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Authors
Advisor(s)
Abstract(s)
Os alimentos são passíveis de diversas formas de degradação, seja pelo oxigénio presente na atmosfera, fatores microbiológicos, enzimáticos, físicos e entre outros, sendo fundamental o estudo de alternativas para conservá-los. A população está cada vez mais preocupada com os aditivos sintéticos utilizados em alimentos, seja pelos estudos referentes aos riscos à saúde, ou pelas opiniões públicas geradas na mídia.
Portanto, a procura e o estudo por alimentos naturais ou com o mínimo de aditivos artificiais está cada vez maior, garantindo uma maior segurança ao consumidor. Plantas são conhecidas por serem fontes ricas em compostos bioativos, visto que esses são considerados uma defesa à agentes externos como microrganismos, agentes oxidantes e radiação ultravioleta, e por isso seus extratos são investigados como uma fonte promissora de aditivos naturais.
Desse modo, os objetivos do presente trabalho envolvem a análise de três plantas: alecrim (Rosmarinus officinalis L.), manjericão (Ocimum basilicum L.) e sálvia (Salvia officinalis L.) referente às suas moléculas conservantes. Realizou-se a otimização da extração dos compostos bioativos com tecnologias sustentáveis e de baixo custo como a extração por ultrassom, utilizando solventes verdes (água e etanol); caracterização química dos extratos obtidos por HPLC-DAD-ESI/MS; avaliação da bioatividade dos extratos (atividade antioxidante, antimicrobiana e citotóxica); incorporação dos extratos otimizados em iogurtes e avaliação da estabilidade dos ingredientes ao longo da vida de prateleira através de parâmetros físicos e químicos como textura, cor e pH; análise microbiológica, nutricional e monitoramento das moléculas conservantes. De acordo com os resultados obtidos, quanto a otimização, verificou-se que a percentagem de solvente é o fator mais relevante para a obtenção de um extrato rico em ácido rosmarínico, seguido pelo tempo de extração e potência do equipamento. Para a atividade antioxidante e antimicrobiana, o extrato de alecrim obteve o melhor resultado, seguido pela sálvia e por fim, o manjericão. Nenhum dos três extratos vegetais avaliados apresentaram hepatotoxicidade, ultrapassando a concentração máxima testada.
Por fim, verificou-se que os extratos vegetais não apresentaram mudanças nas características físico-químicas e nutricionais dos iogurtes. Além disso, não interferiu no crescimento das bactérias lácticas, microrganismo fundamental para o processo de fabricação do iogurte.
Foods are susceptible to various forms of degradation, either by oxygen present in the atmosphere, microbiological factors, enzymatic, physical, and others, and it is essential to study ways of preserving food. The population is increasingly concerned with the synthetic additives used in food, either by studies related to health risks, or by public opinions generated in the media. The demands for non-processed foods or with a minimum of artificial additives is increasing due to an increased awareness of consumers towards whtier diets. Plants are known to be rich sources of bioactive compounds, since these are considered a defense mechanism against external agents such as microorganisms, oxidizing agents, and ultraviolet radiation, and for this reason their extracts are investigated as a promising source of natural additives for the food industry. The objectives of this work involve the study of three plants: rosemary (Rosmarinus officinalis L.), basil (Ocimum basilicum L.) and sage (Salvia officinalis L.) regarding their preservative molecules. The extraction of bioactive compounds was optimized with sustainable and low-cost technologies such as ultrasound extraction (UAE), using green solvents (water and ethanol); chemical characterization of the extracts obtained by HPLC-DAD-ESI/MS; evaluation of the bioactivity of the extracts (antioxidant, antimicrobial and cytotoxic activity; incorporation of the optimized extracts in yogurts and evaluation of the stability of the ingredients over the shelf life by analysing physical and chemical parameters such as texture, color and pH; microbiological and nutritional analysis. According to the obtained results, as for optimization, it was found that the percentage of solvent is the most relevant factor for obtaining an extract rich in rosmarinic acid, followed by the extraction time and ultrasonic power. For the antioxidant and antimicrobial activity, rosemary extract showed the best result, followed by sage and finally, basil. None of the three plant extracts showed hepatotoxicity, exceeding the maximum concentration tested. Finally, the plant extracts did now show changes in the physico-chemical and nutritional characteristics of the yogurts. Moreover, it did not interfere with the growth of lactic acid bacteria, a fundamental microorganism for the yogurt manufacturing process.
Foods are susceptible to various forms of degradation, either by oxygen present in the atmosphere, microbiological factors, enzymatic, physical, and others, and it is essential to study ways of preserving food. The population is increasingly concerned with the synthetic additives used in food, either by studies related to health risks, or by public opinions generated in the media. The demands for non-processed foods or with a minimum of artificial additives is increasing due to an increased awareness of consumers towards whtier diets. Plants are known to be rich sources of bioactive compounds, since these are considered a defense mechanism against external agents such as microorganisms, oxidizing agents, and ultraviolet radiation, and for this reason their extracts are investigated as a promising source of natural additives for the food industry. The objectives of this work involve the study of three plants: rosemary (Rosmarinus officinalis L.), basil (Ocimum basilicum L.) and sage (Salvia officinalis L.) regarding their preservative molecules. The extraction of bioactive compounds was optimized with sustainable and low-cost technologies such as ultrasound extraction (UAE), using green solvents (water and ethanol); chemical characterization of the extracts obtained by HPLC-DAD-ESI/MS; evaluation of the bioactivity of the extracts (antioxidant, antimicrobial and cytotoxic activity; incorporation of the optimized extracts in yogurts and evaluation of the stability of the ingredients over the shelf life by analysing physical and chemical parameters such as texture, color and pH; microbiological and nutritional analysis. According to the obtained results, as for optimization, it was found that the percentage of solvent is the most relevant factor for obtaining an extract rich in rosmarinic acid, followed by the extraction time and ultrasonic power. For the antioxidant and antimicrobial activity, rosemary extract showed the best result, followed by sage and finally, basil. None of the three plant extracts showed hepatotoxicity, exceeding the maximum concentration tested. Finally, the plant extracts did now show changes in the physico-chemical and nutritional characteristics of the yogurts. Moreover, it did not interfere with the growth of lactic acid bacteria, a fundamental microorganism for the yogurt manufacturing process.
Description
Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do Paraná
Keywords
Alimentos Alimentos naturais Conservantes