A Rapid Colour Test for the Detection of Karanja (Pongamia glabra) Oil in other Vegetable Oils

A rapid colour test was development to detect adulteration or contamination of edible or non-edible vegetable oils with karanja (Pongamia glabra) oil either raw or refined with alkali, acid, alcohol or alcohol-alkali and bleached. The test is based on the development of an intense orange to bright red colour on contacting the oil with phosphoric acid. The detection limit is 1%.     

Nutritional quality of detoxified karanja (Pongamia glabra) oil

Fatty acid composition of crude karanja (Pongamia glabra) oil resembles groundnut oil but it contains some toxic phenolic compounds, like karanjin and pongamol. Removal of these phenolic compounds prior to edible use is therefore important. Nutritional quality of the refined karanja oil (detoxified by isopropanol extraction, bleaching and deodorization) has been investigated in rats by feeding this oil where groundnut oil has been used as control. These two oils were fed at a 20% level in each group in an 18% protein and 55% starch diet for six weeks. The refined karanja oil was observed to be utilized in an identical manner to that of groundnut oil as revealed by growth of rats, food efficiency ratio and the lipid profile of serum and liver tissues.     

Epoxidation of karanja (Pongamia glabra) oil by H2O2

Epoxidation of karanja oil (KO), a nondrying vegetable oil, was carried out with peroxyacetic acid that was generated in situ from aqueous hydrogen peroxide and glacial acetic acid. KO contained 61.65% oleic acid and 18.52% linoleic acid, respectively, and had an iodine value of 89 g/100 g. Unsaturated bonds in the oil were converted to oxirane by epoxidation. Almost complete epoxidation of ethylenic unsaturation was achieved. For example, the iodine value of the oil could be reduced from 89 to 19 by epoxidation at 30°C. The effects of temperature, hydrogen peroxide-to-ethylenic unsaturation ratio, acetic acid-to-ethylenic unsaturation ratio, and stirring speed on the epoxidation rate and on oxirane ring stability were studied. The rate constant and activation energy for epoxidation of KO were 10⁻⁶ L·mol⁻¹·s⁻¹ and 14.9 kcal·mol⁻¹, respectively. Enthalpy, entropy, and free energy of activation were 14.2 kcal·mol⁻¹, −51.2 cal·mol⁻¹·K⁻¹, and 31.1 kcal·mol⁻¹, respectively. The present study revealed that epoxides can be developed from locally available natural renewable resources such as KO.     

Pongamia glabra seed oil based poly(urethane–fatty amide)

Poly(urethane–fatty amide) (PUPGFA) was developed to use nonedible and nondrying Pongamia glabra seed oil. The resin was synthesized by the reaction of N,N‐bis(2‐hydroxyethyl) P. glabra fatty amide (HEPGFA) and tolylene‐2,4‐diisocyanate through a one‐shot technique with a minimal amount (8–10%) of organic solvent. The structural elucidation of the resin was carried out by Fourier transform infrared (FTIR), ¹H‐NMR, and ¹³C‐NMR spectroscopic techniques, whereas the curing mechanism was confirmed by FTIR spectroscopy and differential scanning calorimetry. The solubility of the resin was studied in different polar and nonpolar solvents. Thermal analysis was carried out by thermogravimetric analysis and differential thermal analysis techniques. Antibacterial studies of HEPGFA and PUPGFA were performed in the presence of Gram‐negative Salmonella and Gram‐positive Staphylococcus aureus bacteria by an agar diffusion method. Physicochemical, physicomechanical, and corrosion‐resistance tests were performed by standard laboratory methods. PUPGFA had good physicomechanical properties, excellent chemical/corrosion resistance, and moderate antibacterial activities. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

A new color test for detecting pongam(Pongamia glabra) seed oil

A rapid color test for the detection of 3% or more of pongam (Pongamia glabra) seed oil in other fats, based on the intense yellow to bright orange color which the oil gives on coming in contact with antimony trichloride, has been described.     

