Antioxidant capacity of rapeseed meal and rapeseed oils enriched with meal extract

Response surface methodology (RSM) was used to evaluate the quantitative effects of two independent variables: solvent polarity and temperature of the extraction process on the antioxidant capacity (AC) and total phenolics content (TPC) in meal rapeseed extracts. The mean AC and TPC results for meal ranged between 1181–9974 µmol TE/100 g and 73.8–814 mg sinapic acid/100 g of meal. The experimental results of AC and TPC were close to the predicted values calculated from the polynomial response surface models equations (R² = 0.9758 and 0.9603, respectively). The effect of solvent polarity on AC and TPC in the examined extracts was about 3.6 and 2.6 times greater, respectively, than the effect of processing temperature. The predicted optimum solvent polarity of ε = 78.3 and 63.8, and temperature of 89.4 and 74.2°C resulted in an AC of 10 014 µmol TE/100 g and TPC of 863 mg SAE/100 g meal, respectively. The phenolic profile of rapeseed meal was determined by an HPLC method. The main phenolics in rapeseed meal were sinapine and sinapic acid. Refined rapeseed oils were fortified with an extract – rich in polyphenols – obtained from rapeseed meal. The supplemented rapeseed oil had higher AC and TPC than the refined oil without addition of meal extracts. However, AC and TPC in the enriched oils decreased during storage. The TPC in the studied meal extracts and rapeseed oils correlated significantly (p<0.0000001) positively with their AC (R² = 0.9387). Practical applications: Many bioactive compounds extracted from rapeseed meal provide health benefits and have antioxidative properties. Therefore, it seems worth to consider the application of antioxidants extracted from the rapeseed meal for the production of rapeseed oils with potent AC. Moreover, antioxidants extracted from the rapeseed meal were added to refined rapeseed oil in order to enhance its AC. AC was then tested by FRAP assay. FRAP method is based on the reduction of the ferric tripyridyltriazine (Fe³⁺‐TPTZ) complex to the ferrous tripyridyltriazine (Fe²⁺‐TPTZ), and it is simple, fast, low cost, and robust method. FRAP method does not require specialized equipment and can be performed using automated, semi‐automatic, or manual methods. Therefore the proposed FRAP method can be employed by the fat industry laboratories to asses the AC of rapeseed oils and meal.     

Comparison of Two Analytical Methods for Assessing Antioxidant Capacity of Rapeseed and Olive Oils

The oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP) methods were used for the determination of antioxidant capacities (AC) of rapeseed oils at different steps of technological process and olive oils. The mean ORAC and FRAP results obtained for rapeseed oils (1,106–160 and 552–95.6 μmol TE/100 g) were higher than for olive oils (949–123 and 167–32.1 μmol TE/100 g). Although, FRAP values were lower than ORAC values for all studied oils, there is a linear and significant correlation between these two analytical methods (r = 0.9665 and 0.9298, P < 0.0005) for rapeseed and olive oils, respectively). Also, total phenolic compounds in rapeseed oils and olives correlated with antioxidant capacities (correlation coefficient ranged between 0.9470 and 0.8049). The refining process of rapeseed oils decreased the total phenolics content and antioxidant capacities by about 80%.     

Hermetia illucens Larvae as a Living Bioreactor for Simultaneous Food by-Products Recycling and Useful Oil Production

