Supercritical Synthesis of Ethyl Esters via Transesterification from Waste Cooking Oil Using a Co-Solvent

Biofuels became more promising alternative to the fossil fuels because of the depletion of fossil resources, renewability, environmental benefits, and energy security. Ethanolysis of waste cooking oil with hexane as co-solvent was carried out for the production of fatty acid ethyl ester (FAEE). This process reduced the severity of process parameters with high purity biodiesel yield. Process variables such as co-solvent ratio, ethanol to oil molar ratio, reaction temperature and reaction time were optimized. The maximum biodiesel yield of 88% was obtained at ethanol/oil molar ratio of 40:1, co-solvent (hexane) to oil ratio of 0.2% (v/v), reaction temperature of 300°C in 20 min of reaction time. Fatty acid ethyl ester (biodiesel) samples produced from this process were measured and evaluated using GC-MS analytical instrument. Thermo gravimetric analysis (TGA) was also performed to examine the thermal stability of waste cooking oil, ethyl esters and fuel blends. Fuel properties of ethyl esters were determined and compared with the ASTM standards for biodiesel, regular diesel and ethyl esters from different feedstock.

The Global Research Progress of Enzymatic Processing of Oils with Omega 3 Polyunsaturated Fatty Acids

This paper has reviewed that Omega 3 polyunsaturated fatty acids (PUFAs), as an essential fatty acids (EFAs), mainly come from fish oil of marine products, has positive effects on treatment and/or prevention of several diseases. In this review, the recent developments by 2019 in the field of enzymatic modification of oils rich in omega 3 PUFAs have summarized. Several different products, such as structured lipids with a variety of FA compositions, nutritional aspects, omega 3 PUFA concentrates and phospholipids,have discussed from the point of process technology as well as possible applications. Enhancing omega 3 PUFA content in diet involves a number of strategies aiming to modify the content of such FAs in fats and oils. Due to the mild reaction conditions used, especially the lipase specificity, the position as well as content of omega 3 PUFAs in lipid molecules being of importance from the point of bioavailability, enzymatic processing of omega 3 PUFA oil is safe, efficient and preferred over chemical treatments.

Enzymatic synthesis, antioxidant ability and oil-water distribution coefficient of troxerutin fatty acid esters

Troxerutin fatty acid esters were prepared using troxerutin and fatty acid vinyl esters as substrates in pyridine through enzymatic route. The structures of as-prepared compounds were identified by FT-TR, NMR, and ESI-HRMS. Using alkaline protease(≥30 mg/mL) as enzyme, maximum yields reached 58% at 3:1(vinyl hexanoate to troxerutin) in pyridine(water content ≤1%). The yields gradually declined as chain length of acyl donors rose. The antioxidation abilities of the as-obtained compounds were confirmed by both DPPH free radical scavenging and potassium ferricyanide reduction methods. The antioxidation ability of troxerutin fatty acid esters was found lower than that of troxerutin. However, the logP values of troxerutin fatty acid esters varied from 0.15 to 1.94, suggesting that troxerutin fatty acid esters had better lipophilicity than troxerutin(logP =-2.12) when compared to their oil-water distribution coefficients. Overall, these findings look promising as reference for further development of future troxerutin.

Total Replacement of Fish Oil with Vegetable Oils in the Diet of Juvenile Jade Perch Scortum barcoo Reared in Recirculating Aquaculture Systems

