34 research outputs found

    Optimiranje enzimske interesterifikacije mješavine mliječne masti i kanola ulja pomoću imobilizirane lipaze iz Rhizopus oryzae, primjenom metode odzivnih površina

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    Blends of milk fat and canola oil (MF:CNO) were enzymatically interesterified (EIE) by Rhizopus oryzae lipase immobilized on polysiloxane-polyvinyl alcohol (SiO2-PVA) composite, in a solvent-free system. A central composite design (CCD) was used to optimize the reaction, considering the effects of different mass fractions of binary blends of MF:CNO (50:50, 65:35 and 80:20) and temperatures (45, 55 and 65 °C) on the composition and texture properties of the interesterified products, taking the interesterification degree (ID) and consistency (at 10 °C) as response variables. For the ID variable both mass fraction of milk fat in the blend and temperature were found to be significant, while for the consistency only mass fraction of milk fat was significant. Empiric models for ID and consistency were obtained that allowed establishing the best interesterification conditions: blend with 65 % of milk fat and 35 % of canola oil, and temperature of 45 °C. Under these conditions, the ID was 19.77 % and the consistency at 10 °C was 56 290 Pa. The potential of this eco-friendly process demonstrated that a product could be obtained with the desirable milk fat flavour and better spreadability under refrigerated conditions.Mješavina mliječne masti i kanola ulja (MF:CNO) enzimski je interesterificirana pomoću lipaze iz Rhizopus oryzae, imobilizirane na kompozitu od polisiloksana i polivinil-alkohola, u sustavu bez otapala. Da bi se reakcija optimirala, upotrijebljen je centralno složeni dizajn (CCD), pri čemu su ispitani utjecaj masenog omjera MF:CNO (50:50, 65:35 i 80:20) i temperature (45, 55 i 65 °C) na sastav i teksturu interesterificiranih produkata, uz zavisne varijable: stupanj interesterifikacije i konzistenciju pri 10 °C. Na stupanj interesterifikacije bitno su utjecali maseni udio mliječne masti u mješavini i temperatura, dok je na konzistenciju utjecao samo maseni udio mliječne masti. Dobiven je empirijski model pomoću kojeg su utvrđeni optimalni uvjeti interesterifikacije: mješavina 65 % mliječne masti i 35 % kanola ulja, te temperatura od 45 °C. Pri tim je uvjetima postignut stupanj interesterifikacije od 19,77 %, a konzistencija pri 10 °C bila je 56 290 Pa. Pomoću ovog ekološkog postupka može se dobiti proizvod poželjnog mliječnog okusa i bolje mazivosti pri hladnim uvjetima skladištenja

    Avaliação das condições reacionais para a síntese enzimática do butirato de butila empregando lipase de Candida rugosa

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    Lipase de Candida rugosa na forma livre foi usada na síntese de butirato de butila pela esterificação direta de n-butanolcom ácido butírico. Um planejamento fatorial completo 2(4) foi empregado para determinar a influência da razão molar do álcool para ácido (1: 0,5-2,5), concentração de agente dessecante (0-20%), concentração de enzima (40-80 mg) e temperatura de incubação (30-60 °C) no rendimento de esterificação. A concentração de agente dessecante foi o fator mais significativo na esterificação, sendo sua influência negativa. O progresso da esterificação foi favorecido para substratos contendo ácido em excesso, mesmo em baixa concentrações de enzima (40 mg), sendo a conversão de 50%. Na região avaliada, a formação do butirato de butila (26,67 g/L) foi maximizada para razão molar (1:2,5), ausência de agente dessecante, concentração de enzima (80 mg) e temperatura de incubação de 30 °C.Free lipase from Candida rugosa was used for the synthesis of butyl butyrate by direct esterification of butyric acid and butyl alcohol. A full factorial experimental design (2(4)) was employed to determine the effect of alcohol to acid ratio (1: 0.5-2.5), water adsorbent concentration (0-20%), enzyme concentration (40-80 mg) and incubation temperature (30-60 °C) on the esterification yield. Water adsorbent concentration has been found to be the most significant factor on the esterification reaction and its influence was negative. The extent of esterification was higher for substrates containing acid in excess even with a low enzyme concentration of 40 mg and 50% conversion was observed. The maximum predicted values for butyl butyrate yield (92.67%) can be attained with substrate containing acid in excess (molar ratio alcohol to acid 1:2.5), 80 mg enzyme concentration in the absence of water adsorbent at temperature incubation of 30 °C

