Phytochemical characterization and antimicrobial activity of Cymbopogon citratus extract for application as natural antioxidant in fresh sausage.

The development of natural additives is considered an important research topic. In this work, the use of Cymbopogon citratus (CC) extract as a natural additive for chicken sausage refrigerated was investigated. The CC extract was characterized by electrospray ionization with high-resolution time-of-flight mass spectrometry (ESI-ToF-MS) and the identified compounds were directly related to the antioxidant activity demonstrated by CC in the fresh sausage. In total, 31 phytochemical compounds were identified, and 27 of these still were not described in the literature for CC. The antimicrobial activity showed that CC extract is a potential antibacterial agent. Besides, the results showed that CC extract reduced lipid oxidation compared to synthetic additive. The sensorial characteristics were maintained, demonstrating good acceptability by the consumer. The results confirmed that CC can keep the quality of chicken sausage refrigerated for up to 42 days of storage.

Evaluation of the chemical, sensory and volatile composition of sapota-do-Solimões pulp at different ripening stages.

The aim of this study was to evaluate sapota-do-Solimões (Quararibea cordata Vischer) during ripening, verifying physical, chemical and sensory parameters, bioactive and volatile compounds. The pulps were obtained from fruits from the city of Tefé, AM, Brazil and collected at three different ripening stages: unripe (U); ripe collected from the tree (R); and ripe collected from the ground (RG). The biometric and quality parameters, total carotenoids, total phenolic compounds, chemical composition, fatty acids and volatile profiles were analyzed. The sapota-do-Solimões fruits showed positive correlation with evolution of ripened stage of the variables water activity (0.977-0.996), pH (6.53-7.04), soluble solids (8.53-12.65%), total sugars (4.26-7.98%), reducing sugars (0.99-3.14%), non-reducing sugars (3.11-4.60%) and total carotenoids (0.67-1.24 µg/g). Longitudinal and transversal diameters and fruit mass were higher in RG compared with the other ripening stages. The lipids contents increased from 0.16% for U to 0.30% for RG. The palmitic (47.1-86.4), stearic (3.1-5.9), oleic (44.4-131.1) and vaccenic (25.3-37.7) increased while palmitoleic (16.4-10.0) and linoleic (6.6-3.5) decreased. A total of 86 volatile compounds were identified, of which 57 were found in U fruits, 54 in R fruits and 68 in RG fruits. The classes most relevant found were alcohols, aldehydes, esters, ketones, furans and terpenes. An increase in the terpenes (0.4-5.6%) from U fruit to RG fruit showed potentials odoriferous characteristics, as well the increased furans (2.3-20.9%) from U fruit to RG fruit that characterized a sweet and fruity aroma. Consumers didn't detect differences in sensory attributes of the analyzed R and RG fruits. The data showed that the chemical and volatile composition of the fruit was influenced by the ripening stage of the pulp. This is the first time that a study about ripening in sapota-do-Solimões has been reported.

Acute Consumption of Bordo Grape Juice and Wine Improves Serum Antioxidant Status in Healthy Individuals and Inhibits Reactive Oxygen Species Production in Human Neuron-Like Cells.

Few studies investigated the biological effects of American grape cultivars. We investigated the metabolic response after acute consumption of grape juice or wine from Bordo grapes (Vitis labrusca) in a placebo-controlled crossover study with fifteen healthy volunteers. Blood samples were collected 1 hour after the intake of 100 mL of water, juice, or wine to measure TBARS, ABTS, FRAP, glucose, and uric acid levels. To evaluate differences in cellular response, intracellular reactive species production (DCFH-DA) and metabolic mitochondrial viability (MTT) were assessed after exposure of human neuron-like cells (SH-SY5Y) to juice or wine. Glycemia was reduced after juice or wine consumption, whereas blood levels of uric acid were reduced after juice consumption but increased after wine consumption. Juice and wine consumption reduced plasma lipid peroxidation and increased plasma antioxidant capacity (ABTS and FRAP assays). Furthermore, juice inhibited H2O2-induced intracellular production of reactive species (RS) and increased the viability of SH-SY5Y cells. In contrast, wine (dealcoholized) exhibited a per se effect by inducing the production of RS and reducing cell viability. These results indicate a positive impact of acute consumption of Bordo juice and wine on human oxidative status, whereas only juice had protective effects against oxidative stress-induced cytotoxicity.

