Cristiano Ragagnin de Menezes

The role of photoperiods on photobioreactors - A potential strategy to reduce costs.

The aim of this work was evaluate the role of photoperiods (long-term, frequencies and short) on the growth and lipid content of microalgae Scenedesmus obliquus CPCC05. The results showed that Scenedesmus obliquus can store sufficient energy to sustain cell growth for continuous periods of up to 2h in the dark, without affecting the photosynthetic rate. The values for maximum biomass (9.58mg/Lh) and lipid productivities (2.56mg/Lh) were obtained at photoperiod of 0.91:0.09s (light:dark) and 48 t/d, respectively. Moreover, the best trade-offs between biomass productivity and light energy economy occurred in photoperiods of 0.5:0.5s and 0.91:0.09s (light:dark), and those between lipid productivity and light energy economy occurred in the frequency photoperiod of 24 and 48 t/d. Thus, the use of the photoperiods are an effective strategy for reducing costs of microalgal biomass production.

Microencapsulação de probióticos: avanços e perspectivas

Because of their health benefits, probiotics have been incorporated into a range of dairy products, including yogurts, soft-, semi-hard and hard cheeses, ice cream, milk powders and frozen dairy desserts. However, there are still several problems with respect to the low viability of probiotic bacteria in dairy foods. This review focuses mainly on current knowledge and techniques used in the microencapsulation of probiotic microorganisms to enhance their viability during fermentation, processing and utilization in commercial products. Microencapsulation of probiotic bacteria can be used to enhance the viability during processing, and also for the targeted delivery in gastrointestinal tract.

Is it possible to produce a low-fat burger with a healthy n − 6/n − 3 PUFA ratio without affecting the technological and sensory properties?

Burgers subjected to lipid reformulation were made by replacing 50% of the fat component by microparticles containing chia (CO) and linseed (LO) oils obtained by external ionic gelation. The microparticles presented high n-3 PUFAs levels and were resistant to the pH and temperature conditions commonly used in burger processing. The lipid reformulation did not affect hardness and improved important technological properties, such as cooking loss and fat retention. In addition to reducing the fat content of burgers by up to 50%, the lipid reformulation led to healthier PUFA/SFA and n-6/n-3 ratios, and lower atherogenicity and thrombogenicity indices. The burgers with CO microparticles showed a higher lipid oxidation and a lower sensory quality compared to the other treatments. However, the substitution of pork back fat by LO microparticles did not impair the sensory quality of burgers. Therefore, the microencapsulation of n-3 PUFA-rich oils by external ionic gelation can be considered an effective strategy to produce healthier burgers.

Treatment of cattle-slaughterhouse wastewater and the reuse of sludge for biodiesel production by microalgal heterotrophic bioreactors

Microalgal heterotrophic bioreactors are a potential technological development that can convert organic matter, nitrogen and phosphorus of wastewaters into a biomass suitable for energy production. The aim of this work was to evaluate the performance of microalgal heterotrophic bioreactors in the secondary treatment of cattle-slaughterhouse wastewater and the reuse of microalgal sludge for biodiesel production. The experiments were performed in a bubble column bioreactor using the microalgae Phormidium sp. Heterotrophic microalgal bioreactors removed 90 % of the chemical oxygen demand, 57 % of total nitrogen and 52 % of total phosphorus. Substantial microalgal sludge is produced in the process (substrate yield coefficient of 0.43 mgsludge mgchemical oxygen demand−1), resulting in a biomass with high potential for producing biodiesel (ester content of more than 99 %, cetane number of 55, iodine value of 73.5 giodine 100 g−1, unsaturation degree of ~75 % and a cold filter plugging point of 5 oC).

Application of electrolyzed water for improving pork meat quality

The microbiological and oxidative qualities of pork loin sprayed with different types (slightly acidic, acidic and basic) and combinations of electrolyzed water (EWs) were evaluated. The EWs were applied at two temperatures (18° and 30°C) and pressures (30 and 45psi) and the volume corresponded to approximately 10% water commonly used in carcass washing. EW after spraying exhibited a chlorine concentration between 15 and 25ppm. The application of acidic EW (AEW) alone or in combination with basic EW (BEW) decreased (P<0.05) the microbial counts shortly after spraying. In addition, the combination of BEW+AEW (30psi) reduced the mesophilic and psychrotrophic bacteria counts throughout the refrigerated storage (P<0.05). The EWs did not increase the lipid oxidation of the samples. On the other hand, a high protein oxidation was observed in the samples sprayed with AEW and slightly acidic EW (SAEW), while BEW was effective to reduce the oxidation reactions. Therefore, the results showed that the combination BEW+AEW may be a viable alternative to reduce the volume of water used at slaughter and to improve the microbiological quality of pork meat.