To determine the replacement of fish oil with vegetable oils in the diet of juvenile Jade perch Scortum barcoo, four feeds with each a different oil （fish, sunflower, linseed and a mixture of 75% canola and 25% linseed oil）, were fed to Jade perch reared in recirculating aquaculture systems （RAS）. The trial lasted for 10 weeks and the fatty acid （FA） profile of both feed and fish muscle tissue were examined. There was no difference in growth, feed conversion rate （FCR） and mortality. The fish grew from 10 g to 110 g with a FCR of 1.25 and 0 mortality. The FA profile of the fish muscle tissue reflected the FA profile of the feed. The flesh of the fish that were fed the linseed oil diet, were extremely high in omega-3 （n-3） polyunsaturated FA （n-3 PUFA） with 3.75% of wet weight. This is one of the highest concentrations of n-3 PUFA ever recorded in fish flesh. In a finishing feeding test, the remaining vegetable oil fed fish were fed the fish oil diet for another two weeks immediately after the 10 weeks trial, to check for a possible recovery of n-3 highly unsaturated fatty acids （HUFA）. The wash out rate of FA towards n-3 HUFA in the muscle tissue was about 25% over this two weeks period.

Dietary Combination of Fish Oil and Hemoglobin Hydrolysates Alters Serum and Liver Lipid Contents in Rat

Fish oil has been shown to have anti-inflammatory and anti-cancer effects, and to reduce serum triacylglycerol (TAG) levels by stimulating lipid oxidation and inhibiting lipogenesis in the liver. A small number of studies have demonstrated the synergistic effect of fish oil and other bioactive components. This study examined the effect of fish oil in combination with porcine hemoglobin (Hb) hydrolysates on serum and liver lipid contents in rats. Male Wistar rats were divided into four groups;one group was fed a casein and soybean oil-based semi-purified basal diet and other three groups were fed the basal diet supplemented with 2% fish oil, 0.175% Hb hydrolysates, and 2% fish oil plus 0.175% Hb hydrolysates, respectively, for 4 weeks. The fish oil diet decreased serum and liver TAG contents but did not change serum and liver cholesterol levels. The dietary combination of fish oil and Hb hydrolysates decreased serum and liver TAG and cholesterol contents owing to the additive effect of both compounds, and this diet reduced the serum non-high-density lipoprotein cholesterol content as a result of a synergistic effect. This hypolipidemic effect was in part caused by enhanced excretion of fecal fatty acids, neutral steroids, and acidic steroids. The results of this study suggest that the combined intake of fish oil and Hb hydrolysates may play beneficial roles in the prevention of cardiovascular disease as compared with fish oil alone.

Increasing Conjugated Linoleic Acid Content in Milk and Cheese after Supplementing a Blend of Crude Soybean Oil Sediment Combined with Fish Oil to Grazing Dairy Cows

