Kiany Sirley Brandão Cavalcante

The demand for sustainable food preservation has driven the development of biodegradable alternatives to conventional, petroleum-based plastics. This study developed and evaluated bioactive starch-based films incorporated with citrus peel essential oils (lemon, orange, and tangerine) at concentrations ranging from 0.5% to 2% (w/w). The physical, chemical, mechanical, and antimicrobial properties of all film formulations containing 0.5–2% (w/w) essential oils were evaluated. Based on the experimental design, only the selected formulations containing 1 and 2% essential oils were subjected to structural and thermal characterization (XRD, SEM, FTIR, and TGA/DTG), transparency measurements, soil biodegradation, and phytotoxicity assays. FTIR spectroscopy revealed that oil incorporation did not alter the characteristic chemical bands of starch, indicating predominantly physical interactions. The essential oils modulated the physical and mechanical performance of the films. The films containing lemon and tangerine essential oils exhibited superior antimicrobial activity against foodborne pathogens. Furthermore, soil biodegradation was concentration-dependent, with mass loss exceeding 50% within 15 days, while phytotoxicity tests confirmed the environmental safety of the degraded residues. These findings demonstrate that the developed citrus-infused starch films hold great promise as active biodegradable packaging to extend the shelf life of bakery products and mitigate plastic waste.

Essential oil (EO) nanoformulations are emerging as green nanotechnology strategies against Aedes aegypti and Aedes albopictus mosquitoes, which are vectors of arboviruses such as dengue. For the first time, we investigated the larvicidal influence of polysorbate (PS₈₀) against A. albopictus mosquito using simplex centroid design (SCD) in the formulation of EODr nanoemulsions derived from the species Dizygostemon riparius (Plantaginaceae), a plant native to the Cerrado region of Maranhão, Brazil. In addition, we present the ecotoxicological profile of the formulation against A. salina microcrustaceans. EODr was extracted by hydrodistillation, and its chemical profile was analyzed by GC-MS-FID and NMR (¹H, ¹³C, DEPT-135, and 2D). The nanoformulations were characterized by DLS, PDI, ZP, and TEM. The chemical profile indicated the presence of compounds such as fenchol, fenchyl acetate, caryophyllene, and caryophyllene oxide. The SCD contributed to the development of nanostructured formulations with spheroidal morphology, demonstrating effective larvicidal action against A. albopictus mosquitoes with lower toxicity than commercial chemical larvicides.

Em cursos de licenciatura, a experiência da formação inicial deve passar por várias ofertas da educação Básica. Com a Lei nº 9394/96, a oferta de cursos técnicos integrados ao Ensino Médio torna-se importantes espaço para atuação de uma nova carreira de professores da Educação Profissional e Tecnológica (EPT). A oferta de cursos de licenciaturas em Instituições Federais (IFETs) é favorecida à formação e atuação de professores, quando se permite que acadêmicos participem do trabalho docente no cotidiano da Educação Profissional (EP). Nesta pesquisa apresentamos a experiência realizada no Curso Técnico em Eletrotécnica Integrado ao Ensino Médio, partindo da hipótese inicial apresentada pelos alunos de que tinham dificuldades de aprendizagem nos conteúdos de Química, esta pesquisa contou com a participação de duas acadêmicas de Licenciatura em Química do IFMA, campus São Luís/Monte Castelo, demonstrou ser possível ensinar os referidos conteúdos de forma contextualizada, criativa e crítica, logo os tornando significativos para os alunos. A partir do desenvolvimento de estratégias interativas no Ensino de Química no curso técnico mencionado, foi capaz de despertar o mérito desta Ciência e contribuir para o desenvolvimento de novas habilidades do profissional docente da EPT. Participar da prática educativa no contexto da EJA no início da nossa formação, contribuiu para a aquisição de metodologias crítica, investigativa e ativa com reflexos na aprendizagem de forma significativa.

Here we describe and illustrate Dizygostemon riparius (Plantaginaceae, Gratioleae) as a new species from the state of Maranhão, northeastern Brazil. We present morphological and micromorphological descriptions and comparisons, along with illustrations, photographs, and information on its taxonomy, habitat, geographic distribution and conservation status. Dizygostemon riparius differs from D. floribundus, the only other accepted species of the genus, by having the stems sparsely to densely tomentose, the sepals as long as or slightly longer than the corolla tube, the posterior sepal to 1.5 times as wide as any of the other four, the ovary glandular villous, and the leaves larger. The new species is assessed as Endangered (EN) according to IUCN categories and criteria. Additionally, we provide diagnostic features that help to differentiate Dizygostemon from the similar Brazilian genera Achetaria, Stemodia and Tetraulacium.Citation: Scatigna A. V., Brandão C. M., Colletta G. D., Teles R. de M., Cavalcante K. S. B., Souza V. C. & Simões A. O. 2019: Dizygostemon riparius (Plantaginaceae, Gratioleae), a new species from Maranhão, northeastern Brazil. – Willdenowia 49: 177–186. doi: https://doi.org/10.3372/wi.49.49206Version of record first published online on 27 June 2019 ahead of inclusion in August 2019 issue.

Maranhão state in Brazil presents a big potential for the cultivation of several oleaginous species, such as babassu, soybean, castor oil plant, etc... These vegetable oils can be transformed into biodiesel by the transesterification reaction in an alkaline medium, using methanol or ethanol. The biodiesel production from a blend of these alcohols is a way of adding the technical and economical advantages of methanol to the environmental advantages of ethanol. The optimized alcohol blend was observed to be a methanol/ethanol volume ratio of 80 % MeOH: 20 % EtOH. The ester content was of 98.70 %, a value higher than the target of the ANP, 96.5 % (m/m), and the biodiesel mass yield was of 95.32 %. This biodiesel fulfills the specifications of moisture, specific gravity, kinematic viscosity and percentages of free alcohols (methanol plus ethanol) and free glycerin.