Abstract The feedstock cost can comprise more than 75% of the overall biodiesel cost, and then economic issues are the main limitations of biodiesel production. This research focused on the use of alternative feedstock and production processes. The production of fatty acid esters from residues becomes an interesting alternative route since it is possible to reduce the cost of the process. The present work aimed to produce methyl esters from the residual oil of the poultry industry, using a commercial soluble lipase Eversa Transform 2.0® (NS-40116). The effects of methanol (1.2 to 1.8 eqv), water (1 to 2 wt%) and enzyme (0.1 to 0.5 wt%) contents on reaction conversion were evaluated through a 2³ experimental design with three central points, at 45 ºC, 250 rpm for 16 and 24 h of reaction time. From the results, by using 0.3 wt% enzyme, 1.5 wt% water, and 1.5 eqv of methanol it was possible to reach the most effective esters conversion (90.61%).

Abstract The sensory, physical-chemical and microbiological characteristics of boneless chicken thighs and drumsticks stored at different temperatures were evaluated. Samples stored at −6 and −12 °C, in natura and cooked, presented changes in sensory characteristics from the sixth and fifth month of storage, respectively. In natura samples kept at −18 °C presented sensory modification from the eighth month, and cooked samples did not show alterations during 12 months of storage. For lipid oxidation, differences were observed between −6 and −12 °C by the third month and between −12 and −18 °C after 12 months of storage. Related to protein oxidation, samples stored at −18 °C did not differ from the standard (0 days), showing values of 6.03 nmol carbonyl/mg protein after 12 months of storage. Samples under freezing at −6 °C for 12 months presented an increase in psychrotrophic count. This behaviour was not observed in the samples stored at −12 and −18 °C. Considering the different analyzes, the maximum storage period was 6 days at 4 °C, 8 months at –6 and –12 °C and at least 12 months storage at –18 °C.

This study reports the optimization of geranyl butanoate production by esterification of geraniol and butanoic acid in a solvent-free system using two immobilized lipases as catalyst. The operating conditions that optimized geranyl butanoate production were determined to be 40 °C, a geraniol to butanoic acid molar ratio of 3:1, 150 rpm, 5 wt% of enzyme, and 1 h of reaction, which resulted in a reaction conversion of about 97% for Novozyme 435. When homemade Novozyme NZL-102-LYO-HQ (Cal-B) immobilized in polyurethane foam was used as catalyst, the experimental conditions of an alcohol to acid molar ratio of 5:1, 70 °C, 150 rpm, 5 wt% of enzyme, and 1 h of reaction gave a conversion of 95%. New experimental data on enzymatic esterification of geraniol and butanoic acid for geranyl butanoate production are reported in this work, showing that the technique is promising for overcoming the well-known drawbacks of the chemical-catalyzed route.

Abstract Recently, the physical and chemical effects of ultrasound in polymeric materials synthesis have attracted great attention. This work presents the synthesis of novel polymeric materials by polymerization of isophorone diisocyanate with different polyols. Polymers were synthesized by step miniemulsion polymerizations, using ultrasound bath and thermostatic bath. The effects of ultrasound, temperature and polyol type were evaluated by Fourier transform infrared spectroscopy, gel permeation chromatography, dynamic light scattering and titrimetry. Polymerization under ultrasound bath showed that different reaction temperatures in the range between 50 °C and 80 °C directly influence the molecular weight of the polymers, urea/urethane formation and increase of diisocyanate consumption rate. In addition, different polyols used in polymerizations in miniemulsion had a significant effect on the characteristics of the resulting poly(urea-urethane) nanoparticles. Finally, ultrasound assisted polymerizations showed a faster diisocyanate consumption rate, but did not lead to enhanced molecular weights.

Abstract Poly(Thioether-Ester) nanoparticles synthetized via thiol-ene polymerization from a renewable castor oil monomer are produced by miniemulsion polymerization and emulsification/evaporation of pre-formed polymer. Its antioxidant activity, probably due to the oxidation of sulfide groups, is confirmed by 2,2-diphenyl-1-picryl hydrazyl (DPPH) free radical-scavenging and β-carotene/linoleic acid assays, with an amount of polymer required to reduce the initial concentration of DPPH· radicals by 50% of ~195 µg.ml-1 promoting hydrogen or electron exchange and the capability to prevent lipid peroxidation of ~55%. The results show a promising application in food packing.

