Abstract This work aimed to develop extrudates enriched with açaí and evaluate the effect of this fruit on their physicochemical properties and bioactive constituents of these foods. Rice/corn (2 : 1) extrudates containing 0, 2, 4, and 6% of freeze-dried açaí were prepared using a twin-screw extruder and characterized towards proximate composition, the concentration of anthocyanin and carotenoids, and typical process-related extrudate characteristics. The addition of açaí increased the total anthocyanins (from 0 to 20.1 mg 100 g-1) and total carotenoid content (from 1.6 to 6.2 µg g-1). Açaí enrichment elevated the protein and mineral content by 6.3% and 32.2%, respectively. There was no significant difference between the samples regarding the expansion index. Higher incorporation of açaí resulted in crispier snacks extrudates and high total color difference (ΔE). Therefore, açaí (up to 6%) can be regarded as stable in the extrusion conditions applied and be used in extrudates to enhance their bioactive and nutritional properties, providing color and suitable physical characteristics. Açaí extrudates can serve as an alternative for consumers interested in convenience food with bioactive constituents.

Abstract The aim of this study was to develop snack bars nutritionally enriched with Spirulina and evaluate if there was acceptance of the sensorial attributes by schoolchildren. Snack bars enriched with Spirulina (2% and 6%) and a control formulation (0% Spirulina) were prepared. The samples were evaluated regarding nutritional content, microstructure, and sensorial characteristics. Furthermore, the study of stability during storage (30 days) was carried out. The addition of 2% and 6% of Spirulina provided a protein increase of 11.7% and 29.9%, respectively. The physicochemical and microbiological parameters remained stable during the storage of 30 days. Sensory evaluation showed that snack bars enriched with 6% Spirulina presented no significant difference (p > 0.05) compared to the control samples. We concluded that Spirulina can be used as a nutritive ingredient in snack bars designed for infant feeding without sensorial characteristics change.

Abstract Microalgae are photosynthetic microorganisms whose composition and biomass production can be influenced by manipulating the cultivation conditions employed. However, few studies have evaluated the effects of various cultivation conditions in autotrophic and mixotrophic conditions. The present work aimed to evaluate the effects of cultivation conditions on the cell growth and biosynthesis of fatty acids (FAs) by microalgae of the genus Chlorella in autotrophic and mixotrophic cultivation. Evaluation of the effects of the conditions was performed using an experimental design methodology. The highest values of maximum biomass concentration (Xmax) and maximum biomass productivity (Pmax) were obtained in autotrophic cultures. Palmitic acid was the FA obtained at the highest concentration in both cultivation modes. The concentrations of polyunsaturated FAs (PUFAs) ranged from 12.2 to 41.2% in autotrophic cultures and from 11 to 34.3% in the mixotrophic cultures. The variables photoperiod and sodium bicarbonate concentration showed the greatest influence on the Xmax, Pmax, and PUFA concentration in autotrophic and mixotrophic cultivations, respectively. This study verified that the selection of conditions and mode of cultivation contribute to the production of microalgal biomass and FA biosynthesis.

Abstract Carotenoids have a low solubility in water, and therefore their incorporation in foods is impaired. The nanoemulsions are able to protect these compounds and enhance bioavailability. The objective of this study was to develop nanoemulsions with added beta-carotene, evaluating the influence of process variables and the stability at a long storage period. To assess the effects of these variables a Box-Behnken design was performed. The best condition to form a stable emulsion was 7% (w.w-1) of surfactant and 40 °C. All formulations subjected to a thermal stress test remained stable after the test. The use of a higher concentration of soy lecithin (7%, w.w-1) in the development of emulsions conferred greater stability after a freeze-defrost cycle. Furthermore, with this concentration of surfactant, and using a high-speed homogenizer under conditions of 10,000 rpm, 30 °C, and 20 min of shaking time, it was possible to develop stable nanoemulsion with an average diameter of 429 nm. Moreover, the zeta potential indicated system stability. Thus, it was possible to obtain stable nanoemulsion without the use of subsequent equipment, which makes the process less expensive.

