RESUMO

The Eugenia pyriformis Cambess (uvaia) is a well-known source of bioactive compounds. This study investigated the efficiency of Ultrasound-Assisted Extraction (UAE) and Enzyme-Assisted Extraction (EAE) in obtaining uvaia leaf extracts with high antioxidant and antibacterial activity. In a first step, different variables of the leaves were employed to define the best conditions for obtaining the extract with the highest total phenolic content. In a second step, the optimised extracts were characterised. In total, twenty-four phenolic compounds were identified through LC-ESI-MS/MS. The EAE in optimised conditions showed a higher amount of total phenolic compounds and antioxidant potential. It was possible to note an analogous potential of antibacterial activity of the extracts, which showed action mainly against Gram-positive bacteria. These findings suggest that the aqueous extracts of uvaia leaves are feasible, economic, and sustainable alternatives for adding value to uvaia leaves, which are an agricultural residue that is generally underutilised.

RESUMO

Untargeted metabolomics analysis was applied to evaluate the phenolic profile of whole wheat bread with yerba mate (YM) during the bread-making process (flour, dough and bread). The free, bound and total phenolic contents of the samples evaluated by the Folin-Ciocalteu method showed the highest values for the flour, dough and bread samples prepared with 4.5% YM in fine and medium particle sizes (flour 181.48 - 175.26 mg GAE/g; dough 149.62 - 141.40 mg GAE/g; and bread 148.32 - 147.00 mg GAE/g). Globally, 104 phenolic compounds were tentatively identified, belonging to the five subclasses: flavonoids (35), phenolic acids (32), other polyphenols (10), stilbenes (2) and lignan (1). Of these compounds, 24 had the same m/z but showed different fragmentation profiles. A higher number of polyphenols was identified in the bound extracts (77%) than in the free extracts (59%). The addition of 4.5% of YM promoted an improved and more abundant profile of phenolic compounds in the dough and bread. The major compounds found in the samples containing YM were 5-caffeoylquinic acid and caffeic acid. The baking process did not adversely affect the abundance of phenolic compounds. The bread-making process positively affected the phenolic profile due to the release of bound phenolic compounds. At the same time, the addition of YM as a natural ingredient promoted an increase in the polyphenols in the bread.

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RESUMO

This study investigated the effects of different yerba mate (YM) proportions (1.5, 2.5, and 4.5 g YM/100 g whole wheat flour (WWF) and particle sizes (245, 415.5, and 623.9 µm) on dough rheological properties, antioxidant activity, and bread characteristics. The addition of YM leaves led to a possible interaction between its phenolic compounds and the gluten network within the dough, without negative effects on dough formation. However, the larger YM particle size (623.9 µm) caused a weakening of the protein network, resulting in lower quality product compared to the other samples. Improved bread quality was found when the YM leaves were added at 2.5 g YM/100 g WWF. The total amount of phenolic compounds and the antioxidant activity increased as the proportion of YM increased in both flour and bread. Moreover, the phenolic compounds in 2.5 g YM/100 g WWF breads were stable during baking, showing no significant losses in the amount of phenolic compounds and antioxidant activity. These results suggest the YM can be successfully incorporated into baked product, improving its functional characteristics. PRACTICAL APPLICATION: This study evaluates the technological quality of bakery product made by incorporating yerba mate leaves in whole wheat flour. The results will contribute to the production of a bread with greater functional properties due to the presence of polyphenols and phytochemicals.

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RESUMO

BACKGROUND: Knowledge of the structural behavior of dough elaborated using whole grain wheat flour (WGWF) and xylanase is fundamental for the elaboration of products with high nutritional content, especially when the particle size of the flour is altered. In the present study, we investigated the effect of varying concentrations of xylanase on the formation of dough with different particle sizes of WGWF. RESULTS: Phenolic compounds, fibers and proteins are the components that undergo the most change and interfere with dough formation. A small particle size favors the extraction of phenolic compounds and dietary fibers, resulting in a high-quality dough. There was a protective effect of the stable phenolic compounds on the gluten network. An increase in fiber degradation and a decrease in phenolic compounds was noted as the xylanase concentration increased. Although xylanase increased free sulfhydryl (-SH) groups in gluten, there was no change in dough formation and dough stability with an increasing xylanase concentration. CONCLUSION: The WGWF with a smaller particle size does not contribute to the loss of quality in dough elaboration. The addition of intermediate amounts of xylanase (20 mg kg-1 ) in samples with a particle size of 158 µm can be used to improve dough characteristics. © 2019 Society of Chemical Industry.