The effects of feeds containing several food by-products on the fatty acid compositions of Hermetia illucens larvae were studied. Coconut, tomato, apple, and viscera by-products, as well as combinations of control feed containing carbohydrate-rich additives were assayed. Final live weight (mg) and daily growth coefficient (%/day) ranged from 41 and 0.548 (tomato) to 93 and 1.292 (coconut), respectively. Oils containing lauric acid were obtained from larvae-fed vegetable by-products, especially those fed feed containing apple, coconut, and tomato (65.3, 54.4 and 52.3% of total fatty acids, respectively). Feed containing apple and a 1:1 (w/w) mix of control feed and apple by-products yielded the highest proportion of fatty acids in the larvae (23.5 and 15.6 g fatty acids/100 g fresh larvae, respectively). The properties of biodiesel that could be produced from larvae fatty acids were calculated and the following values were obtained: cetane number (58.5–60.2), higher heating value (38.3–39.0 MJ·kg⁻¹), density (0.869–0.873 g·cm⁻³), and induction period, an index of oxidation stability (8.4–150 hours). Such values were within the ranges specified by the ASTM D6751 and Europe EN 14214:2008 standards, while values for cold filter plugging point (−9.6 to 2.8 °C) were adequate for biodiesels intended for use in temperate climates. However, values for kinematic viscosity (2.93–3.58 mm²·s⁻¹) were slightly below the requirements of EN 14214:2008 (3.5–5.0). Overall, larvae fed food by-products produced lauric acid-rich oils, and the calculated properties of the oils were largely suitable for biodiesel production.     

Antioxidant Capacity of Rapeseed Extracts Obtained by Conventional and Ultrasound‐Assisted Extraction

Ultrasound‐assisted extraction (UAE) and conventional solid–liquid extraction were applied to extract total antioxidants from two rapeseed varieties. The antioxidant capacities (AC) of winter and spring rapeseed cultivars were determined by four different analytical methods: ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), 2,2′‐diphenyl‐1‐picrylhydrazyl (DPPH), 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS). The average AC of the studied rapeseed cultivars ranged between 4.21–10.03 mmol Trolox (TE)/100 g, 7.82–10.61 mmol TE/100 g, 8.11–51.59 mmol TE/100 g, 22.48–43.13 mmol TE/100 g for FRAP, CUPRAC, DPPH and ABTS methods, respectively. There are positive correlations between total phenolics (TPC = 804–1625 mg sinapic acid (SA)/100 g) and AC of the studied rapeseed extracts (r = 0.2650–0.9931). Results of the principal component analysis (PCA) indicate that there are differences between the total amounts of antioxidants in rapeseed samples extracted by different extraction techniques. Rapeseed extracts obtained after 18 min of ultrasonication revealed the highest content of total antioxidants. The UAE is a very useful, efficient and rapid technique of oilseed samples preparation for determination of AC by different analytical methods.     

Influence of different reactor types on Nannochloropsis oculata microalgae culture for lipids and fatty acid production

Greenhouse gases emitted into the atmosphere by burning of fossil fuels cause global warming. One option is obtaining biodiesel. Nannochloropsis oculata was cultured under different light intensities and reactors at 25°C for 21 days with f/2 medium to assess their effects on cell density, lipid, and fatty acids (FAs). N. oculata improved cell density on fed-batch glass tubular reactor (7 L) at 200 μmol E m⁻² s⁻¹, yielding 3.5 × 10⁸ cells ml⁻¹, followed by fed-batch Erlenmeyer flask (1 L) at 650 μmol E m⁻² s⁻¹ with 1.7 × 10⁸ cells ml⁻¹. The highest total lipid contents (% g lipid × g dry biomass⁻¹) were 44.4 ± 0.8% for the reactor (1 L) at 650 μmol E m⁻² s⁻¹ and 35.2 ± 0.2% for the tubular reactor (7 L) at 200 μmol E m⁻² s⁻¹, until twice as high compared with the control culture (Erlenmeyer flask 1 L, 80 μmol E m⁻² s⁻¹) with 21.2 ± 1%. Comparing the total lipid content at 200 μmol E m⁻² s⁻¹, tubular reactor (7 L) and reactor 1 L achieved 35.2 ± 0.2% and 28.3 ± 1%, respectively, indicating the effect of shape reactor. The FAs were affected by high light intensity, decreasing SFAs to 2.5%, and increased monounsaturated fatty acids + polyunsaturated fatty acids to 2.5%. PUFAs (20:5n-3) and (20:4n-3) were affected by reactor shape, decreasing by half in the tubular reactor. In the best culture, fed-batch tubular reactor (7 L) at 200 μmol E m⁻² s⁻¹ contains major FAs (16:0; 38.06 ± 0.16%), (16:1n-7; 30.74 ± 0.58%), and (18:1n-9; 17.15 ± 0.91%).     

