Characterization and Benzo[a]pyrene Content Analysis of Camellia Seed Oil Extracted by a Novel Subcritical Fluid Extraction

A novel continuous subcritical n‐butane extraction technique for Camellia seed oil was explored. The fatty acid composition, physicochemical properties, and benzo[a]pyrene content of Camellia seed oil extracted using this subcritical technique were analyzed. Orthogonal experiment design (L₉(3⁴)) was adopted to optimize extraction conditions. At a temperature of 45 °C, a pressure of 0.5 MPa, a time of 50 min and a bulk density of 0.7 kg/L, an extraction yield of 99.12 ± 0.20 % was obtained. The major components of Camellia seed oil are oleic acid (73.12 ± 0.40 %), palmitic acid (10.38 ± 0.05 %), and linoleic acid (9.15 ± 0.03 %). Unsaturated fatty acids represent 83.78 ± 0.03 % of the total fatty acids present. Eight physicochemical indexes were assayed, namely, iodine value (83.00 ± 0.21 g I/100 g), saponification value (154.81 ± 2.00 mg KOH/g), freezing‐point (?8.00 ± 0.10 °C), unsaponifiable matter (5.00 ± 0.40 g/kg), smoke point (215.00 ± 1.00 °C), acid value (1.24 ± 0.03 mg KOH/g), refrigeration test (transparent, at 0 °C for 5.5 h), and refractive index (1.46 ± 0.06, at 25 °C). Benzo[a]pyrene was not detected in Camellia seed oil extracted by continuous subcritical n‐butane extraction. In comparison, the benzo[a]pyrene levels of crude Camellia seed oil extracted by hot press extraction and refined Camellia seed oil were measured at 26.55 ± 0.70 and 5.69 ± 0.04 μg/kg respectively.     

Comparison of Supercritical Fluid and Hexane Extraction Methods in Extracting Kenaf (<Emphasis Type="Italic">Hibiscus cannabinus</Emphasis>) Seed Oil Lipids

The objective of this study was to investigate and compare fatty acids, tocopherols and sterols of kenaf seed oil extracted by supercritical carbon dioxide and traditional solvent methods. Fatty acids, tocopherols and sterols were determined in the extracted oils as functions of the pressure (400 bar, 600 bar), temperature (40 °C, 80 °C) and CO₂ flow rate (25 g/min) using a 1-L extraction vessel. Gas chromatography was used to characterize fatty acids and sterols of the obtained oils while tocopherols were quantified by HPLC. No differences were found in the fatty acid compositions of the various oil extracts and the main components were found to be linoleic (38%), oleic (35%), palmitic (20%) and stearic acid (3%). Extraction of tocopherols using high pressure (600 bar/40 °C, 600 bar/80 °C) gave higher total tocopherols (88.20 and 85.57 mg/100 g oil, respectively) when compared with hexane extraction which gave yield of 62.38 mg/100 g oil. Extraction of kenaf seed oil using supercritical fluid extraction at high temperature (80 °C) gave higher amounts of sterols when compared with hexane extraction.     

Potential Use of Crude Coffee Silverskin Oil in Integrated Bioprocess for Fatty Acids Production

Oil from coffee silverskin (CS) is a potential source of fatty acids with promising applications in several industries. Thus, CS crude oil extraction processes were investigated for further enzymatic hydrolysis for fatty acids production. Firstly, Soxhlet (with 150 mL hexane for 8 hours at 70 °C) and ultrasound-assisted (three times in sequential with 50 mL of hexane for 30 min at 30 °C) extractions were carried out to extract CS oil (3.8% and 3.1%, respectively). The fatty acid profiles obtained by both extraction methods presented a similar composition, shows palmitic (16:0: 32.6–34.4%) and linoleic acids (18:2: 31.5–36.1%) as the main. Then, CS oil extracted by Soxhlet was used as the feedstock for fatty acids production by enzymatic hydrolysis using four commercial lipases. Among the lipases studied, Candida rugosa lipase (CRL) displayed a higher hydrolytic activity (1143.70 U g⁻¹), with a maximum hydrolysis degree of 51.94% (acid value of the CS oil increased from 13.4 to 37.5 mg KOH g⁻¹) after 180 min of reaction. Molecular docking analysis showed that interactions between the CRL active site (Ser209 and His449) and palmitic acid, the fatty acid of highest concentration in CS oil (≈35%), lead to higher hydrolytic activity. The integrated process developed is an advance in fatty acid production and valorization of coffee industry waste, since there is still a promising approach yet to be explored that aims at the utilization of residual CS oil.     

