百香果籽油的抗氧化活性研究

以百香果籽油清除羟基自由基能力和对超氧阴离子自由基的清除能力为指标,研究了百香果籽油的抗氧化活性。同时进一步采用Schaal烘箱法处理油样,在时间变化下,以过氧化值为指标,研究百香果籽油对花生油脂的抗氧化作用。实验结果表明,百香果籽油具有很好的清除超氧阴离子自由基的作用,抑制率维持在66%～95%之间;有较好的清除羟自由基作用,清除率能达到81.7%;对花生油脂有较好的抗氧化作用,抗氧化因子PF为1.67。百香果籽油具有较好的抗氧化能力。     

Oil Content and Fatty Acid Composition in Seeds of Three Safflower Species

Seeds of six safflower (C. tinctorius L.) genotypes and 19 accessions of two wild species were analyzed for oil and fatty acid composition. Oil content ranged from 29.20 to 34.00, 20.04 to 30.80 and 15.30 to 20.80% in C. tinctorius, C. oxyacantha Bieb. and C. lanatus L., respectively. The main fatty acids of oleic, linoleic, palmitic and stearic acids composed 96–99% of the total fatty acids in all species. The sum of myristic, palmitoleic, arachidic, and behenic fatty acids in oil of the species ranged from 0.43 to 0.57%. The oleic acid in seed oil of C. tinctorius, C. oxyacantha and C. lanatus ranged from 12.24 to 15.43, 14.11 to 19.28 and 16.70 to 19.77%, respectively. The corresponding ranges for linoleic acid were 71.05 to 76.12, 63.90 to 75.43 and 62.47 to 71.08%. Palmitic acid in seed oil varied from 5.48 to 7.59% in C. tinctorius, 6.09 to 8.33% in C. oxyacantha and 7.44 to 8.78% in C. lanatus. The stearic acid of the seed oil showed a variation of 1.72 to 2.86, 2.50 to 4.87 and 3.14 to 4.79% in genotypes of these species, respectively. The fatty acids composition of oil among the cultivated and wild species were not considerably different, indicating that seed oil of the wild safflower is possibly suitable for human consumption and industrial purposes.     

Antioxidant Activities and Oxidative Stabilities of Some Unconventional Oilseeds

The oils of some unconventional oilseeds (hemp, radish, terebinth, stinging nettle, laurel) were obtained by a cold-press method in which the total oil content, fatty acids, tocopherol isomers, some metal contents (Ca, Mg, Fe, Cu), antioxidant activity and oxidative stability were determined. The total oil content was determined ranging between 30.68 and 43.12%, and the oil samples had large amounts of unsaturated fatty acids, with oleic acid and linoleic acid. Of all the oils, terebinth seed oil had the highest α-tocopherol content (102.21 ± 1.01 mg/kg oil). Laurel oilseed had the highest antiradical activity in both the DPPH and ABTS assays. The peroxide value of the non-oxidized oils ranged between 0.51 and 3.73 mequiv O₂/kg oil. The TBARS value of the non-oxidized oils ranged between 0.68 ± 0.02 and 6.43 ± 0.48 mmol MA equiv/g oil. At 110 °C, the Rancimat induction period of the oils ranged between 1.32 and 43.44 h. The infrared spectra of the samples were recorded by FTIR spectroscopy. The absorbance values of the spectrum bands were observed and it was determined that some of the chemical groups of oxidized oils caused changes in absorbance. As a result of the present research, the analyzed oils could be evaluated as an alternative to traditionally consumed vegetable oils or as additives to them.     

Changes in the Phytochemical and Bioactive Compounds and the Antioxidant Properties of Wolfberry during Vinegar Fermentation Processes

Wolfberry (Lycium barbarum L.), as a kind of functional fruit, has various nutritional and bioactive components, which exhibit healthy benefits. However, wolfberry is not easy to preserve, and the intensive processing of wolfberry needs to be developed. In the present study, the changes in the phytochemical and bioactive compounds, as well as the antioxidant properties of wolfberry, were evaluated in the brewed processes. We found that the sugar contents were significantly decreased, and the total acids values were significantly increased during the fermentation processes. The sugar and fat contents were low in the wolfberry fruit vinegar after fermentation, which is of benefit to human health. In addition, amino acids were examined during the fermentation processes, and histidine, proline, and alanine were found to be the main amino acids in vinegar. The total phenolics and flavonoids contents were significantly increased by 29.4% and 65.7% after fermentation. 4-Hydroxy benzoic acid, 3-hydroxy cinnamic acid, and chlorogenic acid were the primary polyphenols in the wolfberry fruit vinegar. Moreover, the antioxidant activity of wolfberry fruit vinegar was significantly increased compared with that of wolfberry fruit after the fermentation processes. Polysaccharides and polyphenolics were strongly correlated with the antioxidant activity during the fermentation processes. The findings suggest that wolfberry fruit vinegar has a high antioxidant capability, and could be a beneficial food in the human diet.     

