Felipe K. Sutili

Palm oil hydrolysis catalyzed by lipases under ultrasound irradiation – The use of experimental design as a tool for variables evaluation

Diacylglycerol oil has been increasingly recognized by its good nutritional properties and therefore, different technologies have been developed for obtaining it. The present work focuses on the diacylglycerol production by hydrolysis reaction of the palm oil using the PS IM and TL IM commercial lipases as biocatalysts under ultrasound irradiation. An experimental design (central composite rotatable design--CCRD) adopting surface response was applied as a tool to evaluate the optimal reaction conditions beyond a restrict number of experiments. Reactions were performed in an ultrasound equipment and different variables were investigated, such as temperature (30-55 °C), enzyme content (1-2 wt.% of oil mass), mechanical stirring (300-700 rpm) and reaction time. Both, PS IM and TL IM enzymes showed the best results after 1h and 30 min of reaction under 30 °C and, applying 300 rpm as stirring. On these conditions, the diacylglycerol yield was around 34% and 39%, respectively; considering that 1% PS IM was applied for the first one and, 2% TL IM for the second one. Therefore, it was obtained good yield of a diacylglycerol-rich oil in shorter reaction times under sonication and soft conditions. The mathematic model proposed suggested a satisfactorily representation of the process and good correlation among the experimental results and the theoretical values predicted by the model equation were achieved.

Continuous flow valorization of fatty acid waste using silica-immobilized lipases

Silica immobilized lipases have been prepared and utilized in the valorization of fatty acid-derived food waste streams under continuous flow conditions. Findings demonstrate that better conversions could be obtained when compared with commercially available immobilized enzymes.

A Comprehensive Study on the Activity and Deactivation of Immobilized Lecitase Ultra in Esterifications of Food Waste Streams to Monoacylglycerols

Lecitase Ultra was immobilized on Amberlites XAD2 and XAD4, through physical entrapping under conventional stirring or ultrasound irradiation, and characterized by standard techniques. The resulting immobilized biocatalysts were utilized in the valorization of an acidic food-derived residue from a palm oil refining process to produce monoacylglycerols from isopropylidene glycerol under batch and continuous flow conditions. Results indicated that the immobilized biocatalysts could moderately convert the food waste residue (max. conversion 50-60 %), exhibiting interesting stability under continuous flow conditions.

Lipase immobilized in microemulsion based organogels (MBGs) as an efficient catalyst for continuous-flow esterification of protected fructose

Sugar-based organogels are important esters for the cosmetic, food and pharmaceutical industries due to their intrinsic properties. Chemical routes to obtain these molecules suffer from low yields and undesirable side products. In this way, biocatalysis can be an interesting and efficient alternative, which meets the green chemistry principles. Herein we report our results on the development of a continuous flow process for the production of sugar-based surfactants mediated by immobilized enzymes in microemulsion based organogels, leading to the desired product in high productivities (66.8 to 88.1 g of ester per h per g of lipase).

Optimized Extraction of Resveratrol from Arachis repens Handro by Ultrasound and Microwave: A Correlation Study with the Antioxidant Properties and Phenol Contents

The vegetal species Arachis repens, commonly known as peanut grass, was studied and, for the first time, we detected the presence of the bioactive compound trans-resveratrol (t-RSV). We compared the efficiency of three different methodologies (conventional maceration [CM], ultrasound-assisted extractions [UAE], and microwave-assisted extractions [MAE]) concerning total phenolics (TP) and resveratrol (t-RSV) content, followed by antioxidant activity (AA) evaluation. By CM, at 1 h, the highest RSV content (1.024 ± 0.036 mg/L) and, correspondingly, the highest DPPH capture (23.90 ± 0.04%) were found. The TP contents, at 1 h, presented the highest value (27.26 ± 0.26 mg/g GAE). By the UAE, the maximum yields of TP (357.18 mg/g GAE) and RSV (2.14 mg/L), as well as, the highest AA (70.95%), were obtained by 5 min after a maceration pretreatment, on the solid-solvent ratio 1 : 40 w/v. For MAE, a central composite rotatable design (CCRD) was applied followed by the FFD design in order to evaluate the statistical effects of four independent variables on the extraction of RSV. The optimal conditions established for obtaining the highest recovery (2.516 mg/g) were 20 min; 90% MeOH aq.; 120 rpm; 60°C; and solid-solvent ratio: 1 : 35 w/v. Relevant correlations were established considering the TP and RSV contents, as well as the AA, corroborating obvious advantages of such techniques in terms of high extraction efficiency in shorter times.