Browsing by Author "Gomes, Nayara Resende"

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    Effect of thermosonication on microorganisms, the antioxidant activity and the retinol level of human milk.
    (2020) Parreiras, Paola Machado; Nogueira, Janaina Aparecida Vieira; Cunha, Luciana Rodrigues da; Passos, Maria Cristina; Gomes, Nayara Resende; Breguez, Gustavo Silveira; Falco, Thaís Silva; Bearzoti, Eduardo; Menezes, Camila Carvalho de
    In order to reduce the degradation of naturally-occurring components by conventional heat treatment, alternative processing techniques have been studied to preserve the nutritional properties of processed foods, such as thermosonication. This study evaluates the application of thermosonication for the inactivation of pathogenic microorganisms, and its effect on antioxidant activity and retinol level in donated human milk. We evaluate the effect of thermosonication on Staphylococcus aureus, Escherichia coli, and Salmonella spp. microorganisms in human milk by analyzing the effect of time and temperature of the thermosonication on these microorganisms using a central composite rotatable design. Also evaluated the effects of thermosonication (60 °C/4 min) on antioxidant activity using DPHH (2, 2-diphenyl-1-picrylhydrazyl) free radical and ABTS (2,2′-azino-bis 3- ethylbenzothiazoline-6-sulfonic acid) scavenging methods and on the retinol level in human milk and compared them to the effects of holder pasteurization (62.5 °C/30 min) in vitro. For this evaluation, a pool of the 10 human milk samples was made and distributed 40 mL, from this pool, for two interventions (holder pasteurization and thermosonication) and one control (untreated milk). Both in thermosonication and non-ultra-sound heat treatments, the microorganism counts tended to remain stable at lower temperatures, with the most significant and continuous reductions in thermosonication observed at the points of inflexion of the curves of the adjusted models: at 53.7 °C, 52.0 °C, and 60.9 °C for S. aureus, E. coli, and Salmonella, respectively. Thermosonication also promoted greater decimal reductions of the microorganisms analyzed than heat treatment at 60 °C, 48 °C, and 65 °C for S. aureus, E. coli, and Salmonella, respectively. Holder pasteurization significantly reduced the antioxidant activity when compared to the control, while thermosonication increased it. Retinol level remained stable following both pasteurization and thermosonication. This study could be used to encourage further studies to fill in the remaining gaps for this type of processing on human milk.
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    Impact of ultrasound treatment on viability of Staphylococcus aureus and the human milk antioxidant activity.
    (2022) Gomes, Nayara Resende; Parreiras, Paola Machado; Menezes, Camila Carvalho de; Falco, Thaís Silva; Vieira, Michele Cristina; Passos, Maria Cristina; Cunha, Luciana Rodrigues da
    This study aimed to evaluate the application of thermosonication for the viability of Staphylococcus aureus and the antioxidant activity of HM. The US effect on the S. aureus was measured by counting viable cells in discarded HM immediately before and after different treatments varying time (1, 5 and 10 minutes) and temperature (20, 30, 40, 50 and 60 °C) through surface plating on standard agar. The antioxidant activity evaluation was carried out by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. With Regarding microbiological quality, it can be concluded that treatment with US at 60 °C for 10 minutes was the most effective in terms of reducing the viability of S. aureus, in addition to presenting a significant increase in the content of antioxidants when compared to raw and pasteurized milk samples.
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    O subproduto do corante caramelo IV em alimentos pode causar toxicidade?
    (2021) Gomes, Nayara Resende; Souza, Melina Oliveira de; Menezes, Camila Carvalho de
    O corante caramelo tem sido amplamente utilizado em alimentos e bebidas e é regulamentado globalmente como aditivo químico. As quatro classes distintas do corante caramelo (caramelo simples (I), caramelo sulfito (II), caramelo de amônia (III) e caramelo sulfito-amônia (IV)) são bem caracterizadas e cada uma tem especificidades que variam com os tipos de processamento do composto, especialmente a adição de reagentes que podem dar origem a compostos de baixo peso molecular, como por exemplo, o 4-metilimidazol, subproduto do caramelo IV, que pode ter significativo efeito toxicológico. Tendo em vista o elevado consumo de alimentos industrializados e a potencial exposição em longo prazo desse composto, em diferentes faixas etárias, o objetivo desta revisão foi resumir os estudos mais relevantes disponíveis nos últimos 5 anos sobre os efeitos tóxicos do 4-metilimidazol, nas bases de dados PubMed, Science Direct e Lilacs. Os resultados dos estudos avaliados são divergentes e os mecanismos de toxicidade ainda não estão bem elucidados, apesar de alguns estudos terem encontrado efeitos negativos à saúde com a exposição ao 4-metilimidazol, tornando-se relevante novos estudos para esclarecer a sua real segurança.