Lipid and fatty acid biosynthesis by Rhodotorula minuta

Demand for fatty acids is increasing at an annual rate of 17%, due to their increased use in the oleochemical and transport industries. Presently, vegetable oils are the major source of fatty acids, whereas lipids with fatty acids similar to those of some vegetable oils have been reported to be synthesized by oleaginous microorganisms. In the present study, the culturing conditions for the oleaginous yeast Rhodotorula minuta IIP-33 have been optimized. In contrast to the lipid accumulation characteristics of most oleaginous yeasts, a carbon-to-nitrogen ratio of 30 was favorable for maximal accumulation of lipids (48%) with 22.5% conversion of glucose as carbon substrate. The lipids contained fatty acids in the C₇–C₁₈ range, the relative composition of which varied with culture temperature.     

Relationship between seed mass and linolenic acid in progeny of crosses between cultivated and wild soybean

Soybean [Glycine max (L.) Merr.] oil from current commercial cultivars typically contains ca. 8% linolenic acid (18:3). Applications of plant biotechnology have enabled plant breeders to develop germplasm having as low as 2.0% 18:3. Oils that are naturally low in 18:3 exhibited improved flavor characteristics and greater oxidative stability in high-temperature frying applications compared to hydrogenated soybean oil. As an extension of that research, efforts are underway to characterize genes in soybean that govern expression of higher than normal 18:3 concentration. Such oils may be of interest to the oleochemicals industry for various nonfood applications. Relatively high 18:3 in seed oil is a characteristic trait of the ancestor of modern soybean cultivars, Glycine soja (Sieb. and Zucc.). Accessions of this species have rarely been utilized in soybean improvement, and thus represent a virtually untapped genetic resource for genes governing 18:3 synthesis. We have hybridized cultivated soybean with wild soybean plant introductions. F_3:4 seed from the resultant G. max × G. soja populations exhibited a wide segregation pattern for 18:3 and seed mass. A strong negative association was found between 18:3 concentration and seed mass. Oil concentration was positively correlated with seed mass. Evaluation of glycerolipid composition revealed that high 18:3 was not associated with an altered proportion of phospholipid and triacylglycerol among lines segregating for seed mass. Thus, smaller seed mass may be a convenient trait to distinguish future soybean cultivars with highly polyunsaturated oils from other cultivars in production.     

Developments in oil extraction from microalgae

Microalgae are a diverse group of organisms with significant potential for industrial applications: as feedstock in aquaculture as well as in the production of valuable bioproducts such as lipids, carotenoids and enzymes. Lately, developments in molecular biology have improved production yields of algae bioproducts, thus increasing their industrial relevance. Additionally, variations in bioprocessing factors (i.e. temperature, pH, light, carbon source, salinity, nutrients, etc.) have been used to enhance both biomass and specific bioproducts' productivities. Particularly, microalgae have increasingly gained research interest as a source of specialty lipids such as arachidonic, eicosapentaenoic and docosahexaenoic acids, which are often reported in literature to provide several health benefits. Moreover, there has been a recent resurgence in interest in microalgae as an oil producer for biofuel applications. Significant advances have also been made in upstream processing to generate cellular biomass and oil. However, extracting and purifying oil from algae continues to prove a significant challenge in producing both microalgae bioproducts and biofuel, as microbial oil extraction is relatively energy‐intensive and costly. Thus, developing inexpensive and robust oil extraction and purification processes is a major challenge facing both the microalgae to bioproduct, and biofuel industries. This paper presents an overview, based on the last 10 years, of advances made in technologies for extracting and purifying microalgae oil. We compared solvent extraction technologies with extraction alternatives such as mechanical milling and pressing, enzymatic and supercritical fluid extraction. We also reviewed recent advances based on molecular engineering of microbes to aid oil extraction. Downstream processing for the potential commercial production of microalgae oil not only must consider economic costs, but should also consider minimizing environmental impacts in order to attain sustainable production processes.     

