Produção Técnico e Científica
URI permanente desta comunidadehttps://repositorio.udesc.br/handle/UDESC/129
Navegar
5 resultados
Resultados da Pesquisa
Artigo Acesso restrito Lipase-catalyzed synthesis of poly(ω-pentadecalactone-co-globalide) in supercritical carbon dioxide(2025) Santos R.D.; Rebelatto E.A.; Guindani C.; Madalosso H.B.; Scorsin L.; Mayer, Diego Alex; Oliveira J.V.© 2024 Elsevier B.V.This work investigates the enzymatic ring-opening polymerization of poly(ω-pentadecalactone-co-globalide) using supercritical carbon dioxide as a solvent. Copolymerizations were carried out in a high-pressure variable-volume view cell to evaluate the influence of CO2:monomers mass ratios and the use of chloroform as a cosolvent. Also, Novozym® 435 and Lipura® Flex were compared as catalysts. The highest molar mass obtained with the use of a cosolvent (Mn = 24,380 g mol−1) was achieved in the 1:2:1 (CO2:monomers:chloroform) condition, reflecting the combined effect of the cosolvent and a higher concentration of the monomers, while reactions without it showed better results for molar mass (Mn up to 27,902 g mol−1). Dispersity was higher when a cosolvent was used (Dispersity up to 7.51) than reactions with supercritical carbon dioxide only (Dispersity up to 5.36). Monomer conversions above 97 % and reaction yields from 55.77 wt% up to 79.61 wt% were achieved for copolymerizations with and without a cosolvent, using Novozym® 435 as catalyst. Lipura® Flex produced copolymers with high molar mass (Mn up to 21,605 g mol−1), reaction yields up to 73 wt%, and monomer conversions from 82 % to 96 %.Artigo Acesso restrito Redispersible dry powders containing nanoencapsulated curcumin increase its antioxidant activity(2025) Gundel S.D.S.; Zorzanello B.; Favarin F.R.; Machado E.F.; Silva A.S.D.*; Silva W.L.D.; Morisso F.D.P.; Ourique A.F.© 2024 Elsevier LtdThe present study aimed to develop redispersible spray-dried powders containing curcumin-loaded Eudragit® L100 nanocapsules and evaluate their physicochemical properties and antioxidant potential. The spray drying process showed a yield of over 85%, low residual moisture content (<2%), and all the physicochemical characteristics of the nanocapsules were recovered after the aqueous redispersion of the dry powders. In addition to the dry powders, the following samples were also analyzed: pure curcumin, pure lactose, and curcumin-lactose mix. In TGA and DSC analysis, all samples were thermostable and exhibited no chemical interactions with each other. In FTIR analysis, the nanostructured powder system showed functional groups of the precursors (curcumin and lactose), confirming the effectiveness in the preparation of the nanostructured material. In the evaluation of the free radical scavenging activity of DPPH•, the dry powder containing nanoencapsulated curcumin showed antioxidant activity approximately six times higher than free curcumin. Therefore, spray drying of nanoencapsulated curcumin made it possible to obtain a dry powder with homogeneous aqueous redispersion, as well as promoting the potentiation of the antioxidant activity of curcumin.Artigo Acesso restrito Optimizing propylene production via acetone hydrodeoxygenation: Insights from catalytic studies with Cu/γ-Al2O3 and Hβ zeolite(2025) Trindade A.C.M.; Enzweiler, Heveline; Salau N.P.G.© 2024 Elsevier B.V.Propylene is a crucial light olefin in the petrochemical industry and can be produced via acetone hydrodeoxygenation, which involves two sequential reactions: first, acetone undergoes hydrogenation catalyzed by metallic sites, followed by the dehydration of the resulting isopropanol catalyzed by acidic sites. In this study, propylene production through acetone hydrodeoxygenation was investigated using a physical mixture of 35 wt% Cu/γ-Al2O3 and Hβ zeolite to investigate how various reaction parameters affect acetone conversion and propylene yield. Using the experimental design methodology, empirical models were developed to correlate acetone conversion (Xacet) and propylene yield (Yprop) with the ratio of 35 wt% Cu/γ-Al2O3 to Hβ (CR), total catalyst weight (Cw), hydrogen volumetric flow rate (FH2) and reaction temperature (T). The maximum propylene yield achieved in the catalytic tests was 73.46 %. A long-term test demonstrated the catalyst's reusability, remaining active even after 22 hours of reaction with only a slight decrease in propylene yield. Analysis of the experimental data revealed that increasing T and Cw positively affected propylene yield, whereas higher CR and FH2 had negative effects. According to the Pareto chart, reaction temperature was the most influential variable for propylene yield, followed by CR, FH2 and Cw. For acetone conversion, the order of significance among the variables was T > CR > Cw > FH2.Artigo Acesso restrito Tea tree essential oil and its impact on blue mold, volatile compounds, and postharvest quality of ‘Fuji’ apples: A study of laboratory-extracted and commercial essential oils(2025) da Silva J.C.*; Steffens, Cristiano Andre; Alves J.A.V.*; Moreira, Marcelo Alves; do Amarante C.V.T.*; Casa, Ricardo Trezzi; Espindola B.P.; Bortoluzzi A.L.© 2024 Elsevier LtdThis study evaluated the effects of tea tree essential oil (TTO) on blue mold severity, volatile compound profiles, and postharvest quality of ‘Fuji’ apples during cold storage. Two experiments were conducted using laboratory-extracted TTO from Brazil and commercial TTO from Australia, applied by vaporization at various concentrations. Both types of TTO affected major volatile compounds, including terpinen-4-ol, γ-terpinene, and α-terpinene. The laboratory-extracted TTO had higher of 1,8-cineole, while commercial TTO had more p-cymene. TTO reduced blue mold severity up to 115 μL L−1 (laboratory) and 99 μL L−1 (commercial). Ethylene production decreased with laboratory-extracted TTO up to 64 μL L−1, while commercial TTO decreased ethylene production. Laboratory TTO increased the respiratory up to 41 μL L−1 before declining, whereas commercial TTO continuously decreased the respiratory. Higher concentrations of laboratory TTO decreased flesh firmness and lightness.TTO types altered the apples' volatile profiles, reducing ‘Fuji’ apple aromas.Artigo Acesso restrito The Impact of Sensory Branding and Technology on Consumer Behavior in Physical Retail Experience Design: A Multi-generational Experimental Study(2025) Tonin P.E.H.*; Nickel, Elton Moura; dos Santos F.A.V.*© 2025 Common Ground Research Networks. All rights reserved.The COVID-19 pandemic transformed shopping habits and led to the need to rethink the experience offered in physical stores, incorporating solutions that involve, for instance, sensory branding and technology. How can these solutions influence cognitive processes and responses, leading to positive results for brands and their customers? The research seeks to answer the question through a qualitative experimental research, bringing together participants from different generations in order to provide an inclusive overview of user behavior when faced with these solutions. The sample of twenty-five volunteers was distributed equally into five different groups or generations: Silent Generation, Baby Boomers, Generation X, Generation Y, and Generation Z. With the aim of understanding and tracing experience through the users’ perspective, the experiments included a questionnaire and focus group session, which included the application of complementary techniques, as the Experience Compelling Map, to ensure greater reliability in results. Through this study, a general and inclusive overlook of consumer behavior was obtained as well as an integrated overview of the topic, providing a better understanding for both non-specialists and specialists and contributing to Design practice. The results were compared and generated fourteen guidelines that can become alternatives to enhance physical retail experience.