The aim of the work was to improve the healthy value of milk and cheese fatty acids (FA) by feeding a mix of crude soybean oil sediment (CSOS) combined with fish oil (FO) to grazing dairy cows. The CSOS is a by-product commonly discarded after oil extraction containing 3.3% moisture, 6% total ash and 70.7% oil, locally available, comparatively economic and easy to mix with other feed ingredients. The experiment lasted 55 days from September 30th to November 23th 2018 and was carried out at the dairy farm “Gacef” provider of milk to the dairy industrial plant “Capilla Del Señor” (CDS) located at the Villa María City, Córdoba Province, Argentine. A herd of 80 multiparous Holstein cows producing 24 kg-1 milk·cow-1·day-1 was used. The cows grazed an alfalfa and an oat pasture that represented about 47% of total dry matter (DM) intake supplemented at 8.5 kg DM·cow-1·day-1 with a total mixed ration (TMR) composed (DM basis) by cracked corn grain (35.18%), whole plant corn silage (31.98%), pelletized soyben meal (17.99%), the CSOS supplement (13.85%) and FO (0.99%). The TMR was supplied by halves after each milking time in groupal feeders yielding 1.4 kg·cow-1·day-1 of the CSOS and 0.1 kg·cow-1·day-1 of FO. Before the start of lipid supplementation, milk samples (5) were obtained from the farm-tank representing the standar or reference milk (Ref-Milk). After 21 days of supplementary lipid supply, additional milk samples (5) were obtained representing the modified milk (Mod-Milk). Milk samples were analyzed for chemical composition and milk FA profile. At each time, sufficient quantities of both (Ref- and Mod-Milk) were collected for manufacturing six types of cheeses. The results were analyzed through the Student-T test for independent observations. Oil supplementation did not modify (P > 0.05) the chemical composition of milk. Concentration of butyric acid (C4:0) in milk was not affected (P < 0.858). Concentration of total saturated FA (SFAs) in Ref-Milk averaged 58.83 g 100 g-1 FA and was decreased to 49.67 g 100 g-1 FA in Mod-Milk (P < 0.0001). Monounsaturated FA (MUFAs) increased (P < 0.001) from 32.03 g 100 g-1 FA in Ref-Milk to 38.13 g 100 g-1 FA in Mod-Milk (+19.07%) whereas polyunsaturated FA (PUFAs) increased (+36.1%) from 4.71 to 6.41 (P < 0.004). The Mod-Milk showed a significant (P < 0.002) reduction (-15.3% or 5.9 g 100 g-1 FA) for the total concentration of the potentially atherogenic fraction of milk FA (C12:0 to C16:0). The atherogenic index (AI) also decreased (P < 0.012) from 1.98 in Ref-Milk to 1.42 in Mod-Milk (-28.4%). Concentration of vaccenic acid (VA, trans-11 C18:1) in Mod-Milk averaged 7.77 g 100 g-1 FA which represented a 162 % increase (P < 0.0001) over that observed in Ref-Milk (2.95 g 100 g-1). Concentration of conjugated linoleic acid (CLA, cis-9, trans-11 C18:2) in Ref-Milk averaged 1.47 g 100 g-1 FA and showed an important increase (P < 0.002) in the Mod-Milk (3.86 g 100 g-1 FA, +163%). The omega 6/3 ratio resulted lower (P < 0.012) in the Ref-Milk (2.28) compared to the Mod-Milk (2.83). Milk and cheese FA composition were highly correlated (R2 = 0.99, P < 0.0001). The Mod-Cheeses showed similar results in AI, total concentration of SFAs, MUFAs and PUFAs compared to the milk of origin. Differences in FA composition between the cheeses made with the Ref- and Mod-Milk were equivalent to those described for milks. It is concluded that supplementation with a blend of CSOS supplement and FO was an effective way to improve the healthy value of dairy products by reducing contents of SFAs, atherogenic FAs and the atherogenicity index with a concomitant increase in VA and CLA. Modifications induced in the Mod-Milk were recovered in the Mod-Cheeses. The results obtained may help to reduce saturated fat intake and fight or prevent incidence of non-communicable, cardiovascular and chronic diseases.

Bioactive Fatty Acids Reduce Development of Gastric Cancer Following Duodenogastric Reflux in Rats

Background: Bioactive fatty acids such as the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the modified fatty acid analogue, tetradecylthioacetic acid (TTA), are known to influence inflammatory processes in the body. Our aim was to investigate if diets containing fish oil (FO) enriched with bioactive fatty acids could affect inflammation and development of glandular stomach carcinogenesis in a duodenogastric reflux (DGR) animal model. We also wanted to evaluate if a high-fat diet might increase the risk of developing gastric cancer compared to a low-fat diet. Methods: 185 rats operated on with a gastroenterostomy were randomly allocated to 5 different treatment groups given: low-fat, high-fat, high-fat + FO, high-fat + TTA or high-fat + FO + TTA. The stomachs were removed after 50 weeks and examined by light microscopy with hematoxylin and eosin staining (HE). Immunohistochemical staining against COX-2, PCNA and p53 was performed when adenocarcinomas were found. The plasma fatty acid profile was determined. Results: Adenocarcinomas developed in 21% of animals fed the low-fat diet, 35% in the high-fat group, 16% in the high-fat + TTA group, 21% in the high-fat + FO group and 8.6% in the high-fat + FO + TTA treatment group. COX-2 and PCNA were positive whereas p53 was negative in the majority of the samples. The anti-inflammatory fatty acid index increased after treatment with FO and in combination with FO and TTA. Conclusion: FO and TTA in combination with a high-fat diet significantly lower the risk of developing adenocarcinomas in rats subjected to duodenogastric reflux. This is most likely due to a selective modulation of inflammation.

