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Abstract(s)
Com os diversos problemas ambientais enfrentados atualmente, a redução do uso de materiais de fontes não renováveis é uma estratégia para minimizar os danos causados à natureza. Dessa forma, o presente trabalho visa a redução do uso de plásticos através da formação de um revestimento comestível partindo de uma formulação já patenteada (patente portuguesa nº 110859), incorporado com extrato de Geranium robertianum L. obtido a partir da técnica de micro-ondas. A extração foi otimizada a fim de obter o melhor resultado para a atividade antioxidante através do método do efeito captador de radicais livres DPPH (2,2-difenil-1-picrilhidrazil), utilizando um design experimental com variações de tempo (5-40 min), potência (150-
600 W) e concentração etanólica (0-100 %), onde os parâmetros ótimos obtidos foram de 15 minutos, 545 Watts e 9% de etanol. O extrato otimizado obteve destaque nos ensaios de DPPH (EC50 de 5,35 μg mL-1) e no método da inibição da peroxidação lipídica por espécies reativas do ácido tiobarbitúrico (TBARS) (8,76 μg mL-1). Foi também realizada a caracterização química do extrato optimo, sendo identificados 21
compostos fenólicos através de HPLC-DAD-ESI-MS/MS, com os derivados do galoil e kaempferol como os mais abundantes. O mesmo extrato foi testado para bactérias gram-positivas, gram-negativas e fungos, com destaque nas ações contra Listeria monocytogenes com concentração mínima inibitória (CMI) de 1,25 mg mL-1. Este revestimento comestível, formado com iota-carragenina como composto polimérico estruturante, incorporado com extrato de G. robertianum L., apresentou menores atividades antioxidantes (DPPH e TBARS com EC50 de 30,26 e 20,84 μg mL-1, respetivamente), porém maiores potenciais antimicrobianos que o extrato, com CMIs iguais ou próximas a 3,6 mg mL-1. As avaliações físicas do revestimento mostraram
eficácia na manutenção de cor e uma pequena variância nos sete diferentes parâmetros de textura avaliados (dureza, adesividade, coesividade, elasticidade, gomosidade, mastigabilidade e resiliência) durante quatro dias, quando aplicado sobre uma maçã.
With the rise of several environmental issues, reducing the use of materials from non-renewable sources is a strategy to minimize the damage caused to Nature. Thus, the present work aims to reduce the use of plastics through the development of an edible coating, based on an already patented formulation (Portuguese patent nº 110859) incorporated with Geranium robertianum L. extract, obtained using the microwave assisted extraction technique. The extraction was optimized to achieve the best antioxidant result through the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging method, using an experimental design with variations in time (5-40 min), power (150-600 W), and ethanol concentration (0-100%), where the optimal parameters obtained were 15 minutes, 545 Watts, and 9% ethanol. The optimized extract stood out in the DPPH (EC50 of 5.35 μg mL-1) and through the lipid peroxidationinhibition method by thiobarbituric acid reactive substances (TBARS) (8.76 μg mL-1) assays. The chemical characterization of the optimized extract was also carried out, with 21 phenolic compounds identified through HPLC-DAD-ESI-MS/MS, with galloyl and kaempferol derivatives being the most abundant, besides showing good responses against gram-positive and gram-negative bacteria, and fungi, with notable action against Listeria monocytogenes with a minimum inhibitory concentration (MIC) of 1.25 mg mL-1. This edible coating, based on iota-carrageenan according to the Portuguese patent nº 110859, but incorporated with G. robertianum L. extract, presented lower antioxidant activities (DPPH and TBARS with EC50 of 30.26 and 20.84 μg mL-1, respectively), but higher antimicrobial potentials than the pure extract, with MICs equal to or close to 3.6 mg mL-1. Physical evaluations of the coating showed effectiveness in maintaining color and a small variance in the seven different texture parameters evaluated (hardness, adhesiveness, cohesiveness, elasticity, gumminess, chewiness, and resilience) over four days when applied on an apple.
With the rise of several environmental issues, reducing the use of materials from non-renewable sources is a strategy to minimize the damage caused to Nature. Thus, the present work aims to reduce the use of plastics through the development of an edible coating, based on an already patented formulation (Portuguese patent nº 110859) incorporated with Geranium robertianum L. extract, obtained using the microwave assisted extraction technique. The extraction was optimized to achieve the best antioxidant result through the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging method, using an experimental design with variations in time (5-40 min), power (150-600 W), and ethanol concentration (0-100%), where the optimal parameters obtained were 15 minutes, 545 Watts, and 9% ethanol. The optimized extract stood out in the DPPH (EC50 of 5.35 μg mL-1) and through the lipid peroxidationinhibition method by thiobarbituric acid reactive substances (TBARS) (8.76 μg mL-1) assays. The chemical characterization of the optimized extract was also carried out, with 21 phenolic compounds identified through HPLC-DAD-ESI-MS/MS, with galloyl and kaempferol derivatives being the most abundant, besides showing good responses against gram-positive and gram-negative bacteria, and fungi, with notable action against Listeria monocytogenes with a minimum inhibitory concentration (MIC) of 1.25 mg mL-1. This edible coating, based on iota-carrageenan according to the Portuguese patent nº 110859, but incorporated with G. robertianum L. extract, presented lower antioxidant activities (DPPH and TBARS with EC50 of 30.26 and 20.84 μg mL-1, respectively), but higher antimicrobial potentials than the pure extract, with MICs equal to or close to 3.6 mg mL-1. Physical evaluations of the coating showed effectiveness in maintaining color and a small variance in the seven different texture parameters evaluated (hardness, adhesiveness, cohesiveness, elasticity, gumminess, chewiness, and resilience) over four days when applied on an apple.
Description
Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do Paraná
Keywords
Extração Micro-ondas Carragenina Revestimento Bioatividades