Physicochemical and rheological properties of passion fruit oil and its polyol

Vegetable oils are excellent renewable sources for chemical and oleochemistry industries, since they can be functionalized to be used in various applications. Here we present some physical and physicochemical properties of passion fruit oil and polyol derivatives obtained from this oil. The polyols were obtained by hydroxylation with in situ generation of the performic acid. Physicochemical properties, such as chromatographic analysis, iodine value, index of acidity, peroxide index, fixation index, unsaponifiables, and hydroxyl index were determined according to standard methods. Furthermore, ¹H NMR was examined and physical properties including liquid density and rheometry were characterized as well. The results revealed a wide variation of the physicochemical characteristics among the oils and respective polyols. The NMR analyses demonstrated polyol structures practically without unsaturation. The liquid rheology showed that the viscosity of polyols is at least two orders of magnitude larger than the viscosity of the original oil, confirming that the hydroxylation reaction occurred successfully. The shear viscosity of the polyols did not exhibit a systematic dependence on the shear rate or significant time dependence for the examined samples. The results indicate that the polyol viscosity decreases with the drying time increasing. Practical applications : The use of renewable resources is growing and is attracting great interest in the academic and industrial fields. Vegetable oils have attracted a special attention because of their potential to replace petrochemical derivatives and to contribute to minimizing environmental impacts; vegetable oils are promising candidates for base fluids in environment‐friendly lubricants. Polyols obtained from oils open new possibilities of use as monomers for polyurethanes, which exhibit excellent properties beyond reactivity.     

Neutron activation analysis as a method for measuring soil removal of unsaturated oils and for estimating their degree of aging on fabric

Neutron activation analysis of bromine-tagged oils on fabric provides a quantitative method for evaluating the degree of aging of unsaturated oils on fabric as well as a new method for measuring their soil removal by estimating the quantity of double bonds, before and after laundering. When aged at 21°C for 5 wk, 62, 63, and 20% of double bonds remained for oleic acid, triolein, and squalene, respectively. At 40°C, no double bonds were left after aging of oleic acid and triolein, whereas about 8% of the double bonds remained for squalene. A comparison of this method with the radiotracer method for soil removal measurements shows good agreement between the two methods. Proper treatment time for bromine tagging of unsaturated oils on fabric is any time between 90 s and 10 min under the bromination procedure used. The tagging of double bonds by bromine vapor has advantages of the exact one-to-one reaction ratio between Br₂ and the number of double bonds of unsaturated oleic acid or triolein, as well as a much lower cost than other tagging reagents like OsO₄. Because blank unsoiled fabric was shown to take up Br₂, fabric swatches of the same size should be used as controls in neutron activation analysis. This method has advantages of its sensitivity to small amounts, use of nonlabeled soil, quantitative measurement, and ease of sample preparation over the chemical measurement of iodine value.     

Enzyme technology for the lipids industry: An engineering overview

Enzymes useful in the lipids industry, i.e. lipases, phospholipases and lipoxygenases, are surveyed as to source, pH optimum, specificity and so on. Some useful biochemical reactions catalyzed by these enzymes are discussed: hydrolysis of fats and oils by lipases, transesterifications (acidolysis, alcoholysis, interesterification and aminolysis) of fats and oils by lipases, hydrolysis of lecithin by phospholipase A₂ and transphosphatidylation of phospholipids by phospholipase D. Research and development activities in these fields in the academic and industrial sectors of Japan are discussed. With reference to the lipolytic enzymes’ applications, forms or states with which enzymes and microorganisms are used in microaqueous solvent systems, i.e. in low water-activity media or in nearly anhydrous solvents, are summarized. Some configurations of reactors for the microaqueous biosystems are shown, and some engineering problems involved in the systems are identified. The importance of optimal moisture content control is emphasized.     