Determination and Analysis of Liposoluble Chemical Constituents from Ictalurus punctatus Oil

The lipids was extracted from the internal organs of Ictalurus punctatus by microwave, and its liposoluble chemical constituents was identified and quantified by gas chromatography （GC）/electron impact （EI） mass spectrometry （MS）. Subsequent-ly, the acid catalysis method was used to convert fatty acids to methyl-esters. The total lipids in the pure fat of I. punctatus were found to be about 99%. Twenty-three fatty acids were identified. The major fatty acids found in the oils were normal mo-nounsaturated, polyunsaturated fatty acids and alkane paraffin. Unsaturated fatty acids comprised 72.84% of the total, and the major components of monounsaturated fatty acids were C18：1 （48.52%）, while the polyunsaturated fatty acids were mainly composed of C18：2 （16.54%）. Saturated fatty acids comprised approximately 19.21%of the total. The main components were C16：0 （14.46%） and C18：0 （4.17%）, most of which were medium-long-chain fatty acids. Therefore, catfish oil can be used as an important dietary source of functional fatty acids. The difference between the pro-portion of unsaturated and saturated fatty acids appears to be significant compared to fish of the Cyprinidae family, as catfish skin and muscle have higher protein content and lower fatty content. This study confirms that catfish has excellent nutri-tional quality.

Effect of Dietary Lipid on the Growth, Fatty Acid Composition and Δ5 Fads Expression of Abalone(Haliotis discus hannai Ino) Hepatopancreas

This study investigated the effect of dietary lipid on the growth, fatty acid composition and Δ5 fatty acyl desaturase genes(Fads) expression of juvenile abalone(Haliotis discus hannai Ino) hepatopancreas. Six purified diets were formulated to contain tripalmitin(TP), olive oil(OO, 72.87% 18:1n-9), grape seed oil(GO, 68.67% 18:2n-6), linseed oil(LO, 70.48% 18:3n-3), ARA oil(AO, 41.81% ARA) or EPA oil(EO, 44.09% EPA and 23.67% DAH). No significant difference in survival rate was observed among abalone fed with different diets. Weight gain rate(WGR) and daily growth rate of shell length(DGRSL) were significantly increased in abalone fed with diets containing OO, AO and EO, but decreased in abalone fed with LO diet(P < 0.05) in comparison with those fed with TP. High level of dietary 18:2n-6 resulted in higher content of n-6 polyunsaturated fatty acids(PUFAs) in abalone fed with GO than those fed with TP, OO, LO and EO(P < 0.05). n-3 PUFAs in abalone fed with LO was significantly higher than those in abalone fed with TP, OO, GO and AO(P < 0.05). The highest contents of 20:1n-9 and 22:1n-9 were observed in abalone fed with OO. The expression of Δ5 Fads in hepatopancreas of abalone was enhanced by high concentration of 18:3n-3 and suppressed by dietary LC-PUFAs; however it was not affected by dietary high concentration of 18:1n-9 or 18:2n-6. These results provided valuable information for understanding the synthesis of LC-PUFAs and nutritional regulation of Δ5 Fads expression in abalone.

Is there a role for fish oil in inflammatory bowel disease?

A number of animal and human studies suggest omega3-fatty acids are anti-inflammatory. As a result they may have a therapeutic role in inflammatory bowel disease(IBD). The aim of this review is to briefly assess the literature about the utility of poly-unsaturated fatty acids(PUFAs) in the management of IBD. Taken together, almost all studies suggest some beneficial effects of n-3 PUFAs in IBD but the mechanism remains controversial. In addition, clinical benefit seems to be largely confined to ulcerative colitis. However all studies have concluded that these compounds have no potential for a steroid/aminosalicylic acid sparing effect or to maintain remission. Now the question arises as to whether this treatment is of real value to IBD patients?Clearly they have some therapeutic potential but further work is needed.

