A polypyrrole-modified glassy carbon electrode （PPy/GC electrode） was prepared and its electrocatalytic behavior towards naphthoquinone in the presence of acid was characterized by linear sweep voltammetry （LSV）. ...A polypyrrole-modified glassy carbon electrode （PPy/GC electrode） was prepared and its electrocatalytic behavior towards naphthoquinone in the presence of acid was characterized by linear sweep voltammetry （LSV）. A well-defined new reduction peak appeared at a more positive potential than the original reduction peak. The new reduction peak current was linearly related to the acid value （AV） of oil. Based on it, a rapid electrochemical method for determining AV of transformer oil was developed using PPy/GC electrode. A working curve was obtained in the AV range of 0.01 to 0.40 mg（KOH）.g^-1, with a sensitivity of 39.42 μA0.5/（mg（KOH）.g-l） and the detection limit of 0.0014 mg（KOH）.g^-1 （signal-to-noise ratio is 3, standard deviation is 2.247%）. Moreover, the proposed method has been successfully applied to AV determination of several transformer oil samples with advantages of rapidness, high sensitivity and accuracy compared to the conventional method.展开更多
Hydrolysis of olive oil catalyzed by Candida lipolytica lipase was investigated. The relative concentration of the components in the product was determined by using high performance liquid chromatography（HPLC）. Furt...Hydrolysis of olive oil catalyzed by Candida lipolytica lipase was investigated. The relative concentration of the components in the product was determined by using high performance liquid chromatography（HPLC）. Furthermore, a novel rapid method to detect the hydrolytic process of olive oil was developed based on the relationship between the acid value and the relative concentration of the different components.展开更多
Preparation of biodiesel from waste oils containing 72% of free fatty acids catalyzed by a novel Br?nsted acidic ionic liquid 1-sulfobutyl-3-methylimidazolium hydrosulfate([BHSO_3MIM][HSO_4]) was systematically invest...Preparation of biodiesel from waste oils containing 72% of free fatty acids catalyzed by a novel Br?nsted acidic ionic liquid 1-sulfobutyl-3-methylimidazolium hydrosulfate([BHSO_3MIM][HSO_4]) was systematically investigated.The optimum molar ratio of methanol to waste oils,catalyst amount,reaction temperature and reaction time were 8/1,10%(based on the mass of waste oils),140°C and 6 h,respectively,under which the obtained yield of biodiesel reached 94.9%.Also,[BHSO_3MIM][HSO_4] as a catalyst still retained around 97% of its original catalytic activity after successive re-use of 5 batches(6 h per batch),showing the excellent operational stability.Moreover,the acidic IL [BHSO_3MIM][HSO_4] was able to ef ficiently catalyze conversions of waste oils with different amounts of FFAs(free fatty acids) into biodiesel,and showed tremendous application potential.Therefore,an ef ficient and environmentally friendly catalyst is provided for the synthesis of biodiesel from waste oils with high acid value.展开更多
Synthesis of polyols from carbon dioxide（CO2） is attractive from the viewpoint of sustainable development of polyurethane industry;it is also interesting to adjust the structure of the CO2-polyols for versatile requ...Synthesis of polyols from carbon dioxide（CO2） is attractive from the viewpoint of sustainable development of polyurethane industry;it is also interesting to adjust the structure of the CO2-polyols for versatile requirement of polyurethane.However,when renewable malonic acid was used as a starter,the copolymerization reaction of CO2 and propylene oxide（PO） was uncontrollable,since it proceeded slowly（13 h） and produced 40.4 wt%of byproduct propylene carbonate（PC） with a low productivity of 0.34kg/g.A careful analysis disclosed that the acid value of the copolymerization medium was the key factor for controlling the copolymerization reaction.Therefore,a preactivation approach was developed to dramatically reduce the acid value to 0.6mg（KOH）/gby homopolymerization of PO into oligo-ether-diol under the initiation of malonic acid,which ensured the controllable copolymerization,where the copolymerization time could be shortened by 77%from 13 to 3 h,the PC content was reduced by 76%from 40.4 wt%to 9.4 wt%,and the productivity increased by 61%from 0.34 to 0.55 kg/g.Moreover,by means of preactivation approach,the molecular weight as well as the carbonate unit content in the CO2-diol was also controllable.展开更多
