including animal and plant pathogens, food poisoning and spoilage bacteria. Oils from the two samples of F. vulgare showed a higher and broader degree of inhibition than that of C. maritimum.

Antioxidant and antimicrobial activity of Foeniculum vulgare and Crithmum maritimum essential oils.

The essential oils obtained from five commercial samples of Sicilian aromatic plants, laurel, sage, oregano, rosemary and coriander were analyzed by GC/MS and assayed for their antibacterial, antifungal and antioxidant activities Twenty-five different genera of bacteria and one fungal species were used in this study as test organisms The oils showed a high degree of inhibition against all the microorganisms tested The highest and broadest activity was shown by the oil of oregano, while the oil of sage was the least effective The antioxidant activity of the oils was measured by the modified Thiobarbituric Acid Reactive Species (TBARS) assay, using egg yolk and rat liver as oxidable substrate, in absence and in presence of the radical inducer 2,2'-azobis (2-amidinopropane) dihydrochloride (ABAP) The activities were compared with those of α-tocopherol and 2,6-di-tert-butyl-4-methylphenol (BHT, butylated hydroxytoluene) The oils showed different effectiveness, the oregano oil being endowed with

Chemical Composition, Antimicrobial and Antioxidative Activity of Laurel, Sage, Rosemary, Oregano and Coriander Essential Oils

Saffron (Crocus sativus L.) is an autumnal flowering geophite whose dried stigmas, well known for their aromatic and colouring power, have been used since immemorial time as a spice in human nutrition, for medicinal purposes and as a dye. Many doubts remain on its origin; it was probably selected and domesticated in Crete during the Late Bronze Age. Saffron is an autotriploid geophyte species, self- and out-sterile and mostly male-sterile and therefore unable to produce seed, that reproduces by means of corms. Furthermore, it has a reverse biological cycle compared with the majority of cultivated and spontaneous plants: flowering first in October–November, then vegetative development until May, which means that the vegetative development is not directly important for production of stigmas, but for the production of new corms. Due to its unique biological, physiological and agronomic traits, saffron is able to exploit marginal land and to be included in low-input cropping systems, representing an alternative viable crop for sustainable agriculture. Notwithstanding this great potential and the considerable increase in new generation consumer demand for saffron, the future of the plant is still uncertain. Indeed, the main obstacles to saffron production are: (1) the limited areas of cultivation in countries where it is traditionally grown, (2) the great amount of sophisticated spice, (3) management techniques executed by hand, and (4) the very high price of the spice. Here we review the main biological, genetic and ecological traits associated with agronomic management techniques of saffron in relation to environmental conditions. Colour, taste and aroma are the essential features on which the quality of saffron stigmas is founded. In turn, these aspects are strictly connected with the biomolecular composition of the stigmas, namely, the carotenoids and their derivatives. With this in mind, the biosynthetic pathway that leads to the formation of saffron secondary metabolites and their abundance in the spice is presented, together with the biomedical properties commonly associated with saffron. Furthermore, a detailed overview of the more recent instrumental methods to assess the quality of saffron, strictly from a chemical point of view, will be discussed.

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Giuseppe Ruberto

Papers

Antioxidant activity of selected essential oil components in two lipid model systems

Antimicrobial and antioxidant properties of some commercial essential oils

Antioxidant and antimicrobial activity of Foeniculum vulgare and Crithmum maritimum essential oils.

Chemical Composition, Antimicrobial and Antioxidative Activity of Laurel, Sage, Rosemary, Oregano and Coriander Essential Oils

Saffron, An Alternative Crop for Sustainable Agricultural Systems: A Review