Potential of Fish Wastes as Feedstock for Biodiesel

Fish wastes are the discarded parts include the internal organs, viscera, bones, trimmings, tails, fins and skin of fishes. These discarded portions while disposing of cause major environmental damage. Usually, the discarded parts of fishes are ground into fishmeal for livestock and aquaculture feed. This study was undertaken to explore biodiesel production based on the fatty acids composition. The fish waste sample was collected from Kota Kinabalu, Sabah fish market. The sample was drained for excess water and oven-dried at 55&deg;C - 60&deg;C for complete dryness. Crude oils were extracted in petroleum ether in Soxhlet extraction method. Methylation of the extracted crude fish oil was carried out to yield fatty acid methyl esters (FAME). The FAME was analyzed by GCMS system and the reference to NIST library was used to identify the fatty acids present in the FAME. A total of 21 fatty acids were identified that composed of 53.53% saturated fatty acids (SFA), 22.1% monounsaturated fatty acid (MUFA) and 24.37% polyunsaturated fatty acids (PUFA). The important fatty acids [myristic acid (C14:0), palmitic acid (C16:0), palmitoleic acid (C16:1), oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3), docosapentaenoic acid (C22:5) and docosahexaenoic acid (C22:6)] found in fish oil indicated the potentiality of biodiesel production if fish waste was stocked. The highest percentage of SFA causes higher viscosity, cetane number and density and hence these properties of biodiesel produced from the fish waste are expected to be high. Therefore, the fish waste has high potential of fatty acid in FAME to produce biodiesel through transesterification process.

Renewable Diesel Fuel from Processing of Vegetable Oil in Hydrotreatment Units: Theoretical Compliance with European Directive 2009/28/EC and Ongoing Projects in Spain

Oil hydrotreating units in refineries are aimed at reducing the sulfur content of fuels to accomplish standard par-ticular specifications. However, this process is currently one of the best available technologies to produce biofuels from vegetable oil in a refinery. Vegetable oils can be processed or co-processed in these units if several adaptations are performed, so some properties could be improved in comparison with conventional fuel such as density and cetane number. This study highlights the theoretical greenhouse gases (GHG) emissions (using a life cycle assessment–LCA-approach) of a hydrotreated vegetable oil (HVO) from bibliographical data. Results were compared with other biofuel production processes, such as those obtained by transesterification of vegetable oil (FAME, fatty acid methyl ester). It has also been included the comparison with conventional fossil diesel as a benchmark in order to assess the theoretical compliance with GHG savings proposed in European Directive 2009/28/EC. Finally, ongoing projects and future perspectives in Spain are mentioned.

Azacarbazole n-3 and n-6 polyunsaturated fatty acids ethyl esters nanoemulsion with enhanced efficacy against Plasmodium falciparum

Alternative therapies are necessary for the treatment of malaria due to emerging drug resistance.However,many promising antimalarial compounds have poor water solubility and suffer from the lack of suitable delivery systems,which seriously limits their activity.To address this problem,we synthesized a series of azacarbazoles that were evaluated for antimalarial activity against D10(chloroquine-sensitive)and W2(chloroquine-resistant)strains of P.falciparum.The most active compound,9H-3-azacarbazole(3),was encapsulated in a novel o/w nanoemulsion consisting of ethyl esters of polyunsaturated fatty acids n-3 and n-6 obtained from flax oil as the oil phase,Smix(Tween 80 and Transcutol HP)and water.This formulation was further analyzed using transmission electron microscopy,dynamic light scattering and in vitro and in vivo studies.It was shown that droplets of the 3-loaded nanosystem were spherical,with satisfactory stability,without cytotoxicity towards fibroblasts and intestinal cell lines at concentrations corresponding to twice the IC50 for P.falciparum.Moreover,the nanoemulsion with this type of oil phase was internalized by Caco-2 cells.Additionally,pharmacokinetics demonstrated rapid absorption of compound 3(tmax=5.0 min)after intragastric administration of 3-encapsulated nanoemulsion at a dose of 0.02 mg/kg in mice,with penetration of compound 3 to deep compartments.The 3-encapsulated nanoemulsion was found to be 2.8 and 4.2 times more effective in inhibiting the D10 and W2 strains of the parasite,respectively,compared to non-encapsulated 3.Our findings support a role for novel o/w nanoemulsions as delivery vehicles for antimalarial drugs.