Determination of Physicochemical Properties,Fatty Acid,Tocopherol, Sterol,and Phenolic Profiles of Expeller–Pressed Poppy Seed Oils from Turkey

In this study, the aim was to characterize the physicochemical properties and some bioactive compounds of expeller-pressed oils of five registered poppy seed varieties (TMO–1, Ofis–8, Ofis–96, Ofis–95, Ofis–3) grown in Turkey. The amounts of total carotenoids, chlorophylls, phenols, and antioxidant activities of oils ranged between 0.08–0.24 mg 100 g⁻¹, 0.03–9.04 mg pheophytin a kg⁻¹, 3.41–8.57 mg gallic acid equivalent 100 g⁻¹, and 5.60–7.33 mM Trolox equivalent 100 g⁻¹, respectively. The most abundant fatty acid in poppy seed oils was linoleic acid (69.85–74.02%), followed by oleic acid (13.98–16.99%), and palmitic acid (8.51–9.75%). In addition, poppy seed oils were rich in β–sitosterol (133.47–153.42 mg 100 g⁻¹), campesterol (45.36–58.60 mg 100 g⁻¹), and δ–5–avenasterol (28.21–39.40 mg 100 g⁻¹). High amounts of γ–tocopherol and α–tocopherol were detected. This research is the first study, which identified and quantified the polyphenol, β–carotene, and lutein compounds of expeller–pressed poppy seed oils by HPLC. Tyrosol, apigenin, syringic acid, 3–hydroxytyrosol, luteolin, p–coumaric acid, quercetin, ferulic acid, sinapic acid, and veratric acid were detected in expeller-pressed poppy seed oils.     

Synthesis and Anti-Listeria Properties of Odorless Hybrid Bio-Based n-Phenolic Vegetable Branched-Chain Fatty Acids

Consumers are becoming concerned about the impact of synthetic chemicals on human health and environments, and demanding natural compounds to reduce risk of antibiotic resistance of microorganisms. However, natural compounds are often less effective than synthetic antimicrobials. This challenge may be addressed with the development of bio-based antimicrobial agents. In this study, bio-based n-phenolic branched-chain fatty acids (n-phenolic-branched chain fatty acid [BCFA]) were synthesized from vegetable oil (soybean and safflower) fatty acids and four natural phenolics (phenol, thymol, carvacrol, and creosote), and tested against Listeria innocua. Results revealed that the newly synthesized products in crude form had minimum inhibitory concentrations (MIC) against L. innocua ranging from 3.6 to 116.4 μg mL⁻¹, with phenol-BCFA products having the lowest MIC (3.6 μg mL⁻¹) and minimum bactericidal concentration (MBC) (7.3 μg mL⁻¹). The precursors (unsaturated free fatty acids and phenolics) and noncovalently bound mixture of free fatty acids and phenolics had MIC above 232.7 μg mL⁻¹. After purification by molecular fractionation, n-phenolic-BCFA in the free fatty acid/monomer form were shown to be responsible for the anti-Listeria activity with MIC of 3.6–7.3 μg mL⁻¹ and MBC of 7.3–29.1 μg mL⁻¹. These promising results pave the road for further study of this new class of bio-based compounds, which may lead to their widespread use.     