Epoxidation of karanja (Pongamia glabra) oil catalysed by acidic ion exchange resin

Karanja oil with an iodine value of 89 g/100 g was epoxidised in situ with aqueous hydrogen peroxide and acetic acid in the presence of Amberlite IR‐120 acidic ion exchange resin as catalyst. The effect of the operating variables on the oxirane oxygen content, as well as on the oxirane ring stability and the iodine value of the epoxidised karanja oil, were determined. The variables studied were stirring speed, hydrogen peroxide‐to‐ethylenic unsaturation molar ratio, acetic acid‐to‐ethylenic unsaturation molar ratio, temperature, and catalyst loading. The effects of these parameters on the conversion to the epoxidised oil were studied and the optimum conditions for the maximum oxirane content were established. The proposed kinetic model takes into consideration the two side reactions, namely, epoxy ring opening involving the formation of hydroxy acetate and hydroxyl groups, and the reaction between the peroxyacid and the epoxy group. The kinetic and adsorption constants of the rate equations were estimated by the best fit using Marquardt's algorithm. Good agreement between experimental and predicted data validates the proposed kinetic model. From the estimated kinetic constants, the apparent activation energy for the epoxidation reaction was found to be 11 kcal/mol.     

Modification of karanja oil (Pongamia glabra) by fractionation,blending, and transesterification

In the present study the modification of detoxified and completely refined karanja oil (Pongamia glabra) was studied by physical and chemical means. Karanja oil was fractionated by the detergent fractionation process at low temperature (3 °C). Astearin fraction was obtained with a yield of 11.0 %. The stearin fraction as such or after bioacidolysis, was found to be suitable as margarine fat bases. Karanja oil was also blended with fats like palm stearin, vanaspati, hydrogenated rice bran oil, and hydrogenated soybean oil in various proportions. The blended products as such or after interesterification were found to be suitable as shortenings, margarine fat bases, or vanaspati substitute.     

Studies on self cured zinc-containing Pongamia glabra oil based polyesteramide

Efforts have been made for the development of high performance protective coating materials from non drying oil such as Pongamia glabra oil and their commercialization. Zn-containing self cured Pongamia glabra oil based polyesteramide [Zn-APGPEA] resin was synthesized in situ by the reaction of Pongamia glabra fatty amide diol [HEPGA], poly(styrene-co-maleic anhydride) [SMA] and zinc acetate (different ratios) at 100 ± 5 °C in the presence of an acid catalyst. The physico-chemical characterizations of the resin were carried out by standard laboratory methods. The structural elucidation of the prepared resin was carried out by FTIR, ¹H NMR and ¹³C NMR spectral techniques. The thermal behavior was studied by TGA technique. Antibacterial activity was measured by agar diffusion method against Escherichia coli and Staphylococcus aureus. The effect of the loading of zinc on properties of Zn-APGPEA film was also investigated. The properties of Zn-APGPEA compared with reported self cured Pongamia glabra polyesteramide [APGPEA]. Physico-mechanical and chemical/corrosion resistance test of Zn-APGPEA coatings showed that the presence of zinc metal in APGPEA considerably enhances the overall film performance and also improves antibacterial activity. Therefore, Zn-APGPEA can be used as an anti-corrosive and antibacterial coatings material which may substitute polymers obtained from petroleum.     

A method for isolation of karanjin from the expelled cake of Pongamia glabra

Due to the renewed interest in the production of biodiesel from nonconventional oils like karanja (Pongamia glabra), huge quantity of expelled cake will be generated in near future. However, due to the presence of several antinutritional components, expelled karanja cake cannot be used as feed for poultry and livestock. It needs detoxification and the first step during detoxification is the removal of karanjin, the major bioactive constituent. The present study aimed at isolation of karanjin from expelled cake. Accordingly, a simple and scalable process was developed for the isolation of karanjin with purity in the range of 95–97% from the expelled cake of karanja. Different solvents were screened by varying temperature, time, and amount of extracting solvents to extract karanjin from the expelled cake and dimethyl carbonate (DMC) was found to be the best among them. DMC extraction of 1.0 kg of expelled cake yielded 3.6 g (0.36% with respect to expelled cake) of karanjin of 97% purity.     