The objective of this study is to determine the factors responsible for the acidification of Burundi palm oils. The investigation of the duration of fermentation of palm fruits performed among artisanal producers foun...The objective of this study is to determine the factors responsible for the acidification of Burundi palm oils. The investigation of the duration of fermentation of palm fruits performed among artisanal producers found that more than 89% of producers from commune of Rumonge ferment for more than 5 days while more than 61% of those from commune of Mutimbuzi ferment for 4 days. The determination of acid value using the method of ISO 660:2009 showed that Dura and Tenera varieties fermented for 4 days had respectively 5.9 ± 2.3 and 5.8 ± 1.8 mg of KOH/g of oil for clustered fruits, 7.03 ± 3.4 and 7.02 ± 3.2 mg of KOH/g for destemmed fruits. After 8 days, the acid values of Dura and Tenera varieties obtained were respectively 10.9 ± 4.7 and 12.5 ± 5.4 mg KOH/g for clustered fruits, 12.5 ± 5.4 and 12.5 ± 4.1 mg KOH/g for destemmed fruits. No significant difference was recorded between varieties. On the other hand, a highly significant difference at p < 0.05 was obtained between fruits fermented in the open air (e.g. around the foot of the oil palm, FFOA), in a shed when the fruits were not covered (SFNC) and in a shed when the fruits were covered by branches or straw (SFC). At 8 days of fermentation, the acid values of FFOA, SFNC and SFC were 9.1 ± 0.7 < 12.6 ± 0.8 < 17.7 ± 1.4 for destemmed fruit and 9.1 ± 0.7 < 13.2 ± 1.3 < 13.2 ± 3.2 for clustered fruit, respectively. In light of these results, the acidity of Rumonge palm oil is probably due to the long fermentation time and the technique of covering the fruits during fermentation. These results will allow producers to extract good quality oil and consequently improve the health of consumers.展开更多
Biodiesel is a biomass-based renewable and clean fuel. It can be used directly in existing diesel engines without any modification. In spite of having so many advantages, it has an issue regarding long-term storage st...Biodiesel is a biomass-based renewable and clean fuel. It can be used directly in existing diesel engines without any modification. In spite of having so many advantages, it has an issue regarding long-term storage stability. Biodiesel oxidizes when it comes in proximity of light, temperature, humidity, metals etc. The oxidation causes precipitation and sedimentation in the fuel. Such biodiesel is unfit to use in engines. Hence, this study aims to assess the storage stability of pomelo seed oil （Citrus maxima） biodiesel over a period of five months upon storage both in open and closed condition. Storage stability of biodiesel is determined in terms of acid value, peroxide value and viscosity at regular interval of time. It is observed that there is a strong relationship between oxidation and outside factors such as light, temperature fluctuations and humidity level. Upon exposure to these factors, oxidation in biodiesel accelerated greatly.展开更多
The use of supercritical fluid carbon dioxide (SFCO2) in extraction of lanolin and its alcohol is superior to the conventional solvent extraction method. Its distinctive advantages include high extractive ratio, nonto...The use of supercritical fluid carbon dioxide (SFCO2) in extraction of lanolin and its alcohol is superior to the conventional solvent extraction method. Its distinctive advantages include high extractive ratio, nontoxic and nonflammable solvents, and minimal by -product pollution. The resulting refined lanolin and its alcohol have light color and little odor, and can be used as raw materials for high grade cosmetic products.展开更多
In this paper, the crude camellia oil extracted by cold pressing and deacidified oil, decolorized oil, dewaxed oil and finished tea oil obtained in different refining stages were studied. The changes of acid value, pe...In this paper, the crude camellia oil extracted by cold pressing and deacidified oil, decolorized oil, dewaxed oil and finished tea oil obtained in different refining stages were studied. The changes of acid value, peroxide value and free radical scavenging ability of camellia oil in each stage were compared and analyzed.The results showed that the total phenol content of crude oil was the highest, and the total phenol content of alkali refined crude oil decreased significantly. After dewaxing, the total phenol concentration of camellia oil increased by 63.5%. The reason may be that low temperature conditions contributed to the recovery