bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of oil replenishment during deep‐fat frying of frozen foods in sunflower oil and high‐oleic acid sunflower oil
Authors: Romero Antonio , Cuesta Carmen , Sánchez‐Muniz Francisco J.
Published: May 2007

Frying stability of sunflower oil (SO) with 23% oleic acid and 61% linoleic acid, and of high‐oleic acid sunflower oil (HOSO) with 74% oleic acid and 13% linoleic acid was studied during 20 discontinuous deep‐fat fryings of various frozen foods, with or without frequent replenishment of the used oil with fresh oil. Alterations of both oils were measured by column, gas‐liquid and high‐performance size‐exclusion chromatography. Total polar content and compounds, related to thermoxidative changes, and diacylglycerides, related to hydrolytic changes, increased in all oils during frying but reached higher levels in SO than in HOSO. Nevertheless, the increased levels of diacylglycerides observed may result from the frozen potatoes prefried in palm oil. Oleic acid in HOSO and linoleic acid in SO significantly decreased, but the fatty acid modifications that occurred during the repeated fryings were not only related to thermoxidative alteration but also to interactions between the bath oil and the fat in the fried products. Data from this study also indicated that HOSO performed more satisfactorily than SO in repeated fryings of frozen foods. Moreover, frequent addition of fresh oil throughout the deep‐frying process minimized thermoxidative and hydrolytic changes in the frying oils and extended the frying life of the oils.
Antioxidant properties of myricetin and quercetin in oil and emulsions
Authors: Roedig‐Penman Andrea , Gordon Michael H.
Published: May 2007

The effect of quercetin and myricetin on the stability of sunflower oil and oil‐in‐water emulsions was studied by storage experiments monitored by measurement of peroxide values, conjugated dienes, and headspace volatile analysis. Myricetin showed strong antioxidant activity in oils stored at 60 or 30°C and in oil‐in‐water emulsions stored at 30°C, whether tocopherols or citric acid were present or not; however, quercetin showed similar antioxidant activity in stripped sunflower oil but no activity in oils that contained tocopherols and citric acid. This showed that myricetin is effective owing to strong radical scavenging and metal‐chelating properties, whereas quercetin has weaker radical scavenging activity, although it is also active by metal‐chelation. The effects of copper and iron salts on the antioxidant activity of myricetin and quercetin were studied in sunflower oil and oil‐in‐water emulsions. Quercetin and myricetin enhanced the prooxidant effect of cupric chloride in oil‐in‐water emulsions (pH 7.4), but this effect was not observed with cupric stearate. The addition of myricetin to emulsions that contained ferric chloride at pH 5.4 also produced a strong prooxidant effect, and small prooxidant effects of flavonols were also detected in the presence of cupric chloride under these conditions. However, myricetin and quercetin reduced the prooxidant effect of ferric palmitate in oils. Myricetin also showed a strong antioxidant effect in oil that contained cupric stearate, although quercetin had no significant effect on the oxidative stability of this system. It therefore appears that flavonols may exert a prooxidant effect in the presence of metal salts, but the nature of the metal salt is important in determining whether a prooxidant effect occurs.
Antioxidants from a heated histidine‐glucose model system. I: Investigation of the antioxidant role of histidine and isolation of antioxidants by high‐performance liquid chromatography
Authors: Bersuder P. , Hole M. , Smith G.
Published: May 2007

The radical‐combining activity of Maillard reaction products [MRP(aq)], produced by heating d‐glucose and l‐histidine (3:1) in a 0.1 M phosphate buffer for 10 h at 105°C (final pH 6.53), was estimated directly by means of a diphenylpicrylhydrazyl radical (DPPH·) method. Additionally, the indirect methods of peroxide values changes (oven test), hexanal formation, and protection factors (Rancimat method) were determined on a lipid model system that consisted of sunflower seed oil/water (1:2), emulsified with 3% (w/w) Tween 40. Results from the DPPH· method showed a potential antioxidant activity of MRP(aq), which was confirmed by the indirect methods. Surprisingly, histidine in solution alone (heated or not) exhibited an antioxidant activity greater than or similar to the MRP(aq) activity in the indirect methods with the lipid model system, in contrast to the results from the DPPH· method. The suitability of various solvents for extraction of potential antioxidant compounds from freeze‐dried MRP(aq) was examined, and ethanol extracts showed the greatest activity by the DPPH· method. Consequently, the ethanol extract of freeze‐dried MRP(aq) was separated by means of preparative reverse‐phase high‐performance liquid chromatography (HPLC) with a 0.05 M phosphate buffer (pH 4.4)/water/acetonitrile gradient system. The antioxidant activity of the eluate was measured through the DPPH· method, and a fraction (Fraction A) with antiradical activity was further purified by preparative HPLC. Fraction B was collected, and its freeze‐dried residue exhibited potent antiradical activity, significantly greater than that of the same level of n‐propyl gallate.
Use of α‐tocopherol acetate to improve fresh pig meat quality of full‐fat rapeseed‐fed pigs
Authors: Onibi G. E. , Scaife J. R. , Murray I. , Fowler V. R.
Published: May 2007