Protease inhibitors and in vitro digestibility of karanja (Pongamia glabra) oil seed residue. A comparative study of various treatments

Trypsin and chymotrypsin inhibitor activities (TIA and CIA) were assayed before and after processing of Karanja oil seed residue. Upon treatment, the loss of TIA and CIA varied with the type of processing or extraction: the reduction after solvent extraction ranged between 34 and 15%, respectively. These activities were completely removed in 2.4% HCl; 83.35 and 54.86% were removed on autoclaving; 33.86 and 15.30% on fermentation; and removal was 4.36–83.69% and 3.66–77.59% after exposure to different doses of gamma radiation (1, 5, 10, and 50 KGy). An in vitro digestibility study was carried out to confirm the inactivation of the inhibitors and showed improvements from 45 to 81%, with the maximum observed in 2.4% HCl solvent-refluxed residue. A linear relationship was observed between the reduction in protease inhibitor activities and the improvement in digestibility.     

Cordierite Honeycomb Monoliths Coated with Zirconia and Its Modified Forms for Biodiesel Synthesis from Pongamia glabra

This study investigates the use of cordierite honeycomb monoliths coated with solid acids such as zirconia, Mo(VI)/ZrO₂ and Pt‐SO₄^2?/ZrO₂ and solid bases like zirconia–calcia, zirconia–magnesia mixed oxides in the synthesis of biodiesel from oil (PG‐oil). Solid acids were used for the esterification of free fatty acids in PG‐oil with methanol to reduce the percentage of free fatty acids in the oil followed by transesterification of PG‐oil over solid bases to synthesize biodiesel. The oxide catalysts were coated on honeycombs by an impregnation technique and characterized for their surface acidity/basicity, crystallinity and morphology. The effect of the molar ratio of PG‐oil/methanol in esterification and transesterification was studied. Reactivation and reusability of both solid acid and solid base catalysts was investigated. The catalysts were also prepared in their powder forms and their activity was compared with that of honeycomb coated forms. A twofold increase in the yield of biodiesel was obtained when the catalysts were used in honeycomb coated forms. The results revealed that the honeycombs coated with mixed oxides such as zirconia–calcia and zirconia–magnesia were economical, efficient and eco‐friendly (3e concept) for biodiesel production with ~95 % yield.     

Lipid Profile and Fatty Acid Composition of Moth Bean (Vigna aconitefolia) Seeds

The seeds of moth bean (Vigna aconitefolia) were found to contain 4.5 % of lipid. Fractionation of this lipid by silicic acid column chromatography yielded 44.5 % neutral lipids (NL), 23.4 % glycolipids (GL) and 32.1 % phospholipids (PL). Fatty acid composition of the total lipid and lipid fractions showed that palmitic acid (37.3-54.7 %), stearic acid (7.8-8.0%) oleic acid (6.8-13.9 %) linoleic acid (23.1-35.6 %) and linolenic acid (3.0-10.0%) are the major fatty acids. The phospholipid fraction was found to be different from the rest in containing higher palmitic acid (54.7%) and lower unsaturated fatty acids.     

Oil, Fatty Acid Profile and Karanjin Content in Developing Pongamia pinnata (L.) Pierre Seeds

Oil content, fatty acid composition and karanjin content were studied in developing pongamia seeds, at intervals of 3?weeks from 30?weeks after flowering up to 42?weeks. Three marked stages in seed development were observed at the early green pod stage, the middle half brown stage and the late dark brown stage. Significant variation in seed biomass, pod and seed characteristics were observed. A significant (P?<?0.01) decrease in the moisture content of the seeds was observed during seed development. The oil content gradually increased from 32.06 to 36.53?% as the seed matured. A significant variation in fatty acid composition was detected across all stages of seed development. Palmitic acid (16:0) content marginally decreased from 11.81 to 10.18?%, while stearic acid (18:0) and linolenic acid (18:3) remained constant at all stages of seed maturity. A steady increase in oleic acid (18:1) content from 38.11 to 49.11?% was observed, while the linoleic acid (18:2) content decreased from 30.14 to 18.85?%. The iodine value increased, while the saponification number of oil decreased during seed development. The increase in karanjin content was steady. Seeds harvested after 42?week after flowering yielded the maximum oil with high oleic acid content which could be suitable for biodiesel production.     

