How Information on Superfoods Changes Consumers’ Attitudes: an Explorative Survey Study

Increasing interest in healthy habits has created the market for what is commonly called “superfoods.” The goal of this study was to explore Swiss consumers’ initial and final attitudes toward superfoods as well as their change in attitude toward those foods after being provided selected information. A questionnaire survey was conducted to explore the individual traits of the respondents. The attitudes were assessed at the beginning and end of the survey. Four multiple regression analyses were performed. The results showed that consumers perceiving superfoods’ health benefits and expressing an interest in organic foods were associated with initial and positive attitudes. These predictors remained significantly related to the positive attitude at the end of the survey. Sociodemographic predictors (age and place of residence) were significant factors, with older people and individuals who lived in urban centers showing a higher propensity to improve their attitudes toward superfoods. Individuals with lower perceptions about the benefits of superfoods being healthy and lower levels of cultural participation showed a negative attitude change. Given that this study aims to shed light on the variables that influence the behavior of Swiss consumers toward the superfoods trend, it fills a significant gap in the literature

Obtenção e aplicação de biossurfactantes

Biossurfactantes são compostos ativos em superfícies produzidos por microrganismos e que têm recebido crescente interesse nas últimas décadas pelas vantagens que possuem sobre os surfactantes químicos, tais como biodegrabilidade, baixa toxicidade, produção a partir de fontes renováveis, funcionalidade sob condições extremas de pH e temperatura, estabilidade, entre outros. O potencial de aplicação dos biossurfactantes baseia-se em suas propriedades funcionais, que incluem emulsificação, de-mulsificação, separação, solubilização e redução da tensão superficial. Essas propriedades são aplicadas na agricultura, na construção civil, em indústrias de alimentos, papel, metal, têxteis e farmacêuticas, apresentando seu maior potencial de aplicação na indústria petrolífera, principalmente na limpeza de tanques, na recuperação melhorada de petróleo e em casos de biorremediação, como em derramamentos de óleos em ecossistemas aquáticos. Os microrganismos para a produção de biossurfactantes podem ser bactérias, fungos filamentosos ou leveduras, sendo os principais tipos de biossurfactantes produzidos, os glicolipídios, fosfolipídios, lipossacarídios, lipopeptídios, ácidos graxos e lipídios neutros. Objetiva-se neste artigo revisar os principais aspectos envolvidos na obtenção dos biossurfactantes, os tipos de biossurfactantes produzidos e o potencial de aplicação dos mesmos. Palavras-chave: biossurfactantes, biorremediação, microrganismos. ABSTRACT Application and obtention of biosurfactants Biosurfactants are biological surface-active compounds produced by microorganisms that have been gaining prominence in the last decades due to their advantagens of biodegradability, low toxicity, production on renewable resources, functionality under extreme conditions of pH and temperature, stability and many others. These potential are based on their functional properties of emulsification, de-mulsification, separation, solubilization and surface tension reduction. It presents apllications in many industries as food, cosmetic, pharmaceutical, metal, textile, paper and in the petrol industry, mainly in oil storage tank clean-up, enhanced oil-recovery and oil pollution control. The biosurfactants-producing microorganisms can be bacteria, yeasts and molds, which can produce many kinds of biosurfactants, as glicolipids, phospholipids, liposaccharides, lipopeptides, fatty acids and neutral lipids. The purpose of this paper was to review the principal aspects involved in the obtention of biosurfactants, the biosurfactant-producing microorganisms and their potential of application. Key-words: biosurfactants, bioremediation, microorganisms

Lipid content and Chlorella homosphaera biomass grown under heterotrophic conditions and different carbon and nitrogen concentrations

O crescente interesse no estudo do cultivo de microalgas tem sido realizado visando á produção de biomassa tanto para uso na elaboração de alimentos quanto para a obtenção de compostos bioativos e medicinais com alto valor no mercado mundial. Estes são empregados especialmente no desenvolvimento de alimentos funcionais, por suas propriedades nutricionais e farmacêuticas. O objetivo deste estudo foi avaliar o efeito da concentração das fontes de carbono (glicose, C6H12O6) e nitrogênio (N-NO3) no crescimento heterotrófico e na produtividade lipídica da microalga Chlorella homosphaera. O planejamento fatorial fracionário utilizado foi do tipo 32, o qual totaliza 9 combinações, das quais foram utilizadas apenas 5 combinações sendo uma delas em triplicata. Os fatores de estudo foram as concentrações de glicose (5, 10 e 15 g.L-1) e de N-NO3 (82,5; 165 e 247,5 mg.L-1) e as respostas analisadas foram as concentrações de lipídeos totais e de biomassa. O cultivo realizado com 5 g.L-1 de glicose e 247,5 mg.L-1 de N-NO3 foi o que apresentou maior produção de biomassa (1,22 g.L-1) e maior produtividade lipídica (13,07 mg.L-1.d-1), com predominância dos ácidos graxos palmítico (C16:0 - 23,6 %p/p) e linoléico (C18:1n9 - 22,4 %p/p). A interação entre a concentração de glicose e de N-NO3 influenciou significativamente as respostas concentração de lipídeos totais e a concentração máxima de biomassa. A microalga em estudo produziu a maior concentração de lipídeos quando cultivada com a menor concentração de glicose associada a maior concentração de nitrogênio do planejamento experimental, o que é muito promissor para a indústria.The increasing interest in the study of microalgae cultivation has been oriented to biomass production in order to use it in food preparation, as well as in bioactive compounds with high medicinal value in the world markets. They are especially used in functional food development, owing to their nutritional and pharmaceutical properties. The aim of this study was to evaluate the effect of different concentrations of the carbon source (glucose) and nitrogen source (N-NO3) in heterotrophic growth and lipid productivity of microalga Chlorella homosphaera. The fractional factorial design used was of type 32, which offers 9 combinations, only 5 were used and one of them in triplicate. The factors were glucose (5, 10 and 15 g.L-1) and N-NO3 (82.5; 165 and 247.5 mg.L-1) concentrations and the response variables were the total lipid and the biomass concentrations. The treatment with 5 g.L-1 of glucose and 247.5 mg.L-1 of N-NO3 showed the highest biomass yield (1.22 g.L-1) and the highest lipid productivity (13.07 mg.L-1.d-1), predominantly composed of palmitic (C16:0 - 23.6 %w/w) and linoleic (C18:1n9 - 22.4 %w/w) fatty acids. The interaction between the concentration of glucose and N-NO3 concentration influenced significantly the responses of total lipids and the maximum concentration of biomass. The microalga studied produced a higher concentration of lipids when grown with the lowest concentration of glucose associated with a higher concentration of nitrogen experimental design, which is very promising at the industrial.Facultad de Ciencias Agrarias y Forestale

