Biocompostos das polpas de maracujá e de buriti: caracterização e aplicação em leite
Data
2018-02-28
Autores
Borgonovi, Tais Fernanda
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Nos últimos anos, a população mundial aumentou a procura por alimentos saudáveis; dentre estes produtos, destacam-se os produtos lácteos fermentados. As bactérias mais utilizadas na produção destes produtos fermentados são as bactérias acidoláticas (BAL), que modificam as características nutricionais do produto, e podem proporcionar efeitos fisiológicos desejáveis aos consumidores. Outro fator que vem ganhando destaque é a adição de polpa de frutas aos leites fermentados, pois conferem características tecnológicas e sensoriais agradáveis aos produtos, além de aumentarem o valor nutricional, devido à presença de compostos bioativos das frutas. O presente trabalho foi dividido em três etapas. A etapa 1 foi composta pela coleta e preparação das polpas de frutas, seguida da caracterização quanto à composição centesimal, perfil de ácidos graxos, compostos fenólicos totais, flavonoides totais, carotenoides totais e atividade antioxidante. A polpa de maracujá apresentou maiores teores de umidade, proteína total e cinzas quando comparado com à polpa de buriti. Por outro lado, o buriti apresentou resultados expressivos de lipídeos (sendo 70% de ácidos graxos insaturados), compostos fenólicos totais, flavonoides amarelos e antocianinas, β-caroteno, licopeno e atividade antioxidante. Na etapa 2 foram realizados testes para avaliar o efeito de compostos fenólicos presentes nos extratos das polpas sobre a viabilidade das cepas de bactérias acidoláticas (BAL). A adição de polpas de maracujá e buriti estimulou o crescimento das BAL, demonstrando a utilização das polpas de frutas como fonte de energia para seu desenvolvimento. Lactobacillus casei SJRP38 apresentou maior crescimento na presença das polpas e foi selecionado para elaboração de leite fermentado e acidificado. Na etapa 3, foram produzidos leite fermentado e acidificado controle, com adição de polpa de maracujá e de buriti. Foram avaliados os parâmetros cinéticos para fermentação do leite, contagem de micro-organismos viáveis ao longo do tempo. Os produtos (leite fermentado e acidificado) dos diferentes tratamentos foram caracterizados quanto a sua composição físico-química, acidez, CRA, sinérese, compostos fenólicos totais e atividade antioxidante. O leite fermentado com adição de polpa de maracujá apresentou o menor tempo de acidificação. A população de Lactobacillus casei SJRP38 se manteve estável durante todo o período de estocagem. A acidez títulavel do leite fermentado aumentou, enquanto o leite acidificado reduziu durante o período de estocagem. A capacidade de retenção de água (CRA) aumentou em todos os tratamentos durante o período de estocagem, enquanto a sinérese do leite fermentado se manteve constante. A adição de polpas de frutas contribuiu para aumentar os teores de compostos fenólicos no leite fermentado e acidificado, entretanto houve uma redução durante o período de estocagem, em todos os tratamentos. As polpas de maracujá e de buriti contêm compostos bioativos e apresentam resultados promissores quando usadas simultaneamente com L. casei SJRP38, sem alterar a viabilidade durante a estocagem. Os produtos (leite fermentado ou acidificado) com adição de polpa de buriti se destacaram por apresentarem elevada atividade antioxidante, com potencial para elaboração alimentos funcionais e para proporcionarem efeitos benéficos à saúde.