Synthesis and Characterization of Corn Oil Polyhydroxy Fatty Acids Designed as Additive Agent for Many Applications

Before the advent of the modern food industry, vegetable oils (triglycerides) from many sources had a long history of use as condiments in cooking, personal care, and other therapeutic applications. Industrial applications of vegetable oils outside of food usage, on the other hand, have been limited on account of the shorter shelf-life durability of these oils resulting from the natural unsaturation (carbon–carbon double bonds) in the structure of most triglycerides. In seeking to explore expanded utilization of this renewable resource, we have eliminated the above weakness by chemically modifying the double bonds in the material in an attempt to stabilize the oil. We have used FT-IR and NMR spectroscopy to characterize the derivative whereas the physical and chemical properties of the product in terms of stability and flow characteristics have been investigated using differential scanning calorimetry (DSC), pressure DSC, rheometry and thermogravimetric analysis. In this modification of corn oil the data obtained indicate that the resulting poly-hydroxylated acids are more stable than the native corn oil. Additionally, the obtained properties are unique and such that this product will be amenable to use in cosmetics, pharmaceuticals, and other industrial uses especially as a lubricity enhancing additive in fuel applications.     

Changes in virgin olive oil characteristics during different storage conditions

In this study we have examined the effect of olive oil storage outdoors on a comprehensive series of quality measures. The conditions used were at the extreme of those encountered during the production of bottle oil. Filtered and unfiltered oils were compared as was the influence of inert gas (nitrogen) in the headspace. Increases in K₂₃₂, K₂₇₀ and peroxides over time were very much reduced by inert headspace gas, which also reduced losses of total phenols and oxidative stability. Headspace nitrogen also reduced the rise in unconjugated phenolics as secoiridoid derivatives declined and minimised losses in polyunsaturated fatty acids. The pattern of volatile compounds detected in olive oils stored indoors or outdoors showed subtle differences. Moreover, when stored with air exposure the levels of some negative sensory components such as penten‐3‐ol and hexanal increased while other positives, like trans‐2‐hexenal were reduced. These changes would be expected to reduce quality. Finally, Panel tests were used. All oils lost perceived quality on storage and this was accelerated outdoors while headspace nitrogen slowed the deterioration significantly. Our data show that storage outdoors for 4 months in winter does not reduce olive oil quality significantly and that an inert gas in the headspace is beneficial. Practical applications : The storage of olive oil for bottling is carried out under a variety of conditions. Here we assess the effects of storage outdoors for oils from the main Greek cultivar (Koroneiki) of olive. Detailed analyses of quality (standard measures, different phenolics, lipids and volatiles) as well as Panel tests were used for evaluation. Our data show that, although storage outdoors causes deterioration quicker than indoors, changes are not serious up to 4 months. Furthermore, the use of an inert headspace gas significantly preserved quality both indoors and outdoors. Thus we would strongly recommend the latter measure to producers.     

Replacing fossil oil with fresh oil – with what and for what?

Industrial chemicals and materials are currently derived mainly from fossil‐based raw materials, which are declining in availability, increasing in price and are a major source of undesirable greenhouse gas emissions. Plant oils have the potential to provide functionally equivalent, renewable and environmentally friendly replacements for these finite fossil‐based raw materials, provided that their composition can be matched to end‐use requirements, and that they can be produced on sufficient scale to meet current and growing industrial demands. Replacement of 40% of the fossil oil used in the chemical industry with renewable plant oils, whilst ensuring that growing demand for food oils is also met, will require a trebling of global plant oil production from current levels of around 139 MT to over 400 MT annually. Realisation of this potential will rely on application of plant biotechnology to (i) tailor plant oils to have high purity (preferably >90%) of single desirable fatty acids, (ii) introduce unusual fatty acids that have specialty end‐use functionalities and (iii) increase plant oil production capacity by increased oil content in current oil crops, and conversion of other high biomass crops into oil accumulating crops. This review outlines recent progress and future challenges in each of these areas. Practical applications: The research reviewed in this paper aims to develop metabolic engineering technologies to radically increase the yield and alter the fatty acid composition of plant oils and enable the development of new and more productive oil crops that can serve as renewable sources of industrial feedstocks currently provided by non‐renewable and polluting fossil‐based resources. As a result of recent and anticipated research developments we can expect to see significant enhancements in quality and productivity of oil crops over the coming decades. This should generate the technologies needed to support increasing plant oil production into the future, hopefully of sufficient magnitude to provide a major supply of renewable plant oils for the industrial economy without encroaching on the higher priority demand for food oils. Achievement of this goal will make a significant contribution to moving to a sustainable carbon‐neutral industrial society with lower emissions of carbon dioxide to the atmosphere and reduced environmental impact as a result.     