Extruded snacks enriched with açaí berry: physicochemical properties and bioactive constituents

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

Effect of the Carbon Concentration, Blend Concentration, and Renewal Rate in the Growth Kinetic of Chlorella

The microalgae cultivation can be used as alternative sources of food, in agriculture, residual water treatment, and biofuels production. Semicontinuous cultivation is little studied but is more cost-effective than the discontinuous (batch) cultivation. In the semicontinuous cultivation, the microalga is maintained in better concentration of nutrients and the photoinhibition by excessive cell is reduced. Thus, biomass productivity and biocompounds of interest, such as lipid productivity, may be higher than in batch cultivation. The objective of this study was to examine the influence of blend concentration, medium renewal rate, and concentration of sodium bicarbonate on the growth of Chlorella sp. during semicontinuous cultivation. The cultivation was carried out in Raceway type bioreactors of 6 L, for 40 d at 30°C, 41.6 µmol m−2 s−1, and a 12 h light/dark photoperiod. Maximum specific growth rate (0.149 d−1) and generating biomass (2.89 g L−1) were obtained when the blend concentration was 0.80 g L−1, the medium renewal rate was 40%, and NaHCO3 was 1.60 g L−1. The average productivity (0.091 g L−1 d−1) was achieved with 0.8 g L−1 of blend concentration and NaHCO3 concentration of 1.6 g L−1, independent of the medium renewal rate

Microalgae Polysaccharides: An Overview of Production, Characterization, and Potential Applications

Microalgae and cyanobacteria are photosynthetic microorganisms capable of synthesizing several biocompounds, including polysaccharides with antioxidant, antibacterial, and antiviral properties. At the same time that the accumulation of biomolecules occurs, microalgae can use wastewater and gaseous effluents for their growth, mitigating these pollutants. The increase in the production of polysaccharides by microalgae can be achieved mainly through nutritional limitations, stressful conditions, and/or adverse conditions. These compounds are of commercial interest due to their biological and rheological properties, which allow their application in various sectors, such as pharmaceuticals and foods. Thus, to increase the productivity and competitiveness of microalgal polysaccharides with commercial hydrocolloids, the cultivation parameters and extraction/purification processes have been optimized. In this context, this review addresses an overview of the production, characterization, and potential applications of polysaccharides obtained by microalgae and cyanobacteria. Moreover, the main opportunities and challenges in relation to obtaining these compounds are highlighted

Extraction of poly(3-hydroxybutyrate) from Spirulina LEB 18 for developing nanofibers

The objective of this study was to extract poly(3-hydroxybutyrate) (PHB) from the microalgal biomass of Spirulina LEB 18 for the development of nanofibers by electrospinning method. Different extraction methods were tested. The maximum yield obtained was 30.1 ± 2%. It was possible to produce nanofibers with diameters between 826 ± 188 nm and 1,675 ± 194 nm. An increase in the nanofiber diameter occurred when a flow rate of 4.8 μL min-1 and a capillary diameter of 0.90 mm were used. The nanofibers produced had up to 34.4% of biomass additives, i.e., non-PHB materials. This can be advantageous, because it enables the conservation of microalgal biomass compounds with bioactive functions

Biofunctionalized nanofibers using Arthrospira (Spirulina) biomass and biopolymer

Electrospun nanofibers composed of polymers have been extensively researched because of their scientific and technical applications. Commercially available polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-valerate (PHB-HV) copolymers are good choices for such nanofibers. We used a highly integrated method, by adjusting the properties of the spinning solutions, where the cyanophyte Arthrospira (formally Spirulina) was the single source for nanofiber biofunctionalization. We investigated nanofibers using PHB extracted from Spirulina and the bacteria Cupriavidus necator and compared the nanofibers to those made from commercially available PHB and PHB-HV. Our study assessed nanofiber formation and their selected thermal, mechanical, and optical properties. We found that nanofibers produced from Spirulina PHB and biofunctionalized with Spirulina biomass exhibited properties which were equal to or better than nanofibers made with commercially available PHB or PHB-HV. Our methodology is highly promising for nanofiber production and biofunctionalization and can be used in many industrial and life science applications