RESUMO As embalagens têm como função básica proteger o alimento e garantir a sua integridade comercial. Podem ser produzidas a partir de materiais biodegradáveis com funcionalidades específicas, tais como ação antimicrobiana e antioxidante. Além disso, pesquisas vêm sendo desenvolvidas de modo a substituir os aditivos sintéticos por outros naturais, como os extratos vegetais, devido aos compostos químicos presentes em suas misturas. O poli(butileno adipato co-tereftalato) - (PBAT) vem sendo extensivamente estudado como uma possível substituição aos polímeros convencionais devido à sua biodegradabilidade. Desse modo, o objetivo desse trabalho foi avaliar as potencialidades dos extratos vegetais de jurema preta (Mimosa tenuiflora) e cajueiro (Anacardium occidentale Linn), a fim de aplicá-los como aditivos em embalagens de PBAT com propriedades ativas antioxidantes e antimicrobianas. Os extratos foram obtidos pela técnica de extração Sohxlet em três diferentes tempos, 4, 6 e 8 horas, cujo melhor rendimento ocorreu nos tempos de 6 horas para jurema preta e 4 horas para cajueiro. No teste de presença de flavonóides o extrato de jurema preta apresentou maior concentração e no teste de fenólicos totais, utilizando o método de Folin-Ciocalteau, o cajueiro obteve maior concentração. Ambos os extratos apresentaram capacidades antioxidantes significativas pelos dois métodos, fosfomolibdênio e DPPH. cajueiro apresentou melhor halo de inibição frente ao Staphylococcus aureus, e, por isso, foi determinada a sua concentração mínima inibitória (CMI), 0,0170 g.mL-1. Esse extrato foi incorporado ao PBAT, para o ensaio de migração no meio etanólico, por meio do qual foi determinado um modelo cinético e foi observado que a taxa de migração, 0,0167 ?g.mL-1.min-1, foi reduzida em cerca de um dia, indicando bom potencial do extrato para esses tipos de embalagem.

ABSTRACT Packaging has the basic function of protecting the food and ensuring its commercial integrity. They can be produced from biodegradable materials with specific functionalities such as antimicrobial and antioxidant action. In addition, research has been carried out to replace synthetic additives with natural additives, such as plant extracts, due to the chemical compounds present in their mixtures. Poly (butylene adipate co-terephthalate) - (PBAT) has been extensively studied as a possible replacement for conventional polymers due to its biodegradability. Thus, the objective of this work was to evaluate the potentialities of jurema preta (Mimosa tenuiflora) and cajueiro (Anacardium occidentale Linn) plant extracts in order to apply them as additives in PBAT packages with antioxidant and antimicrobial active properties. The extracts were obtained by the Sohxlet extraction technique at three different times, 4, 6 and 8 hours, with the best yield at 6 hours for jurema preta and 4 hours for cajueiro. In the flavonoid presence test the jurema preta extract presented higher concentration and in the total phenolics test, using the Folin-Ciocalteau method, the cashew tree obtained the highest concentration. Both extracts showed significant antioxidant capacities by the two methods, phosphomolybdenum and DPPH. Cashew tree presented better inhibition halo against Staphylococcus aureus, and therefore its minimum inhibitory concentration (MIC) was determined, 0.0170 g.mL-1. This extract was incorporated into the PBAT for the ethanolic migration test, by means of which a kinetic model was determined and it was observed that the migration rate, 0.0167 ?g.mL-1.min-1, was reduced by about a day, indicating good extract potential for these types of packaging.

In recent years, estrogens have gained notable attention among emerging pollutants, increasingly leading to the need for less laborious analytical methods. Optical sensors are a promising technology for the determination of chemical contaminants in water, acting as an alternative screening method. The aim of this work was to evaluate the performance of poly(vinyl chloride) (PVC) as a sensing phase for the detection of 17β-estradiol in water using mid-infrared spectroscopy and chemometrics. The sensing phase was used for differentiation purposes with an accuracy of 80%, sensitivity of 100% and specificity of 71.4% based on soft independent modeling of class analogy (SIMCA). Satisfactory limits of detection (8.9x10-1 - 2.9 mg L-1), quantification (2.9 - 1.0x10 mg L-1), slope of the analytical curve (5.0x10-4 - 2.4x10-3 L mg-1) and determination coefficients (0.90 - 0.99) were obtained. Kinetically, a extraction time of around 30 min was estimated and in a regeneration study, it was possible to use the same phase after 4 cycles of use. Therefore, the results indicate that the PVC sensing phase is promising for the detection of 17β-estradiol in water by means of mid-infrared spectroscopy and chemometric methods.

Abstract In this work were developed and evaluated new antimicrobial films of polyhydroxybutyrate (PHB) additivated with polyethyleneglycol (PEG) and clove essential oil (CEO). The PHB/PEG/CEO films were prepared using the solution casting technique. The CEO concentrations varied between 0.0 and 15% (w/w), related to the total mass (1.4 g), without considering the solvent used. The CG-MS analysis showed that the major component of the CEO was eugenol (72.96%). The antimicrobial activity from the CEO was evaluated against three bacteria (E. coli, E. aerogenes and S. aureus). The migration of CEO in the films occurred with all tested simulants. Thermal analysis has shown that the addition of 15% w/w of the CEO causes the biggest changes in the chemical structure of the material, resulting in less energy during film processing. The mechanical data demonstrated that the addition of 15% w/w of the CEO results in more flexible films.