Catalytic Synthesis of Higher Aliphatic Amines from the Corresponding Alcohols

Abstract

Aliphatic amines are of considerable industrial importance and find application in almost every field of modern technology, agriculture, and medicine [1], Lower aliphatic amines (C₁ to C₆) are important intermediates for the chemical and pharmaceutical industries. A large number of drugs, herbicides, pesticides, dyes, and other chemicals contain amino pups which originate from reactions with such intermediates, Many important applications of higher aliphatic amines (fatty amines) and their derivatives (most important derivatives are quarternary ammonium compounds) are based on their cationic surface activity. Relatively small amounts of such compounds are usually required to achieve the desired changes in surface and colloidal properties. Thus, not surprising, one of the first applications of fatty amines was in the flotation separation of nonmetallic materials such as potash, feldspar, phosphate, and mica. Today, probably the biggest demand for fatty amines lies in the production of fabric softeners. There are other important applications for aliphatic amines in the plastics and protective coat industries as emulsion stabilizers, mold release agents, pigment dispersers, and flushing agents. They are used as catalysts for polyurethane production. For granular products, alkylamines are used as anticaking and antidusting agents. In the rubber industry they are used as oxidation inhibitors and catalysts for accelerating vulcanization. Aliphatic amines find also many applications in the petroleum industry, especially as corrosion inhibitors and as components of lubricating oils, greases, and fuel oil where they act as sludge dispersants and stabilizers. They are added to gasoline as corrosion inhibitors.     

Structure characterization of films from drying oils cured under infrared light

Drying oils have been considered as water resistant coatings for bio‐based packaging materials; however, their curing rates are slow for industrial applications. Infrared radiation was investigated in this study as a means to increase the curing rate of linseed and tung oils. The effect of oil pretreatment with gamma radiation was also investigated. FTIR spectroscopy was used to monitor chemical changes during oil oxidation. Results indicated that infrared radiation increased the curing rate of linseed and tung oils. The oxidation rate of both oils, as monitored by the decrease of the 3010 cm^?1 FTIR peak, followed an exponential decay. The structure of cured films was examined by SEM. Images of films cross section were used to develop a qualitative model of the curing process. Linseed and tung oil showed differences in structural development during drying. In the case of linseed oil, the formation of a tough skin layer slowed down oxygen diffusion to the oil underneath, resulting in slow curing. For the case of tung oil, the skin layer shrank as it formed allowing oxygen diffusion and fast curing of tung oil. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Perspectives on supercritical fluid processing of fats and oils

Over the past two decades, fats and oils processing using supercritical carbon dioxide (SC-CO₂) has developed from focusing only on extraction to fractionation of complex lipid mixtures, conducting reactions in supercritical fluid media and particle formation techniques for the delivery of bioactive lipid components. Extraction of specialty oils and column fractionation of deodorizer distillates to concentrate tocopherols have reached commercial scale. Even though significant progress has been made in fundamental aspects, many challenges lie ahead to better understand the phase behavior and solubility of multicomponent lipid mixtures in SC-CO₂ and to generate the much needed fundamental data, including transport properties, density and interfacial tension. Considering the increasing consumer demand for “natural” products and stricter government regulations on the use of organic solvents like hexane, the future of SC-CO₂ processing of lipids is bright. Based on the know-how accumulated, integrated processes can be developed, targeting ingredients for both food and non-food industrial applications, which would fit well into a larger biorefinery approach.     

