Lipase catalyzed deacidification of high free fatty acid rice bran oil

Summary Deacidification of high free fatty acid (45%) rice bran oil has been attempted usingMucor miehei lipase for which a mathematical model has been proposed. The optimum values of the significant variables viz. enzyme and glycerol concentrations were determined using the response surface technique.     

Sustainable utilization of oil palm wastes for bioactive phytochemicals for the benefit of the oil palm and nutraceutical industries

For a hectare of oil palm plantation, about 21.63 tonnes of biomass comprising 20.43 % empty fruit bunches, 5.09 % palm kernel shells, 11.65 % oil palm trunks, 50.30 % oil palm fronds and 12.53 % palm pressed fibre is produced per year as wastes which keep raising many environmental concerns as most of them are incinerated and dumped at open sites. Oil palm wastes are found to contain phytochemicals which have anti-cancer, antioxidants and other vital biological activities. About 17–65 kg of carotenoids, 0.1–60 kg phenolic compounds, 0.6–39 kg sterols and 4.0–62 kg tocols could be extracted from these wastes which would not only boost the economy but also help improve human health and promote clean environments. This study assesses the phytochemistry of oil palm wastes and their pharmacological activities beneficial to the nutraceutical industry with the view of utilizing oil palm wastes for sustainable development.     

Enzymatic transesterification of palm stearin and olein blends to produce zero-trans margarine fat

ABSTRACT: BACKGROUND: Food industries aim to replace trans fat in their products by formulations having equivalent functionality and economic viability. Enzymatic transesterification can be a technological option to produce trans free fats targeting commercial applications. RESULTS: Palm stearin and palm olein blends in different ratios were enzymatically transesterified in a solvent free system using a Rhizopus oryzae lipase immobilised onto CaCO3 to produce a suitable fat for margarine formulation. Slip melting points and triacylglycerols profiles were evaluated upon transesterification. Results indicated that all transesterified blends had lower slip melting points than their non transesterified counterparts. Furthermore, the triacylglycerols profile showed a decrease in the concentration of the high melting point triacylglycerols. The rheological analysis showed that margarine prepared with the transesterified blend showed a better spreadability than that of a control margarine prepared with non transesterified fat. Adding powder of dry bark orange to margarine preparation improved its colour and fairly affected its spreadability and rheological behaviour. The margarine prepared with transesterified fat displayed a rheological behaviour that was comparable to that of commercial sample. CONCLUSIONS: This study is an ecofriendly approach to the utilization of relatively low value bioresources like palm stearin and palm olein for making margarine free of trans fatty acids that are now implicated as risk factor for heart diseases.     

Rice bran lipase catalyzed esterification of palm oil fatty acid distillate and glycerol in organic solvent

Rice bran lipase (RBL) was delipidated to enhance its stability in organic solvent and its esterification activity at elevated temperature. The esterification activity of delipidated RBL increased as temperature was increased from 45 to 65°C. The esterification activity of delipidated RBL at 65°C was about 14 times greater than that of the non-delipidated RBL. As temperature was further increased to 75°C, the non-delipidated RBL lost all esterification activity, whereas the delipidated RBL retained approximately 48% of its esterilication activity. The delipidated RBL maintained a relative esterification activity greater than 80% after 16 h of incubation in hexane, whereas the non-delipidated RBL maintained a relative esterification activity of only 50%. A method for production of acylglycerol using delipidated RBL to esterify palm oil fatty acid distillate (PFAD) with glycerol in hexane was successfully developed. The effects of reaction temperatures and type of water removal agents (silica gel and molecular sieve) on the degree of esterification were also examined. A 4 h reaction at 65°C, catalyzed by delipidated RBL and using silica gel as the water removal agent resulted in 53.8% esterification. Thin layer chromatography analysis suggested that the esterified product was primarily comprised of mono-and di-acylglycerols.     

Lipase catalyzed preparation of biodiesel from Jatropha oil in a solvent free system

The monoethyl esters of the long chain fatty acids (biodiesel) were prepared by alcoholysis of Jatropha oil, a non-edible oil, by a lipase. The process optimization consisted of (a) screening of various commercial lipase preparations, (b) pH tuning, (c) immobilization, (d) varying water content in the reaction media, (e) varying amount of enzyme used, and (f) varying temperature of the reaction. The best yield 98% (w/w) was obtained by using Pseudomonas cepacia lipase immobilized on celite at 50 °C in the presence of 4–5% (w/w) water in 8 h. It was found that yields were not affected if analytical grade alcohol was replaced by commercial grade alcohol. This biocatalyst could be used four times without loss of any activity.     

