Concerns about maintaining a healthier diet and consuming less processed foods with chemical additives have been growing over many years because it is known that the accumulation of these substances in the body can influence the development of cancerous diseases. Against this backdrop, the food industry is seeking alternatives derived from natural sources, such as plants and vegetable oils that are rich in bioactive compounds, to be used as substitutes for artificial compounds (Khorshidian, Yousefi, Khanniri, & Mortazavian, 2017; Radünz et al., 2019). Essential oils can be considered as a potential source of industrial applications due to their biological and medicinal properties. They act as bactericides, fungicides, virucides, parasiticides, analgesics

No abstract

No abstract

CuO structures were synthesized by microwave hydrothermal treatment using two different mineralizing agents (NaOH and NH 4 OH) and were evaluated as photocatalysts. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. The XRD patterns indicated the formation of the monoclinic phase in both samples with 13.78 and 14.23 nm crystallite size. SEM analysis showed different agglomerates morphologies based on the mineralization agent employed. The CuO nanostructure synthesized with NH 4 OH presented agglomerated like-plates which results in a spherical shape, whereas the material synthesized with NaOH presented an agglomerate of larger plates. Both samples showed photocatalytic activity against RNL azo dye. The quasi-spherical shape CuO material reached 93 % of the discoloration.

The genus Psidium comprises several native Brazilian plants, such as the araçá and guava trees. They are interesting sources of essential oils (EOs) that can be used as natural preservatives in foods due to their bioactive properties. This work aimed to evaluate and correlate the biological properties of the EOs from araçá and guava leaves with their chemical compounds. The gas chromatography-mass spectrometry (GC/MS) was used to determine the chemical composition of EOs. The antimicrobial activity was tested against 16 foodborne pathogens and the antioxidant capacity was determined by ABTS, DPPH, and FRAP assays. The major compounds identified in the essential oil of araçá (EOA) were β-caryophyllene and β-elemene, representing 38.69% and 7.47%, respectively, whereas β-selinene (13.83%), α-humulene (10.90%), and βcaryophyllene (7.61%) were the major compounds identified in the essential oil of guava (EOG). Both EOs showed activity against Salmonella Enteritidis, with MIC being 1.41 µg/ml for the EOA and 1.37 µg/ml for the EOG. The EOA was more effective than the EOG against strains of Listeria monocytogenes and Pseudomonas aeruginosa, with the MIC being 1.41 µg/ml. The EOA showed 10.43, 12.35, and 3.92 µmol TE/ml at 90 µg/ml whereas the EOG showed 4.54, 8.94, and 3.43 µmol TE/ml at 88 µg/ml for ABTS, DPPH, and FRAP, respectively. Thus, the EOs demonstrated an effective action against foodborne pathogens and free radicals, indicative of their potential use as natural preservatives for foods.Practical Application: Guava and araçá are native Brazilian plants producers of essential oils, natural compounds with antimicrobial and antioxidant potential. The chemical composition of essential oils is responsible for its beneficial properties. The results demonstrated that the essential oils studied are rich in β-caryophyllene and has excellent activity against malefic microorganisms and free radicals, and can also be used as natural preservatives in foods.