Lipase Catalyzed Synthesis of Medium-chain Biodiesel from Cinnamonum camphora Seed Oil

The non-edible camphor tree seed oil was extracted and catalyzed by immobilized lipase for biodiesel production. The oil yield from camphor tree seeds reached 35.2% of seed weight by twice microwave-assisted extractions. Gas chromatography showed that free fatty acid content in camphor tree seed oil was 1.88%, and the main fatty acids were capric acid (53.4%) and lauric acid (38.7%). With immobilized lipase Candida sp. 99–125 as catalyst, several important factors for reaction conditions were examined through orthogonal experiments. The optimum conditions were obtained: water content and enzyme loading were both 15% with a molar ratio of 1:3.5 (oil/ethanol), and the process of alcoholysis was in nine steps at 40 °C for 24 h, with agitation at 170 r·min^− 1. As a result, the medium-chain biodiesel yield was 93.5%. The immobilized lipase was stable when it was used repeatedly for 210 h.     

Characteristics of Laboratory-Processed: Cucurbita foetidissima Seed Oil

The effects of variations in laboratory processing on the quality of the seed oil of the buffalo gourd, Cucurbita foetidissima, were determined. Conditions found most effective were: triple refining at 65 C for 15 min using 16°Be and 20°Be NaOH at 80% of maximum and 20°Be NaOH at the maximum; bleaching at 105 C for 30 min by a mixture of activated bleaching earth (3%) and activated carbon (0.3%); and deodorization with 5% steam at 210 C for 120 min. Processed oil showed these analytical values: carotenoids (3.6 mg/kg), free fatty acids (0.28%), peroxide (0.2 meq/kg), conjugated unsaturated fatty acids (1.59%). Oxidative stability test (AOM) conditions gave peroxide values of 100 in 4.9 hr and 141 in 8 hr. The triglyceride fatty acid composition was 11.9% palmitic, 3.5% stearic, 22.0% oleic and 61.0% linoleic acid.     

Trigonella foenum-graecum L. Seed Oil Obtained by Supercritical CO2 Extraction

Supercritical CO₂ extraction (SC-CO₂) of fenugreek (Trigonella foenum-graecum L.) seed oil and its chemical composition and antioxidant activity were investigated. A central composite design combined with response surface methodology was used to study extraction conditions including pressure, temperature, and time. The optimum extraction conditions were 28.5?MPa extraction pressure, 41?°C extraction temperature, and 118?min extraction time, where 3.78?% yield was predicted. Fenugreek seed oil extracted under optimum conditions by SC-CO₂ was mainly composed of 28.3?% C18:3, 33.45?% C18:2, 9.89?% C16, 8.1?% C18:1, 3.7?% C18, 0.71?% C20, and 0.61?% C22. The fenugreek oil was rich in unsaturated fatty acids (nearly 70?% of the total fatty acids), and polyunsaturated fatty acids accounted for 61.42?% (mass percentage) of the total amount. The 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity increased from 12.5 to 88.4?% when the concentration was increased from 1 to 12?mg/ml. The reducing power of the seed oil was concentration-dependent. The antioxidant activity of the supercritical fluid extraction extract was superior to those obtained by Soxhlet extraction.     