Characterization of oat lipase for lipolysis of rice bran oil

Summary Lipases from plant and microbial sources were screened for lipolysis of rice bran oil (RBO). Oat lipase was found to give reproducibly 60% lipolysis. Factors affecting the efficiency of lipolysis such as oil:emulsifier ratio, duration of homogenization for the substrate preparation, substrate:enzyme ratio, substrate pH, kinetics of lipolysis and efficiency of lipase as a function of pH, oat particle size, its quality and reuseability were studied to assess the feasibility of using of oat lipase for splitting RBO commercially. The efficiency of lipolysis was optimal at (a) RBO:emulsifier (0.5:1) ratio, homogenized for 2.5 min, (b) pH 7.5 and (c) substrate:enzyme ratio of 5 ml: 2 g.     

A two-step acid-catalyzed process for the production of biodiesel from rice bran oil

A study was undertaken to examine the effect of temperature, moisture and storage time on the accumulation of free fatty acid in the rice bran. Rice bran stored at room temperature showed that most triacylglyceride was hydrolyzed and free fatty acid (FFA) content was raised up to 76% in six months. A two-step acid-catalyzed methanolysis process was employed for the efficient conversion of rice bran oil into fatty acid methyl ester (FAME). The first step was carried out at 60 degrees C. Depending on the initial FFA content of oil, 55-90% FAME content in the reaction product was obtained. More than 98% FFA and less than 35% of TG were reacted in 2 h. The organic phase of the first step reaction product was used as the substrate for a second acid-catalyzed methanolysis at 100 degrees C. By this two-step methanolysis reaction, more than 98% FAME in the product can be obtained in less than 8 h. Distillation of reaction product gave 99.8% FAME (biodiesel) with recovery of more than 96%. The residue contains enriched nutraceuticals such as gamma-oryzanol (16-18%), mixture of phytosterol, tocol and steryl ester (19-21%).     

Lipase catalyzed production of monoacylglycerols by the esterification of fish oil fatty acids with glycerol

In this study, we attempted the efficient production of monoacylglycerols (MAG) via the lipase-catalyzed esterification of glycerol with fatty acids obtained from sardine oil. The reaction factors that influenced MAG synthesis were the glycerol to fatty acid mole ratio, amount of enzyme, organic solvent, temperature, and the type of lipase used. Porcine pancreas lipase was selected to catalyze this reaction. The optimum conditions we determined for MAG synthesis were a glycerol to fatty acid mole ratio of 1∶6, 100 mg/mL of lipase, and 30°C in dioxane. Under these conditions, the MAG content was 68% (w/w) after 72 h of reaction. The MAGs synthesized via the lipase-catalyzed esterification of glycerol with fatty acids included monomyristin, monopamiltin, and monoolein, as identified by GCMS.     

Comparative hypoglycemic and nephroprotective effects of tocotrienol rich fraction (TRF) from palm oil and rice bran oil against hyperglycemia induced nephropathy in type 1 diabetic rats

Diabetic nephropathy (DN) is a serious complication confronted by patients with diabetes. Available data indicate that the development of DN is linked to hyperglycemia. Tocotrienol rich fraction (TRF) from palm oil (PO) and rice bran oil (RBO) has been shown to lower the blood glucose level in patients and preclinical animal models. This study was designed to investigate if TRF from PO and RBO could improve the renal function in DN by the virtue of their hypoglycemic and antioxidant activities. Male Wistar rats having an average body weight (bw) 250 g were divided into four groups of six each .The first group served as diabetic control [injected with 55 mg/kg bw of streptozotocin (STZ), intraperitoneally], while the second and third group received PO-TRF and RBO-TRF, respectively, by gavage at a dose of 200 mg/kg bw/day, over a period of 8 weeks post-induction of diabetes. The fourth group comprised of age-matched male Wistar rats that received single intraperitoneal injection of normal saline only and served as control. After 8 weeks of STZ injection and TRF treatment, 24 h urine was collected and animals were sacrificed. Fasting blood glucose, glycosylated hemoglobin, biochemical markers of renal function and oxidative stress were evaluated in serum, urine and kidney tissue. The results show that treatment with PO-TRF as well as RBO-TRF significantly improved the glycemic status and renal function in type 1 diabetic rats but PO-TRF afforded greater efficiency at similar dose as compared to RBO-TRF. In conclusion, PO-TRF was found to be more effective hypoglycemic and nephroprotective agent in DN than RBO-TRF.     

