Journal of the American Oil Chemists' Society (v.88, #4)
Advances in Aqueous Extraction Processing of Soybeans by K. A. Campbell; C. E. Glatz; L. A. Johnson; S. Jung; J. M. N. de Moura; V. Kapchie; P. Murphy (449-465).
Aqueous extraction processing technologies, having advanced in recent years, may be a viable alternative to hexane extraction to separate oil and protein from soybeans. Different extraction strategies incorporating various modes of comminution, extraction buffers, and enzymes allow production of a range of oil and protein products, but also create different processing challenges. Processes capable of achieving high free oil yields often result in a soluble protein fraction difficult to isolate and dilute oil emulsions difficult to break. Other processes can achieve high yields and purities of native soy protein, but with reduced free oil yield or require a high osmotic and ionic strength extraction buffer. This review article discusses these various advanced processes and their relative advantages and disadvantages. In addition, the current understanding of the underlying fundamental concepts of aqueous extraction is discussed in order to help direct future investigations to improve these technologies.
Keywords: Aqueous extraction; Soybeans; Oil; Protein; Demulsification
Characterization of Fatty Oil of Zizyphi spinosi semen Obtained by Supercritical Fluid Extraction by Feng Wang; Xuesong Liu; Yong Chen; Longhu Wang (467-472).
Zizyphi spinosi semen (ZSS) has been widely used for treatment of insomnia in oriental countries. The aim of this study is to characterize the fatty oil of ZSS obtained by supercritical fluid extraction in terms of chemical composition and physicochemical properties. The chemical composition, including fatty acids and unsaponifiable constituents, was analyzed by gas chromatography–mass spectrometer (GC–MS). The results revealed that 9-octadecenoic acid (43.38 ± 0.03%) and 9,12-octadecadienoic acid (40.58 ± 0.03%) were the main fatty acids, and β-sitosterol (37.39 ± 0.02%) and squalene (30.79 ± 0.01%) were the key unsaponifiables. Furthermore, four indexes were assayed according to Chinese Pharmacopeia (2005) to reflect the physicochemical properties of ZSS oil, their values being determined as follows: acid value (10.3 ± 0.1 mg KOH/g), peroxide value (0.05 ± 0.01 g/100 g), saponification value (194.4 ± 0.5 mg KOH/g) and iodine value (109.7 ± 0.8 g I/100 g). The basic information obtained provides data support for quality evaluation and efficacy research of ZSS oil, and suggests its prospects for development in pharmaceutical and food industries.
Keywords: Zizyphi spinosi semen ; Supercritical fluid extraction; Fatty oil; Chemical composition; Physicochemical properties; GC–MS
Production of MLM-Type Structured Lipids Catalyzed by Immobilized Heterologous Rhizopus oryzae Lipase by P. A. Nunes; P. Pires-Cabral; M. Guillén; F. Valero; D. Luna; S. Ferreira-Dias (473-480).
This work aims to produce triacylglycerols (TAG) containing a medium-chain fatty acid (M) at positions sn-1,3 and a long-chain fatty acid (L) at sn-2 position, i.e. TAG of MLM type, by acidolysis of virgin olive oil with caprylic (C8:0) or capric (C10:0) acids, catalyzed by 1,3-selective Rhizopus oryzae heterologous lipase (rROL) immobilized in Eupergit® C and modified sepiolite. This lipase was produced by the methylotrophic yeast Pichia pastoris. Reactions were performed at 25 and 40 °C, for 24 h, either in solvent-free or in n-hexane media, at a molar ratio 1:2 (olive oil:free fatty acid). Higher incorporations of C8:0 (21.6 mol%) and C10:0 (34.8 mol%) into the TAG were attained in solvent-free media, at 40 °C, when rROL immobilized in Eupergit® C was used. In organic media, at 40 °C, only 15.9 and 14.1 mol%, incorporation of C8:0 or C10:0 were, respectively observed. Lower incorporations were attained for both acids (3.4–7.0 mol%) when native ROL (nROL) in both supports and rROL in modified sepiolite were used. rROL in Eupergit® C maintained its activity during the first four or three 23-h batches, respectively when C8:0 (half-life time, t 1/2 = 159 h) or C10:0 (t 1/2 = 136 h) were used, decreasing thereafter following a time delay model.