Thirty‐two pigs were allocated to one of four diets, FFRD0 and FFRD200, containing full‐fat rapeseed (FFR), 150 g/kg [25–50 kg liveweight (LW)], and 250 g/kg (50–90 kg LW), or CD0 and CD200, containing equivalent quantities of rapeseed meal and 34 g/kg (25–50 kg LW) or 59.2 g/kg (50–90 kg LW) coconut oil and lard (0.5:0.5, w/w). Diets FFRD200 and CD200 were supplemented with 200 mg/kg α‐tocopherol acetate (ATA). ATA supplementation significantly (P<0.001) reduced muscle drip loss. The melting point (°C) of subcutaneous fat was significantly lowered by FFR (P<0.001) but increased by ATA supplementation (P<0.05). Tissue α‐tocopherol (AT) concentrations were significantly increased by ATA supplementation. Longissimus dorsi AT concentration was positively correlated with AT concentration in subcutaneous fat (r=0.86) and in plasma at 35 (r=0.65) and 77 (r=0.85) days of feeding (P<0.001). In both L. dorsi and subcutaneous adipose tissue lipids, FFRD caused a significant (P<0.001) decrease in the ratio of n‐6 to n‐3 fatty acids and a significant (P<0.001) increase in the ratio of polyunsaturated to saturated fatty acids. AT supplementation significantly reduced the susceptibility of L. dorsi and subcutaneous fat to lipid oxidation during storage at 4°C for up to 16 d. For all dietary treatments and storage times, lipid oxidation [mg malondialdehyde (MDA)/kg muscle] was greater in the surface layer (0–2.5 mm) of L. dorsi than below the surface (2.5–5 mm). Oxidative stability of L. dorsi lipids to iron‐induced lipid peroxidation was significantly improved (P<0.001) by AT supplementation. Meat from pigs fed FFRD diets was significantly less stable to iron‐induced oxidation (nmoles MDA/mg protein) at the longer incubation periods (100 and 200 min). The susceptibility of L. dorsi to iron‐induced lipid oxidation decreased as the ratio of the tissue concentration of AT to unsaturated fatty acid increased.
Free radicals, oxidative stress, and antioxidants in human health and disease
Authors: Aruoma Okezie I.
Published: May 2007

Free radicals and other reactive oxygen species (ROS) are constantly formed in the human body. Free‐radical mechanisms have been implicated in the pathology of several human diseases, including cancer, atherosclerosis, malaria, and rheumatoid arthritis and neurodegenerative diseases. For example, the superoxide radical (O2·−) and hydrogen peroxide (H2O2) are known to be generated in the brain and nervous systemin vivo, and several areas of the human brain are rich in iron, which appears to be easily mobilizable in a form that can stimulate free‐radical reactions. Antioxidant defenses to remove O2·−and H2O2exist. Superoxide dismutases (SOD) remove O2·−by greatly accelerating its conversion to H2O2. Catalases in peroxisomes convert H2O2into water and O2and help to dispose of H2O2generated by the action of the oxidase enzymes that are located in these organelles. Other important H2O2‐removing enzymes in human cells are the glutathione peroxidases. When produced in excess, ROS can cause tissue injury. However, tissue injury can itself cause ROS generation (e.g., by causing activation of phagocytes or releasing transition metal ions from damaged cells), which may (or may not, depending on the situation) contribute to a worsening of the injury. Assessment of oxidative damage to biomolecules by means of emerging technologies based on products of oxidative damage to DNA (e.g., 8‐hydroxydeoxyguanosine), lipids (e.g., isoprostanes), and proteins (altered amino acids) would not only advance our understanding of the underlying mechanisms but also facilitate supplementation and intervention studies designed and conducted to test antioxidant efficacy in human health and disease.
The tocopherol pattern in human serum is markedly influenced by intake of vitamin E drugs—Results of the german national health surveys
Authors: Melchert H. ‐U. , Pabel E.
Published: May 2007

During national and regional health surveys, done from 1984–1995 in Germany, consumption data for all drugs used by the participants—approximately 18,000 persons—in the last 7 d before the examination were monitored with a detailed drug‐usage questionnaire. The groups examined are representative for the national and regional German inhabitant population aged 25–69 yr. In serum samples of subsamples of the study participants, all tocopherols were measured by isocratic high‐performance liquid chromatography (Si 60 column, fluorescence detection). Consumption data for tocopherol‐containing drugs showed that up to 5% of females and up to 3% of males of the study population used those drugs. During the study period, the serum content of α‐tocopherol (mean values ± SD) rose from 7.5 ± 2.6 mg/L serum to 11.8 ± 2.8 mg/L serum for nonusers and from 11.9 ± 4.3 mg/L serum to 15.3 ± 4.9 mg/L serum in tocopherol‐drug users. Throughout all studies, it could be shown that β‐ and γ‐tocopherol were heavily reduced in those persons taking daily doses ≥50 mg α‐tocopherol. The reduction of the two tocopherols is dose‐dependent and especially pronounced in females using high‐dose α‐tocopherol drugs. Owing to the emerging evidence of the physiological importance concerning the balance of the different tocopherols in biological systems, the possible benefits of using natural tocopherol mixtures from plant origin instead of pure RRR‐α‐tocopherol, gained from permethylation procedures, as vitamin supplements in human nutrition should be considered.
Improvement in the antioxidant status of plasma and low‐density lipoprotein in subjects receiving a red wine phenolics mixture
Authors: Carbonneau Marie‐Annette , Léger Claude L. , Descomps Bernard , Michel Françoise , Monnier Louis
Published: May 2007