Tough thermosetting polyurethanes and adhesives from rubber seed oil by hydroformylation

Rubber seed oil (RSO), extracted from the seeds of rubber trees, is inedible oil with high free fatty acid content. In order to add value to RSO, we prepared a polyol with primary OH groups via hydroformylation/hydrogenation. Free hydroxy fatty acids formed in the process were utilized as reactive diluents, viscosity reducers, and adhesion promoters through hydrogen bonding with the substrate. The structures of the oil and polyol were analyzed using a range of analytical methods. The polyol had a hydroxyl number of 244 mg KOH g⁻¹ and an acid number of 21 mg KOH g⁻¹. The polyurethane prepared from this polyol and diphenylmethane diisocyanate was a highly crosslinked, tough material with a glass transition at 44 °C, high tensile strength and elongation, and attractive electrical properties. When used as a wood adhesive, it displayed extraordinary shear strength characterized by substrate wood failure rather than cohesive failure of the polymer. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48509.     

Production of Low-trans Fatty Acids Edible Oil by Electrochemical Hydrogenation in a Diaphragm Reactor Under Controlled Conditions

Electrochemical hydrogenation is a novel, alternative process for selective hydrogenation of vegetable oils, because of its high extent of hydrogenation and low trans-isomer formation. Electrochemical hydrogenation of soybean oil in a diaphragm reactor with a formate ion concentration of 0.4 mol/l at pH 5.0 under moderate temperature conditions using a current density of 10 mA/cm² was investigated to identify the critical conditions affecting the selective hydrogenation reaction and the resulting fatty acid profile. The optimum composition was an oil-to-formate solution ratio of 0.3 (w/w), 2?C3 g EDDAB in 100 g soybean oil, and 0.8% Pd?CC catalyst loading. The electrochemical hydrogenation reaction of soybean oil was described by first-order kinetics, and the kinetic rate constants and reaction selectivity were determined accordingly. Re-use of the Pd?CC catalyst up to five times was found to be acceptable. A comprehensive evaluation revealed that the most significant conditions affecting the extent of hydrogenation and the trans fatty acids content of final products were operating temperature, pH of the formate solution, and catalyst loading.     

Seed Oil Content and Fatty Acid Composition from Different Populations of Calotropis procera (Aiton) W. T. Aiton (Apocynaceae)

Calotropis procera is a soft-wooded, evergreen, perennial shrub species which grows in a variety of environments including dry habitats such as the Brazilian semi-arid region. This study aimed to evaluate the variation in the oil content and fatty acid composition of C. procera seeds from four climatically different locations in the state of Pernambuco in the northeast of Brazil. The seed oil content of C. procera ranged from 19.7 to 24.0 %. Five main fatty acids were identified, with a predominance of unsaturated linoleic and oleic acids (approximately 70 %). Our results suggesting that environmental conditions influenced the seed oil biosynthesis of C. procera, because the localities with high temperature and low precipitation had increased oil content and total biosynthesis of saturated fatty acids. Multivariate analysis showed high similarity among three localities which share certain physiographic characteristics and climatic conditions such as temperature and precipitation values. The oil profile of C. procera presents interesting features that highlight its potential as a future alternative for the biodiesel market, especially in semi-arid regions.     

Lipase-Catalyzed Acidolysis of Olive Oil with Echium Oil Stearidonic Acid: Optimization by Response Surface Methodology

In this study, our aim was to enrich olive oil with stearidonic acid (SDA) together with polyunsaturated fatty acids (PUFA) by lipase-catalyzed acidolysis using olive oil (OO) and free fatty acids of Echium oil, in the presence of Lipozyme^? TL IM. The reaction conditions were optimized by using response surface methodology. A three-factor, five level central composite circumscribed designs was used to generate the design points. The factors chosen were: substrate molar ratio (S _r, 4–6?mol/mol), reaction temperature (T, 55–65?°C), and reaction time (t, 6–9?h). Targeted incorporation (5?%) of SDA into OO was achieved at substrate molar ratio of 6?mol/mol, 55?°C, and 8.4?h. Model verification performed under these conditions for mg- and g-scale production yielded SDA contents of 4.9 and 4.8?%, respectively. Moreover, it was observed that the structured lipid (SL) obtained under optimum conditions contained approximately 42?% oleic acid and 43?% PUFA including linoleic acid, α-linolenic acid, and γ-linolenic acid. Omega-6/omega-3 fatty acid ratio of SLs was 0.7. Analysis of oxidative properties resulted in lower oxidative stability of SL than unmodified OO. This type of SL containing SDA and other PUFA is believed to be beneficial for human health.     