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Estratégias de fertilização nitrogenada com o emprego de dosagens crescentes demonstram efeitos favoráveis sobre a produtividade e qualidade dos grãos, entretanto têm sido reportado divergências em resultados com relação ao efeito de dosagens, épocas e parcelamentos de aplicação ao longo do ciclo de desenvolvimento da cultura. O objetivo deste estudo foi avaliar a produtividade e características de qualidade protéica em resposta ao manejo de adubação nitrogenada aplicada em cobertura nas cultivares TBIO Itaipu, TBIO Pioneiro, TBIO Quartzo e TBIO Seleto. O experimento foi conduzido em Coxilha RS, nos anos 2012 e 2013. O delineamento experimental utilizado foi em blocos casualizados com três repetições, em esquema fatorial (4 cultivares x 7 manejos). A dose total de N utilizada no trabalho foi de 140 kg ha-1, sendo 30 kg ha-1de N aplicados na semeadura e o restante em cobertura, conforme a época definida em cada tratamento. A produtividade de grãos das cultivares estudadas foi incrementada com a adubação nitrogenada aplicada de forma concentrada no tratamento T2 e manifestou correlação negativa com o conteúdo de proteínas, revelando que a superioridade genotípica para o rendimento de grãos pode afetar negativamente a proporção protéica. Das cultivares estudadas a cultivar TBIO Pioneiro se destacou das demais quanto a força geral de glúten na safra 2012 e a TBIO Seleto foi superior na safra 2013, entretanto, o conteúdo de proteína não evidenciou associação significativa com a força de glúten, revelando que a concentração de proteínas não foi eficiente para predizer a qualidade industrial.

Nitrogen fertilization strategies using increasing dosages demonstrate favorable effects on grain yield and quality; however, differences in results have been reported in relation to the effect of dosages, times and application schedules throughout the development cycle of the crop. The objective of this study was to evaluate the productivity and protein quality characteristics in response to nitrogen fertilization management applied to the cultivars TBIO Itaipu, TBIO Pioneiro, TBIO Quartzo and TBIO Seleto. The experimental design in randomized blocks with three replications, in a factorial scheme (4 cultivars x 7) handlings was used. The experiment was conducted in Coxilha, RS, during the agricultural years of 2012 and 2013. The total dose of N used in the present work was 140 kg ha-1, with 30 kg ha-1 of N being applied at sowing and remainder in coverage, for the time defined in each treatment. The grain yield of the studied cultivars was increased with the nitrogen fertilization applied in a concentrated way in the treatment T2 and showed a negative correlation with the protein content, showing that the genotypic superiority to the yield of grains can negatively affect the protein ratio. Of the cultivars studied TBIO Pioneiro stood out from the others regarding the general gluten strength in the 2012 crop and the TBIO Seleto was superior in the 2013 crop, however, the protein content did not show a significant association with the gluten strength, revealing that the concentration was not efficient to predict industrial quality.

Assuntos

RESUMO

Estratégias de fertilização nitrogenada com o emprego de dosagens crescentes demonstram efeitos favoráveis sobre a produtividade e qualidade dos grãos, entretanto têm sido reportado divergências em resultados com relação ao efeito de dosagens, épocas e parcelamentos de aplicação ao longo do ciclo de desenvolvimento da cultura. O objetivo deste estudo foi avaliar a produtividade e características de qualidade protéica em resposta ao manejo de adubação nitrogenada aplicada em cobertura nas cultivares TBIO Itaipu, TBIO Pioneiro, TBIO Quartzo e TBIO Seleto. O experimento foi conduzido em Coxilha RS, nos anos 2012 e 2013. O delineamento experimental utilizado foi em blocos casualizados com três repetições, em esquema fatorial (4 cultivares x 7 manejos). A dose total de N utilizada no trabalho foi de 140 kg ha-1, sendo 30 kg ha-1de N aplicados na semeadura e o restante em cobertura, conforme a época definida em cada tratamento. A produtividade de grãos das cultivares estudadas foi incrementada com a adubação nitrogenada aplicada de forma concentrada no tratamento T2 e manifestou correlação negativa com o conteúdo de proteínas, revelando que a superioridade genotípica para o rendimento de grãos pode afetar negativamente a proporção protéica. Das cultivares estudadas a cultivar TBIO Pioneiro se destacou das demais quanto a força geral de glúten na safra 2012 e a TBIO Seleto foi superior na safra 2013, entretanto, o conteúdo de proteína não evidenciou associação significativa com a força de glúten, revelando que a concentração de proteínas não foi eficiente para predizer a qualidade industrial.(AU)

Nitrogen fertilization strategies using increasing dosages demonstrate favorable effects on grain yield and quality; however, differences in results have been reported in relation to the effect of dosages, times and application schedules throughout the development cycle of the crop. The objective of this study was to evaluate the productivity and protein quality characteristics in response to nitrogen fertilization management applied to the cultivars TBIO Itaipu, TBIO Pioneiro, TBIO Quartzo and TBIO Seleto. The experimental design in randomized blocks with three replications, in a factorial scheme (4 cultivars x 7) handlings was used. The experiment was conducted in Coxilha, RS, during the agricultural years of 2012 and 2013. The total dose of N used in the present work was 140 kg ha-1, with 30 kg ha-1 of N being applied at sowing and remainder in coverage, for the time defined in each treatment. The grain yield of the studied cultivars was increased with the nitrogen fertilization applied in a concentrated way in the treatment T2 and showed a negative correlation with the protein content, showing that the genotypic superiority to the yield of grains can negatively affect the protein ratio. Of the cultivars studied TBIO Pioneiro stood out from the others regarding the general gluten strength in the 2012 crop and the TBIO Seleto was superior in the 2013 crop, however, the protein content did not show a significant association with the gluten strength, revealing that the concentration was not efficient to predict industrial quality.(AU)

Assuntos