Extraction of bioactive compounds of lemongrass, antioxidant activity and evaluation of antimicrobial activity in fresh chicken sausage / Extração de compostos bioativos de capim-limão, atividade antioxidante e avaliação da atividade antimicrobiana em linguiça frescal de frango

ABSTRACT: The aim of this work was to determine the best extraction condition of bioactive compounds from lemongrass (Cymbopogon citratus), using the conventional method and ultrasonic assisted extraction, varying the temperature, in order to evaluate the antioxidant activity and the antimicrobial activity of the extract with higher antioxidant power in fresh chicken sausages during the storage period. The extracts were obtained by the conventional method (solvent extraction) and by ultrasound assisted extraction, varying the temperature (20°C, 40°C and 60°C). Phenolic compounds, total flavonoids and antioxidant activity were measured by the DPPH, FRAP, ORAC methods. Conventional extraction and ultrasound methods influenced the phenolic and total flavonoid content at all tested temperatures. Conventional and ultrasonic methods did not influence the IC50 at temperatures of 40°C and 60°C. The antioxidant activity by the DPPH method and by the FRAP method was superior in the conventional method at the temperature of 60°C, however by the ORAC method the best results were in the extraction by ultrasound. The results demonstrate that the conventional extraction at 60ºC was better to obtain extracts of lemongrass with greater amount of bioactive compounds. The antimicrobial capacity evaluated in sausage of fresh chicken showed that in the concentration of 1.0% of the extract protected the product as the growth of mesophilic aerobes and against the growth of psychrotrophic bacteria. Lemongrass can be considered as a natural alternative to obtain extracts rich in bioactive compounds, with antioxidant activity and high antimicrobial capacity.

RESUMO: O objetivo deste trabalho foi determinar a melhor condição de extração de compostos bioativos do capim-limão (Cymbopogon citratus), usando o método convencional e extração assistida por ultrassom, em diferentes temperaturas, a fim de avaliar a atividade antioxidante e a atividade antimicrobiana do extrato com maior poder antioxidante em linguiças de frango frescal durante o período de armazenamento. Os extratos foram obtidos pelo método convencional (extração com solvente) e por extração assistida por ultrassom, variando a temperatura (20°C, 40°C e 60°C). Foram medidos os compostos fenólicos, flavonoides totais e atividade antioxidante pelos métodos DPPH, FRAP, ORAC. Os métodos de extração convencional e ultrassom influenciaram no teor de fenólicos e flavonoides totais em todas as temperaturas testadas. Os métodos convencional e ultrassom não influenciaram no IC50 nas temperaturas de 40oC e 60oC. A atividade antioxidante pelo método DPPH e pelo método FRAP foi superior no método convencional na temperatura de 60°C, entretanto pelo método ORAC os melhores resultados foram na extração por ultrassom. Os resultados demonstram que a extração convencional a 60ºC foi melhor para obter extratos de capim-limão com maior quantidade de compostos bioativos. A capacidade antimicrobiana avaliada em linguiça frescal mostrou que na concentração de 1,0% do extrato protegeu o produto quanto o crescimento de aeróbios mesófilos e contra o crescimento de bactérias psicrotróficas. O capim-limão pode ser considerado uma alternativa natural para obtenção de extratos ricos em compostos bioativos, com atividade antioxidante e elevada capacidade antimicrobiana.