Keywords: Acidolysis; Capric acid; Caprylic acid; Olive oil; Rhizopus oryzae lipase; Structured lipids
Aqueous Extraction and Enzymatic Destabilization of Coconut Milk Emulsions by S. N. Raghavendra; K. S. M. S. Raghavarao (481-487).
Fresh and mature coconuts were subjected to deshelling, paring and disintegration. The coconut milk was extracted, treated with an enzyme (protease) at different concentrations and centrifuged, in order to separate it into coconut cream and aqueous phases. Subsequently, coconut cream was subjected to chilling (different temperatures) and thawing to ambient temperature (29 ± 2 °C) followed by centrifugation to obtain a clear virgin coconut oil (VCO). Coconut milk treated with aspartic protease at concentration of 0.02 mg/g, resulted in 90.4 ± 1.2% yield. A maximum yield of 95.3 ± 1.0% was obtained when the treatment of coconut milk with aspartic protease at concentration of 0.02 mg/g was followed by chilling (5 °C) and thawing. Physicochemical properties and fatty acid compositions were evaluated and compared with commercial coconut oil samples. It was found that the oil obtained from present study is low with respect to free fatty acids (0.31%) and peroxide value (0.81 mequiv O2/kg) when compared with the commercial coconut oil samples. Sensory evaluation was also carried out to ensure the product acceptability.
Keywords: Coconut milk; Enzyme treatment; Aqueous extraction; Protease; Destabilization; Chilling; Virgin coconut oil
The Efficacy of Compounds with Different Polarities as Antioxidants in Emulsions with Omega-3 Lipids by A.-D. M. Sørensen; N. S. Nielsen; E. A. Decker; M. B. Let; X. Xu; C. Jacobsen (489-502).
According to the so-called polar paradox hypothesis, the efficacy of an antioxidant in emulsions is highly affected by its polarity and thereby location in the different phases. However, other factors also affect the efficacy of antioxidants in multiphase systems. The aim of this study was to evaluate the efficacy of antioxidants [ascorbic acid, ascorbyl palmitate, ascorbyl CLA and CLA (conjugated linoleic acid)] with different polarities in two different emulsion systems: o/w emulsion (5% oil) and w/o emulsion (98% oil) stabilized with citrem and PGPR, respectively. The efficacy of the antioxidants was compared to their partitioning in an o/w emulsion system and to results obtained from different antioxidant assays: iron reducing power, chelating activity and radical scavenging activity. For the w/o emulsions the efficacy of the antioxidants followed the polar paradox hypothesis: ascorbyl palmitate = ascorbyl CLA > ascorbic acid ≥ CLA > reference. For the o/w emulsion the antioxidative effects were not in accordance with the polar paradox. In the beginning of the storage, ascorbyl palmitate and ascorbic acid were most efficient, however in the end they acted as prooxidants. Ascorbyl CLA was located at the interface but was inactive as an antioxidant. This may be due to impurities or interaction with citrem.
Keywords: O/W emulsion; W/O emulsion; Lipid oxidation; Antioxidant activity and partitioning
Chemical Compositions of Oils from Several Wild Almond Species by Ali Moayedi; Karamatollah Rezaei; Sohrab Moini; Behnam Keshavarz (503-508).