Lipid characteristics and phenolics of native grape seed oils grown in Turkey

Grape seed oils of seven native Turkish cultivars (namely Atfi, Mazruna, Black Kerkü?, Zeyti, Verdani, Karfoki, and Kerkü?) were evaluated for their fatty acids, tocols, phytosterols as well as total phenolics and oxygen radical absorbance capacity (ORAC) values. Among the fatty acids, linoleic acid (18:2ω6) was the most abundant (56.38–68.56%), followed by oleic acid (16.45–29.38%, 18:1ω9), palmitic acid (8.19–9.44%, 16:0), and stearic acid (3.74–4.98%, 18:0). Total tocopherols and tocotrienol amounts varied in the range of 102.30–305.43 and 251.47–468.22 mg/kg, respectively. Beta‐sitosterol was the most abundant sterol among grape cultivars whose concentration ranging from 64.19 to 71.62%. Total phenolic content ranged from 2.19 to 4.70 mg of gallic acid equivalents/100 g oil, being lowest in Zeyti and highest in Verdani. With respect to antioxidant activities, a large variation in ORAC values was observed among grape seed oils (ranging from 1048 µmol of Trolox equivalents (TE)/100 g in Karfoki to 2569 µmol of TE/100 g in Mazruna). Practical applications: The crude grape seed oils extracted from different cultivars are a good source of nutrients, fat‐soluble bioactives, and health‐promoting components.     

The Effect of Type of Oil and Degree of Degradation on Glycidyl Esters Content During the Frying of French Fries

The aim of the study was to determine the effect of oil degradation on the content of glycidyl esters (GEs) in oils used for the frying of French fries. As frying media, refined oils such as rapeseed, palm, palm olein and blend were used. French fries were fried for 40 h in oils heated to 180 °C in 30‐min cycles. After every 8 h of frying, fresh oil and samples were analyzed for acid and anisidine values, color, refractive index, fatty acid composition, and content and composition of the polar fraction. GEs were determined by LC–MS. Hydrolysis and polymerization occurred most intensively in palm olein, while oxidation was reported for rapeseed oil. The degradation of oil caused increased changes in the RI of frying oils. Losses of mono‐ and polyunsaturated fatty acids were observed in all samples, with the largest share in blend. The highest content of GE found in fresh oil was in palm olein (25 mg kg^?1) and the lowest content of GE was found in rapeseed oil (0.8 mg kg^?1). The palm oil, palm olein and blend were dominated by GEs of palmitic and oleic acids, while rapeseed oil was dominated by GE of oleic acid. With increasing frying time, the content of GEs decreased with losses from 47 % in rapeseed oil to 78 % in palm oil after finishing frying.     

Fatty Acid Composition, Antioxidant Properties, and Antiproliferative Capacity of Selected Cold-Pressed Seed Flours

Cold-pressed seed flours from pumpkin, parsley, mullein, cardamom, and milk thistle were examined for total oil, fatty acid profile of the oil, total phenolic content (TPC), scavenging activities against peroxyl (ORAC), hydroxyl (HOSC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (RDSC) radicals, and antiproliferative capacity against HT-29 human colon cancer cells. The cold-pressed parsley seed flour contained a very high concentration of total oil—17.6 g/100 g flour—with primarily C18:1 fatty acid at 86.2 g/100 g fatty acids. All other flour oils had relatively high levels of saturated fats, ranging from 39.0 to 62.9 g/100 g fatty acids. The tested seed flours demonstrated significant TPC and free radical scavenging activities. Milk thistle seed flour had the highest TPC value of 25.2 mg gallic acid equivalent per g flour (GAE mg/g) followed by that of parsley seed flour at 8.1 GAE mg/g. Milk thistle seed-flour extract also had significantly higher antioxidant activities than all other extracts against all tested radicals. The milk thistle seed-flour extract had an ORAC value of 1131 μmol trolox equivalents (TE) per g flour (TE μmol/g), a HOSC value of 893 TE μmol/g, and an RDSC value of 61 TE μmol/g. Also, ORAC, HOSC, and TPC values were significantly correlated (P < 0.01) under the experimental conditions. The cold-pressed milk thistle seed flour inhibited the proliferation of HT-29 cancer cells in a dose-dependent manner. Results from this study suggest that these cold-pressed seed flours may serve as natural sources of antioxidants and may be used to improve human health.     