Ultrasonic assisted extraction to obtain bioactive, antioxidant and antimicrobial compounds from marcela / Extração assistida por ultrassom para obtenção de compostos bioativos, antioxidantes e antimicrobianos de marcela

ABSTRACT: The aim of this study was to evaluate the effect of extraction conditions on bioactive compounds, as well as on antioxidant activity, and the antimicrobial activity of the extracts with the highest antioxidant characteristics. The extracts were obtained by conventional method and ultrasound-assisted extraction at various temperatures (20°C, 40°C and 60°C). Total phenolics, total flavonoids, antimicrobial activity and antioxidant activity were quantified by the methods of DPPH, FRAP, and ORAC, respectively. The conventional extraction method and ultrasound method influenced the phenolic content at all the tested temperatures. Flavonoids were not influenced by extraction methods. The antioxidant activity (DPPH) was highest in the ultrasonic method at temperatures of 40°C and 60°C; however, in the case of the FRAP method the best results were for the conventional extraction method. The conventional and ultrasonic methods did not influence the IC50 at temperatures of 20°C and 40°C, but using ORAC the antioxidant activity was influenced by the methods at all temperatures. The extract obtained at 60°C by the ultrasound method had high antimicrobial action in relation to the strains of Salmonella sp., Escherichia coli, and Staphylococcus aureus. Extraction ultrasonic-assisted can be considered adequate to obtain extracts of marcela, which are rich in bioactive compounds with high antioxidant activity.

RESUMO: O objetivo deste trabalho foi avaliar o efeito das condições de extração sobre os compostos bioativos, bem como sobre a atividade antioxidante e atividade antimicrobiana do extrato com maior característica antioxidante. Os extratos foram obtidos pelo método convencional e extração assistida por ultrassom, variando a temperatura (20oC, 40oC e 60oC). Foram quantificados os fenólicos totais, flavonóides totais, a atividade antimicrobiana, e atividade antioxidante pelos métodos DPPH, FRAP, e ORAC. Os métodos de extração convencional e ultrassom influenciaram no teor de fenólicos em todas as temperaturas testadas. Os flavonóides não sofreram influência dos métodos de extração. A atividade antioxidante (DPPH) foi superior no método ultrassom nas temperaturas de 40°C e 60°C, entretanto pelo método FRAP os melhores resultados foram na extração convencional. Os métodos convencional e ultrassom não influenciaram no IC50 nas temperaturas de 20oC e 40oC, mas a atividade antioxidante pelo método ORAC sofreu influencia dos métodos em todas as temperaturas. O extrato obtido a 60°C pelo método ultrassom possui elevada ação antimicrobiana frente a cepas de Salmonella sp., Escherichia coli, e Staphylococcus aureus. A extração assistida por ultrassom pode ser considerada adequada para obtenção de extratos de marcela, que são ricos em compostos bioativos com alta atividade antioxidante.

Characterization of physiochemical and microbiological properties, and bioactive compounds, of flour made from the skin and bagasse of kiwi fruit (Actinidia deliciosa).

The objective of this study was to analyze the physicochemical and microbiological properties, as well as the bioactive compounds, of flour made from the skin and bagasse of two varieties (Bruno and Monty) of kiwi fruit (Actinidia deliciosa) at two stages of maturation. The flour made with kiwi fruit peel from both varieties showed higher levels of bioactive compounds and antioxidant activity that the flour made with bagasse from both varieties. The flour made with green kiwi fruit skin from the Bruno variety had higher DPPH values and levels of phenolic compounds (1262.34 mg GAE/100g flour), while the Monty variety showed higher FRAP values, vitamin C (189.06 mg/100g flour), flavonoids (486.47 mg/100g flour), chlorophylls (12.13 mg/100g flour) and carotenoids (246.91 µg/100g flour). Flour made from kiwi fruit bagasse can be used to reduce agro-industrial waste. This flour is a promising ingredient which can be used to enrich products providing dietary fiber and bioactive compounds, as well as antioxidant action.