Abstract Cellulases are efficient enzymes for the conversion of cellulose into glucose. Their use in immobilized form enables them to be reused in successive cycles in many biotechnological processes. Unlike conventional methods of immobilization by covalent bonding, in miniemulsion polymerization the immobilization of enzyme and the synthesis of polymer nanoparticles (support) occur simultaneously. Based on these aspects, the immobilization of cellulose on poly(methyl methacrylate) (PMMA) nanoparticles by miniemulsion polymerization was studied. The surfactant type (non-ionic and ionic) and latex pH showed great influence on cellulase activity. High activity values were obtained only when non-ionic surfactant (Lutensol AT50) and buffering agent (NaHCO3) were used simultaneously. MMA polymerization rate and final monomer conversion were not affected by the presence of cellulase. The maximum immobilization efficiency (60%) was obtained when 6 wt.% of cellulase was used and stable PMMA nanoparticles (133 nm) were obtained. The relative activity profile of immobilized cellulase, for pH as well as temperature, was similar to that reported for the free form. Immobilized enzyme keeps its activity throughout seven days when stored at 4 ºC and phosphate buffer pH 6.0. Based on the results obtained in this work, miniemulsion polymerization as a method for cellulase immobilization on PMMA nanoparticles showed to be a promising technique with high possibility of industrial application.

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.

Filamentous fungi were cultured under solid state fermentation of soybean residues to produce lipases. Enzymes produced by Aspergillus niger esterified oleic and butyric acids in the presence of ethanol, while enzymes produced by Aspergillus fumigatus demonstrated no esterification activity toward lauric acid. In case of A. niger, direct lyophilization of fermented bran led to higher esterification activity. The esterification of oleic acid by enzymes of A. fumigatus was neither influenced by pH adjustment nor by the extraction process. Conversions to ethyl esters were higher after pH adjustment with lyophilized liquid extract of A. niger.

This work evaluates the immobilization of Candida antarctica lipase (Fraction B) using poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) nanoparticles as support. The effects of immobilization time (30-150 min) and pH (5-10) on lipase loading were evaluated. The stability of the immobilized enzyme towards temperature (40, 60, and 80 ºC), reuse and storage (at 4 ºC) were also determined. Furthermore, to assess its potential application in a system of interest, the immobilized lipase was used as a catalyst in the esterification of geraniol with oleic acid. The results indicated a time of 120 minutes and pH of 7 as optimal for immobilization. A 21 hour exposure of the PHBV-lipase derivative to 60 ºC showed a 33% reduction of the initial activity while storage at 4 ºC led to a residual activity (5% of the original activity). The derivative was used without significant loss of activity for 4 successive cycles. The use of the immobilized lipase as a catalyst in the production of geranyl oleate led to about 88% conversion of the initial reactants to products.

Lipases produced by a newly isolated Sporidiobolus pararoseus strain have potential catalytic ability for esterification reactions. After production, the enzymatic extracts (conventional crude and precipitated, 'CC' and 'CP', and industrial crude and precipitated, 'IC' e 'IP') were partially characterized. The enzymes presented, in general, higher specificity for short chain alcohols and fatty acids. The precipitated extract showed a good thermal stability, higher than that for crude enzymatic extracts. The 'CC' and 'CP' enzymes presented high activities after exposure to pH 6.5 and 40 ºC. On the other hand, the 'IC' and 'IP' extracts kept their activities in a wide range of pH memory but presented preference for higher reaction temperatures. Preliminary studies of application of the crude lipase extract in the enzymatic production of geranyl propionate using geraniol and propionic acid as substrates in solvent-free system led to a reaction conversion of 42 ± 1.5%.

Omega-3 enriched partial acylglycerols are beneficial for human health. The aim of this study was to obtain monoacylglycerols (MAG) and diacylglycerols (DAG) by means of glycerolysis of fish oil catalyzed by a lipase from Rhizomucor miehei in the presence of food grade surfactants (Tween 65, 80 or 85). Glycerolysis was successful in the reaction media for all the tested surfactants, showing their potential for use as additives in such a system. The best results, however, were obtained for the reaction medium in the absence of surfactant whose peroxide value was the lowest after glycerolysis.

The lipase produced by a newly isolate Sporidiobolus pararoseus strain has potential catalysis ability for esterification reactions. In order to improve its synthetic activity, this work aimed at optimizing 'synthetic lipase' production by submerged fermentation of a conventional media based on peptone, yeast extract, NaCl and olive oil using experimental design technique. According to the results obtained in the first experimental design (2(4-1)), yeast extract and NaCl concentrations were tested to further optimization by response surface methodology. The maximum 'synthetic lipase' activity obtained was 26.9 U/mL in the optimized media (5.0, 6.8, 7.0 and 1.0% (wt/v) of peptone, yeast extract, NaCl and olive oil, respectively), representing a 6.36-fold increase compared to the initial medium. The time course of 'synthetic lipase' production in the optimized condition was evaluated in terms of synthetic activity, protease activity, biomass and total carbon and the maximum synthetic activity was observed during the stationary phase of growth.