Chemical compositions of oils extracted from three wild almond species [Amygdalus scoparia from Beyza, Iran (AZ); A. scoparia from Borazjan, Iran (AJ), and A. hausknechtii from the Firuzabad region, (AH)] and a domestic species, A. dulcis from Estahban, Iran (AD), as a reference, were investigated. Total oil content ranged from 44.4% in AJ to 51.4% in AD. Saponification numbers were in the range of 173.5 (for AJ) to 192.9 for AD. Oxidative stability, total phenolic contents and total wax contents were found to be within the ranges 11.7–14.0 h, 33.9–43.2 and 2.05–2.53%, respectively. The main monounsaturated fatty acid (MUFA) was oleic acid ranging from 66.7% for AH to 69.7% for AZ. The only polyunsaturated fatty acid (PUFA) was linoleic acid ranging from 18.2% for AZ to 23.0% for AD. The major saturated fatty acid was palmitic acid. MUFA contents and MUFA to PUFA ratio in the oils from wild almond species as well as those in the domestic one were found at higher levels than those in the common vegetable oils such as soybean, various nut oils, and also those from the seeds of pomegranate, grape, date and sesame. Oils from wild almond species investigated here are rich in oleic acid and can be considered as potential vegetable oils in the human diet.
Keywords: Fatty acid composition; Oil source; Oil indices; Oxidative stability; Wild almond species
Regiospecific Analyses of Triacylglycerols of Hoki (Macruronus novaezelandiae) and Greenshell™ Mussel (Perna canaliculus) by Matthew R. Miller; Nigel B. Perry; Elaine J. Burgess; Susan N. Marshall (509-516).
The lipid profiles of the two most important New Zealand marine oil sources were investigated, with particular attention to the regioisomeric compositions of triacylglycerides (TAG), using 13C-nuclear magnetic resonance analysis. Oils from hoki (Macruronus novaezelandiae) and Greenshell™ mussel (Perna canaliculus) (GSM) were analyzed for their lipid content, lipid class and fatty acid profile. The regiospecific distribution of long chain (C ≥ 20) polyunsaturated fatty acids (LC-PUFA) between the sn-1,3 and sn-2 glycerol positions was calculated from 13C responses in the carbonyl region in the triacylglycerol fraction. Rendered hoki oil (RHO) produced from the viscera and filleting discards, had a similar lipid profile to that of hoki liver oil (HLO) confirming that the liver is the major source of oil in RHO. The regioisomeric distribution of fatty acids showed differences between the two oil sources. Docosahexaenoic acid (DHA) had a regioisomeric distributional preference to the sn-2 position in TAG from all the oils (59.2% HLO, 54.3% RHO and 63.4% GSM). Eicosapentaenoic acid (EPA) had a more even distribution along the triacylglycerol backbone in hoki TAG (29.1% HLO, 33.6% RHO) while there was a slight sn-2 positional preference in the GSM TAG (37.6%). This regioisomeric information is vital to distinguish LC-PUFA-rich marine oils from other marine sources for authentication purposes.
Keywords: Phospholipids; Triacylglycerols; Fatty acid composition; 13C NMR; Eicosapentaenoic acid; Docosahexaenoic acid; Lipid molecular species
Kinetic Study on Oxirane Cleavage of Epoxidized Palm Oil by Ruihua Guo; Chuanguo Ma; Shangde Sun; Yuxiang Ma (517-521).
A ring-opened product (EPO-HOAc) was prepared using epoxidized palm oil (EPO) and acetic acid (HOAc). The kinetics of the oxirane cleavage of EPO were investigated at 50, 60, 70, 80, and 90 °C, respectively, in the presence of HOAc. The rate equation of oxirane cleavage was as follows: r = k[Ep][CH3COOH]1.6 ([Ep] is the molar concentration of oxiranes, [CH3COOH] is the molar concentration of HOAc), and the activation energy of oxirane cleavage was 40.28 kJ mol−1. The structure of EPO-HOAc was confirmed by FT-IR and 1H NMR. The oxidative stability of EPO-HOAc was better than that of palm oil (PO), and the pour point of EPO-HOAc was lower than that of PO and EPO, which made EPO-HOAc more suitable for biodegradable lubricant materials than PO and EPO.
Keywords: Epoxidized palm oil; Oxirane cleavage; Kinetics; Acetic acid
Enzyme Treatments to Enhance Oil Recovery from Condensed Corn Distillers Solubles by Sandra Majoni; Tong Wang; Lawrence A. Johnson (523-532).