Estimating Oil and Protein Content of Sesame Seeds Using Image Processing and Artificial Neural Network

Image processing has many applications in different fields of agriculture. The present study aimed to use image processing techniques and artificial neural networks (ANN) to estimate oil and protein contents of sesame genotypes without the use of time-consuming and costly laboratory methods. The proposed method accurately estimates the parameters in sesame seeds without destructing the genetically valuable material. In this study, a set of 138 morphological features were extracted from the digital image of 125 sesame seed genotypes. A multilayer perceptron (MLP) ANN was then employed to estimate oil and protein contents and determine the relationship between estimated values and laboratory-measured values. The efficiency of this model was compared to radial bases function (RBF), extended RBF (ERBF), GRNN, M5-Rule, M5-Tree, support vector machine regression, and linear regression models. Results showed that MLP performed better in estimating qualitative parameters of seeds in the sesame germplasm. The model estimated oil content with an root mean square error (RMSE) of 2.13% (the accuracy of 97.87%) and an R² of 0.93. Protein content was estimated by an RMSE of 0.378% (the accuracy of 99.62%) and an R² of 0.96.     

Antioxidant Property,Thymoquinone Content and Chemical Characteristics of Different Extracts from Nigella sativa L. Seeds

In this study, Nigella sativa L. seeds were extracted using supercritical carbon dioxide (SC-CO₂) and Soxhlet. Chemical characteristics, fatty acid composition, antioxidant activity and thymoquinone content of N. sativa L. extracts obtained through different methods were investigated and compared. It was revealed that antioxidant activity and thymoquinone content could be significantly different for SC-CO₂ and Soxhlet extracts. The results for fatty acid composition indicated that linoleic acid, palmitic acid and oleic acid were the main fatty acids in both extracts. The SC-CO₂ extraction could provide an extract with higher quality and antioxidant activity compared to Soxhlet extraction method and can be considered a more appropriate method for attaining a high-quality extract.     

绝缘油中T501抗氧化剂含量检测方法比较

阐述了分光光度法、液相色谱法和红外光谱法检测变压器油中T501抗氧化剂含量的原理,比较了三种方法检测的优缺点,结合本实验室利用红外光谱法测定变压器油的实际经验,并对红外光谱法测定绝缘油中T501含量的不确定度来源进行了分析,计算出此方法的不确定度,T501抗氧化剂含量在0.1%～0.5%浓度范围内,取包含因子k=2,在置信概率为0.95%时的相对扩展不确定度为1.28%。可知利用红外光谱法检测油中T501抗氧化剂含具有准确、快速、简便、稳定性好的特点。     

中国非常规油气资源分布综述

煤层气、油砂、油页岩、致密砂岩气和页岩气是目前最为现实的非常规汕气资源。我国的非常规油气资源在勘探开发上急需新技术、新方法的突破,积极创新将有效促进我国在非常规油气勘探方向的发展。对我国非常规油气资源的资源量、富集程度以及分布特点进行了概述。     

Antioxidant Activity and Total Polyphenols Content of Camellia Oil Extracted by Optimized Supercritical Carbon Dioxide

In this study, Camellia oil is co-extracted from Camellia oleifera seeds and green tea scraps by supercritical carbon dioxide (SC-CO₂), which is optimized on the extraction yield, ABTS-scavenging activity, and total polyphenols content (TPC) of oil by single-factor experiments combined with response surface methodology (RSM). The extraction temperature, pressure, dynamic time, carbon dioxide (CO₂) flow rate, and seed mass ratio were investigated with single-factor experiments. The results indicated the optimum CO₂ flow rate and dynamic extraction time were 15 L hour⁻¹ and 60 min (i.e., 2.382 kg CO₂/100 g sample). Furthermore, the complicated effects of extraction temperature (40–50 °C), pressure (20–30 MPa), and seed mass ratio (0.25–0.75) were optimized by RSM based on the Box–Behnken design (BBD). The models with high R-squared values were obtained and used to predict the optimum operating conditions of the process. Under the optimum operating conditions (i.e., temperature of 46 °C, pressure of 30 MPa, and seed mass ratio of 0.35), the extraction yield, ABTS-scavenging activity, and TPC of oil were 14.43 ± 0.17 g/100 g sample, 73.70 ± 0.34%, and 2.18 ± 0.05 mg GAE/g oil, which were in good agreement with the predicted values. In addition, the experiments indicated that the Camellia oil obtained was rich in polyphenols, resulting in better oxidation stability and antioxidant activity than the original oil.     