of phenolic structure in camellia oil, and without the influence of alkaline solution, the damage degree of phenolic substances was greatly reduced, thus elevating the total phenol content. The lowest peroxide value of camellia oil was observed in the alkali-refining deacidification stage, which decreased by 29.3%. Crude oil had the highest acid value and concentration of antioxidant substances. After alkali-refining deacidification,the acid value and the concentration of antioxidant substances dropped by 85.3%and 88.9%, respectively. Total phenols had the strongest correlation with acid value,followed by free radical scavenging ability, and the correlation with peroxide value was not obvious.展开更多
Minced pork paste was mixed with cooked rice and noodle resulted in very popular traditional gourmet meal in Taiwan. The 100 ℃, 4 h was normally cooking condition for commercial business. However, the pressure cooker...Minced pork paste was mixed with cooked rice and noodle resulted in very popular traditional gourmet meal in Taiwan. The 100 ℃, 4 h was normally cooking condition for commercial business. However, the pressure cooker with higher cooking temperature （106 ℃, 116 ℃ and 121 ℃） and different cooking time were under studied in order to improving efficiency, quality and even cost down. The samples of neck pork substitute, cooking at 106℃, 100 rain; 116℃, 75 min; 121 ℃, 45 min with different pressure were perfomed the result as well as traditional 20% fat in ordinary formulation and cooking at 100℃ for 4 h. During storage, the products were taste acceptable for 4 weeks at 4 ℃, 4 months at - 18 ℃ and better than 1 day at 25 ℃ storage.展开更多
This study assessed the effect of processing method on the carotenoid profile of oil from three varieties of Nigerian oil palm fruits (Elaise guinensis). Specific varieties of the Elaise guinensis, which are the dura,...This study assessed the effect of processing method on the carotenoid profile of oil from three varieties of Nigerian oil palm fruits (Elaise guinensis). Specific varieties of the Elaise guinensis, which are the dura, pesifera and tenera were obtained from National Institute for Oil Palm Research (NIFOR) in Edo state, Nigeria. The samples were divided into two and processed using two different methods as commonly practiced in south-eastern Nigeria, the hot and cold processes. The oil extracted from each of the processes was then analyzed for oil characteristics using standard analytical methods while the carotenoid profile was analyzed using HPLC C-21 column. The results generated were subjected to the one-way analysis of variance (ANOVA). The results of carotenoid constituent identified include: lutein, neurosporene (trans), neurosporene (cis), α-Zeacarotene(cis), α-Zeacarotene(trans), phytoene, phytofluene, β-zeacarotene, 13 and 13’ cis α-carotene, 13 cis β-carotene, trans α-carotene, 9 cis α-carotene, trans β-carotene, αcarotene a(cis), α-carotene b(cis), α-carotene (trans), γ-carotene (trans), γ-carotene b(cis), lycopene (cis) and lycopene (trans). The results of physicochemical characteristics of the oil samples extracted range from 0.922 ± 0.004 - 0.916 ± 0.001 for specific gravity (SG), 8.10 ± 0.17 - 4.88 ± 0.04 mg KOH/g for acid value, 4.29% ± 0.02% - 2.44% ± 0.02% for free fatty acid value (FFA), 6.00 ± 0.21 to 204.67 ± 0.98 mgKOH/g for saponification value and 9.53 ± 0.23 - 5.25 ± 0.33 mEq/kg;for peroxide value while the carotenoids values were between 53.735 ± 0.10 and 123.389 ± 0.20 mg/100g. From the result, we can observe that the main constituent of the palm oil carotenoid is the β-carotene which makes up to about 80% of the total carotene. Statistical analysis revealed that no significant difference exists between the mean of each of the processing methods on the carotenoid profile of the oil sample analyzed.展开更多
Ultraviolet （UV） irradiation is proven to be an effective method to reduce aflatoxin in peanut oil, but the changes of peanut oil quality are not clear, especially in storage life. In this study, impacts of UV irr...Ultraviolet （UV） irradiation is proven to be an effective method to reduce aflatoxin in peanut oil, but the changes of peanut oil quality are not clear, especially in storage life. In this study, impacts of UV irradiation treatment on quality of peanut oil were investigated. Acid value, iodine value, oxidative stability and total phenol content that refer to rancidity and oxidation of oil were estimated under 365 nm UV irradiation processing and during different storage time. Results indicated that acid value was increased slightly under irradi-ation and in storage life while iodine value, total phenol content and oxidative stability de-clined weakly. Changes of these quality indexes were all within safe and acceptable levels. It can be confirmed by this study that UV irradiation is a safe strategy for AFB1 detoxification in peanut oil and not influence upon quality and stability of peanut oil.展开更多
