This study focused on the preparation of docosahexaenoic acid(DHA) and eicosapentaenoic acid(EPA)enriched-triacylglycerols by enzymatic interesterification using tuna oil and capric acid. The content of DHA+EPA is 26....This study focused on the preparation of docosahexaenoic acid(DHA) and eicosapentaenoic acid(EPA)enriched-triacylglycerols by enzymatic interesterification using tuna oil and capric acid. The content of DHA+EPA is 26.86% in the tuna oil used in this study. A response surface methodology(RSM) was used to optimize the reaction parameters(reaction temperature, substrate molar ratio, enzyme amount and reaction time), and the optimized conditions were determined to be: reaction temperature 58℃, substrate molar ratio(capric acid : tuna oil) 4:1, enzyme amount 4%, and reaction time 7.5 h. Under the optimized conditions, the content of DHA+EPA in the glycerides was 40.03%, which is 13.17% higher than that in raw tuna oil. In addition,the MLM-type structured lipids containing medium chain fatty acids(capric acid) at positions sn-1,3 and a long chain fatty acid(DHA/EPA) at the position sn-2 may have many health benefits for humans.展开更多
In this study, a composite of form-stable phase change materials （FSPCMs） were prepared by the incorporation of a eutectic mixture of capric-palmitic-stearic acid （CA-PA-SA） into expanded vermiculite （EV） via va...In this study, a composite of form-stable phase change materials （FSPCMs） were prepared by the incorporation of a eutectic mixture of capric-palmitic-stearic acid （CA-PA-SA） into expanded vermiculite （EV） via vacuum impregnation. In the composites, CA-PA-SA was utilized as a thermal energy storage material, and EV served as the supporting material. X-ray diffraction and Fourier transform infrared spectroscopy results demonstrated that CA-PA-SA and EV in the composites only undergo physical combination, not a chemical reaction. Scanning electron microscopy images indicated that CA-PA-SA is sufficiently absorbed in the expanded vermiculite porous network. According to differential scanning calorimetry results, the 70 wt% CA-PA-SA/EV sample melts at 19.3 ℃ with a latent heat of 117.6J/g and solidifies at 17.1 ℃ with a latent heat of 118.3J/g. Thermal cycling measurements indicated that FSPCMs exhibit adequate stability even after being subjected to 200 melting-freezing cycles. Furthermore, the thermal conductivity of the composites increased by approximately 49.58% with the addition of 5 wt% of Cu powder. Hence, CA-PA-SA/EV FSPCMs are effective latent heat thermal energy storage building materials.展开更多
In order to improve the thermal storage capacity of expanded vermiculite（EV） based formstable composite PCM（FS-PCM） via organic modification of EV, first, EV was modified with a sodium stearate（Na St） as surface...In order to improve the thermal storage capacity of expanded vermiculite（EV） based formstable composite PCM（FS-PCM） via organic modification of EV, first, EV was modified with a sodium stearate（Na St） as surface modifier, and organic EV（OEV） with hydrophobicity and higher adsorption capacity for fatty acid was obtained. A novel capric-stearic acid eutectic（CA-SA）/OEV FS-PCM with high thermal storage capacity was then developed. OEV and CA-SA/OEV were characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, differential scanning calorimetry（DSC）, thermal gravimetry（TG）, and thermal cycling test. Results showed that OEV has obvious hydrophobicity and a higher adsorption capacity for fatty acid. Its adsorption ratio has increased by 48.71% compared with that of EV. CA-SA/OEV possesses high thermal storage density（112.52 J/g）, suitable melting temperature（20.49 ℃）, good chemical compatibility, excellent thermal stability and reliability, indicating great application potential for building energy efficiency. Moreover, organic modification of inorganic matrix may offer novel options for improving its adsorption capacity for organic PCMs and increasing heat storage capacity of corresponding FS-PCMs.展开更多
目的比较6种脂肪酸对高胆固醇血症小鼠体质量和血脂的影响。方法建立C57BL/6J小鼠高胆固醇血症模型,分别用含2%的辛酸(C8∶0)、癸酸(C10∶0)、油酸(C18∶1)、α-亚麻酸(C18∶3)、棕榈酸(C16∶0)和硬脂酸(C18∶0)高胆固醇饲料喂养12周,1...目的比较6种脂肪酸对高胆固醇血症小鼠体质量和血脂的影响。方法建立C57BL/6J小鼠高胆固醇血症模型,分别用含2%的辛酸(C8∶0)、癸酸(C10∶0)、油酸(C18∶1)、α-亚麻酸(C18∶3)、棕榈酸(C16∶0)和硬脂酸(C18∶0)高胆固醇饲料喂养12周,12周时检测血脂及脂蛋白相关指标。结果研究12周后各组小鼠体质量均显著增加,辛酸(C8∶0)、癸酸(C10∶0)、油酸(C18∶1)对控制体质量增加的作用较棕榈酸(C16∶0)和硬脂酸(C18∶0)差异显著(P<0.05);6种脂肪酸均显示出不同程度血总胆固醇(total cholesterol,TC)和低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)降低,高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)与低密度脂蛋白胆固醇比值(HDL-C/LDL-C)增加的作用。辛酸(C8∶0)、癸酸(C10∶0)和α-亚麻酸(C18∶3)降低TC和LDL-C及升高HDL-C/LDL-C比值的作用比油酸、棕榈酸和硬脂酸显著(P<0.05)。结论中链的饱和脂肪酸(saturated fatty acid,SFA)较长链的SFA降低小鼠体质量和血脂的作用显著。展开更多
基金Supported by the National Key Project of Fundamental Research( G2 0 0 0 0 7810 2 ) and the National Natural ScienceFoundation of China( No. 2 9992 5 90 - 5 )
文摘This study focused on the preparation of docosahexaenoic acid(DHA) and eicosapentaenoic acid(EPA)enriched-triacylglycerols by enzymatic interesterification using tuna oil and capric acid. The content of DHA+EPA is 26.86% in the tuna oil used in this study. A response surface methodology(RSM) was used to optimize the reaction parameters(reaction temperature, substrate molar ratio, enzyme amount and reaction time), and the optimized conditions were determined to be: reaction temperature 58℃, substrate molar ratio(capric acid : tuna oil) 4:1, enzyme amount 4%, and reaction time 7.5 h. Under the optimized conditions, the content of DHA+EPA in the glycerides was 40.03%, which is 13.17% higher than that in raw tuna oil. In addition,the MLM-type structured lipids containing medium chain fatty acids(capric acid) at positions sn-1,3 and a long chain fatty acid(DHA/EPA) at the position sn-2 may have many health benefits for humans.