Mass spectrometric characterization ofVernonia galamensis oil

Vernonia galamensis seed oil is a natural source of epoxidized triacylglycerols, which consist of 52% trivernolin and a mixture of other triacylglycerols. Epoxidized oils are used for industrial applications, such as coatings and plastic formulations. To determine the major molecular species present in Vernonia oil, desorption chemical ionization/mass spectrometry and mass spectrometry/mass spectrometry were used to determine its glyceride composition. Seven triacylglycerols predominated: divernoloylarachidonate, trivernolin, divernoloylstearate, divernoloyloleate, divernoloyllinoleate, dilinolenoyl vernolate and divernoloylpalmitate.     

Bio-based flexible polyurethane foam synthesized from palm oil and natural rubber

As environment friendly polymers are required to reduce the green-house gas emissions and global warming, bio-based polyurethane foam (PUF) is attracting interest from the industrial sector and researchers. Bio-based polyols for PUF have been synthesized from various renewable resources, mostly plant oils. The present study explored a novel bio-based PUF produced from a mixture of bio-based polyols synthesized from palm oil and natural rubber. Palm oil-based polyol (POP) was synthesized via an epoxidation reaction of double bonds of palm oil followed by complete oxirane ring-opening. Hydroxy telechelic natural rubber (HTNR) was synthesized by oxidative degradation using periodic acid and sodium borohydride. For comparison, two diisocyanates were used: toluene-2,4-diisocyanate and polymeric methylene diphenyl diisocyanate. POP and HTNR were miscible and all PUFs showed polyhedral semi-closed cells and hardness was in the flexible foam range. One possible application of the novel PUF could be thermal insulation.     

Characteristics of safflower seed oils of turkish origin

Technological characteristics of oils extracted from seventeen varieties of safflower seeds (Carthamus tinctorius L.) of Turkish origin were investigated for their utilization prospects in the food industry and in other industrial sectors. Standard procedures were applied to determine the technological characteristics of seventeen varieties of safflower seeds and the safflower seed oils; fatty acid compositions were determined by gas-liquid chromatography. Results show that safflower seed oils are suitable both for food and industrial purposes.     

Effect of extraction systems on the quality of virgin olive oil

Research has been carried out to ascertai the effects of different processing systems on olive oil quality. Tests were performed in industrial oil mills that were equipped with both pressure and centrifugation systems. Results show that oils extracted from good-quality olives do not differ in free fatty acids, peroxide value, ultraviolet absorption and organoleptic properties. Polyphenols ando-diphenols contents and induction times are higher in oils obtained from good-quality olives by the pressure system because it does not require addition of water to the olive paste. The centrifugation system requires the addition of warm water to the olive paste and helps to obtain oils with a lower content of natural antioxidants. Oils obtained from poorquality or from ripe olives in continuous centrifugal plants are lower in free fatty acids than those obtained by the pressure system. Dr. Mario Solinas is deceased—May 23, 1993.     

Characterization of forced oxidation of sardine oil: Physicochemical data and mathematical modeling

It is of major interest to the food industry to understand the mechanisms and kinetics underlying spontaneous oxidation of marine oils because these polyunsaturated fatty acid (PUFA)-rich oils, the object of several health claims, have been repeatedly recommended for dietary intake. The present study attempts to characterize forced oxidation and hydrolytic breakdown of glycerides and fatty acids in sardine oil. A simple, first-order mathematical model was postulated and successfully fitted to the experimental data. This model confirmed that the rate of decrease in concentration of intact fatty acid moieties is almost directly proportional to the number of double bonds present. Therefore, as expected, the rate of oxidative decay was virtually independent of chain length, with an overall activation energy of ca. 22 kJ mol⁻¹. Additionally, the rate of hydrolysis was correlated with the rate of oxidative decay. With the exception of fatty acids possessing more than four double bonds, PUFA proved to be relatively stable to oxidation for up to 10 h at 50–70°C, and the qualitatively richest pattern of volatiles was obtained when the reaction was performed at the highest temperature (80°C).     