<i>In Vitro</i>Anti-Diabetic Activities and Phytochemical Analysis of Bioactive Fractions Present in <i>Meriandra dianthera, Aloe camperi</i>and a Polyherb

This paper reports the in vitro anti-diabetic profile of certain medicinal plants traditionally used in Eritrea for the management of type 2 diabetes. The crude methanolic extracts and fractions of Meriandra dianthera, Aloe camperi, a Polyherb and their fractions were investigated. The in vitro screening of the crude extracts has generally elicited a dose dependent α-glucosidase and α-amylase inhibition activities. M. dianthera displayed the highest α-glucosidase inhibitory activity (IC50: 0.074 ± 0.032 mg/mL) at the highest concentration tested (0.800 mg/mL) relative to A. camperi, the Polyherb and Acarbose (IC50: 0.37 ± 0.052, 0.56 ± 0.024 and 0.55 ± 0.029 respectively). The α-glucosidase inhibition activities of A. camperi and M. dianthera, except for the Polyherb and Acarbose, were significantly different (P < 0.05) at various ranges of concentrations (0.025 - 0.800 mg/mL). The percentage α-amylase inhibitions of M. dianthera, A. camperi, the Polyherb and Acarbose, at the highest concentrations (0.800 mg/mL), were 78.3%, 15.9%, 16.4%, and 82.9% respectively. A. camperi and the Polyherb displayed lower α-amylase inhibitory activities (IC50: 1.72 ± 0.06 and 2.57 ± 0.07 mg/mL respectively) compared to Acarbose and M. dianthera (IC50: 0.31 ± 0.01 and 0.43 ± 0.02 mg/mL respectively). For the α-amylase inhibition activity, even at lower concentrations (0.025 mg/mL), there were statistically significant differences (P < 0.01) among the values generated for all the extracts. The in vitro anti-diabetic screening of the fractions, at 0.800 mg/ml, displayed characteristic enzyme inhibition activities. Generally, the non-polar fractions showed higher enzyme inhibitory activities compared to the polar fractions. The most bioactive non-polar fractions, thus, were subjected to GC-MS analysis and presented various essential oils, fatty acid methyl esters (FAMEs) and benzoic acid derivatives in those plants.

An exploratory pilot of factors associated with premenstrual syndrome in minority women

Purpose:This investigation explored factors associated with premenstrual syndrome(PMS)in minority women,and compared the response of minority and non-minority women supplemented with omega-3 fatty acids(FA)in the form of fish oil.Methods:This descriptive,correlational,retrospective pilot was a secondary data analysis.Participants consuming 2 g of fish oil/d(n=15)in the larger study were included.The Moos Menstrual Distress Questionnaire(MMDQ)was assessed monthly for two months to acquire a mean baseline MMDQ score.The total sample was stratified to evaluate racial variations in PMS symptoms(non-minority,n=7;minority,n=8).MMDQ score at 5 months was compared to the mean baseline score within each group.Results:Fish oil supplementation significantly reduced PMS symptoms in both groups(nonminority p=0.002;minority p=0.046)with a large effect of 1.4 for both groups.Mean MMDQ total scores were not significantly different between groups at 5 months.Conclusions:This pilot evidence of improved PMS symptoms in minority and non-minority groups related to fish oil supplementation supports a universal treatment approach and highlights need for a larger-scale investigation.