Fatty Acid Profile of Kenaf Seed Oil

The fatty acid profile of kenaf (Hibiscus cannabinus L.) seed oil has been the subject of several previous reports in the literature. These reports vary considerably regarding the presence and amounts of specific fatty acids, notably (12,13-epoxy-9(Z)-octadecenoic (epoxyoleic) acid, but also cyclic (cyclopropene and cyclopropane) fatty acids. To clarify this matter, two kenaf seed oils (from the Cubano and Dowling varieties of kenaf) were investigated regarding their fatty acid profiles. Both contain epoxyoleic acid, the Cubano sample around 2 % and the Dowling sample 5-6 % depending on processing. The cyclic fatty acids malvalic and dihydrosterculic were identified in amounts around 1 %. Trace amounts of sterculic acid were observed as were minor amounts of C17:1 fatty acids. The results are discussed in the context of the fatty acid profiles of other hibiscus seed oils.     

Kinetics of supercritical carbon dioxide extraction of borage and evening primrose seed oil

In the present work, high‐pressure extraction of borage (Borago officinalis L.) and evening primrose (Oenothera biennis L.) seed oil, containing the valuable γ‐linolenic acid (GLA), has been investigated. Extraction was performed with supercritical carbon dioxide on a semi‐continuous flow apparatus at pressures of 200 and 300 bar, and at temperatures of 40 and 60 °C. A constant flow rate of carbon dioxide in the range from 0.17 to 0.20 kg/h was maintained during extraction. The extraction yields obtained using dense CO₂ were similar to those obtained with conventional extraction using hexane as solvent. The composition of extracted crude oil was determined by GC analysis. The best results were obtained at 300 bar and 40 °C for both seed types extracted, where the quality of oil was highest with regard to GLA content. The evening primrose seed oil extracted with supercritical fluid extraction was particularly rich in unsaturated fatty acids: up to 89.7 wt‐% of total free fatty acids in the oil. The dynamic behavior of the extraction runs was analyzed using two mathematical models for describing the constant rate period and the subsequent falling rate period. Based on the experimental data, external mass transfer coefficients, diffusion coefficients and diffusivity in solid phase were estimated. Results showed good agreement between calculated and experimental data.     

Characteristics of Oil from Hulless Barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.) Bran from Tibet

The bran of hulless barley (Hordeum vulgare L.) from Tibet was investigated. This paper reports on the physicochemical characteristics, lipid classes and fatty acids of the oil from the bran. The petroleum (60–90 °C) extract of hulless barley bran was found to be 8.1%. The investigated physiochemical parameters included density at 40 °C (0.96 g/cm³), refractive index at 40 °C (1.41), melting point (30.12 °C), acid value (11.6 mg KOH/g), peroxide value (19.41 μg/g), saponification value (337.62 mg KOH/g), iodine value (113.51 mg iodine/g) and unsaponifiable matter (4.5% of total lipids).The amount of neutral lipids in the crude oil was the highest (94.55% of total lipids), followed by glycolipids (4.20% of the total lipid) and phospholipids (1.25% of the total lipid). Linoleic acid (75.08% of total fatty acids) followed by palmitic acid (20.58% of total fatty acids), were the two major fatty acids in the oil. The results show that the oil from the hulless barley bran could be a good source of valuable essential fatty acids.     

Comparative Evaluation of Physicochemical Properties of Jatropha Seed Oil from Malaysia,Indonesia and Thailand

The jatropha oil was extracted from the jatropha seeds collected from different origins viz., Malaysia, Indonesia and Thailand. The physicochemical properties such as density, viscosity, percentage free fatty acid (FFA), iodine value, saponification value and peroxide value of the extracted jatropha seed oil were evaluated. The evaluation of fatty acid composition using gas chromatography (GC) revealed that, oleic (42.4–48.8%) and linoleic acid (28.8–34.6%) are the dominant fatty acids present in the jatropha seed oil. The saturated fatty acids such as palmitic and stearic acid lie in the range 13.25–14.5 and 7–7.7%, respectively. The observed major triacylglycerol (TAG) composition was OOL (22.94–25.75%) and OLL (15.52–20.77%).     