The Bioeconomy of Microalgal Carotenoid-Rich Oleoresins Produced inAgroindustrial Biorefineries

The techno-economic evaluation of the obtaining process of a natural mixed carotenoid-rich oleoresin from microalgae dried biomass is presented in this paper. The process is based on solvent extraction on industrial scale, and the oleoresin obtained is suspended in soybean oil at a concentration of 20%. The oleoresin is compound of a mix of trans and cis isomers of carotenoids, having as the major carotenoid the all-trans-β-carotene, in amounts close to 37%. The experimental data were used to estimate the costs of an industrial plant that has the potential to generate 569,016 tons of microalgal biomass per year, in which 107,902.5 kilograms per year are represented by total carotenoids. Based on the determination of the cost analysis, it was demonstrated that the natural mixed carotenoidrich oleoresin in soybean oil has a production cost estimated as USD 146.9 per kilogram.

Nanoestruturas contendo compostos bioativos extraídos de plantas

Many natural compounds, extracted from fruits and vegetables, have promising potential for maintaining and promoting health as well as preventing and treating some diseases. In the food industry, the use of plant extracts, as an alternative to chemical or synthetic antioxidants and antimicrobials to combat the foodborne pathogens, inhibiting lipid oxidation and thus extending the shelf life is an increasing trend. However, most of bioactive compounds present in these extracts such as polyphenols, carotenoids, alkaloids, among others, have low water solubility, stability and bioavailability. In this sense, nanotechnology is an innovative approach that has potential applications in nutraceutical research, since it improves these characteristics, besides enhance their absorption, protect them from premature degradation in the body and prolong their circulation time. There are different nanostructured systems that can be used in foods such as liposome, polymeric nanoparticles, lipid solid nanoparticles and nanoemulsions. This work presents a review of the main nanostructured systems used for association of different plant extracts and some technological applications.

Determinação do teor de umidade em grãos empregando radiação micro-ondas

The determination of moisture in grains is an important quality parameter, since the water content in food has an influence on both storage and commercialization of product. The methods often used for determination of moisture in grains are based on the loss on drying in an oven (LOD). Although it is easy to perform, this method spent about 24h of heating, usually at 105°C, to obtain the result. In the present study is proposed the determination of the loss on drying assisted by microwave radiation (MALOD) for samples of grounded grains of white rice, brown rice, peas, beans, bean, black beans, chick-peas, lentils and corn, in order to reduce the analysis time. Parameters such as irradiated power, sample mass, container and influence of irradiation time with microwave were evaluated and the results were compared with those obtained by LOD (suggested by MAPA) and also by infrared radiation (IRLOD). It was found that there was no significant difference in moisture content in samples between 2 and 15g using LOD, but there were hot spots for MALOD (carbonization of the sample) with masses higher than 2g. Similar results for moisture content were found by the use of different containers (glass weighing bottle and polypropylene flasks) and the polypropylene cups were selected due to the reduction of conditioning time of flasks. The agreement of MALOD with the official method was between 94% and 102% and only 50min were enough to determine the moisture of all grains, making a reduction of analysis time by 29 times.

Green and fast determination of the alcoholic content of wines using thermal infrared enthalpimetry

An innovative use of thermal infrared enthalpimetry (TIE) is proposed for the determination of alcoholic content of red and white wines. Notwithstanding the presence of ethanol in beverages, absolute ethanol was added directly to wines, and the temperature rise caused by the heat of dilution was monitored using an infrared camera. Analytical signals were obtained in only 10 s for four samples simultaneously, and a calibration curve was constructed with hydroalcoholic reference solutions. A linear calibration curve was obtained from 3.0 to 18.0% (v/v) ethanol (R2 = 0.9987). The results showed agreement ranging from 98.2 to 104.0% with 942.06 and 969.12 methods of AOAC. Organic compounds (e.g., sugar) did not interfere in the determinations. The proposed method provided fast results, with a throughput of 480 samples per hour and negligible energy consumption (0.001 kWh). In addition, the consumption of reagents was reduced when compared with conventional method fulfilling green analytical chemistry requirements.

Microalgae as Nanofactory for Production of Antimicrobial Molecules

In recent decades, due to increasing bacterial resistance, have been developed researches to find molecules with antimicrobial activity. The searches for new compounds, especially unexplored sources such as microalgae are a potential alternative. Microalgae are microorganisms extremely diverse and ubiquitous; they have advantages to become a powerful nanofactory due to the variety of metabolic compounds as the ability to form metallic nanoparticles with antimicrobial effect. This mini-review shows the importance of integrating nanotechnology with microalgae and/ or their products for the preservation and formation of molecules to be applied in prophylactic therapy and infectious.