Effect of long term feeding of rice bran oil upon lipids and lipoproteins in rats

The effects of feeding two levels of rice bran oil (RBO) on the growth, lipid parameters, and fatty acid composition of the plasma and liver of rats (Wistar strain) were compared with those produced on animals which had been fed the same levels of peanut oil (PNO). The control animals were fed synthetic diets containing 5 and 20% peanut oil (PNO) and the experimental groups were fed similar diets, containing the same level of rice bran oil (RBO). There was no significant difference with respect to the organ weights between the control and the experimental groups. In general, groups fed 20% oil gained more weight than groups fed 5% oil. The animals which received rice bran oil in their diet had, in general, comparatively lower levels of cholesterol, triglycerides and phospholipids. On the other hand, animals receiving 20% rice bran oil in their diet, showed an increase of 20% in high density lipoproteins (HDL-C), within 18 weeks (p<0.05), when compared to the animals fed with peanut oil. Similarly, low density lipoprotein cholesterol (LDL-C) and very low density lipoprotein cholesterol (VLDL-C) were lower in RBO-fed groups, than in the PNO-fed groups. There was, however, no significant differences in the cholesterol/phospholipid (C/P) ratio of the two groups. Analysis of plasma and of liver fatty acids indicated, in a general way, the type of fat consumed. There were no significant difference in the P/S ratio, nor any in the oleic/linoleic, oleic/stearic, palmitoleic/palmitic, oleic/palmitic, and oleic/palmitoleic ratios. Furthermore, levels of saturated (SAFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids were identical in both the groups. Thus, our results suggest that feeding a high level of rice bran oil (RBO) has no deleterious effect on the growth and blood lipid profile of rats.Abbreviations PNO peanut oil - RBO rice bran oil - HDL-C high density lipoprotein cholesterol - LDL-C low density lipoprotein cholesterol - VLDL-C very low density lipoprotein cholesterol - SAFA saturated fatty acids - MUFA mono-unsaturated fatty acids     

Production of vanillin from waste residue of rice bran oil by Aspergillus niger and Pycnoporus cinnabarinus

A new technology of transforming ferulic acid, which was from waste residue of rice bran oil, into vanillin was developed by a combination of fungal strains Aspergillus niger CGMCC0774 and Pycnoporus cinnabarinus CGMCC1115. Various concentrations of ferulic acid were compared, and the highest yield reached 2.2 g l(-1) of vanillic acid by A. niger CGMCC0774 in a 25 l fermenter when concentration of ferulic acid was 4 g l(-1). The filtrate of A. niger CGMCC0774 culture was concentrated and vanillic acid in the filtrate was bio-converted into vanillin by P. cinnabarinus CGMCC1115. The yield of vanillin reached 2.8 g l(-1) when 5 g l(-1) of glucose and 25 g of HZ802 resin were supplemented in the bioconversion medium. The 13C isotope analysis indicated that delta13C(PDB) of vanillin prepared was much different from chemically synthesized vanillin.     

Microwave-assisted preparation of bagasse and rice straw for the removal of emulsified oil from wastewater

The present study was carried out to examine modified bagasse and rice straw as absorbents for the removal of emulsified oil by a microwave-assisted technique. The raw adsorbents were chemically modified with sodium hydroxide and surfactant solution for better adsorption of oil. The surface modification was confirmed through Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (SEM) analysis. Batch studies were performed to identify the influence of contact time, pH, dosage, speed, and temperature on the percentage of removal of emulsified oil from the wastewater. A maximum oil removal of 98.07% and 98.72% was achieved in microwave-assisted bagasse and rice straw at 313 K. The obtained data were compared with isotherm and kinetic models to understand the mechanism behind the adsorption. From the Langmuir isotherm model, a maximum adsorption capacity of 192.58 and 276.82 mg/g was observed for modified bagasse and rice straw. The oil-loaded raw and microwave-assisted adsorbents can act as a potential energy source for renewable energy.     