Physical‐chemical characteristics and oxidative stability of oil obtained from lyophilized raspberry seed

Fresh raspberry (Rubus idaeus), cultivar Willamette, was freeze‐dried (lyophilization). A byproduct of lyophilization is “fine dust” of raspberry consisting of finely ground raspberry fruit body and seed. The seeds were separated. The seed oil was isolated and its physical and chemical characteristics were determined. Parameters that characterize the seed and quality of the oil were examined, including fatty acid composition, oxidative stability under different storage conditions, and radical‐scavenging activity. The fatty acid composition was determined by GC/FID and the contents of the dominant fatty acids were found as: oleic 16.92%, linoleic 54.95%, and α‐linolenic acid 23.97%. The oxidative stability of the oil was poor. The induction period by Rancimat test at 100 °C was 5.2 h. The radical‐scavenging activity is similar to that of resveratrol [1,3‐benzenediol 5‐(1^E‐2‐4‐hydroxy‐phenyl‐ethyl)]. Although this product is used in the candy industry, it would be far more useful if raspberry oil of satisfactory quality could be extracted. This paper demonstrates that sifted lyophilized seeds can be used for the extraction of oils. This process allows for maximal usage of the byproducts, reduces losses and it increases the development of new products.     

Full Characterisation of Crambe abyssinica Hochst. Seed Oil

This work was dedicated to reporting the full chemical and physical characterisation of Crambe abyssinica Hochst. seed oil. The oil from the seeds was extracted using n-hexane. The seeds contain about 30?% oil. Density, refractive index, colour, smoke point, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters, the relative position of fatty acids in C₁ and C₃ carbon glycerol, sterols, tocopherols, peroxide value, $ \mathop E\nolimits_{{1{\text{cm}}}}^{1\,\% } $ at 232?nm, and the susceptibility to oxidation measured by the Rancimat method were determined. The oil was found to contain high levels of unsaturated fatty acids, especially C22:1 (63.77?%). The dominant saturated acid was C22:0 (2.14?%). The oil was also found to contain high levels of β-sitosterol (51.93?%), campestanol (21.98?%), and brassicasterol (12.35?%). α-, γ-, and δ-Tocopherols were detected up to levels of 7.67, 125.04, and 3.99?mg/kg, respectively. The induction period (at 110?°C and 20?l/h) of the oil was 8.83?h. The relative position of fatty acids in C₁ and C₃ position was as follows: linoleic 0.45?%, oleic 8.84?%, and erucic 90.72?%. The thermal profile of the oil presented a single peak at ?20.94?°C.     

Methyl Esters (Biodiesel) from and Fatty Acid Profile of Gliricidia sepium Seed Oil

Increasing the supply of biodiesel by defining and developing additional feedstocks is important to overcome the still limited amounts available of this alternative fuel. In this connection, the methyl esters of the seed oil of Gliricidia sepium were synthesized and the significant fuel‐related properties were determined. The fatty acid profile was also determined with saturated fatty acids comprising slightly more than 35 %, 16.5 % palmitic, 14.5 % stearic, as well as lesser amounts of even longer‐chain fatty acids. Linoleic acid is the most prominent acid at about 49 %. Corresponding to the high content of saturated fatty acid methyl esters, cold flow is the most problematic property as shown by a high cloud point of slightly >20 °C. Otherwise, the properties of G. sepium methyl esters are acceptable for biodiesel use when comparing them to specifications in biodiesel standards but the problematic cold flow properties would need to be observed. The ¹H‐ and ¹³C‐NMR spectra of G. sepium methyl esters are reported.     

