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The first harvest of Humulus lupulus (var. Cascade) in Brazil in 2016 originated as an aromatic hop that nowadays is gaining attention from the brewery industry. However, the chemical composition and the properties of this hop have not been well documented to date. In this study, the chemical profile of the phenolic compounds and essential oils of Cascade hops produced in Brazil (BH) and the USA (UH) was determined. The major phenolic compounds identified by LC-ESI-MS-MS in BH and UH were protocatechuic acid, isoquercitrin, and ferulic acid (4.18–11.39; 2.44–4.90; and 1.45–4.48 mg 100 g−1, respectively). The profile of essential oils was shown to differ between the two samples. The compounds trans-β-farnesene (20.60%), β-selinene (18.78%), myrcene (16.57%), and α-selinene (16.22%) were the main compounds in the BH essential oil, while the essential oil of UH showed a high content of α-humulene (35.35%), myrcene (22.35%), β-caryophyllene (12.81%), and trans-β-farnesene (10.59%). A higher antioxidant activity (by DPPH and ABTS) was observed for hop extracts when compared to the essential oils. The results indicated that the Brazilian hop sample analyzed had higher radical scavenging when compared to an American hop sample (associated with its bioactive compound composition). The Cascade hop from Brazil appears to be a high-quality raw material showing significant potential for future industrial applications. [ABSTRACT FROM AUTHOR]

Summary: Bioactive compounds from Brazilian hop (Humulus lupulus L.) cultivars were extracted by ultrasound and their phenolic profile compared with commercial hop from the USA. The most effective extraction conditions (solution of ethanol 49%, at 52 °C and a solid/liquid ratio of 1 g per 34 mL) for the total phenolic compounds (TPC) were determined using a Central Composite Rotatable Design. The Brazilian hop showed higher content of TPC (33.93 ± 0.67 mg GAE g−1), total flavonoids (54.47 ± 0.10 mg QE g−1) and higher antioxidant activity (ABTS: EC50 21.29 ± 1.36 μL mL−1; DPPH: EC50 3.91 ± 0.17 μL mL−1) when compared with the USA hop. The main phenolic compounds present in the extracts were the flavonoids isoquercitrin and quercetin. The antioxidant properties of the Brazilian hop extract had not been reported yet in the literature for this raw material, thus showing potential to be incorporated in polymeric films used as active packaging. [ABSTRACT FROM AUTHOR]

This study presents a green synthesis of silver nanoparticles (AgNPs) using essential oils as an environmentally friendly alternative to the toxic chemical reducing agents. A trial screening was performed using the essential oils of oregano (Origanum vulgare), thyme (Thymus vulgaris), clove (Syzygium aromaticum L.), rosemary (Rosmarinus officinalis L.) and Poiretia latifolia. The best results regarding the formation of AgNPs (tested by UV–Vis spectrophotometry) were observed when using clove essential oil, which major compound eugenol (80%) was chosen for another synthesis as a control sample. Transmission Electron Microscopy and Dynamic Light Scattering demonstrated that AgNPs were predominantly spherical-shaped. Additionally, Small-Angle X-ray Scattering (SAXS) provided more accurate results, revealing a nanostructure with medium-sized particles between 18.6 nm (AgNP-Eugenol) and 22.4 nm (AgNP-Clove). The developed AgNPs presented antimicrobial activity against Staphylococcus aureus in different concentrations (40–100 μL mL−1), with a Minimum Inhibitory Concentration of 40 μL mL−1, thus considered bactericidal agents. This report showed that the AgNP-Clove present similar characteristics compared to AgNP-Eugenol, revealing the former as a cheaper and reliable alternative matrix to obtain silver nanoparticles, aiming at the future application of AgNPs in food packaging. Image 1 [ABSTRACT FROM AUTHOR]