Continuous and consecutive conversion of free fatty acid in rice bran oil to triacylglycerol using immobilized lipase

Free fatty acid (FFA), monoacylglycerol (MG) and diacylglycerol (DG) in high-FFA rice bran oil were continuously converted with glycerol (G) to form triacylglycerol (TG), using lipase fromRhizomucor miehei immobilized on anion-exchange resin. The reaction was continued for more than 1 month by a reactor with two circulation loops, each being connected to a fixed-bed reactor and a dehydrator. The reaction of 2 FFA + G DG + 2H₂O appeared to occur until the glycerol was exhausted; the reaction of FFA + DG TG + H₂O then followed. The consecutive esterificaion continued in the presence of 2–8 ppm water and the TG content reached 74%–88%. The industrial feasibility of this process was assessed from the standpoints of enzyme cost and value added by esterification.     

Bacterial community shift for monitoring the co-composting of oil palm empty fruit bunch and palm oil mill effluent anaerobic sludge

A recently developed rapid co-composting of oil palm empty fruit bunch (OPEFB) and palm oil mill effluent (POME) anaerobic sludge is beginning to attract attention from the palm oil industry in managing the disposal of these wastes. However, a deeper understanding of microbial diversity is required for the sustainable practice of the co-compositing process. In this study, an in-depth assessment of bacterial community succession at different stages of the pilot scale co-composting of OPEFB-POME anaerobic sludge was performed using 454-pyrosequencing, which was then correlated with the changes of physicochemical properties including temperature, oxygen level and moisture content. Approximately 58,122 of 16S rRNA gene amplicons with more than 500 operational taxonomy units (OTUs) were obtained. Alpha diversity and principal component analysis (PCoA) indicated that bacterial diversity and distributions were most influenced by the physicochemical properties of the co-composting stages, which showed remarkable shifts of dominant species throughout the process. Species related to Devosia yakushimensis and Desemzia incerta are shown to emerge as dominant bacteria in the thermophilic stage, while Planococcus rifietoensis correlated best with the later stage of co-composting. This study proved the bacterial community shifts in the co-composting stages corresponded with the changes of the physicochemical properties, and may, therefore, be useful in monitoring the progress of co-composting and compost maturity.     

Energy and nutrient use of palm kernels, palm kernel meal and palm kernel oil in diets for growing pigs

A metabolism experiment was conducted with 13 gilts over four periods to investigate the effects of age or weight of pigs, level of inclusion and methods of estimation of apparent digestible (DE) and metabolizable (ME) energy and nutrient digestibility of full-fat palm kernels (FFPK), recombined palm kernel oil and meal (OPKM) and palm kernel oil (PKO). Each palm kernel product was evaluated at levels equivalent to added oil of 40, 80 and 120 g kg⁻¹ in a basal diet. Extracted palm kernel meal (PKM) was also evaluated in the basal diet at the same level as in OPKM. Thus, 13 treatments arranged in four blocks (time periods) constituted the experimental data analysed using a randomised complete block design. Digestible energy and ME contents and apparent digestibility of nitrogen (ADN), dry matter (ADD) and oil (AOD - employing two oil analytical methods) of palm kernel products were estimated by single level assay and by regression with the latter yielding DE values of 40.2, 19.5, 22.1 and 13.1 MJ/kg DM for PKO, FFPK, OPKM and PKM, respectively. The corresponding values for AOD were 1.08, 0.93, 1.03 and 0.88. While the level of inclusion and pig weight (over the range 40–76 kg) did not significantly affect dietary energy and nutrient digestibility of palm kernel products, the form of oil inclusion had considerable effect with OPKM being better utilized than FFPK. Digestibility of oil in the palm kernel products measured by the ether extract (EE) method was, in general, significantly higher than that estimated by the acid ether extract (AEE) procedure. The results suggest the necessity for digestibility coefficients of oils and fats in oil bearing ingredients to be re-evaluated in the light of the currently applied analytical method as figures obtained using the traditional ether extract method may not be applicable to the true nutritional value of feed ingredients and consequently may lead to imprecise diet formulation.     

Lipase catalyzed reaction of L-ascorbic acid with cinnamic acid esters and substituted cinnamic acids

To perform the lipase-catalyzed synthesis of L-ascorbic acid derivatives from plant-based compounds such as cinnamic and ferulic acid under mild reaction conditions, the activities of immobilized Candida ntarctica lipase with different cinnamic acid esters and substituted cinnamic acids were compared. As a result, immobilized C. ntarctica lipase was found to prefer vinyl cinnamic acid to other esters such as allyl-, ethyl-, and isobutyl cinnamic acids as well as substituted cinnamic acids such as p-coumaric acid, caffeic acid, ferulic acid, and sinapic acid. Based on these results, large-scale synthesis of 6-O-cinnamyl-L-ascorbic acid ester was performed using immobilized C. ntarctica lipase in dry organic solvent, resulting in 68% yield (493 mg) as confirmed by ¹³C-NMR.     