Localisation of Storage Reserves in Developing Seeds of Pongamia pinnata (L.) Pierre, a Potential Agroforestry Tree

Pongamia pinnata is an important oil yielding perennial tree species. The aim of the present study was to document the histological and ultrastructural change that is occurring during pongamia seed development. The seeds were sampled at five stages of development at intervals of 3 weeks starting from 30 weeks after flowering up to 42 weeks. The seed development was followed microscopically using toluidine blue staining. The seed coat was made up of an external layer of palisade cells, an internal layer of hourglass cells followed by a parenchymatous cell layer and aleurone cell layer. The seed reserve compounds such as polysaccharides, proteins and starch showed distinct histochemical characterisation. Lignin was mainly found in the seed coat cell layers, while polysaccharides, proteins and starch granules in the cotyledon cells. The ultrastructural studies showed marked cellular changes during the seed development. The cell size varied from 9.4 to 78 μm during the seed development. The number of oil bodies per cell ranged from 200 to 300 at 42 weeks after flowering. Protein storage vacuoles were observed during the later stages of seed development. The plastids contained electron-dense starch granules. The seeds harvested after 42 weeks after flowering had maximum physiological maturity with high oil content and other seed reserve materials. This basic knowledge on pongamia seed development could invariably be used for further understanding of biochemical changes that might be involved in the biosynthetic pathway of oil.     

Transesterification of karanja (Pongamia pinnata) oil by solid basic catalysts

The transesterification of karanja oil with methanol was carried out using solid basic catalysts. Alkali metal‐impregnated calcium oxide catalysts, due to their strong basicity, catalyze the transesterification of triacylglycerols. The alkali metal (Li, Na, K)‐doped calcium oxide catalysts were prepared and used for the transesterification of karanja oil containing 0.48–5.75% of free fatty acids (FFA). The reaction conditions, such as catalyst concentration, reaction temperature and molar ratio of methanol/oil, were optimized with the solid basic Li/CaO catalyst. This catalyst, at a concentration of 2 wt‐%, resulted in 94.9 wt‐% of methyl esters in 8 h at a reaction temperature of 65 °C and a 12 : 1 molar ratio of methanol to oil, during methanolysis of karanja oil having 1.45% FFA. The yield of methyl esters decreased from 94.9 to 90.3 wt‐% when the FFA content of karanja oil was increased from 0.48 to 5.75%. The performance of this catalyst was not significantly affected in the presence of a high FFA content up to 5.75%. The catalytic activities of Na/CaO and K/CaO were also studied at the optimized reaction conditions. In these two cases, the reaction initially proceeds slowly, however, leading to similar yields as in the case of Li/CaO after 8 h of reaction time. The purified karanja methyl esters have an acid value of 0.36 mg KOH/g and an ester content of 98.6 wt‐%, which satisfy the American as well as the European specifications for biodiesel in terms of acid value and ester content.     

LPEATs Tailor Plant Phospholipid Composition through Adjusting Substrate Preferences to Temperature

Acyl-CoA:lysophosphatidylethanolamine acyltransferases (LPEATs) are known as enzymes utilizing acyl-CoAs and lysophospholipids to produce phosphatidylethanolamine. Recently, it has been discovered that they are also involved in the growth regulation of Arabidopsis thaliana. In our study we investigated expression of each Camelina sativa LPEAT isoform and their behavior in response to temperature changes. In order to conduct a more extensive biochemical evaluation we focused both on LPEAT enzymes present in microsomal fractions from C. sativa plant tissues, and on cloned CsLPEAT isoforms expressed in yeast system. Phylogenetic analyses revealed that CsLPEAT1c and CsLPEAT2c originated from Camelina hispida, whereas other isoforms originated from Camelina neglecta. The expression ratio of all CsLPEAT1 isoforms to all CsLPEAT2 isoforms was higher in seeds than in other tissues. The isoforms also displayed divergent substrate specificities in utilization of LPE; CsLPEAT1 preferred 18:1-LPE, whereas CsLPEAT2 preferred 18:2-LPE. Unlike CsLPEAT1, CsLPEAT2 isoforms were specific towards very-long-chain fatty acids. Above all, we discovered that temperature strongly regulates LPEATs activity and substrate specificity towards different acyl donors, making LPEATs sort of a sensor of external thermal changes. We observed the presented findings not only for LPEAT activity in plant-derived microsomal fractions, but also for yeast-expressed individual CsLPEAT isoforms.     