It is commonly accepted that oxidized low‐density lipoprotein (ox‐LDL) plays an important role in coronary heart disease (CHD) and etiologically related atherogenesis. Consumption of wine may contribute to the low risk of CHD in the Mediterranean population. These findings raise the question of the in vivo antioxidant role of wine phenolic compounds after a prolonged supplementation period in healthy human volunteers. We found that subjects, receiving 2 g/d of an alcohol‐free red wine‐extracted phenolic compound (RWPC) mixture for 14 d (which was equivalent to about 1 L/d of the red wine), exhibited an increase in the plasma antioxidative capacity and in LDL vitamin E by blood sampling under fasting conditions. The fact that the LDL Cu2+‐oxidizability was not decreased can be explained by both the lack of phenolic compound affinity for the lipoprotein particle, highlighted by LDL dialysis, and the insufficient increase in LDL vitamin E, as shown by the relationship between vitamin E content and oxidation resistance of LDL evidenced by literature data. These results support that RWPC could play a coantioxidant role, similar to that of vitamin C, possibly accounting for their LDL vitamin E sparing effect and their beneficial role in lowering CHD risks.
Dietary fish oil inhibits Δ6‐desaturase activity in vivo
Authors: Raz Amiram , Kamin‐Belsky Nurit , Przedecki Fiorenza , Obukowicz Mark
Published: May 2007

Liver Δ6‐desaturase activity was determined in mice which were made deficient in (i) n‐6 and n‐3 polyunsaturated fatty acids (PUFA), (ii) n‐6 PUFA, or (iii) arachidonic acid (AA). Initially, the mice were subjected to two cycles of a fasting (1 d)/refeeding (2–3 d) protocol in which they were refed an essential fatty acid‐deficient (EFAD) diet during the refeeding period. This 1‐wk fasting/refeeding protocol, referred to as F/R EFAD, produced a rapid and substantial decline in tissue n‐3 and n‐6 PUFA and a corresponding increase in n‐9 fatty acids, notably oleic acid and Mead acid (20:3n‐9). Combined liver Δ6‐desaturase/elongase/Δ5‐desaturase activities in vivo were quantified by measuring the conversion of 14C‐linoleic acid (LA) to 14C‐AA in mouse liver. Although F/R EFAD caused, as expected, a substantial decline in liver AA and LA content, the conversion of 14C‐LA to 14C‐AA was the same in these mice as in chow‐fed controls (approximately 33–34%). Subsequent refeeding of F/R EFAD mice with an EFAD diet, supplemented with corn oil, restored tissue n‐6 PUFA levels without altering the conversion of 14C‐LA to 14C‐AA. In contrast, refeeding with an EFAD diet, supplemented with fish oil, inhibited 14C‐LA to 14C‐AA conversion by 78%. Significantly, inhibition of conversion of 14C‐LA to 14C‐AA was maintained in F/R EFAD mice that were subsequently fed an EFAD diet supplemented with a 1:1 mixture of fish oil/corn oil. This latter protocol yielded a unique liver fatty acid composition in which AA was selectively depleted, whereas LA and the n‐3 PUFA were increased. The data suggest that dietary n‐3 C20–22 PUFA negatively regulate the in vivo synthesis of n‐6 PUFA at the level of the Δ6‐desaturase.
Long‐chain polyunsaturated fatty acids influence both β‐ and α‐adrenergic function of rat cardiomyocytes
Authors: Ponsard B. , Durot I. , Fournier A. , Oudot F. , Athias P. , Grynberg A.
Published: May 2007

Dietary polyunsaturated fatty acids (PUFA) have been reported to lower the incidence of cardiovascular diseases, but neither the mechanisms that determine these protective effects nor the specific influence of n‐3 vs. n‐6 PUFA series has been well established. The purpose of this work was to demonstrate the influence of the membrane long‐chain fatty acid composition on the spontaneous contractile activity and the adrenergic function of rat cardiomyocytes in culture. Cells were grown for 24 h in a standard culture medium and then for 4 d in media that contained either n‐3 (eicosapentaenoic acid and docosahexaenoic acid) or n‐6 (arachidonic acid) PUFA. The n‐6/n‐3 ratio was 1.2 in n‐3 cells compared with 20.1 in n‐6 cells. The basal contractile properties of these cardiomyocytes were not affected by the PUFA phospholipid composition. However, these modifications influenced the adrenoceptor function because the β‐adrenergic stimulation by isoproterenol (10−7 M) induced a positive chronotropic response that was significantly greater in n‐3 cells. Moreover, the chronotropic response to α‐adrenoceptor stimulation by phenylephrine (10−6 M) appeared significantly more pronounced in the n‐3 cells than in the n‐6 cells. However, the parameters related to the inotropic response induced by these agonists did not differ significantly between the two groups of cells. These results suggested that the membrane long‐chain PUFA composition does not influence the basal cardiac contractility and automaticity but is able to modulate the chronotropic function of both α‐ and β‐adrenoceptors.
Peroxisomal metabolism of adrenic acid; No Δ4 desaturase detected in rat liver peroxisomes
Authors: Haugen T. S. , Mimouni V. , Pedersen J. I. , Grav H. J. , Christiansen E. N.
Published: May 2007

The existence of a peroxisomal Δ4 desaturation of 22:4n‐6 and 22:5n‐3 to yield, respectively, 22:5n‐6 and 22:6n‐3 has been questioned. An alternative pathway has been formulated to include microsomal chain elongation and Δ6 desaturation and peroxisomal chain shortening. We incubated [1‐14C]adrenic acid (22:4n‐6) in a system for desaturation (i.e., in the presence of NADH) with purified rat liver peroxisomes. The fatty acids were separated as methyl derivatives by high‐performance liquid chromatography. Four ultraviolet‐absorbing product peaks appeared, three of which contained radioactivity, which we investigated as methyl, trimethylsilyl, and oxazoline derivatives on gas chromatography‐mass spectrometry. In addition to adrenic and arachidonic acids, the product peaks were trans‐enoyl, hydroxy, and keto derivatives of adrenic acid: the three first steps of β‐oxidation cycle. This indicated that the NAD‐dependent dehydrogenase step in the peroxisomal β‐oxidation cycle of adrenic acid was inhibited due to a high concentration of added NADH. Incubation in the presence of NAD instead of NADH reduced radioactivity in the peaks that corresponded to intermediates, while radioactivity in the acid‐soluble fraction increased considerably, consistent with a complete β‐oxidation cycle of adrenic to arachidonic acid. There were no indications of Δ4 desaturation in purified peroxisomes incubated in a standard desaturation system. Instead, adrenic acid as substrate underwent β‐oxidation.
Conjugated linoleic acid and oxidative stress
Authors: Banni Sebastiano , Angioni Elisabetta , Contini Maria Stefania , Carta Gianfranca , Casu Viviana , Iengo Giorgio Amedeo , Melis Maria Paola , Deiana Monica , Dessì Maria Assunta , Corongiu Francesco P.
Published: May 2007