Fatty acid composition of oil from soybean leaves grown at extreme temperatures

Leaves from soybean (Glycine max (L.) Merr.) plants were assayed to determine if the relationship between temperature and relative fatty acid composition observed in the seed oil also existed for the triglycerides in the leaf oil. Leaf samples were harvested from eight soybean lines (A5, A6, C1640, Century, Maple Arrow, N78-2245, PI 123440 and PI 361088B) grown at 40/30,28/22 and 15/ 12°C day/night. At 40/30 and 28/22°C, seven fatty acids were observed at a level greater than 1.0%. These included the five major fatty acids found in the seed oil: palmitic (16:0), stearic (18:0), oleic (18:1), linoleic (18:2) and linolenic (18:3) acid; plus two fatty acids that had retention times the same as palmitoleic (16:1) and γ-linolenic (18:3 g) acid. In addition, an eighth fatty acid that had a retention time the same as behenic (22:0) acid was found in the leaves of all lines at 15/12°C. Palmitic, palmitoleic and stearic acid content did not differ significantly over temperatures. The oleic and linoleic acid content were each highest at 15/12°C, while the γ-linolenic and the linolenic acid content were each highest at 40/30°C. The fatty acid composition of the triglyceride portion of the leaf oil did not display the same pattern over temperatures as that observed for seed oil.     

Application of Taguchi Method in the Enzymatic Modification of Menhaden Oil to Incorporate Capric Acid

Structured lipids (SL) were produced using menhaden oil and capric acid or ethyl caprate as the substrate. Enzymatic reaction conditions were optimized using the Taguchi method L9 orthogonal array with three substrate molar ratio levels of capric acid or ethyl caprate to menhaden oil (1:1, 2:1, and 3:1), three enzyme load levels (5, 10, and 15% [w/w]), three temperature levels (40, 50, and 60 °C), and three reaction times (12, 24, 36 hours). Recombinant lipase from Candida antarctica, Lipozyme^® 435, and sn‐1,3 specific Rhizomucor miehei lipase, Lipozyme^® RM IM (Novozymes North America, Inc., Franklinton, NC, USA), were used as biocatalysts in both acidolysis and interesterification reactions. Total and sn‐2 fatty acid compositions, triacylglycerol (TAG) molecular species, thermal behavior, and oxidative stability were compared. Optimal conditions for all reactions were 3:1 substrate molar ratio, 10% [w/w] enzyme load, 60 °C, and 16 hours reaction time. Reactions with ethyl caprate incorporated significantly more C10:0, at 30.76 ± 1.15 and 28.63 ± 2.37 mol% versus 19.50 ± 1.06 and 9.81 ± 1.51 mol%, respectively, for both Lipozyme^® 435 and Lipozyme^® RM IM, respectively. Reactions with ethyl caprate as substrate and Lipozyme^® 435 as biocatalyst produced more of the desired medium‐long‐medium (MLM)‐type TAGs with polyunsaturated fatty acids (PUFA) at sn‐2 and C10:0 at sn‐1,3 positions.     

Physicochemical Properties and Fatty Acid Profile of Phoenix Tree Seed and its Oil

Various components of Phoenix tree (Firmiana simplex) seed were determined. Oil, protein, moisture, ash, and fiber accounted for 27.8 ± 0.3, 19.7 ± 0.4, 7.5 ± 0.2, 4.4 ± 0.3, and 31.23 ± 0.93 % (w/w) of the seed, respectively. The acid value, peroxide value, saponification value, and unsaponifiable matter content of Phoenix tree seed oil extracted using the Soxhlet method were 3.73 ± 0.02 mg KOH/g, 1.97 ± 0.21 mmol/kg, 183.74 ± 2.37 mg KOH/g, and 0.90 ± 0.05 g/100 g, respectively. The total tocopherol content was 54.5 ± 0.5 mg/100 g oil, which consisted mainly of δ‐tocopherol (29.5 ± 0.6 mg/100 g oil) and γ‐tocopherol (13.8 ± 0.8 mg/100 g oil). Linoleic acid (L, 30.2 %), oleic acid (O, 22.2 %), and sterculic acid (S, 23.2 %) were the main unsaturated fatty acids of Phoenix tree seed oil. The saturated fatty acids included palmitic acid (17.4 %) and stearic acid (St, 2.9 %). The work shows the first report of sterculic acid in seeds of this species. This oil can be used as a raw material to produce sterculic acid.