Phytochemical Characterization of Chinese Bayberry (Myrica rubra Sieb. et Zucc.) of 17 Cultivars and Their Antioxidant Properties

In order to fully understand the variations of fruit quality-related phytochemical composition in Chinese bayberry (Myrica rubra Sieb. et Zucc.), mature fruit of 17 cultivars from Zhejiang and Jiangsu provinces was used for the investigation of fruit quality attributes, including fruit color, soluble sugars, organic acids, total phenolics, flavonoids, antioxidant capacity, etc. Sucrose was the main soluble sugar, while citric acid was the main organic acid in bayberry fruit. The content of total phenolics and total flavonoids were positively correlated with 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) antioxidant activity and 2,2ʹ-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity. Five anthocyanidins, i.e., delphinidin–hexoside (Dp–Hex), cyanidin-3–O-galactoside (C-3–Gal), cyanidin-3–O-glucoside (C-3–Glu), pelargonidin-3–O-glucoside (Pg-3–Glu) and peonidin-3-O-glucoside (Pn-3–Glu), and seven flavonols compounds, i.e., myricetin-3-O-rhamnoside (M-3–Rha), myricetin deoxyhexoside–gallate (M-DH–G), quercetin-3-O-galactoside (Q-3–Gal), quercetin-3–O-glucoside (Q-3–Glu), quercetin-3–O-rhamnoside (Q-3–Rha), kaempferol-3–O-galactoside (K-3–Gal) and kaempferol-3–O-glucoside (K-3–Glu), were identified and characterized among the cultivars. The significant differences in phytochemical compositions among cultivars reflect the diversity in bayberry germplasm, and cultivars of good flavor and/or rich in various health-promoting phytochemicals are good candidates for future genetic breeding of bayberry fruit of high quality. In conclusion, our results may provide important information for further breeding or industrial utilization of different bayberry resources.     

Solvent and Extraction Conditions Control the Assayable Phenolic Content and Antioxidant Activities of Seeds of Black Beans,Canola and Millet

The effects of extraction solvent and conditions on the total phenolic content (TPC) and antioxidant activity of black beans, canola and foxtail millet were investigated. The antioxidant activity was assayed using 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity (DRSA) and oxygen radical absorbance capacity (ORAC). Four solvent systems, namely 70 % acetone, 80 % ethanol, 80 % methanol and a mixture of acetone/methanol/water (7:7:6, v/v/v) were used. The extraction methods adopted in this study included refluxing, homogenization, cold extraction and sonication. The TPC as measured using the Folin Ciocalteu's method were 12.35–28.39, 2.43–16.73, and 1.78–5.06 µmol catechin equivalents/g dry matter (dm) for canola, black beans and foxtail millet, respectively. Aqueous acetone afforded the highest TPC for black beans and canola. Within the same solvent system used, the TPC, DRSA and ORAC obtained from different extraction techniques differed for black beans, canola and foxtail millet. The results demonstrated that the solvent system as well as method influenced the extraction of phenolic compounds and their antioxidant activities, depending on the type of matrix in which phenolics were embedded.     

Oil, Fatty Acid Profile and Karanjin Content in Developing Pongamia pinnata (L.) Pierre Seeds

Oil content, fatty acid composition and karanjin content were studied in developing pongamia seeds, at intervals of 3?weeks from 30?weeks after flowering up to 42?weeks. Three marked stages in seed development were observed at the early green pod stage, the middle half brown stage and the late dark brown stage. Significant variation in seed biomass, pod and seed characteristics were observed. A significant (P?<?0.01) decrease in the moisture content of the seeds was observed during seed development. The oil content gradually increased from 32.06 to 36.53?% as the seed matured. A significant variation in fatty acid composition was detected across all stages of seed development. Palmitic acid (16:0) content marginally decreased from 11.81 to 10.18?%, while stearic acid (18:0) and linolenic acid (18:3) remained constant at all stages of seed maturity. A steady increase in oleic acid (18:1) content from 38.11 to 49.11?% was observed, while the linoleic acid (18:2) content decreased from 30.14 to 18.85?%. The iodine value increased, while the saponification number of oil decreased during seed development. The increase in karanjin content was steady. Seeds harvested after 42?week after flowering yielded the maximum oil with high oleic acid content which could be suitable for biodiesel production.     