At the present time, conjugated linoleic acid (CLA) is the subject of a growing number of studies since it has been demonstrated to possess anticarcinogenic and antiatherogenic activities in experimental animal models and to increase in some pathological states in humans. In both situations, CLA has been claimed to be involved in oxidative stress, as an antioxidant in the first case and as a primary product of a free‐radical attack on polyunsaturated fatty acids (PUFA) in the other. The controversial results are due mostly to a lack of a suitable methodology because the presence of conjugated dienes (CD) in lipid moiety has been taken for years as evidence of lipid peroxidation due to the occurrence of this structure in fatty acid hydroperoxides. We have recently developed a new methodology that consists of the extraction of fatty acids, including CD fatty acid hydroperoxides, by mild saponification and their separation and identification by high‐performance liquid chromatography with diode array detector. Fatty acid analyses of liver homogenate, oxidized in vitro either with Fe‐ADP or t‐butyl hydroperoxide (t‐ButylHP), of lamb and rats fed CLA at levels known to prevent carcinogenesis, showed that CLA and its metabolites steadily decreased during oxidative stress and that they are more prone to oxidation than their corresponding methylene‐interrupted fatty acids. No significant antioxidant effect of CLA was detected in any model tested. However, CD fatty acid hydroperoxides increased in the t‐ButylHP model but not in the Fe‐ADP model, owing probably to the degradation of CD fatty acid hydroperoxides induced by this oxidative agent. In conclusion, CLA and its metabolites seem to behave, under oxidative stress, as regular PUFA. Thus, it is highly unlikely that the peculiar effects of CLA are directly related to interference in lipoperoxidative processes.
Isolation of chemically induced mutants in borage (Borago officinalis L.)
Authors: De Haro‐Bailón A. , Del Rio M.
Published: May 2007

γ‐Linolenic acid (GLA, 18:3 Δ6,9,12) has been reported to be helpful in the treatment of a wide range of disorders. Borage (Borago officinalis L.) is an annual plant of renewed interest because the seeds are an important source of GLA. The failure to retain mature seeds until harvest limits the total seed and GLA yield per plant and is the major limiting factor for the commercial production of borage. In the course of a mutagenesis program, an agronomically good line of white‐flowered borage (RG‐001) was treated with ethyl methane sulfonate. As a result of this program, several types of mutants were identified in the M2 generation of plants: a chlorotic mutant (type A); a mutant with increased number of sepals, petals, and ovules but reduced fertility (type B); and mutants with closed flowers (type C1) or partially opened flowers (type C2) that had increased seed retention. The type C mutants are the first reported borage plants with a nonshattering habit. After crossing type B plants with normal plants, a new mutant (type B1) was obtained with higher fertility and higher seed production per flower than those from normal plants. These mutants could be used to develop borage lines that would be superior to those currently available as a source of GLA.
Synthesis and physicochemical characterization of mixed diacid triglycerides that contain elaidic acid
Authors: Elisabettini P. , Lognay G. , Desmedt A. , Culot C. , Istasse N. , Deffense E. , Durant F.
Published: May 2007

The synthesis of symmetrical and asymmetrical palmito‐ and stearo‐elaidic triglycerides (PEP, SES, EPP, PEE, ESS, and SEE, in which P=palmitic, S=stearic, and E=elaidic acid) was undertaken to investigate their polymorphism. The chemical pathways and the purification steps, including crystallization and adsorption chromatography, are described. The different chromatographic analyses (gas‐liquid chromatography: carbon number profile and fatty acid methyl ester profile, and high‐performance liquid chromatography) revealed that the purity of the synthesized products was superior to 99% except for SES (>96%). The thermal behavior, as well as the polymorphism of these triglycerides, has been investigated by means of differential scanning calorimetry and powder X‐ray diffraction spectroscopy at variable temperatures. The six compounds crystallize according to a double chainlength packing. The most stable polymorphic form of palmito‐elaidic triglycerides belongs to the β′ variety, whereas the stearo‐elaidic triglycerides are β stable.
Total and partial erucate of pentaerythritol. Infrared spectroscopy study of relationship between structure, reactivity, and thermal properties
Authors: Eychenne Valérie , Mouloungui Zéphirin , Gaset Antoine
Published: May 2007

Esters of neopentylpolyols are an important starting base for synthetic lubricants. These bulky esters are generally prepared by an esterification reaction between a carboxylic acid and a neopentylpolyol. Because neopentylpolyols have a number of primary alcohol sites, a variety of partial esters is formed before total esters. In the present study, we investigated the reaction between pentaerythritol and erucic acid. The composition of the reaction mixture in erucic acid, partial esters, and total esters was monitored by thin‐layer chromatography, coupled with flame‐ionization detection. The pure esters and the esters in solution at different concentrations in xylene at different temperatures were analyzed by Fourier transform infrared spectroscopy. Erucic acid and partial esters in xylene coexist in the free form and as bound complexes. These findings furthered understanding of the reactivity and thermal properties of the partial esters.
Pilot batch production of specific‐structured lipids by lipase‐catalyzed interesterification: Preliminary study on incorporation and acyl migration
Authors: Xu X. , Balchen S. , Høy C. ‐E. , Adler‐Nissen J.
Published: May 2007