基金Project(11JJ3015)supported by the Natural Science Foundation of Hunan Province,China
文摘A polypyrrole-modified glassy carbon electrode （PPy/GC electrode） was prepared and its electrocatalytic behavior towards naphthoquinone in the presence of acid was characterized by linear sweep voltammetry （LSV）. A well-defined new reduction peak appeared at a more positive potential than the original reduction peak. The new reduction peak current was linearly related to the acid value （AV） of oil. Based on it, a rapid electrochemical method for determining AV of transformer oil was developed using PPy/GC electrode. A working curve was obtained in the AV range of 0.01 to 0.40 mg（KOH）.g^-1, with a sensitivity of 39.42 μA0.5/（mg（KOH）.g-l） and the detection limit of 0.0014 mg（KOH）.g^-1 （signal-to-noise ratio is 3, standard deviation is 2.247%）. Moreover, the proposed method has been successfully applied to AV determination of several transformer oil samples with advantages of rapidness, high sensitivity and accuracy compared to the conventional method.
基金the National Natural Science Foundation of China(Nos 20072011 and 20272017)
文摘Hydrolysis of olive oil catalyzed by Candida lipolytica lipase was investigated. The relative concentration of the components in the product was determined by using high performance liquid chromatography（HPLC）. Furthermore, a novel rapid method to detect the hydrolytic process of olive oil was developed based on the relationship between the acid value and the relative concentration of the different components.
基金Supported by the National Natural Science Foundation of China(21676104,21336002,21376096)the Open Funding Project of the State Key Laboratory of Bioreactor Engineeringthe Program of State Key Laboratory of Pulp and Paper Engineering(2017ZD05)
文摘Preparation of biodiesel from waste oils containing 72% of free fatty acids catalyzed by a novel Br?nsted acidic ionic liquid 1-sulfobutyl-3-methylimidazolium hydrosulfate([BHSO_3MIM][HSO_4]) was systematically investigated.The optimum molar ratio of methanol to waste oils,catalyst amount,reaction temperature and reaction time were 8/1,10%(based on the mass of waste oils),140°C and 6 h,respectively,under which the obtained yield of biodiesel reached 94.9%.Also,[BHSO_3MIM][HSO_4] as a catalyst still retained around 97% of its original catalytic activity after successive re-use of 5 batches(6 h per batch),showing the excellent operational stability.Moreover,the acidic IL [BHSO_3MIM][HSO_4] was able to ef ficiently catalyze conversions of waste oils with different amounts of FFAs(free fatty acids) into biodiesel,and showed tremendous application potential.Therefore,an ef ficient and environmentally friendly catalyst is provided for the synthesis of biodiesel from waste oils with high acid value.
基金supported by the National Natural Science Foundation of China(51321062,21134002)
文摘Synthesis of polyols from carbon dioxide（CO2） is attractive from the viewpoint of sustainable development of polyurethane industry;it is also interesting to adjust the structure of the CO2-polyols for versatile requirement of polyurethane.However,when renewable malonic acid was used as a starter,the copolymerization reaction of CO2 and propylene oxide（PO） was uncontrollable,since it proceeded slowly（13 h） and produced 40.4 wt%of byproduct propylene carbonate（PC） with a low productivity of 0.34kg/g.A careful analysis disclosed that the acid value of the copolymerization medium was the key factor for controlling the copolymerization reaction.Therefore,a preactivation approach was developed to dramatically reduce the acid value to 0.6mg（KOH）/gby homopolymerization of PO into oligo-ether-diol under the initiation of malonic acid,which ensured the controllable copolymerization,where the copolymerization time could be shortened by 77%from 13 to 3 h,the PC content was reduced by 76%from 40.4 wt%to 9.4 wt%,and the productivity increased by 61%from 0.34 to 0.55 kg/g.Moreover,by means of preactivation approach,the molecular weight as well as the carbonate unit content in the CO2-diol was also controllable.