Vegetable oil raw materials

Vegetable oils that are important to the chemical industry include both edible and industrial oils, which contribute 24% and 13.5%, respectively, compared to 55% for tallow, to the preparation of surfactants, coatings, plasticizers, and other products based on fats and oils. Not only the oils themselves but also the fatty acids recovered from soapstock represent a several billion pound resource. Coconut oil is imported to the extent of 700-1,000 million pounds per year. Its uses are divided about equally between edible and industrial applications. Safflower oil has a relatively small production, but 15–25% of the oil goes into industrial products. Soybean oil, the major edible oil of the world, is produced in the United States at the rate of 11,000 million pounds per year with more than 500 million pounds going into industrial uses, representing 5% of the total production. Castor oil is imported to the extent of about 100 million pounds per year. Linseed oil production has declined drastically over the last 25 years but still amounts to about 100 million pounds per year. Oiticica and tung oils are imported in lesser amounts than castor and linseed oils. New crops that have industrial potential, as well as the traditional vegetable oil crops, include seed oils from crambe,Limnanthes, Lesquerella, Dimorphotheca, Vernonia, andCuphea plants. Crambe oil contains up to 65% erucic acid. Oil fromLimnanthes contains more than 95% of fatty acids above C₁₈.Lesquerella oil contains hydroxy unsaturated acids resembling ricinoleic acid from castor oil.Dimorphotheca oil contains a conjugated dienol system.Vernonia oils contain as much as 80% epoxy acids. TheCuphea oils contain a number of short chain fatty acids. Of these, crambe,Limnanthes, andVernonia are probably the most developed agronomically. Competition between vegetable oils and petrochemicals for the traditional fats and oil markets has been marked over the past 25 years, but prices for petrochemicals have accelerated at a greater rate than those for vegetable oils; and, it is now appropriate to reexamine the old as well as the new markets for fatty acids.     

Deep hydrodesulphurization and hydrogenation of diesel fuels on alumina-supported and bulk molybdenum carbide catalysts

Deep hydrodesulphurization (HDS) of diesel fuels has been carried out on P (Ni)-promoted or non-promoted Mo₂C-supported γ-Al₂O₃ and bulk Mo₂C under standard industrial conditions (613 K, 3 MPa). The effect of the promoter was investigated for different feedstocks on HDS and hydrogenation (HYD) with very low levels of sulfur. The temperature effect was also followed. The HDS conversion indicates that phosphorus promoted alumina supported carbide catalysts are as active as a commercial Co-Mo/Al₂O₃ catalyst for low levels of sulfur in the feed. Furthermore, the refractory compounds such as 4,6-dimethyldibenzothiophene are only transformed on molybdenum carbide catalyst in industrial conditions for hydrotreated gas oils. With gas oils with less than 50 wt ppm in sulfur, phosphorus promoted molybdenum carbide catalysts become more active than commercial catalysts for the HYD of the aromatic compounds and the HDS or the HDN of the feedstock.     

产油酵母菌——可再生油脂的潜在资源

目前利用单细胞油的方式包括生产特种油脂、作为生活消费品中植物油的替代品以及作为石油基燃料的替代品。基于地利用生物柴油副产物甘油的兴趣,介绍了利用工业甘油培养弯假丝酵母菌方面开展优化油脂生产条件的工作,并以弯假丝酵母为例,阐述了产油酵母菌的研究和发展前景。