Outdoor pilot-scale cultivation of Spirulina sp. LEB-18 in different geographic locations for evaluating its growth and chemical composition.

This study evaluated whether outdoor cultivation of Spirulina sp. in different geographical locations affected its growth and biomass quality, with respect to the chemical composition, volatile compound and heavy metal content, and thermal stability. The positive effect of solar radiation and temperature on biomass productivity in Spirulina sp. cultivated in the northeast was directly related to its improved nutritional characteristics, which occurred with an increase in protein, phycocyanin, and polyunsaturated fatty acid (mainly γ-linolenic) content. The biomass produced in Northeast and South Brazil showed high thermal stability and had volatile compounds that could be used as biomarkers of Spirulina, and their parameters were within the limits of internationally recognized standards for food additives; hence, they have been considered safe foods. However, the growth of crops in south Brazil occurred at lower rates due to low temperatures and luminous intensities, indicative of the robustness of microalgae in relation to these parameters.

Antioxidant, antimicrobial, antiparasitic, and cytotoxic properties of various Brazilian propolis extracts.

Propolis is known for its biological properties and its preparations have been continuously investigated in an attempt to solve the problem of their standardization, an issue that limits the use of propolis in food and pharmaceutical industries. The aim of this study was to evaluate in vitro antioxidant, antimicrobial, antiparasitic, and cytotoxic effects of extracts of red, green, and brown propolis from different regions of Brazil, obtained by ethanolic and supercritical extraction methods. We found that propolis extracts obtained by both these methods showed concentration-dependent antioxidant activity. The extracts obtained by ethanolic extraction showed higher antioxidant activity than that shown by the extracts obtained by supercritical extraction. Ethanolic extracts of red propolis exhibited up to 98% of the maximum antioxidant activity at the highest extract concentration. Red propolis extracts obtained by ethanolic and supercritical methods showed the highest levels of antimicrobial activity against several bacteria. Most extracts demonstrated antimicrobial activity against Staphylococcus aureus. None of the extracts analyzed showed activity against Escherichia coli or Candida albicans. An inhibitory effect of all tested ethanolic extracts on the growth of Trypanosoma cruzi Y strain epimastigotes was observed in the first 24 h. However, after 96 h, a persistent inhibitory effect was detected only for red propolis samples. Only ethanolic extracts of red propolis samples R01Et.B2 and R02Et.B2 showed a cytotoxic effect against all four cancer cell lines tested (HL-60, HCT-116, OVCAR-8, and SF-295), indicating that red propolis extracts have great cytotoxic potential. The biological effects of ethanolic extracts of red propolis revealed in the present study suggest that red propolis can be a potential alternative therapeutic treatment against Chagas disease and some types of cancer, although high activity of red propolis in vitro needs to be confirmed by future in vivo investigations.

Chemical Composition and Biological Activity of Extracts Obtained by Supercritical Extraction and Ethanolic Extraction of Brown, Green and Red Propolis Derived from Different Geographic Regions in Brazil.

The variations in the chemical composition, and consequently, on the biological activity of the propolis, are associated with its type and geographic origin. Considering this fact, this study evaluated propolis extracts obtained by supercritical extraction (SCO2) and ethanolic extraction (EtOH), in eight samples of different types of propolis (red, green and brown), collected from different regions in Brazil. The content of phenolic compounds, flavonoids, in vitro antioxidant activity (DPPH and ABTS), Artepillin C, p-coumaric acid and antimicrobial activity against two bacteria were determined for all extracts. For the EtOH extracts, the anti-proliferative activity regarding the cell lines of B16F10, were also evaluated. Amongst the samples evaluated, the red propolis from the Brazilian Northeast (states of Sergipe and Alagoas) showed the higher biological potential, as well as the larger content of antioxidant compounds. The best results were shown for the extracts obtained through the conventional extraction method (EtOH). However, the highest concentrations of Artepillin C and p-coumaric acid were identified in the extracts from SCO2, indicating a higher selectivity for the extraction of these compounds. It was verified that the composition and biological activity of the Brazilian propolis vary significantly, depending on the type of sample and geographical area of collection.

Determination of Parameters for the Supercritical Extraction of Antioxidant Compounds from Green Propolis Using Carbon Dioxide and Ethanol as Co-Solvent.

The aim of this study was to determine the best processing conditions to extract Brazilian green propolis using a supercritical extraction technology. For this purpose, the influence of different parameters was evaluated such as S/F (solvent mass in relation to solute mass), percentage of co-solvent (1 and 2% ethanol), temperature (40 and 50°C) and pressure (250, 350 and 400 bar) using supercritical carbon dioxide. The Global Yield Isotherms (GYIs) were obtained through the evaluation of the yield, and the chemical composition of the extracts was also obtained in relation to the total phenolic compounds, flavonoids, antioxidant activity and 3,5-diprenyl-4-hydroxicinnamic acid (Artepillin C) and acid 4-hydroxycinnamic (p-coumaric acid). The best results were identified at 50°C, 350 bar, 1% ethanol (co-solvent) and S/F of 110. These conditions, a content of 8.93±0.01 and 0.40±0.05 g/100 g of Artepillin C and p-coumaric acid, respectively, were identified indicating the efficiency of the extraction process. Despite of low yield of the process, the extracts obtained had high contents of relevant compounds, proving the viability of the process to obtain green propolis extracts with important biological applications due to the extracts composition.