The objective of this study was to determine the effect of enzyme hydrolysis of various corn components on oil recovery from condensed corn distillers solubles (CCDS). Hydrolysis with a commercial protease significantly increased oil recovery as the enzyme concentration increased, with the greatest oil recovery being 70% at 10% v/w (dry weight basis) enzyme concentration. Increasing centrifugal force from 8,500 to 12,240×g was only slightly effective for the non-enzyme treated samples. Reducing CCDS particle size by grinding with a mortar and pestle increased oil recovery to 83% when an enzyme combination of a commercial cellulase mixture and a protease was used. Particle size reduction of CCDS by high-speed blending resulted in low oil recovery, but the oil recovery was significantly improved after enzyme treatment. Zein-lipid interaction was very strong when tested in a model system, with only 10% of the oil being freed by centrifugation alone. Following enzyme hydrolysis of the zein-oil complex with a protease, oil recovery was increased to 97%. Overall, enzyme hydrolysis and further particle size reduction showed a small, albeit statistically significant, effect in increasing oil recovery from CCDS. These small increases may not justify the use of enzymes or processing modifications to reduce particle size in the ethanol industry, nonetheless, these data may provide a reference or insight to design more effective treatments for oil recovery.
Keywords: CCDS; Protein–lipid interactions; Carbohydrate–lipid interactions; Oil recovery; Corn oil
Physicochemical Characteristics of Nigella Seed (Nigella sativa L.) Oil as Affected by Different Extraction Methods by Ali Khoddami; Hasanah M. Ghazali; Ali Yassoralipour; Yogeshini Ramakrishnan; Ali Ganjloo (533-540).
The physicochemical properties of crude Nigella seed (Nigella sativa L.) oil which was extracted using Soxhlet, Modified Bligh–Dyer and Hexane extraction methods were determined. The effect of different extraction methods which includes different parameters, such as temperature, time and solvent on the extraction yield and the physicochemical properties were investigated. The experimental results showed that temperature, different solvents and extraction time had the most significant effect on the yield of the Nigella oil extracts. The fatty acid (FA) compositions of Nigella seed oil were further analyzed by gas chromatography to compare the extraction methods. The C16:0, C18:1 and C18:2 have been identified to be the dominant fatty acids in the Nigella seed oils. However, the main triacylglycerol (TAG) was LLL followed by OLL and PLL. The FA and TAG content showed that the composition of the Nigella seed oil extracted by different methods was mostly similar, whereas relative concentration of the identified compounds were apparently different according to the extraction methods. The melting and crystallization temperatures of the oil extracted by Soxhlet were −2.54 and −55.76 °C, respectively. The general characteristics of the Nigella seed oil obtained by different extraction methods were further compared. Where the Soxhlet extraction method was considered to be the optimum process for extracting Nigella seed oil with a higher quality with respect to the other two processes.
Keywords: Nigella seed oil; Oil extraction methods; Physicochemical characteristics; Fatty acid profile
Development and Characterization of Water-Blown Polyurethane Foams from Diethanolamides of Karanja Oil by Aruna Palanisamy; M. S. L. Karuna; T. Satyavani; D. B. Rohini Kumar (541-549).
The present study focuses on the use of renewable resource, namely karanja oil for the development of polyurethane foams. The non-edible oil was chemically modified into the diethanolamide by hydroxylation followed by transamidation. The structure of the diethanolamide was confirmed by proton nuclear magnetic resonance spectroscopy, infrared spectroscopy and gas chromatography–mass spectrometry and used as polyol to prepare water-blown polyurethane foams. Polyurethane foams were produced with carbon dioxide as the blowing agent generated by the reaction between excess polymeric MDI with water. Foams were prepared by a hand mixing process which involved blending of the diethanolamide with polypropylene glycol, polymeric MDI, water, catalyst and surfactant. The hydroxyamide content, catalyst nature and molecular weight of polypropylene glycol were varied and the effect on the properties was studied. Foam rise time and other physical properties such as density, compression strength and flexural strength were evaluated. Optical microscopy was used to study the morphology to reveal the closed cell nature and other structure–property relationships.