Effect of Hydrothermal Treatment of Rapeseed on Antioxidant Capacity of the Pressed Rapeseed Oil

Response surface methodology (RSM) was used to evaluate the quantitative effects of two independent variables, rapeseed moisture content and conditioning temperature, on the antioxidant capacity (AC) and total phenolic (TPC), tocopherol (TTC), and phosphorus contents (PC) in the pressed rapeseed oils. The mean AC results for the crude rapeseed oils ranged from 199.8 to 947.2 μmolTE/100 g. TPC and PC in the crude rapeseed oils correlated significantly (P < 0.01) and positively with AC of oils (R ² = 0.9498 and 0.4396, respectively). The experimental results of AC, TPC, and PC were close to the predicted values calculated from the polynomial response surface model equations (R ² = 0.9801, 0.9747 and 0.9165, respectively). The effect of oil processing temperature on AC and TPC was about 1.5 times greater than the effect of moisture level in rapeseed.     

Comparative Study of Fatty Acid Composition,Total Phenolics,and Antioxidant Capacity in Rapeseed Mutant Lines

There is limited variability within rapeseed germplasm in Morocco. Induced mutation was recently used to generate novel genetic variability and develop mutant lines combining desirable traits. In this context, nine promising advanced rapeseed M₂ mutant lines and the wild-type variety “INRA-CZH2” were evaluated for their seed oil content, fatty acid composition, total phenolic content (TPC), and free-radical scavenging activity (FRSA) by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods. The results showed significant variability among all mutants in seed oil content (38.14–42.04%) and fatty acids (SAFA = 5.49–10.99%, MUFA = 50.33–71.62%, PUFA = 22.89–8.68%). The mutant H2M-5 exhibited the highest fraction of MUFA and the lowest proportion of SAFA and PUFA, while the mutant H2M-4 showed the highest SAFA and PUFA amounts and the lowest MUFA level. TPC varied from 2.16 to 4.35 mg GAE/100 g. The highest amount was found in the mutant H2M-1, which is about twice that of other mutants and the wild-type variety. FRSA differed significantly among the samples, and the variations observed for DPPH and ABTS methods were 40.5–59.28% and 40.31–59.86%, respectively. FRSA was positively correlated to TPC in the sampled oils (r = 0.801 and 0.802, P < 0.01). This is the first report emphasizing the biochemical potential of rapeseed varieties and novel mutants in Morocco. H2M-1, H2M-4, and H2M-5 were proposed for the Rapeseed National Breeding Program, as they showed higher levels in some biochemical traits of interest.     

Investigation of hotpot oil based on beef tallow and flavored rapeseed oil in commercial hotpot seasoning

This study aimed to investigate the quality of hotpot oil from various hotpot seasonings. For this, 12 representative hotpot seasonings with beef tallow (BT) and flavored rapeseed oil (FRO) were collected before the hotpot oil was extracted. The oil content, sensory evaluation scores, physiochemical properties, fatty acid composition, harmful substances, and nutrient content of the hotpot oil were subsequently analyzed. The results showed that the oil content of the hotpot seasoning was 38.3%–58.2%. Furthermore, the BT hotpot oils produced better sensory scores (7–8.5), and their oxidative stability (12.08–13.17 h) was higher on average than that of the FRO hotpot oils. Additionally, the FRO hotpot oils had higher contents of unsaturated fatty acid (81.70%–97.32%), phytosterol (3466.07–6110.37 ppm), tocopherol (182.91–1276.17 mg kg⁻¹), and polyphenol (34.48–61.94 mg kg⁻¹). The factor analyses revealed that the FRO and BT hotpot oils were significantly different and were affected by the iodine value, acid value, and linoleic acid and phytosterol contents. Practical applications: It is necessary to improve the nutritional value and taste of hotpot oils to facilitate rapid development in the hotpot seasoning industry. This study showed FRO was a positive mediator of antioxidant, anti-inflammatory, and anticancer effects owing to its richness of nutritional compounds, such as polyphenols, phytosterols, and tocopherols. In comparison, BT was found to have a lower nutritional value than FRO but added a unique taste and aroma to the hotpot. The use of blended oil as raw oil could also improve the quality of hotpot oil. This information will provide an important guide to the nutritional value and industrial production of hotpot oil. Blended oil is a promising raw oil for future use in hotpot seasoning processing to meet consumer demands for nutritious and pleasantly flavored hotpot oil.     