Effects of water content, reaction time, and their relationships in the production of two types of specific‐structured lipids (sn‐MLM‐ and sn‐LML‐types: L‐long chain fatty acids; M‐medium chain fatty acids) by lipase‐catalyzed interesterification in a solvent‐free system were studied. The biocatalyst used was Lipozyme IM (commercial immobilized lipase). The substrates used for sn‐MLM‐type were fish oil and capric acid, and medium chain triacylglycerols and sunflower free fatty acids for sn‐LML‐type. The observed incorporation with the time course agrees well with the Michaelis‐Menten equation, while the acyl migration is proportional to time within the range of 20 mol% acyl migration (MLM‐type: Mf=0.2225 T, R2=0.98; LML‐type: Mf=0.5618 T, R2=0.99). As water content (wt%, on the enzyme basis) increased from 3.0 to 11.6% for MLM‐type and from 3.0 to 7.2% for LML‐type in the solvent‐free systems, the incorporation rates in the first 5 h increased from 3.34 to 10.30%/h, and from 7.29 to 11.12%/h, respectively. However, the acyl migration rates also increased from 0.22 to 1.12%/h and from 0.56 to 1.37%/h, respectively. Different effects in the production of two totally position‐opposed lipids can be observed. Presumably these are caused by the different chain length of the fatty acids. The relationships between reaction time and water content are inverse and give a quantitative prediction of incorporation and acyl migration in selected reaction conditions and vice versa. The acyl migration can not be totally avoided in present systems, but can be reduced to a relatively low level. Acyl migration during the downstream processing has also been observed and other factors influencing the acyl migration are briefly discussed.
Efficient lipase‐catalyzed production of tailor‐made emulsifiers using solvent engineering coupled to extractive processing
Authors: Edmundo Castillo , Valérie Dossat , Didier Combes , Alain Marty
Published: May 2007

Within the framework of enzymatic biosurfactant synthesis, the development of reaction processes leading to a selective and efficient production is of crucial interest. In this work, we proposed an enzymatic method for producing 1(3)‐monooleoyl‐rac‐glycerol using a commercial immobilized lipase, the Lipozyme®. To avoid the blockage of the enzyme by the presence of insoluble glycerol, the latter was adsorbed onto dried silica gel. The selective monoester production (83%) was obtained using 2‐methyl‐2‐butanol amended n‐hexane (90:10, vol/vol) as reaction medium. The observed decrease in the substrate conversion, in a medium containing 2‐methyl‐2‐butanol, was countered by coupling to the reaction an inline selective recovery method for the produced monoester by adsorption onto a silica gel column located at the outflow of the reaction vessel. This process leads to an efficient monooleoyl glycerol production with a high oleic acid conversion (71%) and to the recovery of a 100% pure monooleoyl glycerol.
Cellulose esterification with fatty acids and acetic anhydride in lithium chloride/N,N‐dimethylacetamide medium
Authors: Vaca‐Garcia C. , Thiebaud S. , Borredon M. E. , Gozzelino G.
Published: May 2007

Homogeneous esterification of cellulose with saturated fatty acids (n‐octanoic to n‐octadecanoic) was accomplished with acetic anhydride co‐reactant in lithium chloride/N,N‐dimethylacetamide (LiCl/DMAc) medium. Cellulose mixed triesters (CMT) were obtained after 5 h at 130°C with an average of 2.2 acetyl groups and 0.8 fatty substituents per anhydroglucose unit. A mixed acetic‐fatty anhydride, formed in situ, accounts for the grafting of the fatty moiety. The purified products were characterized and compared to the analogous cellulose simple fatty triesters (CST) that were synthesized from fatty acid chlorides in pyridine medium. Dynamic contact angle with water, glass transition, and storage moduli were correlated with the length of the fatty substituents. The CMT proved to be highly hydrophobic and more mechanically resistant than the CST.
Proteins from Crambe abyssinica oilseed. I. Isolation procedure
Authors: Massoura E. , Vereijken J. M. , Kolster P. , Derksen J. T. P.
Published: May 2007

Crambe abyssinica is a promising new oil crop because of the specific properties of its oil. However, little information is available concerning the properties of the proteins, which constitute a major component of the seed. Therefore, a method for the isolation of proteins from Crambe seeds was developed. Protein extractability for whole and dehulled Crambe meal was studied as a function of pH. Highest extractability was obtained with dehulled meal at pH 11. Double extraction at this pH increased the extractability to about 66%. Protein precipitation from the above‐mentioned extract was studied as a function of pH with and without addition of a precipitating agent, i.e., carboxymethylcellulose (CMC). Addition of CMC resulted in a protein recovery of about 75% at pH 4.4. Without CMC, about half of the protein was recovered by isoelectric precipitation. The remaining soluble protein could be concentrated by ultrafiltration with a recovery of about 65%. The developed process, not including CMC addition, results in two protein fractions, i.e., an isoelectric precipitate (protein content 75%) and a retentate (protein content 87%), which together account for about 50% of the protein present in Crambe meal. Application of heat decreased protein extractability, but the protein contents of the resulting fractions were comparable to those from non‐heat‐treated meal.
Proteins from Crambe abyssinica oilseed. II. Biochemical and functional properties
Authors: Massoura E. , Vereijken J. M. , Kolster P. , Derksen J. T. P.
Published: May 2007

