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Food ingredients obtained from natural sources have been a constant demand from the food industry, since the consumers are avoiding the consumption of foods prepared with synthetic additives. In this study, red cabbage (Brassica oleracea L. var. capitata L. f. rubra) anthocyanin-rich extract was microencapsulated to produce a natural food colorant. For this, the microparticles were produced by spray drying using the concentrated (CE) and raw extract (RE) of red cabbage, in different concentrations of maltodextrin and arabic gum. The results obtained demonstrated that the CE presented 50.76 ± 1.13 mg anthocyanins 100 g−1, which means 1.6-fold higher anthocyanins than the RE. Also, the microparticles obtained from CE showed up to 85 mg anthocyanin 100 g−1. The formulations containing the highest amount of maltodextrin resulted in the highest yield, reaching 67%. The moisture content in macroparticles varied between 6.25 and 16.42% and the water activity ranged from 0.48 to 0.64, which is a positive value for future food application. The microparticles presented a uniform appearance and homogenous size distribution, with spherical shapes and smooth surfaces. The microparticles containing a high amount of arabic gum showed a tendency to degradation in the thermogravimetric analysis. Otherwise, the interaction between maltodextrin and arabic gum was beneficial to improve the thermal stability of microparticles, confirmed by the glass transition temperature between 37 and 90 °C. In conclusion, the microparticles produced with red cabbage anthocyanin-rich extract can be a promising approach to use as a natural food colorant. • Microparticles were produced with red cabbage anthocyanin-rich extract. • The effect of maltodextrin and arabic gum was evaluated. • Red cabbage anthocyanins are successfully encapsulated by maltodextrin-arabic gum. • Microencapsulated anthocyanin-rich extract can be used as a natural food colorant. [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]

Essential oils (EOs) have been used for thousands of years. They are highly beneficial to human health due to their antioxidant and antimicrobial properties, besides protecting food from deterioration. This current study looks at the essential oils Origanum vulgare and Thymus vulgaris encapsulated in zein nanocapsules using the nanoprecipitation method with a non-ionic Pluronic surfactant. The encapsulation success of EOs was confirmed using transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). EOS-loaded nanocapsules showed physical and chemical stability in storage (at 4 °C and 20 °C) for 90 days of monitoring with regard to antioxidant activity, encapsulation efficiency, polydispersion index, and zeta potential. The controlled release of nanoparticles is explained by the Korsmeyer–Peppas kinetic model. Nanocapsules have greater antimicrobial activity against gram-positive than gram-negative bacteria. The nanocapsules produced also presented high thermal resistance to baking processes, protecting the bread from the proliferation of moulds and yeasts. Image 1041 • Zein nanocapsules with essential oils were efficient during 90 days of observation. • Loaded nanocapsules with essential oils had antioxidant and antimicrobial activity. • Nanocapsules present high thermal resistance, protecting the essential oils from degradation. • Korsmeyer–Peppas kinetic model is considered as satisfactory to explain the control release of nanoparticles. • Loaded nanocapsules with the essential oils extended the shelf life of bread. [ABSTRACT FROM AUTHOR]