Virgin rapeseed oils obtained from different rape varieties by cold pressed method – their characteristics,properties, and differences

The aim of the present study was to compare different rape varieties. For this purpose oil from six different varieties of rapeseeds was cold pressed under laboratory conditions. In the obtained rapeseed oils the fatty acids composition and minor components, characteristic values (acid value; AV and TOTOX), oxidative stability (DSC test), and volatiles were determined and a sensory evaluation was carried out. The highest oxidative stability was found for oil from sample 5 (IP = 158 min), which also has the lowest amount of C18:3 (7.8%), chlorophylls (0.083 mg/kg), and metals (Cu²⁺ 0.02 mg/kg and Fe²⁺ 0.08 mg/kg). This oil has also the lowest AV (0.17 mg KOH/g), which may be related to the lowest moisture content of the seeds prior to extraction. It was characterized by the highest rapeseed flavor intensity. The lowest induction period was observed for samples 3 and 6 (100 min). Although sample 3 had the same low level of metals as sample 5 and the highest concentration of tocopherols (635 mg/kg), PUFA (33.9%), and AV (1.37 mg KOH/g) it also had the lowest intensity of rapeseed flavor among the analyzed oils. Sample 6, despite its low percentage of PUFA (24.7%), conjugated diens and triens, and the lowest content of total volatiles (0.4Vs), had the highest concentration of metals (Cu²⁺ 0.04 mg/kg and Fe²⁺ 0.34 mg/kg).     

Investigation of Oil and Protein Contents of Eight Sudanese Lagenaria siceraria Varieties

The composition of the oil and protein contents of eight Lagenaria siceraria varieties was characterized in order to evaluate their suitability as a source of edible oil and protein. The physicochemical properties and fatty acids of seed oils were determined. The oil yield ranged from 24.11 to 26.32 %. The refractive indices and relative densities of the oils fell within the narrow ranges of 1.464–1.468 and 0.857–0.907 g/cm³, respectively. The saponification value ranged from 158.48 to 179.52 mg KOH/g, unsaponifiable matter was between 0.749 and 0.937 %, and the peroxide values were lower than Codex values for vegetable oils. The principal fatty acids were linoleic (62.1–67.9 %), oleic (11.54–15.46 %), palmitic (12.13–14.03 %), and stearic (6.71–7.71 %) acids. Low linolenic acid levels were also observed (<1 %) within the range of 0.32–0.44 %. The major essential amino acids were arginine (2.04–3.77 g/100 g), leucine (1.245–1.726 g/100 g), phenylalanine (0.803–1.396 g/100 g), and lysine (0.921–1.383 g/100 g). The non‐essential amino acids were glutamic acid (2.5–4.37 g/100 g), aspartic acid (1.39–2.36 g/100 g), serine (0.69–1.19 g/100 g), glycine (0.79–1.37 g/100 g), alanine (0.72–1.37 g/100 g), and proline (0.63–1.02 g/100 g). Nine minerals (Na, Ca, Mg, K, Cu, Fe, Mn, Zn, and P) were determined with significant (p < 0.05) differences. The studied oils showed promising results and can be used in the food, cosmetics, and pharmaceutical industries. This is the first study on the eight L. siceraria seed varieties grown in Sudan, opening the way for further studies on these seeds.     

