Determination of CO2 solubility in Perna perna mussel and analysis of the suitability of the ideal and non-ideal gas models

In SGS (Soluble Gas Stabilization) processes, the carbon dioxide (CO2 ) is dissolved into the food product under controlled temperature, pressure, and gas/product ratio. The prediction of CO2 solubility can be achieved using a computational code using equations of state from experimental data on CO2 concentration in food. In this work, the solubility of CO2 in Perna perna mussels was obtained using Ideal Gas law and Virial, Van der Waals, Soave-Redlich-Kwong, and Peng-Robinson equations. The SGS process was performed at varying system pressure (200–600 kPa), temperature (0–6 °C), and gas/product (g/p) (mussels) ratio (1:1–5:1) in the cooked and shucked mussels for 65 h. A total of 11 experiments, arranged in a 23 experimental design, with triplicate runs at the central point, were performed. The compressibility factor indicated that the Ideal Gas state is a good approximation only for experiments 1, 2, 5, and 6. It was observed that the pressure and the gas/product ratio exert a more significant influence on the CO2 solubilization process in the mussel. Visual Basic for Applications (VBA) to perform thermodynamic calculations showed to be a great resource regarding complex calculations

Lipase-catalyzed ethanolysis of Jatropha curcas L. oil assisted by ultrasonication

ABSTRACT Transesterification of non-edible oils using immobilized lipase is a promising process for biodiesel production. Thus, this study aimed to evaluate the enzymatic transesterification of the non-edible Jatropha curcas oil for FAEE production under ultrasound irradiation in a solvent-free system. The effects of enzyme concentration, water concentration, molar ratio of ethanol to oil and ultrasound power on the FAEE conversion have been evaluated. The results show that enzyme concentration and irradiation power have a positive significant effect on FAEE conversion, where an increase in these variables leads to higher conversions. Conversion above 54% of FAEE was achieved with 1.5 hours of reaction time using ultrasound irradiation, reducing reaction time by at least 3 times, when compared with the same experimental conditions without ultrasound irradiation. Results showed that ultrasound can improve reaction conversion mainly by enhancing the mass transfer between the constituents of the reactions

Inactivation of Listeria monocytogenes using supercritical carbon dioxide in a high-pressure variable-volume reactor

AbstractThis work evaluates the inactivation of Listeria monocytogenes through the use of supercritical carbon dioxide. For this purpose, the experimental design methodology was employed as a tool to assess the effects of temperature, depressurization rate, pressure cycling and the mass ratio of cell suspension to CO2. It was observed that the depressurization rate and mass of cell suspension to CO2 ratio were statistically significant and inactivation kinetics was verified to be of first-order. It was also observed that the inactivation increased with increasing depressurization rates in the range of 6–12 MPa min−1, keeping nearly constant above the upper value. The decimal reduction times ranged from 15.38 to 20.41 min. Results obtained in this work may be quite useful to the food industry committed to microorganism inactivation using the innovative supercritical carbon dioxide technology

Enzymatic esterification of stearic acid and ethanol for ethyl stearate production

Ethyl stearate is an ester obtained by the esterification of stearic acid and ethanol. Esters are organic substances that can be found in nature and it is of great importance pharmaceutical industry, perfumes, polymers, cosmetics and in the food industry. Ethyl stearate is widely used in the perfume industry in fragrances in small concentrations, and can also be used as artificial flavoring, generally as additives to enhance the aroma of a drink or a food. This study aimed to evaluate the enzymatic synthesis of ethyl stearate in a free-solvent system. For the synthesis the effect of the agitation of 150 at 250 rpm and molar ratio between the substrates of 1:1 at 1:7 (acid:alcohol) was evaluated since the temperature (60 °C) and enzyme concentration (1%, wt of acid) were kept constant. Commercial ipases Novozym 435 and NS 88011 were tested and Novozym 435 showed better performance (82% conversion) for the synthesis of ethyl stearate. The highest conversion (92%) in ethyl stearate in the optimized condition was obtained at molar ratio of 1:5, 60 °C, 200 rpm of agitation, enzyme concentration of 1 wt%, 24 h of reaction and addition of alcohol fractionated in three portions in the first hours of reaction. This study also evaluated the possibility of reuse of the biocatalyst, obtaining satisfactory results of 60% in three cycles

Improvement of Organic Agriculture with Growth-Promoting and Biocontrol Yeasts

Organic agriculture has significantly expanded over the years, increasing population. The productive methodology adopted in globalized agricultural systems reinforced the need to develop technologies that reduce the problems caused by the excessive use of pesticides and synthetic fertilizers. Some progress is being made by applying yeasts in agriculture due to the advantages associated with their use, such as promoting plant growth, biological control, inhibition of pathogens, and production of phytohormones. This chapter discusses studies that demonstrate the potential of yeasts in agriculture for biocontrol and plant growth. Yeasts are widely disseminated in the soil, increase and promote biological control, and show positive and promising results in the management of various phytopathogens. The interactions of these organisms influence multiple processes, such as the mineralization of organic matter in the soil, nutrient cycle, disease and weed control, and ecological balance. Efforts must be made to enable the production and application of yeasts as control agents in agriculture. Considering the diversity of yeast species present in the soil, their morphological, physiological, and phenotypic properties, understanding interactions and environmental effects integrating an ecological scenario is the key to good agricultural practices in a more sustainable context

Enzymatic synthesis of butyl stearate in solvent-free system

Butyl stearate is an ester obtained by the esterification of stearic acid and butanol, which is used a solvent and spreading agent for creams and creamy lotions. It has been important for the cosmetics industry as it often acts as substitute for mineral and vegetable oils. It also has emollient properties, having the advantage of not leaving the greasy sensation on the skin and providing the sensation of softness. Considering the importance of this ester, this work aimed to evaluate the enzymatic production of butyl stearate. All experiments for the production of this ester were conducted in an orbital shaker, varying the agitation of 150 at 250 rpm and substrates molar ratio of 1:1 at 1:7 (acid:alcohol), while the temperature (60 °C) and enzyme concentration (1%, wt of acid) were kept constant. First, two immobilized commercial enzymes were tested (Novozym 435 and NS 88011), where the enzyme that gave the best results (conversion of 84%) was the Novozym 435. So, the optimization of butyl stearate production was performed using Novozym 435. The best result, conversion of 92%, was observed in the condition of 60 °C, substrates molar ratio of 1:2, 1 wt% of the enzyme, 200 rpm and with the addition of alcohol fractionated in three portions in the first hours of reaction. The biocatalyst reuse was also evaluated, leading to satisfactory results, 70% of conversion after five cycles of use

The bioherbicidal potential of isolated fungi cultivated in microalgal biomass

This study evaluated the bioherbicidal potential of wild fungi grown on microalgal biomass from the digestate treatment of biogas production. Four fungal isolates were used and the extracts were evaluated for the activity of different enzymes and characterized by gas chromatography coupled with mass spectrometry. The bioherbicidal activity was assessed by application on Cucumis sativus, and the leaf damage was visually estimated. The microorganisms showed potential as agents producing an enzyme pool. The obtained fungal extracts presented different organic compounds, most acids, and when applied to Cucumis sativus, showed high levels of leaf damage (80-100 +/- 3.00%, deviation relative to the observed average damage). Therefore, the microbial strains are potential biological control agents of weeds, which, together with the microalgae biomass, offer the appropriate conditions to obtain an enzyme pool of biotechnological relevance and with favorable characteristics to be explored as bioherbicides, addressing aspects within the environmental sustainability.[GRAPHICS