Abstract The biological assimilation of the sugars present in lignocellulosic residues has gained prominence since these residues are the most abundant and economic residues in nature. Thus, the objective of this work was to determine whether the use of D-xylose and L-arabinose as sources of carbon in Synechococcus nidulans and Spirulina paracas cultures affects the growth and production of proteins and carbohydrates. Kinetic growth parameters, pentose consumption, protein content and carbohydrates were evaluated. Synechococcus nidulans and Spirulina paracas consumed all concentrations of pentose used. The highest cellular concentration (1.37 g.L-1) and the highest protein productivity (54 mg.L-1.d-1) were obtained for Spirulina paracas, which was submitted to the addition of 38.33 mg.L-1 D-xylose and 1.79 mg.L-1 L-arabinose. The use of pentose promoted the accumulation of proteins for the studied microalgae. This is one of the first works to report protein bioaccumulation as a result of pentose addition.

Abstract Hydrophilic polymers can form hydrogels, which are able to absorb and retain as much water as one hundred times their weight. Polymers based on natural products have been drawing attention since they are biocompatible, biodegradable and nontoxic. The aims of this study were to produce and to characterize a biopolymer with superabsorbent properties from fish protein isolates. Hydrogels were produced from protein isolates from Whitemouth croaker processing wastes chemically modified. The extension of change in lysine residues, kinetics in water-uptake capacity, pH effect, ionic strength over the absorption of water by hydrogels and the behavior of the biopolymer when subject to successive hydration and dehydrations were investigated. Results showed that acid modified protein without ethanol treatment reached a maximum absorption of 103.25 gwater/gdry gel, while the same sample modified with ethanol reached 216.05 gwater/gdry gel.

RESUMO O uso de enzimas pelas indústrias possibilita o desenvolvimento de processos tecnológicos com eficiência similar aos realizados pela natureza, o que faz dessa tecnologia um dos campos mais promissores na síntese de compostos de alto valor agregado. O presente trabalho teve por objetivo estudar a produção de lipase por Burkholderia cepacia utilizando a metodologia de superfície de resposta. Foram utilizadas as variáveis concentrações de fonte de potássio, magnésio, óleo de soja, água de maceração de milho e pH. Foi observado que, dentro das concentrações utilizadas, o potássio, a água de maceração de milho e o óleo de soja influenciaram positivamente na produção de lipase. O Bioflo III se destacou dentre os biorreatores empregados para a produção da enzima, possivelmente devido a melhor distribuição dos fenômenos de transferência de massa e movimento, alcançando valores de até 2,43 U mL-1 em 120 horas de fermentação.

ABSTRACT The use of enzymes on an industrial scale has enabled the development of technological processes with an efficiency similar to those made by nature, which makes this technology one of the most promising fields in new technologies for synthesis of high-added value compounds. This paper aimed to study the production of lipase by Burkholderia cepacia using the response surface methodology. We used the following variables: concentrations of potassium, magnesium, soybean oil, corn steep liquor and pH. We observed that, among the used concentrations, potassium, corn steep liquor and soybean oil positively influenced the lipase production. Bioflo III showed the best performance among the bioreactors used for the enzyme production, possibly due to a better distribution of mass and movement transfer phenomena, reaching values of up to 2.43 U mL-1 at 120 hours of fermentation.

ABSTRACT The food, training, and health are crucial for a good performance in sports. Intense physical activity takes the athlete to maintain a very unstable balance between energy demand and consumption of nutrients. Spirulina microalga has a nutritional profile that renders it an ideal food supplement, because has high protein content, also contains vitamins, minerals, and pigments. In this context, the study aimed to develop, characterize and evaluate the stability of foods enhanced with Spirulina, which are intended for athletes. In this study, six different supplements were developed (electrolyte replenisher, muscle enhancer, and recovery supplement), without and with Spirulina. The electrolyte replenisher with Spirulina compared to the product without the microalga, showed an increase of 0.35% (w/w) in mineral content. The carbohydrates content of the developed recovery supplement with Spirulina was 2% (w/w) higher than the muscle enhancer without Spirulina. It was not observed increased in the nutritional content of muscle recovery when added Spirulina. However, it is known that Spirulina presents active compounds with important functions for the body. Thus, the composition of the foods satisfied the nutritional needs of athletes. Regarding the stability of developed foods, the shelf life was estimated between 9 and 11 months.