Physicochemical Characteristics and Technological Properties of Lupinus mutabilis Oil

The aim of the presented study is to examine the physicochemical parameters of the lipids present in Lupinus mutabilis seed and to compare the results with the available data for other commonly used vegetable oils. The oil quality indexes, oxidative stability index (OSI), and melting characteristics are examined. Andean lupin oil has remarkably high oxidative stability (OSI = 65 h) comparable to high-oleic oils counterparts. Quality parameters meet commonly accepted standards, including peroxide value (3.95 meq O₂ kg⁻¹) and p-anisidine value (1.25). The acid number value is 1.85 mg KOH g⁻¹. The iodine value is 110.27 g/100 g, while the enthalpy required to increase the temperature of the sample from −60 to 80 °C is equal to 57.41 kJ kg⁻¹. The beginning of the melting event (T_onset) and the phase transition temperature (T_peak) values for L. mutabilis seed oil are −29.46 and −22.63 °C, respectively. The presented results indicate the unusually high oxidative stability of the oil obtained from L. mutabilis seeds, which opens up a whole spectrum of application possibilities, e.g., designing blends with other commonly used vegetable oils to enhance their low stability. Practical Applications: The presented results provide insight into physicochemical parameters of the lipid fraction isolated from Lupinus mutabilis seeds. Andean lupin oil has very high oxidative stability, comparable to high-oleic rapeseed and sunflower oils. Therefore, the identified potential use of the studied oils is, e.g. an additive that can increase the stability of commercial vegetable oils characterized by much lower oxidative stability.     

Chemical Composition of Seed Oils Recovered from Different Pear (Pyrus communis L.) Cultivars

Lipophilic bioactive compounds in oils recovered from the seeds of eight pear (Pyrus communis L.) cultivars were studied. Oil yield in pear seeds ranged between 16.3 and 31.5 % (w/w) dw. The main fatty acids were palmitic acid (6.13–8.52 %), oleic acid (27.39–38.17 %) and linoleic acid (50.73–63.78 %), all three representing 96–99 % of the total detected fatty acids. The range of total tocochromanols was between 120.5 and 216.1 mg/100 g of oil. Independent of the cultivar, the γ‐tocopherol was the main tocochromanol and constituted approximately 88 %. The contents of the carotenoids and squalene were between 0.69–2.99 and 25.5–40.8 mg/100 g of oil, respectively. The β‐sitosterol constituted 83.4–87.6 % of total sterols contents, which ranged between 276.4 and 600.1 mg/100 g of oil. Three significant correlations were found between oil yield and total contents of sterols (r = ?0.893), tocochromanols (r = ?0.955) and carotenoids (r = ?0.685) in pear seed oils.     

The Content and Composition of Total,Free, and Esterified Sterols of Lotus Plumule Oil by GC–MS/FID

This study investigated the content and composition of total, free, and esterified sterols of three varieties of lotus plumule oil (Hunan lotus, Jiangxi lotus, and Fujian lotus) using GC–MS/FID. The fatty acid composition of sterol fatty acid esters (SFAE) was also analyzed and compared with that of triglycerides. Results showed that total sterol of lotus plumule oil (12.10–14.21 g/100 g) was higher than that of other plant oils (corn germ oil, 1.11 g/100 g; rapeseed oil, 0.78 g/100 g). No significant difference was found among the total sterol contents of the three types of lotus plumule oils (p > 0.05). Most sterol existed in ester forms (81.8–89.1%) rather than in free forms (8.4–10.1%). β‐Sitosterol (71.4–73.4%), and campesterol (6.2–7.5%) were the predominant fractions of free sterols. β‐Sitosterol (41.3–53.7%) and ?5‐avenasterol (27.1–31.1%) were the predominant fractions of esterified sterols, followed by campesterol (12.1–13.0%) and ?7‐avenasterol (3.4–3.7%). Linoleic acid (63.6–65.8%), oleic acid (8.3–10.4%), and behenic acid (9.0–9.9%) were the main fatty acids of SFAE, which were different from those of triglycerides. The results from this study suggest that lotus plumule oil may be a good resource of SFAE and can be used as a supplemental ingredient in functional foods.