Keila de Souza Silva

The rhizomes of the turmeric (Curcuma longa L.) and ginger (Zingiber officinale Roscoe) plant are commercialized for culinary and medicinal use, presenting antioxidant, anti-inflammatory and even antitumor activity. The leaves of these plants are considered post-harvest waste. The aim of this study was to evaluate the antioxidant potential of turmeric and ginger leaf extracts. After drying the leaves in an oven at 40ºC, cold extraction was performed by exhaustive maceration in methanol. The methanolic crude extract was partitioned in ascending order of polarity and the hexane, dichloromethane, ethyl acetate and hydromethanolic fractions were obtained. The antioxidant activity of the extracts and fractions was evaluated by the DPPH and ABTS methods and the results were expressed in μM of Trolox per g/extract. By the DPPH method, both in turmeric and ginger, the fraction that showed the highest antioxidant activity was ethyl acetate (752.18 and 393.32 μM Trolox/g, respectively). For ABTS, the highest antioxidant activity was in dichloromethane (935.54 and 704.31 μM Trolox/g, respectively), followed by ethyl acetate (393, 23 and 607.77 μM Trolox/g, respectively), indicating turmeric with higher antioxidant potential.

O presente trabalho teve como objetivo principal estudar, avaliar, e comparar, a estabilidade térmica das interações entre proteína de soja isolada com três polissacarídeos ajustados em pHs extremos 3 e 11. Resultados sugeriram que a interação de matrizes filmógenas SPI + alginato se mostrou mais termoresistente, com Tonset = 67,7. Tanto a DTG como a DSC foram sensíveis para identificação das temperaturas de maior cinética da desnaturação. A DSC explorou as temperaturas de agregação térmica superiores à 113,0 para as soluções na fase pós-desnaturação, com exceção na mistura SPI + pectina. Após a análise dos resultados termoanáliticos das soluções os filmes preparados foram ajustados em pH 11 e tratados nas temperaturas otimizadas características a partir dos resultados da DTG. Temperaturas de agregação térmica dos filmes foram identificadas nos perfis exotérmicos DSC dos filmes SPI, SPI + pectina, SPI + alginato e SPI + goma alfarroba sugerindo que com o aquecimento pós-desnaturação as ligações covalentes tendem a se formarem. No entanto, devido a pouca variação da entalpia envolvida nestes fenômenos, os resultados sugeriram fragilidade nas ligações químicas após a gelificacão das proteínas e misturas nos filmes. As micrografias obtidas indicam alterações morfológicas com a temperatura de tratamento térmico. Resultados das propriedades mecânicas demonstram atenuação da magnitude das propriedades mecânicas com o aquecimento

The present study aimed to manufacture active biodegradable films from soy protein isolate (SPI), locust bean gum (LBG) and caruru and blackjack leaf extract. The interaction between the compounds was evaluated through the analysis of FTIR. The effect of extract addition on the microstructure, mechanical properties, antioxidant capacity, UV radiation absorption capacity, color and opacity of the film were evaluated. All extracts interacted with the protein, however only two treatments interacted with the LBG present in the film. Addition of extracts in the film provided an increase in antioxidant activity. The addition of the blackjack extract increased the tensile strength of the films, but reduced their elasticity. The addition of caruru extract, however, not favoring the resistance of the films. All the extracts darkened the films and the caruru extract provided more greenish films than all the other made films. The films containing blackjack extract presented a higher intensity of light absorption in the spectral range of ultraviolet A and C.

This study investigated the influence of blanching on the drying kinetics of papaya from the perspective of the microstructure of the tissue and the water sorption behavior. Drying kinetics and water effective diffusion coefficients were determined based on Fick’s law considering shrinkage. Intense cellular changes were observed in blanched tissues images obtained by light microscopy and transmission electron microscopy. Heat pretreatment increased the water diffusion coefficients and the drying rates in comparison with fresh fruit. Severe color changes were induced by blanching, resulting in color loss during drying. At intermediate moisture ranges, sorption isotherms of blanched papayas showed lower water sorption capacity than those of fresh fruit, therefore the critical moisture for microbial growth in fresh papayas is higher than in blanched ones. The compensation theory was satisfied for fresh fruit but not for blanched fruit, which presented distinctive sorption behavior attributed to cellular damage caused by heat pretreatment.