    Physico-chemical, spectroscopical and thermal characterization of biodiesel obtained by enzymatic route as a tool to select the most efficient immobilized lipase

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    Two microbial lipases from Burkholderia cepacia and Pseudomonas fluorescens were evaluated as catalysts for the enzymatic transesterification of beef tallow with ethanol and the most efficient lipase source was selected by taking into account the properties of the product to be used as fuel. Both lipases were immobilized on an epoxy silica-polyvinyl alcohol composite by covalent immobilization and used to perform the reactions under the following operational conditions: beef tallow-to-ethanol molar ratio of 1:9, 45ºC and 400 units of enzymatic activity per gram of fat. Products, characterized using Fourier Transform Infrared spectroscopy (FTIR), viscosimetry, thermogravimetry and ¹H NMR spectroscopy, suggested that the biodiesel sample obtained in the reaction catalyzed by Burkholderia cepacia lipase has the best set of properties for fuel usage

    Effect on the enzymatic hydrolysis of lipids from dairy wastewater by replacing Gum Arabic emulsifier for sodium chloride

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    The objective of this work was to evaluate the replacement of Gum Arabic for sodium chloride to reduce fat and organic contents in dairy wastewater using two low cost commercially available lipase preparations from animal source (Kin Master - LKM and Nuclear- LNU). The best performance was achieved when lipase Nuclear (LNU) was used as catalyst. In addition, this lipase preparation has also lower cost, which makes its use a quite promising technique for reduction of suspended solids as proteins and lipids contents found in wastewater generated by dairy industries.O objetivo deste trabalho foi verificar o efeito do cloreto de sódio em substituição à goma arábica, na redução do teor de lipídeos presentes em efluentes de laticínios empregando duas preparações de lipases pancreáticas adquiridas no mercado nacional (Kin Master - LKM e Nuclear- LNU). A preparação enzimática LNU foi mais eficiente na redução de proteínas e lipídeos, mostrando ser uma alternativa promissora para uso no pré-tratamento de águas residuárias com elevado teor desses compostos

    Avaliação das condições reacionais para a síntese enzimática do butirato de butila empregando lipase de Candida rugosa Evaluation of the reaction conditions for the enzymatic synthesis of the butyl butyrate using lipase from Candida rugosa

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    Lipase de Candida rugosa na forma livre foi usada na síntese de butirato de butila pela esterificação direta de n-butanolcom ácido butírico. Um planejamento fatorial completo 2(4) foi empregado para determinar a influência da razão molar do álcool para ácido (1: 0,5-2,5), concentração de agente dessecante (0-20%), concentração de enzima (40-80 mg) e temperatura de incubação (30-60 °C) no rendimento de esterificação. A concentração de agente dessecante foi o fator mais significativo na esterificação, sendo sua influência negativa. O progresso da esterificação foi favorecido para substratos contendo ácido em excesso, mesmo em baixa concentrações de enzima (40 mg), sendo a conversão de 50%. Na região avaliada, a formação do butirato de butila (26,67 g/L) foi maximizada para razão molar (1:2,5), ausência de agente dessecante, concentração de enzima (80 mg) e temperatura de incubação de 30 °C.<br>Free lipase from Candida rugosa was used for the synthesis of butyl butyrate by direct esterification of butyric acid and butyl alcohol. A full factorial experimental design (2(4)) was employed to determine the effect of alcohol to acid ratio (1: 0.5-2.5), water adsorbent concentration (0-20%), enzyme concentration (40-80 mg) and incubation temperature (30-60 °C) on the esterification yield. Water adsorbent concentration has been found to be the most significant factor on the esterification reaction and its influence was negative. The extent of esterification was higher for substrates containing acid in excess even with a low enzyme concentration of 40 mg and 50% conversion was observed. The maximum predicted values for butyl butyrate yield (92.67%) can be attained with substrate containing acid in excess (molar ratio alcohol to acid 1:2.5), 80 mg enzyme concentration in the absence of water adsorbent at temperature incubation of 30 °C