Caracterização e avaliação das propriedades antioxidantes de filmes biodegradáveis incorporados com polpas de frutas tropicais / Characterization and evaluation of the antioxidant properties of biodegradable films incorporated with tropical fruit pulps

O trabalho teve como objetivo desenvolver e caracterizar embalagens ativas flexíveis formuladas pela incorporação de polpas de frutas tropicais a uma matriz polimérica de amido de mandioca plastificada com glicerol, avaliando as propriedades mecânicas, de barreira e a eficácia antioxidante destas embalagens durante o armazenamento. As embalagens foram produzidas por casting, com concentrações fixas de amido de mandioca (4,5%) e glicerol (1,0%), e concentrações de polpa de manga, acerola e seriguela entre 5 e 20%. Foram caracterizadas as propriedades de barreira (espessura, umidade, sólidos totais, atividade de água e solubilidade) e propriedades mecânicas dos filmes. A ação antioxidante dos aditivos incorporados foi avaliada através do armazenamento do azeite de dendê embalado com os filmes contendo os aditivos naturais, monitorando a sua oxidação por 40 dias, sob condições de oxidação acelerada (63%UR/30°C). A adição das polpas de frutas aos filmes promoveu um aumento da resistência mecânica. Os filmes com as polpas incorporadas desempenharam efeito antioxidante sobre o azeite de dendê durante os 40 dias de armazenamento, podendo ser aplicados para o controle da oxidação deste produto.

This research aimed to develop and characterize flexible active packages formulated by the incorporation of pulps from tropical fruits to a polymeric matrix of manioc starch, plasticized with glycerol. The mechanical properties, the barriers and the antioxidant efficacy of these packages were evaluated during storing. The packages were produced by casting, with fixed concentrations of manioc starch (4.5%) and glycerol (1.0%), and variable concentrations of mango, acerola and seriguela pulps between 5 and 20%. The barrier properties (width, humidity, total solids, water activity and solubility) and the mechanical properties of the films were evaluated. The antioxidant action of the additives incorporated was evaluated through the storage of palm oil packed with the films containing the natural additives. Its oxidation was monitored for 40 days, under conditions of accelerated oxidation (63%UR/30ºC). The addition of fruit pulps to the films promoted an increase of the mechanical resistance. The films with the added pulps performed an antioxidant effect on the palm oil during the 40 days storage, which could be applied for the oxidation control of this product.

Caracterização e avaliação das propriedades antioxidantes de filmes biodegradáveis incorporados com polpas de frutas tropicais / Characterization and evaluation of the antioxidant properties of biodegradable films incorporated with tropical fruit pulps

O trabalho teve como objetivo desenvolver e caracterizar embalagens ativas flexíveis formuladas pela incorporação de polpas de frutas tropicais a uma matriz polimérica de amido de mandioca plastificada com glicerol, avaliando as propriedades mecânicas, de barreira e a eficácia antioxidante destas embalagens durante o armazenamento. As embalagens foram produzidas por casting, com concentrações fixas de amido de mandioca (4,5%) e glicerol (1,0%), e concentrações de polpa de manga, acerola e seriguela entre 5 e 20%. Foram caracterizadas as propriedades de barreira (espessura, umidade, sólidos totais, atividade de água e solubilidade) e propriedades mecânicas dos filmes. A ação antioxidante dos aditivos incorporados foi avaliada através do armazenamento do azeite de dendê embalado com os filmes contendo os aditivos naturais, monitorando a sua oxidação por 40 dias, sob condições de oxidação acelerada (63%UR/30°C). A adição das polpas de frutas aos filmes promoveu um aumento da resistência mecânica. Os filmes com as polpas incorporadas desempenharam efeito antioxidante sobre o azeite de dendê durante os 40 dias de armazenamento, podendo ser aplicados para o controle da oxidação deste produto.(AU)

This research aimed to develop and characterize flexible active packages formulated by the incorporation of pulps from tropical fruits to a polymeric matrix of manioc starch, plasticized with glycerol. The mechanical properties, the barriers and the antioxidant efficacy of these packages were evaluated during storing. The packages were produced by casting, with fixed concentrations of manioc starch (4.5%) and glycerol (1.0%), and variable concentrations of mango, acerola and seriguela pulps between 5 and 20%. The barrier properties (width, humidity, total solids, water activity and solubility) and the mechanical properties of the films were evaluated. The antioxidant action of the additives incorporated was evaluated through the storage of palm oil packed with the films containing the natural additives. Its oxidation was monitored for 40 days, under conditions of accelerated oxidation (63%UR/30ºC). The addition of fruit pulps to the films promoted an increase of the mechanical resistance. The films with the added pulps performed an antioxidant effect on the palm oil during the 40 days storage, which could be applied for the oxidation control of this product.(AU)

Bi-functional biobased packing of the cassava starch, glycerol, licuri nanocellulose and red propolis.

The aim of this study was to characterize and determine the bi-functional efficacy of active packaging films produced with starch (4%) and glycerol (1.0%), reinforced with cellulose nanocrystals (0-1%) and activated with alcoholic extracts of red propolis (0.4 to 1.0%). The cellulose nanocrystals used in this study were extracted from licuri leaves. The films were characterized using moisture, water-activity analyses and water vapor-permeability tests and were tested regarding their total phenolic compounds and mechanical properties. The antimicrobial and antioxidant efficacy of the films were evaluated by monitoring the use of the active films for packaging cheese curds and butter, respectively. The cellulose nanocrystals increased the mechanical strength of the films and reduced the water permeability and water activity. The active film had an antimicrobial effect on coagulase-positive staphylococci in cheese curds and reduced the oxidation of butter during storage.