A eficiência de quatro sanitizantes, ácido peracético, clorexidina, quaternário de amônio e ácidos orgânicos, foi testada neste trabalho, usando diferentes bactérias reconhecidas como problemas na indústria de carnes, Salmonella sp., S. aureus, E. coli and L. monocytogenes. O efeito da concentração dos sanitizantes (0,2; 0,5; 0,6; 1,0; 1,1 e 1,4%) a diferentes temperaturas (10 e 45 °C) e tempo de contato (2, 10, 15, 18 e 25 minutos) foi avaliado. Testes na planta industrial foram também conduzidos considerando os resultados obtidos previamente. De uma maneira geral, o ácido peracético apresentou maior eficiência usando menores concentrações (0,2%) e tempos de contato (2 minutos) a 10 °C. Os testes em escala industrial mostraram que o ácido peracético apresentou uma boa performance em concentrações e tempos de contato inferiores aos sugeridos pelas empresas fornecedoras. Os usos da clorexidina e do quaternário de amônio levaram a resultados razoáveis nas condições indicadas e os ácidos orgânicos foram ineficientes nas concentrações indicadas em relação ao Staphylococcus aureus. De uma maneira geral, os resultados mostraram que a escolha do sanitizante mais adequado dependerá do micro-organismo contaminante, tempo disponível para aplicação do sanitizante e custo do processo.

The efficiency of four Sanitizers - peracetic acid, chlorhexidine, quaternary ammonium, and organic acids - was tested in this work using different bacteria recognized as a problem to meat industry, Salmonella sp., S. aureus, E. coli and L. monocytogenes. The effects of sanitizer concentration (0.2, 0.5, 0.6, 1.0, 1.1 and 1.4%), at different temperatures (10 and 45 °C) and contact time (2, 10, 15, 18 and 25 minutes) were evaluated. Tests in an industrial plant were also carried out considering previously obtained results. In a general way, peracetic acid presented higher efficiencies using low concentration (0.2%) and contact time (2 minutes) at 10 °C. The tests performed in industrial scale showed that peracetic acid presented a good performance in concentration and contact time lower than that suggested by the suppliers. The use of chlorhexidine and quaternary ammonium led to reasonable results at the indicated conditions, and organic acids were ineffective under concentration and contact time higher than those indicated by the suppliers in relation to Staphylococcus aureus. The results, in general, show that the choice for the most adequate sanitizer depends on the microorganism contaminant, the time available for sanitizer application, and also on the process cost.

The aim of this work is to report the performance of different supports for the immobilization of commercial porcine pancreatic lipase. The immobilization tests were carried out in several types of Accurel, activated alumina, kaolin, montmorillonite, ion exchange resins and zeolites. The characterization of the supports showed differences in terms of specific area and morphology. The characteristics of the supports influenced the amount of enzyme adsorbed, yield of immobilization and esterification activity of the resulting immobilized catalyst. The clays KSF and natural and pillared montmorillonites presented potential for use as support for lipase immobilization in terms of yield and esterification activity. Yields of immobilization of 76.32 and 52.01% were achieved for clays KSF and natural montmorillonite, respectively. Esterification activities of 754.03, 595.51, 591.88 and 515.71 U.g-1 were obtained for lipases immobilized in Accurel MP-100, Amberlite XAD-2, mordenite and pillared montmorillonite, respectively.

Este trabalho teve como objetivo o uso da metodologia de planejamento de experimentos para avaliação dos efeitos de parâmetros de processo na produção de empanados de peixe em escala industrial. Os efeitos destes parâmetros nas características físico-químicas e microbiológicas do produto final foram avaliados através de um planejamento completo 24. As variáveis independentes estudadas foram temperaturas do filé e da polpa, temperatura da gordura e da água adicionadas na formulação do produto, bem como razão entre tempo de extração da proteína e tempo de emulsão. As análises físico-químicas mostraram que maiores temperaturas de adição de polpa e filé de peixe resultaram em uma menor concentração de proteína no produto final. As análises microbiológicas realizadas resultaram em contagens de Staphylococcus coagulase positiva, totais e termotolerantes de acordo com a legislação vigente.

This work reports the use of experimental design for the assessment of the effects of process parameters on the production of fish nuggets in an industrial scale environment. The effect of independent factors on the physicochemical and microbiological parameters was investigated through a full 24 experimental design. The studied factors included the temperature of fish fillet and pulp in the mixer, the temperature of the added fat, the temperature of water and the ratio of protein extraction time to emulsion time. The physicochemical analyses showed that the higher temperature of the pulp and fillet of fish, the lower the protein in the final product. Microbiological analyses revealed that the counting of Staphylococcus coagulase positive, total and thermo-tolerant coliforms were in accordance with the current legislation.