文摘The objective of this study is to determine the factors responsible for the acidification of Burundi palm oils. The investigation of the duration of fermentation of palm fruits performed among artisanal producers found that more than 89% of producers from commune of Rumonge ferment for more than 5 days while more than 61% of those from commune of Mutimbuzi ferment for 4 days. The determination of acid value using the method of ISO 660:2009 showed that Dura and Tenera varieties fermented for 4 days had respectively 5.9 ± 2.3 and 5.8 ± 1.8 mg of KOH/g of oil for clustered fruits, 7.03 ± 3.4 and 7.02 ± 3.2 mg of KOH/g for destemmed fruits. After 8 days, the acid values of Dura and Tenera varieties obtained were respectively 10.9 ± 4.7 and 12.5 ± 5.4 mg KOH/g for clustered fruits, 12.5 ± 5.4 and 12.5 ± 4.1 mg KOH/g for destemmed fruits. No significant difference was recorded between varieties. On the other hand, a highly significant difference at p < 0.05 was obtained between fruits fermented in the open air (e.g. around the foot of the oil palm, FFOA), in a shed when the fruits were not covered (SFNC) and in a shed when the fruits were covered by branches or straw (SFC). At 8 days of fermentation, the acid values of FFOA, SFNC and SFC were 9.1 ± 0.7 < 12.6 ± 0.8 < 17.7 ± 1.4 for destemmed fruit and 9.1 ± 0.7 < 13.2 ± 1.3 < 13.2 ± 3.2 for clustered fruit, respectively. In light of these results, the acidity of Rumonge palm oil is probably due to the long fermentation time and the technique of covering the fruits during fermentation. These results will allow producers to extract good quality oil and consequently improve the health of consumers.
文摘Biodiesel is a biomass-based renewable and clean fuel. It can be used directly in existing diesel engines without any modification. In spite of having so many advantages, it has an issue regarding long-term storage stability. Biodiesel oxidizes when it comes in proximity of light, temperature, humidity, metals etc. The oxidation causes precipitation and sedimentation in the fuel. Such biodiesel is unfit to use in engines. Hence, this study aims to assess the storage stability of pomelo seed oil （Citrus maxima） biodiesel over a period of five months upon storage both in open and closed condition. Storage stability of biodiesel is determined in terms of acid value, peroxide value and viscosity at regular interval of time. It is observed that there is a strong relationship between oxidation and outside factors such as light, temperature fluctuations and humidity level. Upon exposure to these factors, oxidation in biodiesel accelerated greatly.
基金Science Foundation of National Education Commission(99053)
文摘The use of supercritical fluid carbon dioxide (SFCO2) in extraction of lanolin and its alcohol is superior to the conventional solvent extraction method. Its distinctive advantages include high extractive ratio, nontoxic and nonflammable solvents, and minimal by -product pollution. The resulting refined lanolin and its alcohol have light color and little odor, and can be used as raw materials for high grade cosmetic products.
文摘In this paper, the crude camellia oil extracted by cold pressing and deacidified oil, decolorized oil, dewaxed oil and finished tea oil obtained in different refining stages were studied. The changes of acid value, peroxide value and free radical scavenging ability of camellia oil in each stage were compared and analyzed.The results showed that the total phenol content of crude oil was the highest, and the total phenol content of alkali refined crude oil decreased significantly. After dewaxing, the total phenol concentration of camellia oil increased by 63.5%. The reason may be that low temperature conditions contributed to the recovery of phenolic structure in camellia oil, and without the influence of alkaline solution, the damage degree of phenolic substances was greatly reduced, thus elevating the total phenol content. The lowest peroxide value of camellia oil was observed in the alkali-refining deacidification stage, which decreased by 29.3%. Crude oil had the highest acid value and concentration of antioxidant substances. After alkali-refining deacidification,the acid value and the concentration of antioxidant substances dropped by 85.3%and 88.9%, respectively. Total phenols had the strongest correlation with acid value,followed by free radical scavenging ability, and the correlation with peroxide value was not obvious.