    Comparative performance of microbial lipases immobilized on magnetic polysiloxane polyvinyl alcohol particles

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    Microbial lipase from Mucor miehei and Candida rugosa were immobilized by covalent binding onto magnetized polysiloxane polyvinyl alcohol particles (POS-PVA). The resulting immobilized derivatives were evaluated in aqueous solution (olive oil hydrolysis) and organic solvent (butyl butyrate synthesis). Higher catalytic activities were found when the coupling procedure was made with M. miehei lipase. Immobilized M. miehei lipase also showed a better operational stability and a higher half-life than C. rugosa lipase after the successive batches of esterification. The performance of C. rugosa immobilized derivative was constrained by the low lipase loading used in the immobilizing step. Further information regarding the both immobilized derivatives was also obtained through chemical composition (FTIR)

    Síntese do butirato de n-butila empregando lipase microbiana imobilizada em copolímero de estireno-divinilbenzeno Synthesis of butyl butyrate by microbial lipase immobilized onto styrene-divinylbenzene copolymer

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    <abstract language="eng">This work investigates the reaction parameters of an immobilized lipase in the esterification reaction of n-butanol and butyric acid. Microbial lipase from Candida rugosa was immobilized onto styrene-divinylbenzene copolymer (STY-DVB) and subsequently introduced in an organic medium containing substrates in appropriate concentrations. Heptane was selected as solvent on the basis of its compatibility with the resin and the enzyme. The influence of molar ratio of acid to alcohol, amount of immobilized lipase and temperature on the butyl butyrate formation was determined. The results were compared with those achieved with free lipase and Lipozyme (commercially immobilized lipase) under the same operational conditions

    Anaerobic biodegradability of dairy wastewater pretreated with porcine pancreas lipase

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    Lipids-rich wastewater was partial hydrolyzed with porcine pancreas lipase and the efficiency of the enzymatic pretreatment was verified by the comparative biodegradability tests (crude and treated wastewater). Alternatively, simultaneous run was carried out in which hydrolysis and digestion was performed in the same reactor. Wastewater from dairy industries and low cost lipase preparation at two concentrations (0.05 and 0.5% w.v-1) were used. All the samples pretreated with enzyme showed a positive effect on organic matter removal (Chemical Oxygen Demand-COD) and formation of methane. The best results were obtained when hydrolysis and biodegradation were performed simultaneously, attaining high COD and color removal independent of the lipase concentration. The enzymatic treatment considerably improved the anaerobic operational conditions and the effluent quality (lower content of suspended solids and less turbidity). Thus, the use of enzymes such as lipase seemed to be a very promising alternative for treating the wastewaters having high fat and grease contents, such as those from the dairy industry

    Biochemical modification of milkfat

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    Made available in DSpace on 2019-09-11T20:58:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2010Recent advances for improving physicochemical and nutritional properties of lipids are reviewed, with emphasis on products attaining by biochemical processing of natural fats and oils. Enzymatic interesterification provides an important route to modify physical and nutritional properties of milkfat without generating trans isomers. This process makes use of lipases, a versatile class of enzyme that is able to perform efficiently the target modification in both solvent and solvent free systems. The present review covers important features of lipases, lipase-catalyzed interesterification reactions and their effects on the composition and texture of the resulting product.[Santos, Júlio César dos] Universidade de Taubaté, BrazilNunes, Gisele Fátima Morais; Paula, Ariela Veloso de; Castro, Heizir Ferreira de] Universidade de São Paulo, Brazi
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