The aim of the study was to evaluate the effect of the jambolan (Syzigium cumini L.) peel and leaves extract added in pectin based edible coating onto color changes, mass loss and β-carotene retention of minimally processed papaya during storage at 5 ±2 °C for 9 days. Leaves and peels were crushed in water in solid:liquid ratio, 1:1.5 and 1:2.0 and filtrered to obtain vegetable extracts. After, aqueous solutions were prepared adding 2% of pectin and 5% of extract. The mass loss increasing in all treatments evaluated in this work, being that in the final of 9 days of storage, control and P2 (peel 2%) treatment presented the highest loss, 6.23 and 10.12% respectively. The L1.5 (leaf 1.5%) treatment was the one presented the lowest percentage of mass loss (3.8%). The values of () of the control samples reduced significantly during the storage period, reaching 21% of reduction after 9 days. Coating with vegetable extract from jambolan peel and leaf reduced the loss of β-carotene in minimally processed papaya during the storage, being that the treatment P1.5 provided the highest retention value of the compound. The results demonstrated that the studied coating set with extracts (peel and leaves) of jambolan, was efficient to preserve the color, the mass loss and the β-carotene content of the minimally processed papaya.

This research evaluated the influence of blanching on osmotic dehydration in sucrose solutions of papaya of Formosa cultivar. The characterization of invertase present in the fruits was also done. Blanching possibly caused damages to the cellular structure resulting in higher water loss, sugar gain and, thus, effective diffusion coefficients than fresh papayas during osmotic dehydration. The invertase extracted from papaya pulp presented optimum temperature of 45 °C and optimum pH of 4.8. Considering the low production cost of papaya and the invertase characteristics, the fruit shows to be a potential source for the referred enzyme extraction.

This study evaluated the influence of heat input change on the drying kinetics, energy consumption, the color, and carotenoid retention during the drying of mangoes. The drying conditions in the first stage were 95°C for 40 min and 80°C for 40 min, so that the surface temperatures of the fruit at the end of this stage were around 60°C. The temperatures of the second stage and corresponding continuous drying (control) were 70 and 60°C. As a result, the thermal intermittence influenced the drying kinetics, causing significant reductions in the overall process time and providing energy savings when compared to continuous drying. The color parameters did not show relevant changes as result of the intermittent drying while good carotenoid retention was obtained in intermittent conditions, when the second stage was 60°C. Therefore, the carotenes were more sensitive to a temperature of 70°C, which highlights the importance of limiting the temperature of the mango to 60°C during the two drying stages to better preserve the quality of the dehydrated fruit. Moreover, the high air temperatures used in the first stage were advantageous for reducing the overall process time and providing energy saving.Practical Applications: Drying is an operation well known for the food industry. However, in so many cases, dryers are not designed with energy consumption in mind. Moreover, simple procedures can bring savings in convective drying, as shown in the present study, where the application of two‐stages in the convective drying of mangoes was advantageous to reduce the overall drying time and provide energy savings in relation to continuous drying. Besides that, good carotenoid retention was obtained using low temperature (60°C) at the second stage. The results can be useful for design of dryers and drying process, considering different temperatures. Intermittent drying of high moisture foods by varying the drying air temperature can be applied both on an industrial scale, in continuous belt dryers or in tunnel dryers, and on a small scale, using two or more dryers with different temperatures.

A obra intitulada “Prática e Pesquisa em Ciência e Tecnologia de Alimentos 2” foi elaborada a partir das publicações da Atena Editora e apresenta uma visão ampla sobre as novidades da área. Esta obra é composta por 15 capítulos bem estruturados e agrupados por assuntos. Muitos são os problemas a serem solucionados relacionados ao consumo alimentar humano, por isso a prática e a pesquisa de alimentos devem estar bem alinhadas. O desenvolvimento de novos produtos é essencial para melhorar a qualidade de consumo e disponibilizar uma oferta alimentar de qualidade superior para todos os públicos, uma vez que, novas estilos alimentares como o veganismo e outros, vem sendo adotados em uma escala crescente. Não obstante, a otimização dos processos de fabricação e de controle de qualidade alimentar são indispensáveis quando o assunto é a saúde. Neste sentido, os estudos que são apresentados aqui, alinham-se a estes temas e trazem novas analises que condizem com as necessidades emergentes da prática e pesquisa em ciência e tecnologia de alimentos. A Atena editora, reconhecendo importância dos trabalhos científicos, oferece uma plataforma consolidada e confiável para a divulgação, propiciando aos autores um meio para exporem e divulgarem seus resultados, enriquecendo o conhecimento acadêmico e popular. Por fim, esperamos que a leitura deste trabalho seja agradável e que as novas pesquisas possam propiciar a base intelectual ideal para que se desenvolva novas soluções, cuidados e desenvolvimento cientifico acerca destes temas. Flávio Brah (Flávio Ferreira Silva)