文摘Minced pork paste was mixed with cooked rice and noodle resulted in very popular traditional gourmet meal in Taiwan. The 100 ℃, 4 h was normally cooking condition for commercial business. However, the pressure cooker with higher cooking temperature （106 ℃, 116 ℃ and 121 ℃） and different cooking time were under studied in order to improving efficiency, quality and even cost down. The samples of neck pork substitute, cooking at 106℃, 100 rain; 116℃, 75 min; 121 ℃, 45 min with different pressure were perfomed the result as well as traditional 20% fat in ordinary formulation and cooking at 100℃ for 4 h. During storage, the products were taste acceptable for 4 weeks at 4 ℃, 4 months at - 18 ℃ and better than 1 day at 25 ℃ storage.
文摘This study assessed the effect of processing method on the carotenoid profile of oil from three varieties of Nigerian oil palm fruits (Elaise guinensis). Specific varieties of the Elaise guinensis, which are the dura, pesifera and tenera were obtained from National Institute for Oil Palm Research (NIFOR) in Edo state, Nigeria. The samples were divided into two and processed using two different methods as commonly practiced in south-eastern Nigeria, the hot and cold processes. The oil extracted from each of the processes was then analyzed for oil characteristics using standard analytical methods while the carotenoid profile was analyzed using HPLC C-21 column. The results generated were subjected to the one-way analysis of variance (ANOVA). The results of carotenoid constituent identified include: lutein, neurosporene (trans), neurosporene (cis), α-Zeacarotene(cis), α-Zeacarotene(trans), phytoene, phytofluene, β-zeacarotene, 13 and 13’ cis α-carotene, 13 cis β-carotene, trans α-carotene, 9 cis α-carotene, trans β-carotene, αcarotene a(cis), α-carotene b(cis), α-carotene (trans), γ-carotene (trans), γ-carotene b(cis), lycopene (cis) and lycopene (trans). The results of physicochemical characteristics of the oil samples extracted range from 0.922 ± 0.004 - 0.916 ± 0.001 for specific gravity (SG), 8.10 ± 0.17 - 4.88 ± 0.04 mg KOH/g for acid value, 4.29% ± 0.02% - 2.44% ± 0.02% for free fatty acid value (FFA), 6.00 ± 0.21 to 204.67 ± 0.98 mgKOH/g for saponification value and 9.53 ± 0.23 - 5.25 ± 0.33 mEq/kg;for peroxide value while the carotenoids values were between 53.735 ± 0.10 and 123.389 ± 0.20 mg/100g. From the result, we can observe that the main constituent of the palm oil carotenoid is the β-carotene which makes up to about 80% of the total carotene. Statistical analysis revealed that no significant difference exists between the mean of each of the processing methods on the carotenoid profile of the oil sample analyzed.
基金This work was supported by the Natural Science Foundation o f China （31401601）, National Key Project for Agro-product Quality ＆ Safety Risk Assessment, PRC （GJFP2015007）, Special Fund for Grain-scientif-ic Research in the Public Interest （201513006-02）.
文摘Ultraviolet （UV） irradiation is proven to be an effective method to reduce aflatoxin in peanut oil, but the changes of peanut oil quality are not clear, especially in storage life. In this study, impacts of UV irradiation treatment on quality of peanut oil were investigated. Acid value, iodine value, oxidative stability and total phenol content that refer to rancidity and oxidation of oil were estimated under 365 nm UV irradiation processing and during different storage time. Results indicated that acid value was increased slightly under irradi-ation and in storage life while iodine value, total phenol content and oxidative stability de-clined weakly. Changes of these quality indexes were all within safe and acceptable levels. It can be confirmed by this study that UV irradiation is a safe strategy for AFB1 detoxification in peanut oil and not influence upon quality and stability of peanut oil.
