Jorcilene dos Santos Silva

The present study aimed to use pumpkin by-products (seeds and peels) for the production of gelatin-based biodegradable film (FBs). For this purpose, the incorporation of defatted pumpkin seed flour (DPSF) and ethanolic extract of pumpkin peels (EEPP) into FBs, produced by casting, was evaluated. The FBs were characterized in terms of thickness, visual evaluation, humidity, water solubility, UV/VIS barrier, color parameters, microscopy, Fourier transform infrared spectroscopy (FTIR), biodegradability in soil and the content of phenolic compounds and flavonoids. In general, all the formulations showed film-forming capacity; however, the greater incorporation of DPSF (formulations F3 and F6) provided heterogeneous films and the different formulations did not influence the thickness and humidity of the FBs. Due to the presence of hydrophilic groups in flour, the solubility of FBs was changed with their incorporation into FBs. Regarding color parameters, the incorporation of DPSF and EEPP influenced the values of a*, b* and C*, presenting light transmission and opacity of 0.61 to 5.83 (A/mm), respectively. The incorporation of pumpkin by-products contributed to the improvement of the UV/VIS barrier of FBs. The FBs presented in the FTIR analysis, bands characteristic of gelatin and lecithin-based films. The addition of DPSF increased the concentration of total phenolic compounds in the films. The samples incorporated with DPSF and EEPP showed less residue in the biodegradability tests from the 11th day onwards, inferring that their incorporation speeds up the biodegradation process.

Leaves (LV), stems (STs), and inflorescences (IFs) of Pfaffia glomerata are usually discarded despite containing various bioactive compounds, especially β-ecdysone saponin. The objective was to optimize by desirability (DI) the ultrasound-assisted extraction (UAE) of bioactive compounds (total phenolics (TPCs), antioxidant activity (AA), and total saponins) from the aerial parts (LV, ST, and IF) of P. glomerata. Ideal drying conditions were determined and the drying kinetics were evaluated. LV, STs, and IFs were dried and extracted (0.06 g/mL 80% EtOH) in a USS (6 cm × 12 mm, pulse 3/6 s) by Central Composite Design (CCD), varying sonication power (140–560 W) and time (11–139 min), with TPC, AA by DPPH, and total saponin content as responses. The DI indicated that the higher TPC, AA, and saponin levels were obtained at 136.5 min and 137.87 W (STs), and 138.6 min and 562.32 W (LV and IFs). IF extracts contained higher saponin, TPCs, and AA. Higher β-ecdysone levels (3.90 mg g⁻¹) were present in the leaves. Several phenolics were detected in area parts of P. glomerata, the most abundant being p-coumaric acid (LV) and nicotinic acid (STs and IFs). These compounds provide potential health benefits. Phytol was found in all extracts. Extracts by UAE from leaves have antibacterial potential, with demonstrated inhibitory effects against S. aureus, E. coli, L. monocytogenes, S. Typhi, and P. aeruginosa, and presented bactericidal effects against E. coli, L. monocytogenes, and S. Typhi. Aerial parts of P. glomerata can be used to obtain extracts by UAE rich in bioactive compounds, providing complete utilization of the plant and sustainability to cultivation. This work represents the first report on the application of ecofriendly UAE techniques to extract bioactive compounds from the aerial parts of Brazilian ginseng.

Resumo A resistência antimicrobiana em cepas de Escherichia coli tem contribuído para a busca por produtos alternativos ao seu uso, como os extratos vegetais. O objetivo deste estudo foi avaliar o perfil dos genes de resistência a cefalosporinas em isolados de E. coli com fenótipo de produção de beta-lactamase de espectro estendido (ESBL), a composição fenólica e a atividade antibacteriana do extrato etanólico de Pereskia aculeata contra cepas isoladas de frangos de um dia de vida e em crescimento. Para determinar a Concentração Inibitória Mínima (CIM) e a Concentração Bactericida Mínima (CBM) do extrato etanólico de P. aculeata, foram selecionados isolados de E. coli que apresentaram perfil ESBL em uma das origens (pintos de um dia ou frangos em crescimento). Os genes de resistência blaCTX-M-1, blaCTX-M-2, blaCTX-M-8 e blaSHV foram detectados com maior percentual em isolados de frangos em crescimento. O extrato de P. aculeata apresentou diversos compostos fenólicos, sendo o ácido málico e a rutina os predominantes. A determinação da CIM foi possível em apenas dois isolados de E. coli, um do Aviário A (frangos em crescimento) e outro do Aviário B (pintos de um dia). Em ambos os casos, a CIM foi de 20 mg/mL. Na cepa ATCC 25922 de E. coli, utilizada como cepa padrão para a avaliação do teste, a CIM foi de 20 mg/mL. Conclui-se que isolados de E. coli provenientes de pintos de um dia e frangos em crescimento carregam genes de resistência a cefalosporinas, e que não há diferença na CIM do extrato etanólico de P. aculeata Mill. quando comparadas cepas com perfil fenotípico ESBL àquelas que não apresentam esse perfil, demonstrando a necessidade de estudos adicionais com plantas com potencial antimicrobiano.

Antimicrobial resistance in Escherichia coli strains has contributed to the search for alternative antimicrobial products, such as plant extracts. The objective of this study was to evaluate the profile of cephalosporin-resistance genes in E. coli isolates with an extended-spectrum ß-lactamase (ESBL) production phenotype, and the phenolic composition and antibacterial activity of the ethanolic extract of Pereskia aculeata against strains isolated from 1-day-old and growing chickens. To determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the ethanolic extract of P. aculeata, E. coli isolates that exhibited an ESBL profile when isolated from either 1-day-old chicks or growing chickens were selected. The resistance genes blaCTX-M-1, blaCTX-M-2, blaCTX-M-8, and blaSHV were detected in a higher percentage of isolates from growing chickens. The P. aculeata extract was found to contain several phenolic compounds, with malic acid and rutin being predominant. Determination of MIC was only possible for two E. coli isolates (one from Broiler house A (growing chickens) and the other from Broiler house B (1-day-old chicks) - and for the standard strain E. coli ATCC 25922; in all cases, the MIC was 20 mg/mL. These findings indicate that E. coli isolates from both age groups carried cephalosporin-resistance genes and exhibit similar susceptibility to the P. aculeata extract, regardless of ESBL phenotype. These results highlight the need for further research into plant-based antimicrobials.