Keywords: Karanja oil; Diethanolamide; Polyurethane foam; Compression strength
Glycerolysis of Soybean Oil with Crude Glycerol Containing Residual Alkaline Catalysts from Biodiesel Production by David A. Echeverri; Fernando Cardeño; Luis A. Rios (551-557).
The glycerolysis reaction of soybean oil was evaluated using crude glycerol obtained from the transesterification of soybean oil with methanol, catalyzed by sodium methoxide and sodium hydroxide, without any purification step other than the methanol removal. Crude glycerol with the lower content of remaining inorganic catalyst produced the highest concentration of monoglycerides (about 42%). The effect of the addition of water on the glycerolysis reaction was analyzed, evidencing a low formation rate of products in the first stages of the reaction due to the transformation of the inorganic catalyst to soaps, which are weaker bases. The sample of crude glycerol that led to the best results was evaluated at several temperatures. It was observed that the reaction with crude glycerol exhibits a lower formation rate of monoglycerides at low temperatures (160 and 180 °C) compared with the reaction with pure glycerol and catalyzed with NaOH. This behavior was explained by the lower activity of the soaps present in the crude glycerol respect to the inorganic base. Above 200 °C the reaction is very fast and the monoglycerides formed are consumed to produce diglycerides.
Keywords: Glycerolysis; Crude glycerol; Monoglycerides; Biodiesel; Transesterification
Proximate Composition and Fatty Acid Profile of Pongamia pinnata, a Potential Biodiesel Crop by Manju Bala; T. N. Nag; Sandeep Kumar; Manmohan Vyas; Arun Kumar; N. S. Bhogal (559-562).
The chemical characteristics of Pongamia pinnata seeds, focussing on proximate composition and the fatty acid profile of its oil, are presented. The proximate composition of P. pinnata seeds was: 3.8% ash, 9.7% sugar, 7.07% protein, 24% oil, 10.7% free amino acids, and 0.24% free fatty acids. The oil was extracted from seeds by use of different solvents and the highest yield (29%) was obtained by use of n-hexane. Monounsaturated and polyunsaturated fatty acids accounted for 63.3 and 22.9%, respectively, of the seed oil. Oleic acid was the major fatty acid but a substantial amount of erucic acid was also detected; this was not reported in previous studies. The level of erucic acid and the presence of toxic flavonoids, for example karanjin, pongapin, and pongaglabrin, render the oil inedible according to WHO recommendations. However, low levels of saturated and polyunsaturated fatty acids with desirable cetane number and iodine value suggest potential for application as a biodiesel fuel.
Keywords: Biodiesel; Fatty acids; Karanja; Pongamia pinnata ; Proximate composition
Minimizing the Cost of Biodiesel Blends for Specified Cloud Points by Paul S. Wang; Joseph Thompson; Jon Van Gerpen (563-572).
When used as a biodiesel fuel, isopropyl esters are expensive compared to the more common methyl esters. However, isopropyl esters have better cold flow properties than methyl esters, allowing the use of highly saturated feedstocks such as tallow or lard. It has not been determined if isopropyl esters can be part of an economical biodiesel (B100) blend for a specified cloud point, which allows for an objective material cost comparison. This work explores this question through the use of an empirical cloud point model that has been developed and validated. Constrained cost minimization was performed using the cloud point model and historical prices for alcohols and triglycerides. Case studies using 2003 and 2006 average prices are presented. The results indicate that an expensive component such as isopropyl ester can be part of an economical blend under the market conditions. For isopropyl esters to be feasible as an economical blend component, they have to be derived from a highly saturated feedstock that is less expensive than soybean oil by $0.10/lb. This price differential is most applicable to a biodiesel blend that has a cloud point between 5 and 10 °C.
Keywords: Biodiesel; Blending; Cloud point; Cost minimization; Methyl esters; Isopropyl esters; Soy; Tallow
Antifungal Activity of Essential Oil and Extracts of Piper chaba Hunter Against Phytopathogenic Fungi by Atiqur Rahman; Sharif M. Al-Reza; Sun Chul Kang (573-579).