Bis(monoacylglycero)phosphate as a Macrophage Enriched Phospholipid

Bis(monoacylglycero)phosphate (BMP) is a structural isomer of phosphatidylglycerol (PtdGro) with an unusual sn‐1:sn‐1′ fatty acyl configuration and is found almost exclusively in late endosomes/lysosomes. BMP comprises only about 1–2 % of the total phospholipids in most mammalian cells, but accumulates in tissues of humans and animals with lysosomal storage disorders including the gangliosidoses. Total BMP content was significantly greater in cells of macrophage/microglial origin than in cells of macroglial origin. BMP composition was similar in tumorigenic/metastatic macrophages and non‐tumorigenic macrophages/microglia. Finally, BMP fatty acid composition differed between cells grown in culture and obtained in vivo suggesting an influence from growth environment.     

The Phospholipid Composition of Kangaroo Spermatozoa Verified by Mass Spectrometric Lipid Analysis

Cryopreservation of kangaroo sperm has not been successful so far, and yet there is no promising cryopreservation protocol for these cells available. However, conservation of gametes is extremely important, particularly in the context of preserving endangered species. As spermatozoa are comprised of different membrane systems, the composition of these membranes might account for difficulties in cryopreservation. Lipids, as the main components, affect the physical properties of biological membranes and play a major role in sperm maturation. Therefore, knowledge of the lipid composition is crucial for any further step toward the preservation of the species. We used MALDI‐TOF, ESI‐IT, tandem mass spectrometry, and thin layer chromatography to investigate the lipid composition of epididymal spermatozoa of four different kangaroo species. Spectra of these species were very similar with respect to the identified lipid species. Tremendous changes in the lipid composition during the transit of sperm from caput to cauda epididymis could be seen, specifically an increase in poly‐unsaturated fatty acids, ether lipids, and plasmalogens, as well as a reduction in mono‐ and di‐unsaturated fatty acids. Additionally, phosphatidylcholines containing docosatrienoic acid (22:3), a heretofore unknown fatty acid for sperm membranes, showed the highest abundance in kangaroo sperm.     

STUDIES OF TRANSESTERIFICATION OF KARANJA (Pongamia pinnata) OIL IN A PACKED BED REACTOR

Studies were made to determine the influence of different reaction temperatures and residence times on biodiesel yield by transesterification of karanja oil (Pongamia pinnata) in the presence of methanol using a solid acid heterogeneous catalyst in a continuous process. Recycle runs were conducted by further transesterification of the organic phases (first run mixture of methyl ester and unconverted oil) in the presence of methanol under similar conditions. High-pressure liquid chromatography (HPLC) reveals poor biodiesel yield even with an increase in the reaction temperature and residence time in the first run. Biodiesel yield obtained from the recycle runs, however, was greatly increased over that of the first-run biodiesel yield. Recycle transesterification at a reaction temperature of 240°C and residence time of 50 min gives a maximum yield value of 97.74%. Consequently, irrespective of the presence of high free fatty acids and other impurities in karanja oil, recycling the organic phase of the first run significantly enhances the biodiesel yield.     

Phospholipid Hydrolysis and Transphosphatidylation by Phospholipase D from Indian Mustard Seeds in Two-Phase Systems

Phospholipase D (PLD), isolated from Indian mustard seeds and purified to homogeneity, has recently been identified as typical α‐type PLD with a high activity toward phosphatidylcholine (PC) in an aqueous mixed micellar system (Khatoon et al. 2014, Phytochemistry 117, 65–75). In light of biocatalytical application, we have now studied the enzyme in aqueous‐organic two‐phase systems and compared the results with the properties of the enzyme in aqueous mixed micellar systems. n‐Hexane containing 5–10 mol% of 1‐ or 2‐octanol proved to be optimal as an organic solvent in the two‐phase system, whereas anionic detergents such as sodium dodecyl sulfate or sodium deoxycholate were favorable components in the mixed micellar system. The optimum pH value (5.5–5.6) and the optimum Ca²⁺ ion concentration (70 mM) were independent of the reaction system. The head group selectivity in terms of activity toward different phospholipids (PC > phosphatidylethanolamine > phosphatidylglycerol) was similar in both types of reaction systems. Also, the K_M values toward PC were on the same order of magnitude. In contrast, the V_max value in the two‐phase system was 20‐fold lower than in the mixed micellar system. The enzyme was able to catalyze the substitution of choline in PC by ethanolamine, glycerol, and ethylene glycol with high efficiency. l ‐Serine was exchanged for choline with low activity. Myo‐inositol was not an alcohol acceptor, but promoted the hydrolysis of PC.