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Aditivos naturais: potencial conservante na indústria alimentar
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A crescente procura por alimentos mais saudáveis, sustentáveis e com rótulos mais transparentes tem impulsionado a investigação de alternativas naturais aos conservantes
sintéticos utilizados pela indústria alimentar. Paralelamente, a valorização de subprodutos agroindustriais tem emergido como uma estratégia promissora para a redução do desperdício alimentar e promoção da economia circular. Neste contexto, diferentes matrizes vegetais constituem fontes relevantes de compostos bioativos com potencial aplicação como conservantes naturais.
O presente trabalho teve como objetivo desenvolver e caracterizar um extrato natural rico em compostos bioativos com potencial aplicação como conservante alimentar, recorrendo
à valorização de diferentes matrizes vegetais, nomeadamente urtiga (Urtica dioica), bioresíduos de romã e brócolos. Inicialmente, foram avaliadas as atividades antioxidante e antimicrobiana, bem como a toxicidade dos extratos, de forma a selecionar a matriz com maior potencial bioativo e segurança de utilização. A urtiga foi selecionada para estudos posteriores, tendo o seu processo de extração sido otimizado através da metodologia de superfície de resposta, considerando como variáveis de resposta a atividade antioxidante, o teor de massa seca e o perfil individual de compostos fenólicos.
Posteriormente, o processo de extração foi otimizado através da metodologia de superfície de resposta, utilizando a extração assistida por ultrassom e considerando como
variáveis independentes a potência do ultrassom, o tempo de extração e a proporção etanol/água. A otimização teve como objetivo maximizar a atividade antioxidante, o teor de
massa seca e a recuperação de compostos fenólicos. As condições ótimas determinadas pelos modelos matemáticos foram posteriormente validadas experimentalmente.
O extrato otimizado foi caracterizado por HPLC-DAD-ESI/MS, permitindo a identificação de sete compostos fenólicos, correspondentes a quatro ácidos fenólicos e três
flavonoides, com um teor total de 19,8 mg/g de extrato seco. Os flavonoides constituíram a classe predominante (11,6 mg/g), destacando-se a quercetina-3-O-rutinosídeo (rutina) como
composto maioritário, seguida da quercetina-3-O-glicosídeo. Entre os ácidos fenólicos identificados destacaram-se os ácidos cafeoilquínicos e o ácido dicafeoilmálico. Estes
compostos estão associados a reconhecidas propriedades antioxidantes e anti-inflamatórias, reforçando o potencial bioativo do extrato obtido.
A validação experimental das condições ótimas confirmou a adequação do processo de extração desenvolvido, sendo posteriormente realizada uma comparação com um extrato
comercial de urtiga. Os resultados obtidos demonstram o potencial da urtiga como fonte de compostos fenólicos de interesse para a indústria alimentar, evidenciando a viabilidade da
utilização de extratos naturais como alternativa sustentável aos conservantes sintéticos e contribuindo para o desenvolvimento de ingredientes alinhados com o conceito de clean label.
The growing demand for healthier, more sustainable foods with more transparent labeling has driven research into natural alternatives to the synthetic preservatives used by the food industry. At the same time, the valorization of agro-industrial byproducts has emerged as a promising strategy for reducing food waste and promoting the circular economy. In this context, various plant matrices constitute significant sources of bioactive compounds with potential application as natural preservatives. The objective of this study was to develop and characterize a natural extract rich in bioactive compounds with potential application as a food preservative, utilizing different plant matrices, namely stinging nettle (Urtica dioica), pomegranate biowaste, and broccoli. Initially, the antioxidant and antimicrobial activities, as well as the toxicity of the extracts, were evaluated to select the matrix with the greatest bioactive potential and safety of use. Stinging nettle was selected for further studies, and its extraction process was optimized using response surface methodology, with antioxidant activity, dry matter content, and the individual profile of phenolic compounds considered as response variables. Subsequently, the extraction process was optimized using response surface methodology, employing ultrasound-assisted extraction and considering ultrasound power, extraction time, and the ethanol/water ratio as independent variables. The optimization aimed to maximize antioxidant activity, dry matter content, and the recovery of phenolic compounds. The optimal conditions determined by the mathematical models were subsequently validatedexperimentally. The optimized extract was characterized by HPLC-DAD-ESI/MS, allowing the identification of seven phenolic compounds, corresponding to four phenolic acids and three flavonoids, with a total content of 19.8 mg/g of dry extract. Flavonoids constituted the predominant class (11.6 mg/g), with quercetin-3-O-rutinoside (rutin) standing out as the major compound, followed by quercetin-3-O-glycoside. Among the identified phenolic acids, caffeoylquinic acids and dicaffeoylmalic acid stood out. These compounds are associated with recognized antioxidant and anti-inflammatory properties, reinforcing the bioactive potential of the obtained extract. Experimental validation of the optimal conditions confirmed the suitability of the extraction process developed, and a comparison was subsequently conducted with a commercial nettle extract. The results obtained demonstrate the potential of stinging nettle as a source of phenolic compounds of interest to the food industry, highlighting the feasibility of using natural extracts as a sustainable alternative to synthetic preservatives and contributing to the development of ingredients aligned with the clean label concept.
The growing demand for healthier, more sustainable foods with more transparent labeling has driven research into natural alternatives to the synthetic preservatives used by the food industry. At the same time, the valorization of agro-industrial byproducts has emerged as a promising strategy for reducing food waste and promoting the circular economy. In this context, various plant matrices constitute significant sources of bioactive compounds with potential application as natural preservatives. The objective of this study was to develop and characterize a natural extract rich in bioactive compounds with potential application as a food preservative, utilizing different plant matrices, namely stinging nettle (Urtica dioica), pomegranate biowaste, and broccoli. Initially, the antioxidant and antimicrobial activities, as well as the toxicity of the extracts, were evaluated to select the matrix with the greatest bioactive potential and safety of use. Stinging nettle was selected for further studies, and its extraction process was optimized using response surface methodology, with antioxidant activity, dry matter content, and the individual profile of phenolic compounds considered as response variables. Subsequently, the extraction process was optimized using response surface methodology, employing ultrasound-assisted extraction and considering ultrasound power, extraction time, and the ethanol/water ratio as independent variables. The optimization aimed to maximize antioxidant activity, dry matter content, and the recovery of phenolic compounds. The optimal conditions determined by the mathematical models were subsequently validatedexperimentally. The optimized extract was characterized by HPLC-DAD-ESI/MS, allowing the identification of seven phenolic compounds, corresponding to four phenolic acids and three flavonoids, with a total content of 19.8 mg/g of dry extract. Flavonoids constituted the predominant class (11.6 mg/g), with quercetin-3-O-rutinoside (rutin) standing out as the major compound, followed by quercetin-3-O-glycoside. Among the identified phenolic acids, caffeoylquinic acids and dicaffeoylmalic acid stood out. These compounds are associated with recognized antioxidant and anti-inflammatory properties, reinforcing the bioactive potential of the obtained extract. Experimental validation of the optimal conditions confirmed the suitability of the extraction process developed, and a comparison was subsequently conducted with a commercial nettle extract. The results obtained demonstrate the potential of stinging nettle as a source of phenolic compounds of interest to the food industry, highlighting the feasibility of using natural extracts as a sustainable alternative to synthetic preservatives and contributing to the development of ingredients aligned with the clean label concept.
Descrição
Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do Paraná
Palavras-chave
Compostos fenólicos Conservantes naturais Extração assistida por ultrassom Otimização Urtiga