Hypocholesterolemic effect of physically refined rice bran oil: studies of cholesterol metabolism and early atherosclerosis in hypercholesterolemic hamsters

Physically refined rice bran oil containing 2-4% nontriglyceride components as compared to other vegetable oils appears to be associated with lipid lowering and antiinflammatory properties in several rodent, primate and human models. These experiments were designed to investigate possible mechanisms for the hypocholesterolemic effect of the physically refined rice bran oil and to examine its effect on aortic fatty streak formation. In the first experiment, 30 hamsters were fed, for 8 weeks, chow-based diets plus 0.03% added cholesterol and 5% (wt/wt) coconut, canola, or physically refined rice bran oil (COCO, CANOLA or PRBO animal groups, respectively). Both plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly reduced in PRBO but not in CANOLA relative to COCO. PRBO also showed a significant 15-17% reduction in cholesterol absorption and significant 30% increase in neutral sterol (NS) excretion with no effect on bile acid (BA) excretion. Both CANOLA and PRBO showed a significant 300-500% increase in intestinal 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and significant (>25%) decrease in hepatic HMG-CoA reductase activities with respect to COCO. In a second experiment, 36 hamsters were fed chow-based diets with 0.05% added cholesterol, 10% coconut oil and 4% additional COCO, CANOLA or PRBO. Relative to COCO and CANOLA, plasma TC and LDL-C were significantly reduced in PRBO. Early atherosclerosis (fatty streak formation) was significantly reduced (48%) only in PRBO, relative to the other two. These results suggest that the lipid lowering found in PRBO is associated with decreased cholesterol absorption, but not hepatic cholesterol synthesis, and that the decrease in fatty streak formation with this oil may be associated with its nontriglyceride components not present in the other two diets.     

Utilization of oil palm decanter cake for cellulase and polyoses production

The abundance of oil palm decanter cake (OPDC) is a problem in oil palm mills. However, this lignocellulosic biomass can be utilized for cellulase and polyoses production. The effectiveness of chemical and physical pretreatment in reducing the lignin content was studied by saccharification using a Celluclast 1.5 L and scanning electron microscope. Physicochemical pretreatment of OPDC with 1% (w/v) NaOH and autoclaving at 121°C for 20 min increased potential polyoses produced to 52.5% and removed 28.7% of the lignin content. The optimized conditions for cellulase production by a locally isolated fungus were a time of 120 h, a substrate of untreated OPDC, a spore concentration of 1 × 10⁷ spore/mL, a temperature of 30°C, and a pH between 7.0 and 7.5. Trichoderma asperellum UPM1 produced carboxymethylcellulase (CMCase), ??-glucosidase and filter paper activity (FPase) in the following concentrations: 17.35, 0.53, and 0.28 U/mL, respectively. Aspergillus fumigatus UPM2 produced the CMCase, ??-glucosidase and FPase in the following amounts: 10.93, 0.76, and 0.24 U/mL. The cellulases from T. asperellum UPM1 produced 2.33 g/L of polyoses and the cellulases from A. fumigatus UPM2 produced 4.37 g/L of polyoses.     

A critical comparison of methyl and ethyl esters production from soybean and rice bran oil in the presence of microwaves

Transesterification of vegetable oils (from soybeans and rice bran) into methyl and ethyl esters using a batch microwave system was investigated in this study. A critical comparison between the two alcohols was performed in terms of yields, quality, and reaction kinetics. Parameters tested were temperature (60, 70 and 80 °C) and time (5, 10, 15 and 20 min). At all tested conditions, more than 96% conversion rates were obtained for both ethanol and methanol. Use of microwave technology to assist the transesterification process resulted in faster reaction times and reduced catalyst requirement (about ten-fold decrease). Methanol required lower alcohol:oil ratios than normally used in conventional heating, whereas ethanol required higher molar ratios. All esters produced using this method met ASTM biodiesel quality specifications. Methanol performed better in terms of performance and costs, while ethanol may have some environmental and safety benefits.