ABSTRACT Spirulina is a microalgal genre that has the capacity to produce various bioproducts with applications in several areas including the energy sector. The study aimed to assess the ability of CO2 biofixation, biodiesel and other biocompounds production by Spirulina sp LEB 18 cultured in air-lift photobioreactor. The microalgae presented a rich macronutrient composition: protein (47.3%), carbohydrates (13.4%) and a high lipid content (32.7%) in a media with nitrogen reduction, CO2 using air-lift photobiorector. Furthermore, 160 mg.L.d-1 of CO2 was biofixed, generating a maximum biomass yield of 0.02 g.L.d-1. The lipids evaluated for biodiesel production presented a theoretical yield of 19.8% for in situ transesterification and 47.9% for conventional transesterification. The microalgal biomass has potential for producing biodiesel that can be applied instead or in mixture with traditional diesel fuel. The study of obtaining energy associated with the production of other high value-added biocompounds from the microalgal biomass is of high importance because in this way, the viability of biofuel production by this microorganism can be increased.

ABSTRACT Microalgae are efficient at using solar energy to turn CO2 and nutrients into biomass containing lipids, proteins, carbohydrates and other compounds that may be used to produce bioproducts for human and animal consumption and pharmaceutical use. The aim of this study was to assess the effect of the NaNO3 and NaCl concentration on the growth kinetics, the biomass composition and the ability to biofix CO2 using the microalga Spirulina sp. LEB 18. The assays were carried out according to a 22 central composite design (CCD) with different concentrations of NaNO3 (1.25, 1.88 and 2.50 g L-1) and NaCl (1.00, 15.0 and 30.0 g L-1). The assays were carried out in 2 L vertical tubular photobioreactors at 30°C, 12 h light/dark and an injection of 12.0% v/v of CO2 at 0.3 vvm. The best growing results (Xmax = 1.60 g L-1, Pmax = 0.109 g L-1 d-1, μmax = 0.208 d-1) and CO2 biofixation rate (197.4 mg L-1 d-1) were observed in the assay with 1.25 g L-1 NaNO3 and 1.00 g L-1 NaCl. Increasing the NaCl concentration produced biomass with a higher carbohydrate content, while increasing the NaNO3 concentration reduced the protein concentration. According to the results, in addition to using Spirulina as a source of protein, it can also be used as a source of carbohydrates and to biologically remove CO2 from the atmosphere.

Abstract Microalgae are studied because of their biotechnological potential. The growth of microalgae aims at obtaining natural compounds. Due to the large amount of accumulated polymer waste, one of the solutions is the use of biodegradable polymers. The objective of this work was to select biopolymer-producing microalgae and to study the cell growth phase in which maximum production occurs. Microalgae Cyanobium sp., Nostoc ellipsosporum, Spirulina sp. LEB 18 and Synechococcus nidulans were studied. The growth was carried out in closed 2 L photobioreactors kept in a chamber thermostated at 30 °C with an illuminance of 41.6 μmolphotons.m-2.s-1 and a 12 h light/dark photoperiod. The biopolymers were extracted at times of 5, 10, 15, 20 and 25 d. The microalgae that had the highest yields were Nostoc ellipsosporum and Spirulina sp. LEB 18 with crude biopolymer efficiency of 19.27 and 20.62% in 10 and 15 d, respectively, at the maximum cell growth phase.