Little information is available concerning the properties of proteins that constitute a major component of the seed of Crambe abyssinica. Therefore, a method was developed to isolate these proteins. This procedure resulted in two fractions, an isoelectric precipitate (Fraction 1) and a retentate after ultrafiltration (Fraction 2). Biochemical and functional properties of both fractions were studied. Gel permeation chromatography revealed that high‐molecular‐weight proteins (>669,000 Da) are present only in Fraction 1, whereas Fraction 2 consists of proteins with lower molecular weights (<200,000 Da). Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, in the presence of mercaptoethanol, showed that both fractions consist of proteins that range mainly from 40,000 to less than 14,400 Da. Fraction 1 was highly soluble only at acid and alkaline pH values, while the solubility of Fraction 2 remained high (>80%) over the whole pH range tested. Addition of NaCl did not have any profound effect on the solubility of Fraction 2, but it increased significantly that of Fraction 1 in the isoelectric range. Foaming properties of Fraction 1 were better than those of chicken egg white only at pH 9, whereas those of Fraction 2 were superior at almost every pH value studied. Addition of NaCl improved significantly the foaming properties of Fraction 1 at all pH values tested but did not have a profound effect on the foaming properties of Fraction 2. Both fractions had good emulsifying properties only at alkaline pH values.
Analysis of conjugated linoleic acid isomers and content in french cheeses
Authors: Lavillonnière F. , Martin J. C. , Bougnoux P. , Sébédio J.‐L.
Published: May 2007

Conjugated linoleic acid (CLA) occurs in food as a result of microbial enzymatic reactions, free radical‐type oxidation, and heat treatment. CLA is found in animal products, such as meat and dairy products, especially in cheeses. The CLA composition of 12 different French cheeses was determined by a combination of different analytical methods: reversed‐phase high‐performance liquid chromatography (RP‐HPLC), gas chromatography‐mass spectrometry (GC‐MS), GC‐Fourier transform infrared (GC‐FTIR), and silver nitrate thin‐layer chromatography (AgNO3‐TLC). New isomers (Δ8,10‐ and Δ11,13‐octadecadienoic acids with all possible cis and trans configurations) that co‐eluted with previously identified isomers (Δ9c,11t‐; Δ9t,11c‐; Δ10c,12t‐; Δ10t,12c‐; Δ11c,13c‐; Δ9c,11c‐; Δ10c,12c‐; Δ9t,11t‐; Δ10t12t‐octadecadienoic acids) were detected. Δ9c,11t‐Octadecadienoic acid was the major CLA isomer in these cheeses. All isomers were present in each product, whatever the production process. However, CLA content in the cheeses varied from 5.3 to 15.80 mg/g of cheese fat, which depended primarily on the origin of the milk (season, geography) and somewhat on the production process.
Determination of trans fatty acids in hydrogenated vegetable oils by attenuated total reflection infrared spectroscopy: Two limited collaborative studies
Authors: Adam M. , Chew M. , Wasserman S. , McCollum A. , McDonald R. E. , Mossoba M. M.
Published: May 2007

An attenuated total reflection infrared spectroscopy procedure was collaboratively studied among two sets of five laboratories for quantitating the total trans fatty acid levels in neat (without solvent) hydrogenated vegetable oils, measured as triacylglycerols in one study, and as fatty acid methyl ester derivatives in the other. Unlike the fatty acid methyl esters, the triacylglycerols required no derivatization but had to be melted prior to measurement. To obtain a symmetric absorption band at 966 cm−1 on a horizontal background, the single‐beam spectrum of the trans‐containing fat was “ratioed” against that of a refined oil or a reference material that contained only cis double bonds. A single‐bounce horizontal attenuated total reflection cell that requires 50 µL of undiluted test samples was used for oils, melted fats, or their methyl esters. For fatty acid methyl esters, the reproducibility relative standard deviations were in the range of 0.9 to 18.46% for 39.08 to 3.41% trans, determined as methyl elaidate per total fatty acid methyl esters. For five pairs of triacylglycerol blind duplicates, the reproducibility and repeatability relative standard deviations were in the ranges of 1.62 to 18.97%, and 1.52 to 13.26%, respectively, for 39.12 to 1.95% trans, determined as trielaidin per total triacylglycerols. Six pairs of spiked triacylglycerol blind duplicates (quality assurance standards) exhibited high accuracy in the range of 0.53 to 40.69% trans and averaged a low bias of 1.3%. These statistical analysis results were compared to those collaboratively obtained by the recently adopted AOCS Cd14‐95 and AOAC 994.34 Infrared Official Methods.
CO2 laser infrared optothermal spectroscopy for quantitative adulteration studies in binary mixtures of extra‐virgin olive oil
Authors: Favier Jan Paul , Bicanic Dane , Cozijnsen Jan , van Veldhuizen Beb , Helander Per
Published: May 2007

Optothermal window spectroscopy at CO2 laser infrared wavelengths was used to detect the extent of adulteration of extra‐virgin olive oil by sunflower and safflower oils. A good linearity between the strength of optothermal signal and the concentration of each adulterating compound was found. Predicted limits of detection presently attainable by this new method are 6 (w/w) and 4.5% (w/w) for extra‐virgin olive oil adulterated with safflower oil and sunflower oil, respectively, and were confirmed experimentally; the corresponding relative errors were 0.3 and 0.18%. Interference effects are comparable to those encountered in other spectroscopic methods at the same wavelength.
Rapid methods for predicting the appearance of turbidity in sunflower oil and their comparison with cold tests
Authors: Baltanás Miguel A. , Molina Hugo , Silva Carlos
Published: May 2007