The efficacy of the essential oil and various leaf extracts of Piper chaba Hunter was evaluated for controlling the growth of some important phytopathogenic fungi. The hydrodistilled essential oil was analysed by GC–MS. Fifty-three compounds representing 95.1% of the total oil were identified, of which α-humulene (16.4%), caryophyllene oxide (12.2%), viridiflorol (8.1%), globulol (7.4%), β-selinene (7.1%), spathulenol (6.2%), (E)-nerolidol (5.1%), linalool (4.5%) and 3-pentanol (3.5%) were the major compounds. The oil (1,000 ppm) and organic extracts (1,500 ppm) of P. chaba Hunter displayed a great potential of antifungal activity as a growth inhibition against the tested phytopathogenic fungi, Fusarium oxysporum KACC 41083, Phytophthora capsici KACC 40157, Colletotrichum capsici KACC 410978, Fusarium solani KACC 41092 and Rhizoctonia solani KACC 40111 in the range of 55.1–70.3% and minimum inhibitory concentration ranging from 125 to 500 μg/ml. The oil had also a strong detrimental effect on spore germination of all the tested fungi along with concentration as well as time-dependent kinetic inhibition of P. capsici. The results obtained from this study may contribute to the development of new antifungal agents to protect crops from fungal diseases.
Keywords: Piper chaba Hunter; Piperaceae; Essential oil; α-Humulene; Antifungal activity; MIC
Camelina sativa Oil Deodorization: Balance Between Free Fatty Acids and Color Reduction and Isomerized Byproducts Formation by Robert Hrastar; Ling-Zhi Cheong; Xuebing Xu; Rasmus Leth Miller; Iztok Jože Košir (581-588).
Camelina sativa oil is characterized by its high content (up to 40 wt%) of α-linolenic acid and its unique flavor. It is considered to have beneficial health properties and is suitable for food and cosmetic uses. In the present study, response surface methodology was used to optimize processing parameters for bench-scale deodorization of camelina oil. The mathematical models generated described the effects of process parameters (temperature, steam flow, time) on several deodorization quality indicators: free fatty acids (FFA), trans fatty acids (TFA), color, and polymerized triglycerides (PTG). These newly established models can be used as a tool to identify optimum deodorization process conditions within chosen constraints. Based on the optimization of minimum retained FFA with the constraint of a maximum allowable TFA, deodorization parameters can be defined. At a constant steam flow rate of 42 ml/h, a temperature range of 210–220 °C, and deodorization time of 70–120 min were defined. 220 °C appears to be a critical upper temperature limit; above this temperature, isomerization rates significantly increase.
Keywords: Camelina sativa ; Deodorization; Response surface methodology (RSM); trans fatty acid; Optimization
Production of PUFA Concentrates from Poultry and Fish Processing Waste by Dipak Patil; Ahindra Nag (589-593).
In fish and poultry processing, viscera are generally considered as a waste product and often discarded. Chicken and hilsa fish (Hilsa ilisa) viscera were used for the production of polyunsaturated fatty acids (PUFA) linoleic (18:2n-6), eicosapentaenoic (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3). Free fatty acids (FFA) were extracted by alkaline hydrolysis of chicken and fish viscera; yields were 5.2 and 5.9% (w/w) respectively. PUFA concentrates were obtained by a two step process—deduction of saturated fatty acids (FA) by low temperature crystallization in acetone followed by urea inclusion compound-based fractionation. Acetone treatment removed 90 and 96% of saturated FA in chicken and fish viscera respectively with FA to acetone ratio of 1:12 (w/v). Using an urea to FA ratio (w/w) of 4.0, chicken viscera produced a maximum of 84.1% of PUFA concentrates containing 82.1% of linoleic acid with a yield of 10% where as in the case of fish viscera the maximum PUFA concentrates were 91.3% containing 78.2% of EPA-DHA with the yield of 11%. Thus, the utilization of poultry and fish processing waste into the production of PUFA concentrates has been shown.
Keywords: Viscera; Urea complex fractionation; Polyunsaturated fatty acid