The ability of three commercially available lipases to mediate the hydrolysis of the soybean oil to yield concentrated of essential fatty acids was evaluated. The tested lipases were from microbial (Candida rugosa and Thermomyces lanuginosa) and animal cells (Porcine pancreatic lipase). In terms of free fatty acids, microbial lipases were more effective to promote the enzymatic hydrolysis of the soybean oil (over 70%) than the porcine pancreatic lipase (24%). In spite of this, porcine pancreatic lipase (PPL) showed the most satisfactory specificity towards both essential fatty acids and was, therefore, chosen to carry out additional studies. An experimental design was performed taking into consideration the enzyme and NaCl amounts as independent variables. The main effects were fitted by multiple regression analysis to a linear model and maximum fatty acids concentration could be obtained using 3.0 wt% of lipase and 0.08 wt% of NaCl. The mathematical model representing the hydrolysis degree was found to describe adequately the experimental results. Under these conditions, concentrations of 29.5 g/L and 4.6 g/L for linoleic and linolenic acids, respectively, were obtained.
BACKGROUND: Reactions performed under solvent-free conditions give processes that are environmentally friendly, since most solvents are polluting agents. In this work, the performance of Candida rugosa lipae (CRL) immobilized on styrene-divinylbenzene (STY-DVB) or controlled pore silica (CPS), and the commercial lipase Novozym 435, was evaluated for the synthesis of butyl esters in solvent-free systems (SFS). A 2 2 full factorial design was used to study the influence of the organic acid chain length and the biocatalyst concentration on the esterification performance.
Recebido em 27/3/07; aceito em 26/10/07; publicado na web em 13/8/08 MONOGLYCERIDES: PRODUCTION BY ENZYMATIC ROUTE AND APPLICATIONS: Monoglycerides (MAG) are non-ionic surfactants, widely used in the pharmaceutical, food and cosmetic industries. Although MAGs are manufactured on an industrial scale by chemical glycerolysis of oils and fats, new developments in lipase catalyzed synthesis have been studied as an alternative to the classical method seeking to use clean technology and green chemistry. In this work, different methods such as glycerolysis, selective hydrolysis of fats and oils, and esterification of fatty acids or transesterification of esters with glycerol are presented. The properties and applications of the monoglycerides are also included in this review.Keywords: monoglycerides; lipase; glycerolysis. INTRODUÇÃOMonoglicerídeos são surfatantes não iônicos, que possuem o status GRAS (Generally Recognized as Safe) pela FDA (Food and Drugs Administration-USA), sendo amplamente utilizados nas indústrias farmacêuticas, de alimentos e de cosméticos, 1 por não apresentarem efeitos colaterais quando ingeridos ou irritações na pele, ao contrário dos tensoativos iônicos.2 São basicamente monoésteres formados por ácidos graxos e glicerol, dependendo da orientação das moléculas duas formas isoméricas podem existir, conforme apresentado na Figura 1. Na indústria farmacêutica, os monoglicerídeos (MAG) são utilizados como emolientes para emplastos, liberando lentamente a medicação. Na indústria alimentícia são mais comumente utilizados como emulsificantes em uma ampla gama de produtos como margarinas, derivados do leite, doces e molhos, enquanto que na indústria de cosméticos, são empregados como agentes texturizantes e para melhorar a consistência de cremes e loções.3 Na Tabela 1 são sumarizados diferentes tipos de monoglicerídeos e algumas de suas principais aplicações.A produção mundial de monoglicerídeos é estimada em cerca de 180 mil t por ano, 13 das quais aproximadamente 85 mil são consumidas nos EUA, correspondendo a 70% do total de emulsificantes usados em produtos alimentícios. 14 Normalmente, os MAG são sintetizados quimicamente via gliceró-lise de triglicerídeos empregando catalisadores inorgânicos (Ca (OH) 2 , NaOH) a 220-250 °C.15 A utilização de temperaturas elevadas, além de acarretar um alto consumo energético, é responsável pela parcial degradação dos produtos, com formação de subprodutos escuros e sabor de queimado. 16 Desta forma, quando esta rota é usada, se obtém um produto constituído por uma mistura que contém cerca de 35-60% de monoglicerídeos, 35-50% de diglicerídeos, 1-20% de triglicerídeos, 1-10% de ácidos graxos livres, e o sal de metal alcalino resultante.Tanto fatores técnicos como regulatórios da FDA e da União Européia, entre outras, têm incentivado o desenvolvimento de processos menos poluentes para a síntese de emulsificantes, especialmente para aqueles usados em aplicações farmacêuticas ou relacionados à área de alimentos. 17Recentemente a síntese de MAG catalisada por lipases t...
This work investigated the in vivo and in vitro effects of HgCl2 and ZnCl2 on metabolic enzymes from tissues of young rats to verify whether the physiological and biochemical alterations induced by mercury and prevented by zinc are related to hepatic and renal glucose metabolism. Wistar rats received (subcutaneous) saline or ZnCl2 (27 mg/kg/day) from 3 to 7 days old and saline or HgCl2 (5.0 mg/kg/day) from 8 to 12 days old. Mercury exposure increased the hepatic alanine aminotransferase (∼6-fold) and glucose 6-phosphatase (75%) activity; zinc pre-exposure prevented totally and partially these mercury alterations respectively. In vitro, HgCl2 inhibited the serum (22%, 10 μM) and liver (54%, 100 μM) alanine aminotransferase, serum (53%) and liver (64%) lactate dehydrogenase (10 μM), and liver (53%) and kidney (41%) glucose 6-phosphatase (100 μM) from 10- to 13-day-old rats. The results show that mercury induces distinct alterations in these enzymes when tested in vivo or in vitro as well as when different sources were used. The increase of both hepatic alanine aminotransferase and glucose 6-phosphatase activity suggests that the mercury-exposed rats have increased gluconeogenic activity in the liver. Zinc prevents the in vivo effects on metabolic changes induced by mercury.
This work investigated the effects of copper as preventive treatment against mercury-induced alterations in young rats. Wistar rats were treated (subcutaneous) with saline or CuCl(2) · 2H(2) O (6.9 mg/kg/day) from 3 to 7 days old and with saline or HgCl(2) (5.0 mg/kg/day) from 8 to 12 days old. Rats were sacrificed 24 h after the last dose. Mercury-exposed rats presented inhibition of liver (43%) and kidney (52%) porphobilinogen (PBG)-synthase activity and serum lactic dehydrogenase activity (50%). Also, an increase of the serum creatinine and urea levels around threefold and fivefold was observed, respectively. Pre-exposure to copper partially prevented the mercury effect on liver but not on kidney PBG synthase, and prevented the increase of the creatinine levels. Blood and brain PBG synthase and serum alanineaminotransferase activities, as well as glycemia, and liver glycogen content were not altered by treatments. These results show that copper, although being an essential metal, is inefficient as a preventive agent against mercury poisoning in parameters investigated after the end of mercury exposure.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.