Spice plants have a great influence on world history. For centuries, different civilizations have used them to condiment the foods of kings and nobles and applied them as embalming preservatives, perfumes, cosmetics, and medicines in different regions of the world. In general, these plants have formed the basis of traditional medicine and some of their derived substances have been utilized to treat different human diseases. Essential oils (EOs) obtained from these plants have been also used as therapeutic agents and have shown supportive uses in remedial practices. The discovery and development of bioactive compounds from these natural products, based on their traditional uses, play an important role in developing the scientific evidence of their potential pharmaceutical, cosmetic, and food applications. In the present review, using recent studies, we exhibit a general overview of the main aspects related to the importance of spice plants widely used in traditional medicine: Cinnamomum zeylanicum (true cinnamon), Mentha piperita (peppermint), Ocimum basilicum (basil), Origanum vulgare (oregano), Piper nigrum (black pepper), Rosmarinus officinalis (rosemary), and Thymus vulgaris (thyme); and we discuss new findings of the bioactive compounds obtained from their EOs, their potential applications, as well as their molecular mechanisms of action, focusing on their antioxidant activity. We also exhibit the main in vitro methods applied to determine the antioxidant activities of these natural products.

This study evaluated Bacaba powder produced in a spouted bed as a source of bioactive compounds and high energy value. The conditions influencing the drying process parameters (yield, moisture level, phenolic and anthocyanin retention) as well as simultaneous optimization (optimal conditions) of production were also considered. Drying was most efficient at 75 °C using maltodextrin concentrations above 20.0% (w/w). Higher anthocyanin retention (92.52%) at 65 °C (p = 0.0003), and a maltodextrin concentration of 20.0% (w/w) resulted in high retention of phenolics (95.38%). Accordingly, the operations tested under the desirability function (68 °C, maltodextrin concentration of 21.7% w/w, and air velocity of 1.3 × minimum spouting velocity (Vjm) m s-1) resulted in a process yield of 55.04% and the dry basis (d.b.) composition results were: total phenolics (376.43 mg GAE 100 g-1), energetic value (612.64 kcal 100 g-1), lipids (47.74 g 100 g-1), carbohydrates (27.79 g 100 g-1), protein (15.10 g 100 g-1), and dietetic fiber (8.45 g 100 g-1). The high solubility (92%), flowability (14%), energy, and bioactive characteristics of Bacaba powder suggest the potential for many applications, such as development of dietary supplements, high-energy drinks, milk-based and instant products, and bakery products.

Leaves of Lippia thymoides (Verbenaceae) were dried in an oven at 40, 50 and 60 °C and the kinetic of drying and the influence of the drying process on the chemical composition, yield, and DPPH radical scavenging activity of the obtained essential oils were evaluated. The composition of the essential oils was determined with gas chromatography-mass spectrometry and gas chromatography-flame ionization detection analyses. The influence of drying on the chemical composition of the essential oils of L. thymoides was evaluated by multivariate analysis, and their antioxidant activity was investigated via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The Midilli model was the most appropriate to describe the behavior of drying kinetic data of L. thymoides leaves. Thymol was the major compound for all analyzed conditions; the maximum content was obtained from fresh leaves (62.78 ± 0.63%). The essential oils showed DPPH radical scavenging activity with an average of 73.10 ± 12.08%, and the fresh leaves showed higher inhibition (89.97 ± 0.31%). This is the first study to evaluate the influence of drying on the chemical composition and antioxidant activity of L. thymoides essential oils rich in thymol.

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The aim of this study was to optimize the conditions for spray drying açaí extract using both response surface methodology and desirability function. Drying was based on an experimental design, where air temperature and feed flow were the independent variable. A high yield of açaí powder was obtained, with low‐moisture content and high anthocyanin retention. The desirability function indicated that a temperature of 134°C and a feed flow of 9.00 ml/min constitute the optimal drying conditions (p < .05), under which the yield was 56.22% with high anthocyanin retention (80.99%) and low‐moisture content (2.71 g 100 g−1). Scanning electron microscopy revealed the presence of spherical particles with average size <10.00 μm, and energy‐dispersive spectroscopy confirmed the nature of the organic dye. The açaí powder was highly soluble (94.38%) and nonhygroscopic (hygroscopicity of 7.87%), indicating its potential as an additive in instant products and beverage industries.Practical applicationsSpray drying is a viable technique for obtaining powdered products with their original characteristics preserved. This study proposes optimized conditions for producing açaí powder. The results indicate high yield, low degradation of anthocyanins, and low‐moisture content, which are fundamental characteristics for application as subsidy for the products of food and pharmaceutical industries. Herein, we suggest the potential use of açaí powder in many applications, including the development of dietary supplements, high‐energy drinks, milk‐based products, and instant and bakery products.