Waste Cooking Oil as a Substrate for Biodiesel Production

The effectiveness of adsorptive treatment of waste cooking oils was assessed in terms of suitability for biodiesel production. New technologies involving standard diesel engines have been developed using biofuel products from vegetable oils and waste animal fats based on environmental and economic considerations. The potential application of used rapeseed oil after treatment with a mixture of active carbon （AR） and magnesium silicate （MG） as energy source was studied. The results were compared with substrates standard in the Vogel＆Noot GmbH technology for the transesterification of oils and fats.

Development of Technology for Producing a Fat Composition Based on Ester for Fattening Leather

An ester based on the secondary and by-products of oil and fat and alcohol hydrolysis is obtained for fattening the skin. Distilled fatty acids are used as a secondary product for the preparation of the ester, and fusel oil as a by-product. The main physicochemical properties of the ester obtained were determined. An ester-based formulation has been developed to fatten clothing skins from fine raw materials. The recommended is technological scheme of obtaining a composition for fattening leather.

不同脂肪源在猪生产中的作用与应用

饲粮中的脂肪是猪能量和必需脂肪酸的重要来源。不同脂肪源所含脂肪酸的种类和比例不同,其独特的脂肪酸组成对猪的生长性能与繁殖性能具有不同的改善作用。近年来,不同油脂在猪生产中的应用日益广泛,但其应用效果及作用机制仍不清晰。文章介绍了亚麻籽油、豆油、鱼油、不同碳链长度脂肪酸和大豆磷脂等在猪生产中的研究进展,探讨了不同脂肪源对不同阶段猪的影响,评估了氧化油脂对猪生产的负面作用及其防控办法,并对其未来发展方向进行了展望,为不同脂肪源在猪生产中的合理应用提供参考依据。

鱼油ω-3 PUFAs的功能特性研究进展

由各种水产副产物精制提取的鱼油可广泛应用于食品、药品以及动物饲料的加工。鱼油中的二十二碳六烯酸和二十碳五烯酸是ω-3多不饱和脂肪酸(ω-3 polyunsaturated fatty acids,ω-3 PUFAs)的主要功能活性成分,食品鱼油具有健康促进作用。该文结合国内外研究进展,重点综述近年来鱼油ω-3多不饱和脂肪酸的主要功能特性,并针对鱼油主要功能特性的不足进行分析,以期为鱼油功能活性成分在医药和食品领域的深度开发提供参考。

磁性固相萃取-气质联用-同位素内标法精准检测白酒中8种高级脂肪酸乙酯

高级脂肪酸乙酯是引起酒体浑浊的关键因素之一。为系统分析白酒中的高级脂肪酸乙酯以改善白酒生产过程中的浑浊问题,建立了一种基于氨基化四氧化三铁(Fe_(3)O_(4)-NH_(2))磁性固相萃取结合气质联用技术的方法,用以同时测定白酒中8种高级脂肪酸乙酯。通过考察酒样的pH值、离子强度、吸附剂用量、吸附时间、解吸溶剂种类、解吸溶剂酸碱度、解吸时间等因素,确定了较佳的萃取条件。结果表明:这8种高级脂肪酸乙酯在各自的质量浓度范围内线性关系良好,相关系数R 2均大于0.99;方法检出限和定量限分别为9.1~42.9μg/L和5.2~200.0μg/L;回收率为79.6%~99.3%,相对标准偏差(n=3)为8.0%~10.7%。应用此方法,并结合同位素内标法对24种不同香型和品牌的白酒样品中8种高级脂肪酸乙酯进行精准定量,发现它们的种类和质量浓度存在显著差异。其中,在酱香型白酒中,高级脂肪酸乙酯的检出率最高,达到100%。该方法简便快捷,样品萃取只需10 min,具有高灵敏度和准确性,能够有效避免传统液-液萃取技术的背景干扰问题,可为实现白酒中高级脂肪酸乙酯的精准检测提供一种新的方法。