Two rapid turbidimetric methods have been applied to determine the content of wax in refined and refined‐bleached sunflowerseed oils in the range of 0 to 120 ppm. Synthetic wax‐oil mixtures were prepared to construct calibration plots. Turbidimetric results were compared with visual evaluation of these mixtures as well as of the industrial oils by an expert panel, during 2 wk, under cold‐test (0°C) and tempering (15°C) conditions. Based on the standard AOCS cold‐test, the visual turbidity threshold of these Argentine oils was under 40 ppm, a value significantly lower than that found in European cultivars. Also, while both types of industrial oils passed the cold‐test, the refined oil developed cloudiness after tempering for 14 d, whereas the refined‐bleached oil remained transparent. Because the calibration plots showed that the turbidity difference values, given by these fast methods, corresponded to wax contents that caused visible turbidity but fell into the nonsensitive region of the instrument, a simple standard addition technique was used to extend their sensitivity to these low wax contents. With this improvement, oils that contained more than 40 ppm of wax by fast turbidimetry, which can be expected to develop cloudiness on storage in the winter season, can be promptly identified, thus allowing any desired corrective action.
Purity assessments of major vegetable oils based on δ13C values of individual fatty acids
Authors: Woodbury Simon E. , Evershed Richard P. , Barry Rossell J.
Published: May 2007

The fatty acid compositions and δ13C values of the major fatty acids of more than 150 vegetable oils were determined to provide a database of isotopic information for use in the authentication of commercial maize oil. After extraction of oils from seeds, nuts or kernels, and methylation, fatty acid compositions were determined by capillary gas chromatography. All compositions were within the ranges specified by the Codex Alimentarius. Gas chromatography combustion‐isotope ratio mass spectrometry was employed to determine the δ13C values of the major fatty acids of the oils. A large number of pure maize oils and potential adulterant oils from various parts of the world were studied to assess the sources of variability in δ13C values. Such information is vital to establishing the compound specific isotope technique as a reliable means of assessing vegetable oil purity. Variability in δ13C values was related to the geographical origin of the oil, year of harvest, and the particular variety of oil. This suggests that the ultimate δ13C values of fatty acids are determined by a combination of environmental and genetic factors.
Performance studies of various cracking catalysts in the conversion of canola oil to fuels and chemicals in a fluidized‐bed reactor
Authors: Katikaneni Sai P. R. , Adjaye John D. , Idem Raphael O. , Bakhshi Narendra N.
Published: May 2007

Studies were conducted at atmospheric pressure at temperatures in the range of 400–500°C and fluidizing gas velocities in the range of 0.37–0.58 m/min (at standard temperature and pressure) to evaluate the performance of various cracking catalysts for canola oil conversion in a fluidized‐bed reactor. Results show that canola oil conversions were high (in the range of 78–98 wt%) and increased with an increase in both temperature and catalyst acid site density and with a decrease in fluidizing gas velocity. The product distribution mostly consisted of hydrocarbon gases in the C1–C5 range, a mixture of aromatic and aliphatic hydrocarbons in the organic liquid product (OLP) and coke. The yields of C4 hydrocarbons, aromatic hydrocarbons and C2–C4 olefins increased with both temperature and catalyst acid site density but decreased with an increase in fluidizing gas velocity. In contrast, the yields of aliphatic and C5 hydrocarbons followed trends completely opposite to those of C2–C4 olefins and aromatic hydrocarbons. A comparison of performance of the catalysts in a fluidized‐bed reactor with earlier work in a fixed‐bed reactor showed that selectivities for formation of both C5 and iso‐C4 hydrocarbons in a fluidized‐bed reactor were extremely high (maximum of 68.7 and 18 wt% of the gas product) as compared to maximum selectivities of 18 and 16 wt% of the gas product, respectively, in the fixed‐bed reactor. Also, selectivity for formation of gas products was higher for runs with the fluidized‐bed reactor than for those with the fixed‐bed reactor, whereas the selectivity for OLP was higher with the fixed‐bed reactor. Furthermore, both temperature and catalyst determined whether the fractions of aromatic hydrocarbons in the OLP were higher in the fluidized‐bed or fixed‐bed reactor.
Eicosapentaenoic acid and docosahexaenoic acid production potential of microalgae and their heterotrophic growth
Authors: Vazhappilly Rema , Chen Feng
Published: May 2007

Twenty microalgal strains were investigated in photoautotrophic flask cultures for their potential for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) production. The highest EPA proportion (% of total fatty acids) was produced by Monodus subterraneus UTEX 151 (34.2%), followed by Chlorella minutissima UTEX 2341 (31.3%) and Phaeodactylum tricornutum UTEX 642 (21.4%). The highest DHA proportion (% of total fatty acids) was obtained in Crypthecodinium cohnii UTEX L1649 (19.9%), followed by Amphidinium carterae UTEX LB 1002 (17.0%) and Thraustochytrium aureum ATCC 28211 (16.1%). Among the 20 strains screened, the EPA yield was high in M. subterraneus UTEX 151 (96.3 mg/L), P. tricornutum UTEX 642 (43.4 mg/L), Chl. minutissima UTEX 2341 (36.7 mg/L), and Por. cruentum UTEX 161 (17.9 mg/L) owing to their relatively high biomass concentrations. The DHA yield was high in C. cohnii UTEX L1649 (19.5 mg/L) and A. carterae UTEX LB 1002 (8.6 mg/L). Heterotrophic growth of these 20 microalgae was also tested on two different carbon sources, acetate and glucose. All microalgae except Nannochloropsis oculata UTEX LB 2164 showed growth on glucose (5 g/L) under heterotrophic conditions. Twelve of them could grow heterotrophically when acetate (1 g/L) was used as their sole carbon and energy source.
Separation of palm carotene from crude palm oil by adsorption chromatography with a synthetic polymer adsorbent
Authors: Baharin B. S. , Abdul Rahman K. , Abdul Karim M. I. , Oyaizu T. , Tanaka K. , Tanaka Y. , Takagi S.
Published: May 2007