In recent years, there has been an increase in the world population demand for healthy foods, which include fermented dairy products. The most commonly used strains for the production of such fermented products are lactic acid bacteria (LAB), which modify the nutritional characteristics of the products, and additionally may provide desirable beneficial physiological effects to consumers. The addition of fruit pulp to fermented milk has also gained importance, since they confer valuable technological and sensorial characteristics to the products, besides increasing their nutritional value, due to the content of bioactive compounds. The present work was divided into three phases. In the phase 1, fruit pulps were obtained, prepared and characterized by means of chemical composition, fatty acid profile, total phenolic compounds, total flavonoids, total carotenoids and antioxidant activity. Passion fruit pulp presented higher moisture, total protein and ashes values when compared to buriti pulp. On the other hand, buriti pulp presented higher values of lipids (70% of unsaturated fatty acids), total phenolic compounds, yellow flavonoids and anthocyanins, β-carotene, lycopene and antioxidant activity. In phase 2, tests were carried out to evaluate the effect of phenolic compounds present in the pulps extracts on the viability of LAB strains. The addition of both passion fruit and buriti pulps stimulated the growth of LAB, demonstrating that these fruit pulps can be used as a source of energy for bacteria growth. Lactobacillus casei SJRP38 presented the highest growth in the presence of fruti pulps and was selected for the preparation of fermented and acidified milk. In phase 3, fermented and acidified milk with passion fruit and buriti pulps were produced. The kinetic parameters and the count of viable microorganisms during storage of fermented milk were determined. Both types of products (fermented and acidified milk) were characterized regarding their chemical composition, acidity, water holding capacity (WHC), syneresis, total phenolic compounds and antioxidant activity. Fermented milk with the addition of passion fruit pulp showed the shortest acidification time. Lactobacillus casei SJRP38 population remained stable throughout the storage period. The acidity of fermented milk increased, while the acidified milk reduced its acidity during the storage period. The WHC of all treatments increased during the storage period, on the other hand the syneresis of fermented milk remained stable. The addition of fruit pulps contributes to increase the phenolic content of both fermented and acidified milk, but there was a reduction of these compounds during the storage period in all treatments. Passion fruit and buriti pulps contain bioactive compounds and showed promising results when used simultaneously with L. casei SJRP38, without altering the strain viability during storage. The products (fermented or acidified milk) with the addition of buriti pulp were distinguished by their high antioxidant activity, with the potential to be added to functional foods and to provide beneficial health effects.
In recent years, there has been an increase in the world population demand for healthy foods, which include fermented dairy products. The most commonly used strains for the production of such fermented products are lactic acid bacteria (LAB), which modify the nutritional characteristics of the products, and additionally may provide desirable beneficial physiological effects to consumers. The addition of fruit pulp to fermented milk has also gained importance, since they confer valuable technological and sensorial characteristics to the products, besides increasing their nutritional value, due to the content of bioactive compounds. The present work was divided into three phases. In the phase 1, fruit pulps were obtained, prepared and characterized by means of chemical composition, fatty acid profile, total phenolic compounds, total flavonoids, total carotenoids and antioxidant activity. Passion fruit pulp presented higher moisture, total protein and ashes values when compared to buriti pulp. On the other hand, buriti pulp presented higher values of lipids (70% of unsaturated fatty acids), total phenolic compounds, yellow flavonoids and anthocyanins, β-carotene, lycopene and antioxidant activity. In phase 2, tests were carried out to evaluate the effect of phenolic compounds present in the pulps extracts on the viability of LAB strains. The addition of both passion fruit and buriti pulps stimulated the growth of LAB, demonstrating that these fruit pulps can be used as a source of energy for bacteria growth. Lactobacillus casei SJRP38 presented the highest growth in the presence of fruti pulps and was selected for the preparation of fermented and acidified milk. In phase 3, fermented and acidified milk with passion fruit and buriti pulps were produced. The kinetic parameters and the count of viable microorganisms during storage of fermented milk were determined. Both types of products (fermented and acidified milk) were characterized regarding their chemical composition, acidity, water holding capacity (WHC), syneresis, total phenolic compounds and antioxidant activity. Fermented milk with the addition of passion fruit pulp showed the shortest acidification time. Lactobacillus casei SJRP38 population remained stable throughout the storage period. The acidity of fermented milk increased, while the acidified milk reduced its acidity during the storage period. The WHC of all treatments increased during the storage period, on the other hand the syneresis of fermented milk remained stable. The addition of fruit pulps contributes to increase the phenolic content of both fermented and acidified milk, but there was a reduction of these compounds during the storage period in all treatments. Passion fruit and buriti pulps contain bioactive compounds and showed promising results when used simultaneously with L. casei SJRP38, without altering the strain viability during storage. The products (fermented or acidified milk) with the addition of buriti pulp were distinguished by their high antioxidant activity, with the potential to be added to functional foods and to provide beneficial health effects.
Descrição
Palavras-chave
Alimentos funcionais, Compostos fenólicos, Probióticos, Leite fermentado, Frutas, Functional foods, Phenolic compounds, Probiotics, Fermented milk, Fruits