Total Gossypol Content and Properties of Cottonseed Oil as Affected by Borax Treatment Before and After Oil Storage

Crude cotton seed oil obtained by hydraulic press in two Egyptian factories was used. The oil was treated with different concentrations of borax before and after oil storage. Treatment with borax decreased the total gossypol content of the oil by 94.6–99.3% whether the borax treatment was carried out before or after crude oil storage. Crude oil storage prior to borax treatment resulted in oil of dark colour, hard to bleach, even after borax treatment as the borax treated bleached oil had a colour of 9.5–24 red units. While borax treatment prior to oil storage resulted in oil of light colour of 3.7–4.8 and 3.0–4.0 red units before and after storage of the borax treated oil, respectively. Borax treatments had no undesirable effect on the viscosity, refractive index, surface tension, free fatty acids, saponification value, and iodine value of the oil.     

我国大力发展非常规油气资源的重要意义

面对常规油气资源的严重短缺,非常规油气资源以其资源量大、分布集中、开发技术日益成熟而成为全球能源市场的新宠。大力发展非常规油气资源是缓解我国能源供需矛盾的关键,是解决我国石油安全及由此引发的国家安全问题的重要措施。同时,大力发展非常规油气资源有利于我国能源的战略性接替,有利于能源结构的转变,实现经济的可持续增长。     

Fatty Acid- and Tocopherol-Pattern in Oil Seeds

Diets should contain 1 I.U. Vitamin E/g polyunsaturated fatty acids (PUFA). This requirement is fulfilled in decreasing order by hazel-nut, almond, copra, oilpalm-kernels, oilpalm-mesocarp and maize. In pistachio-nuts, hickory-nuts, groundnuts, walnuts, sesame and poppy-seed the Vit. E/PUFA-ratio is between 0.8 and 0.15. But these figures may vary even within a plant species, because cultivation of 6 sunflower-varieties in temperate and tropical climate as well as the analysis of safflower varieties differing in linoleic acid revealed a genetical and environmental variability of the Vit. E/PUFA-ratio.     

油价对非常规和替代石油发展的影响

介绍了近年来国际油价高涨引发的人们对非常规和替代石油的乐观期待,指出高油价推动的资源价格全面上涨增大了开发非常规和替代石油的风险,而油价的周期性变化将对发展非常规和替代石油带来巨大的经济风险。     

Phytochemical Screening and Polyphenolic Antioxidant Activity of Aqueous Crude Leaf Extract of Helichrysum pedunculatum

We evaluated the in vitro antioxidant property and phytochemical constituents of the aqueous crude leaf extract of Helichrysum pedunculatum. The scavenging activity on superoxide anions, DPPH, H₂O₂, NO and ABTS; and the reducing power were determined, as well as the flavonoid, proanthocyanidin and phenolic contents of the extract. The extract exhibited scavenging activity towards all radicals tested due to the presence of relatively high total phenol and flavonoids contents. Our findings suggest that H. pedunculatum is endowed with antioxidant phytochemicals and could serve as a base for future drugs.     

中国非常规油气资源潜力及分布

我国非常规油气资源形式多样,分布广泛,资源潜力巨大,若能成功开发与利用,将可以弥补未来很长一个时期常规油气资源的不足,对于增加我国油气资源后备储量,提高油气产量,具有重要的战略意义。     

Evaluation of the Phenolic Content and Antioxidant Activity of Different Seed and Nut Cakes from the Edible Oil Industry

The objective of this work was to extract water‐soluble compounds from different seed and nut cakes under the same conditions and compare the phenolic content and antioxidant activity of the cake extracts. Seed cakes of sunflower, pumpkin, flaxseed and defatted sesame, and nut cakes of almond, pecan, macadamia and hazelnut were used in the experiments. Extracts were obtained by solid–liquid extraction with a water/ethanol solution (20:80, v/v). Total phenolic content, flavonoids, flavan‐3‐ols and condensed tannins in the extracts were determined using spectrophotometric analysis. Antioxidant properties of the extracts were determined by the DPPH and ABTS radical scavenging methods, and by determination of the reducing power and chelating activity. The extract from pecan nut cake presented the highest amounts of all compounds analyzed, followed by sunflower seed and hazelnut cake extracts. These samples also had the highest effects on the ABTS and DPPH radicals, as well as the uppermost reducing powers. The extracts from pecan nut and sunflower and sesame seeds were analyzed using HPLC and individual phenolics were further characterized.