基金financially supported by the National Natural Science Foundations of China (Grant Nos. 51472222 and 51372232)the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20130022110006)the Fundamental Research Funds for the Central Universities for financial support (Grant No. 2652016046)
文摘In this study, a composite of form-stable phase change materials （FSPCMs） were prepared by the incorporation of a eutectic mixture of capric-palmitic-stearic acid （CA-PA-SA） into expanded vermiculite （EV） via vacuum impregnation. In the composites, CA-PA-SA was utilized as a thermal energy storage material, and EV served as the supporting material. X-ray diffraction and Fourier transform infrared spectroscopy results demonstrated that CA-PA-SA and EV in the composites only undergo physical combination, not a chemical reaction. Scanning electron microscopy images indicated that CA-PA-SA is sufficiently absorbed in the expanded vermiculite porous network. According to differential scanning calorimetry results, the 70 wt% CA-PA-SA/EV sample melts at 19.3 ℃ with a latent heat of 117.6J/g and solidifies at 17.1 ℃ with a latent heat of 118.3J/g. Thermal cycling measurements indicated that FSPCMs exhibit adequate stability even after being subjected to 200 melting-freezing cycles. Furthermore, the thermal conductivity of the composites increased by approximately 49.58% with the addition of 5 wt% of Cu powder. Hence, CA-PA-SA/EV FSPCMs are effective latent heat thermal energy storage building materials.
基金Funded by the Major State Research Development Program of China during the 13th Five-Year Plan Period(No.2016YFC0700904)the Science and Technology Support Program of Hubei Province(Nos.2014BAA134 and 2015BAA107)
文摘In order to improve the thermal storage capacity of expanded vermiculite（EV） based formstable composite PCM（FS-PCM） via organic modification of EV, first, EV was modified with a sodium stearate（Na St） as surface modifier, and organic EV（OEV） with hydrophobicity and higher adsorption capacity for fatty acid was obtained. A novel capric-stearic acid eutectic（CA-SA）/OEV FS-PCM with high thermal storage capacity was then developed. OEV and CA-SA/OEV were characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, differential scanning calorimetry（DSC）, thermal gravimetry（TG）, and thermal cycling test. Results showed that OEV has obvious hydrophobicity and a higher adsorption capacity for fatty acid. Its adsorption ratio has increased by 48.71% compared with that of EV. CA-SA/OEV possesses high thermal storage density（112.52 J/g）, suitable melting temperature（20.49 ℃）, good chemical compatibility, excellent thermal stability and reliability, indicating great application potential for building energy efficiency. Moreover, organic modification of inorganic matrix may offer novel options for improving its adsorption capacity for organic PCMs and increasing heat storage capacity of corresponding FS-PCMs.
文摘目的比较6种脂肪酸对高胆固醇血症小鼠体质量和血脂的影响。方法建立C57BL/6J小鼠高胆固醇血症模型,分别用含2%的辛酸(C8∶0)、癸酸(C10∶0)、油酸(C18∶1)、α-亚麻酸(C18∶3)、棕榈酸(C16∶0)和硬脂酸(C18∶0)高胆固醇饲料喂养12周,12周时检测血脂及脂蛋白相关指标。结果研究12周后各组小鼠体质量均显著增加,辛酸(C8∶0)、癸酸(C10∶0)、油酸(C18∶1)对控制体质量增加的作用较棕榈酸(C16∶0)和硬脂酸(C18∶0)差异显著(P<0.05);6种脂肪酸均显示出不同程度血总胆固醇(total cholesterol,TC)和低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)降低,高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)与低密度脂蛋白胆固醇比值(HDL-C/LDL-C)增加的作用。辛酸(C8∶0)、癸酸(C10∶0)和α-亚麻酸(C18∶3)降低TC和LDL-C及升高HDL-C/LDL-C比值的作用比油酸、棕榈酸和硬脂酸显著(P<0.05)。结论中链的饱和脂肪酸(saturated fatty acid,SFA)较长链的SFA降低小鼠体质量和血脂的作用显著。