Abstract This study was conducted to develop PCL nanofibers with the incorporation of microalgae biopeptides and to evaluate the stability of chicken meat cuts during storage. PCL and PCL/biopeptides nanofibers were formed by electrospinning method, and the diameters obtained were 404 and 438 nm, respectively. The tensile strength, elongation, melting temperature and thermal stability of biopeptide-added PCL nanofibers were 0.245 MPa, 64%, 56.8 °C and 318 °C, respectively. PCL/biopeptide nanofibers showed a reducing power of 0.182, inhibition of 22.6% and 12.4% for DPPH and ABTS radicals, respectively. Chicken meat cuts covered by the PCL/biopeptide nanofibers showed 0.98 mgMDA∙kg-1 and 25.8 mgN∙100g-1 for TBARS and N-BVT analysis, respectively. Thus, the PCL/biopeptide nanofibers provided greater stability to the product and control of oxidative processes ensuring the product quality maintenance during the 12 d of storage.

Abstract Nowadays the demand for practical food like snacks increases worldwide, however the nutritional value in most these formulations is reduced. Due to its chemical composition with high protein concentration, the microalga Spirulina has been used on the production of enriched foods. The present study aimed to evaluate the effects of Spirulina sp. LEB 18 addition on snacks formulations and extrusion conditions on the physicochemical and structural properties of snacks. Protein concentration and physical properties such as expansion index, bulk density, hardness, water absorption index, water solubility index and color were determined. The results showed that the addition of Spirulina sp. LEB 18, temperature in the last zone of the extruder and feed moisture influenced the product responses. The increase in feed moisture increased the hardness, bulk density and water absorption index of the snacks. Higher concentrations of microalga produced snacks with higher protein content, total color difference (ΔE) and compact structure. The addition of 2.6% Spirulina produced snacks with up to 11.3% protein and with adequate physical and structural properties for consumption. Thus, snacks containing Spirulina are an alternative to the demand for healthy food of practical consumption.

ABSTRACT The food, training, and health are crucial for a good performance in sports. Intense physical activity takes the athlete to maintain a very unstable balance between energy demand and consumption of nutrients. Spirulina microalga has a nutritional profile that renders it an ideal food supplement, because has high protein content, also contains vitamins, minerals, and pigments. In this context, the study aimed to develop, characterize and evaluate the stability of foods enhanced with Spirulina, which are intended for athletes. In this study, six different supplements were developed (electrolyte replenisher, muscle enhancer, and recovery supplement), without and with Spirulina. The electrolyte replenisher with Spirulina compared to the product without the microalga, showed an increase of 0.35% (w/w) in mineral content. The carbohydrates content of the developed recovery supplement with Spirulina was 2% (w/w) higher than the muscle enhancer without Spirulina. It was not observed increased in the nutritional content of muscle recovery when added Spirulina. However, it is known that Spirulina presents active compounds with important functions for the body. Thus, the composition of the foods satisfied the nutritional needs of athletes. Regarding the stability of developed foods, the shelf life was estimated between 9 and 11 months.

ABSTRACT Nanofibers are materials that present high elasticity, strength, porosity and surface-area-to-volume ratio. The electrospinning method is the most widely adopted technique for forming polymeric nanofibers due to repeatability, easy scale-up process and production of long and continuous nanofibers. This method produces nanofibers with diameters ranging from 10 nm to 1000 nm. The process is regulated by many parameters which significantly affecting the morphology of the nanofibers, and through the proper handling of these parameters are obtained desired nanofibers in morphology and diameters. Based on this, the objective of this work was to evaluate the size and morphology of nanofibers obtained by different conditions of the electrospinning process. The electrospinning technique will be utilized to produce nanofibers with polyacrylonitrile (PAN) polymer and solvent N, N-dimethylformamide (DMF). The polymer solutions (10% (w/v)) were injected through of the capillary with diameter 0.45; 0.55; 0.70 and 0.80 mm. The distances from the collector to the capillary were tested between 100 and 200 mm, voltage between 15 and 25 kV, and feed rate of the solution between 100 and 1000 µL/h. All of the tests were conducted at 22 °C with the relative humidity level controlled at 65±1%. The morphology and size of nanofibers were evaluated by Scanning Electron Microscopy (SEM). Thus, the development of nanofibers with small diameter and high pore volume facilitate bioactive molecules loading and / or transport of nutrients and wastes, and allow the polymeric nanofibers become important class of biomaterials.