Palm carotene was successfully concentrated from crude palm oil by a single‐stage chromatographic process on a synthetic porous polymer. Carotene was concentrated to about 105 ppm solution, which is about 160 times the original concentration in crude palm oil. Carotene recovery varied from 40 to 65% depending upon chromatographic conditions. The fatty acid composition of the palm oil did not change during the carotene recovery process, and the carotene composition was also almost the same as that in palm oil. Adsorption isotherms of the adsorbent differed from other adsorbents. This new recovery method for palm carotene may be suitable as an edible palm oil pretreatment process due to its efficient mass recovery of a valuable bioresource.
Structured lipids: Lipase‐catalyzed interesterification of tricaproin and trilinolein
Authors: Fomuso Lydia B. , Akoh Casimir C.
Published: May 2007

Structured lipids were synthesized by interesterification of trilinolein and tricaproin with sn‐1,3‐specific (IM 60) and nonspecific (SP 435) lipases. The interesterification reaction was performed by incubating a 1:2 mole ratio of trilinolein and tricaproin in 3 mL hexane at 45°C for the IM 60 lipase from Rhizomucor miehei, and at 55°C for the SP 435 lipase from Candida antarctica. Reaction products were analyzed by reverse‐phase high‐performance liquid chromatography with an evaporative light‐scattering detector. The fatty acids at the sn‐2 position were identified after pancreatic lipase hydrolysis and analysis with a gas chromatograph. IM 60 lipase produced 53,5 mol% dicaproyllinolein (total carbon number = C33) and 22.2% monocaproyldilinolein (C45). SP 435 lipase produced 41% C33 and 18% C45. When caproic acid was used in place of tricaproin as the acyl donor, the IM 60 lipase produced 62.9% C33. The effects of variation in mole ratio, temperature, added water, solvent polarity, and time course on the interesterification reaction were also investigated. In the absence of organic solvent, IM 60 lipase produced 52.3% C33.
Purification of pregastric lipases of caprine origin
Authors: Lai Douglas T. , Stanley Roger D. , O’Connor Charmian J.
Published: May 2007

Pregastric lipases from kid (KPGL) and goat (GPGL) were purified from the commercial extracts by different chromatographic procedures. The total recovery of activity for both purification methods was ca. 10%, and the specific activities of KPGL and GPGL were 533 and 546 U/mg, respectively, at pH 6.5, 35°C for tributyrylglycerol (TBG) as substrate in a casein/lecithin emulsion. The purification factors were 130‐ and 76‐fold for the goat and kid lipases, respectively. The purified lipases from kid and goat showed the same 50 kDa protein band on sodium dodecyl sulfate‐polyacrylamide gel electrophoresis and an identical sequence for the first 11 amino acids. The optimal pH for the lipases was within the pH range 6–7, with maximal activity at pH 6.5. The stability of the purified lipases was decreased dramatically at pH>6.5, but was enhanced by the addition of albumin.
Castor bean lipase as a biocatalyst in the esterification of fatty acids to glycerol
Authors: Tüter Melek
Published: May 2007

Castor bean lipase was investigated as biocatalyst in the esterification of fatty acids to glycerol. For this purpose, pressed seeds were pretreated with phosphate‐citrate buffer solution at optimal preincubation time and pH and used as a lipase source in esterification of fatty acids with glycerol. The effect of process parameters in the esterification, i.e., molar ratios of reactants, temperature, water content of glycerol and concentration of lipase, were determined by using pretreated castor bean.
Determination of seed oil content and fatty acid composition in sunflower through the analysis of intact seeds, husked seeds, meal and oil by near‐infrared reflectance spectroscopy
Authors: Pérez‐Vich B. , Velasco L. , Fernández‐Martínez J. M.
Published: May 2007

A methodological study was conducted to test the potential of near‐infrared reflectance spectroscopy (NIRS) to estimate the oil content and fatty acid composition of sunflower seeds. A set of 387 intact‐seed samples, each from a single plant, were scanned by NIRS, and 120 of them were selected and further scanned as husked seed, meal, and oil. All samples were analyzed for oil content (nuclear magnetic resonance) and fatty acid composition (gas chromatography), and calibration equations for oil content and individual fatty acids (C16:0, C16:1, C18:0, C18:1, and C18:2) were developed for intact seed, husked seed, meal, and oil. For intact seed, the performance of the calibration equations was evaluated through both cross‐ and external validation, while cross‐validation was used in the rest. The results showed that NIRS is a reliable and accurate technique to estimate these traits in sunflower oil (validation r2 ranged from 0.97 to 0.99), meal (r2 from 0.92 to 0.98), and husked seeds (r2 from 0.90 to 0.97). According to these results, there is no need to grind the seeds to scan the meal; similarly accurate results are obtained by analyzing husked seeds. The analysis of intact seeds was less accurate (r2 from 0.76 to 0.85), although it is reliable enough to use for pre‐screening purposes to identify variants with significantly different fatty acid compositions from standard phenotypes. Screening of intact sunflower seeds by NIRS represents a rapid, simple, and cost‐effective alternative that may be of great utility for users who need to analyze a large number of samples.