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Advisor(s)
Abstract(s)
Atualmente, existe uma preocupação da indústria alimentar na substituição de aditivos
sintéticos por ingredientes naturais. Os extratos naturais obtidos a partir de plantas
surgem como possíveis alternativas aos conservantes sintéticos, nomeadamente
dos antioxidantes. Neste trabalho, pretendeu-se comprovar a eficácia de extratos ricos
em catequina, obtido a partir de frutos de Arbutus unedo L. (medronho) e em ácido rosmarínico
obtido a partir de folhas de Ocimum basilicum L. (manjericão), como conservantes
naturais de pão, comparando a sua eficácia com aditivos sintéticos normalmente
aplicados a produtos de panificação. Após a avaliação das propriedades antioxidantes
(valores EC50 do efeito bloqueador de radicais de DPPH = 595 e 351 μg/ mL, para medronho
e manjericão, respetivamente) e antimicrobianas (contra 8 bactérias e 8 fungos) e
confirmação da ausência de citoxicidade (numa cultura primária de células de fígado),
os extratos ricos em (+)-catequina e ácido rosmarínico foram incorporados no pão. O
seu efeito foi comparado com o ácido ascórbico (E300), o sorbato de potássio (E202)
e com uma amostra controlo (pão sem aditivos) imediatamente após a incorporação
e após 3 e 7 dias de armazenamento, à temperatura ambiente e protegidos da luz. Os
pães aditivados com os extratos naturais, especialmente de manjericão, apresentaram
maior capacidade antioxidante do que os pães com ácido ascórbico e sorbato de potássio,
tendo todos mantido as suas propriedades nutricionais. Em geral, os resultados
obtidos demonstraram que os extratos podem ser utilizados no desenvolvimento de
pão, substituindo os conservantes sintéticos, sem interferir nas características físicas e
nutricionais dos produtos finais.
Currently, the food industry is focused on replacing synthetic additives with natural ingredients. Natural extracts obtained from plants have emerged as possible alternatives to synthetic preservatives, namely in the class of antioxidants. In this work we intend to prove the efficacy of an extract rich in catechin, obtained from Arbutus unedo L. (strawberry tree) fruits, and of an extract rich in rosmarinic acid obtained from Ocimum basilicum L. (basil) leaves, as natural preservatives of bread and compare these results to synthetic additives which are normally used in bakery products. After evaluation of the antioxidant (EC50 values for DPPH scavenging activity = 595 and 351 μg/ mL, for strawberry tree fruits and basil leaves, respectively) and antimicrobial (against 8 bacteria and 8 fungi food contaminants) properties, and confirmation of cytotoxicity absence (in porcine liver primary cells), the extracts rich in (+)-catechin and rosmarinic acid were incorporated into the bread. Its effect was compared to ascorbic acid (E300), potassium sorbate (E202) and to a control sample (bread without additives), immediately after incorporation and in the 3rd and 7th day of storage, protected from light at room temperature. The breads incorporated with the natural extracts, especial basil, presented a higher antioxidant capacity than the breads incorporated with ascorbic acid and potassium sorbate, while the nutritional profile was not affected. Overall, the obtained results demonstrate that these extracts could be used in the development of new bread formulations replacing the synthetic preservatives, without interfering with the physical and nutritional characteristics of the final product.
Currently, the food industry is focused on replacing synthetic additives with natural ingredients. Natural extracts obtained from plants have emerged as possible alternatives to synthetic preservatives, namely in the class of antioxidants. In this work we intend to prove the efficacy of an extract rich in catechin, obtained from Arbutus unedo L. (strawberry tree) fruits, and of an extract rich in rosmarinic acid obtained from Ocimum basilicum L. (basil) leaves, as natural preservatives of bread and compare these results to synthetic additives which are normally used in bakery products. After evaluation of the antioxidant (EC50 values for DPPH scavenging activity = 595 and 351 μg/ mL, for strawberry tree fruits and basil leaves, respectively) and antimicrobial (against 8 bacteria and 8 fungi food contaminants) properties, and confirmation of cytotoxicity absence (in porcine liver primary cells), the extracts rich in (+)-catechin and rosmarinic acid were incorporated into the bread. Its effect was compared to ascorbic acid (E300), potassium sorbate (E202) and to a control sample (bread without additives), immediately after incorporation and in the 3rd and 7th day of storage, protected from light at room temperature. The breads incorporated with the natural extracts, especial basil, presented a higher antioxidant capacity than the breads incorporated with ascorbic acid and potassium sorbate, while the nutritional profile was not affected. Overall, the obtained results demonstrate that these extracts could be used in the development of new bread formulations replacing the synthetic preservatives, without interfering with the physical and nutritional characteristics of the final product.
Description
Keywords
Arbutus unedo L. Ocimum basilicum L. Conservantes naturais Pão
Pedagogical Context
Citation
Sallawi, Takwa; Caleja, Cristina; Barreira, João C.M.; Sokovic, Marina; Achour, Lofti; Barros, Lillian; Ferreira, Isabel C.F.R. (2018). Arbutus unedo L. and Ocimum basilicum L. as natural preservers of bread. In Martins, Anabela (Ed.) V Encontro de Investigadores do Instituto Politécnico de Bragança: livro de resumos. Bragança: Instituto Politécnico. ISBN 978-972-745-235-4
Publisher
Instituto Politécnico de Bragança