棕櫚油基甘油二酯的性質(zhì)研究及其塑性脂肪貯藏穩(wěn)定性的評價(jià)
發(fā)布時(shí)間：2018-09-10 09:01
【摘要】：甘油二酯(DAG)油脂不僅具有減輕體重和降低餐后血脂等健康的生理功能,還具有獨(dú)特的理化性質(zhì),因而備受關(guān)注,利用這些特性可以將富含DAG的脂肪加工成各種類型且具有減肥作用的塑性脂肪產(chǎn)品。因此,本文以棕櫚硬脂(PS)、棕櫚中間分提物(PMF)、棕櫚油(PO)、棕櫚軟脂(POL)和低芥酸菜籽油(RSO)為試驗(yàn)對象,通過系統(tǒng)研究不同棕櫚油基DAG油脂分子組成、熔化結(jié)晶性質(zhì)、晶體形態(tài)、流變性質(zhì)、質(zhì)構(gòu)特性,并研究棕櫚油基DAG的結(jié)晶機(jī)理,不同富含DAG油脂之間相互作用后對油脂體系相關(guān)性質(zhì)的影響以及富含甘油二酯塑性脂肪的貯藏穩(wěn)定性,探索用富含DAG的油脂替代普通油脂制備棕櫚油基塑性脂肪的可行性,為推廣DAG功能性食用油提供科學(xué)的理論依據(jù)。主要研究結(jié)果如下所示:(1)選擇Lipozyme TL IM固定化脂肪酶作為催化劑,在叔丁醇體系進(jìn)行甘油解反應(yīng),脂肪酶的添加量為底物油的5%(w/w),反應(yīng)溫度為70℃,其中棕櫚油基油脂的叔丁醇與底物油的體積比為4:1,底物與甘油的摩爾濃度比為1:2,PMF和PO甘油解的反應(yīng)時(shí)間為36h,PS和POL為24h,RSO的叔丁醇與底物油的體積比為3:1、底物與甘油的摩爾濃度比1:3,反應(yīng)時(shí)間為36h,在此條件下,TAG轉(zhuǎn)化率較高,也能得到高含量的DAG。通過分子蒸餾純化后,PS、PMF、PO、POL、RSO中的DAG含量分別為89.45%、92.61%、90.43%、89.87%、92.67%。(2)棕櫚油基油脂轉(zhuǎn)為甘油二酯后,脂肪酸構(gòu)成未發(fā)生變化,各組分含量變化不顯著,滑動熔點(diǎn)升高,塑性范圍變寬,晶型由β′型為主變?yōu)棣滦蜑橹�。熔化結(jié)晶性質(zhì)發(fā)生明顯改變,結(jié)晶曲線和熔化曲線均向高溫區(qū)偏移,并且在高溫區(qū)出現(xiàn)了新的吸熱峰和放熱峰。在相同的溫度下,棕櫚油基DAG油脂的成核和結(jié)晶速率明顯快于其相應(yīng)原油,而且其成核機(jī)制對溫度的敏感度較低。震蕩流變結(jié)果表明,棕櫚油基DAG油脂的|G*|曲線和δ曲線達(dá)到平衡時(shí)的時(shí)間跨度較小,且曲線變化趨勢更陡峭。棕櫚油基DAG油脂的晶體網(wǎng)絡(luò)結(jié)構(gòu)是由細(xì)小的針狀晶體聚集而成的,與其相應(yīng)原油相比,晶體尺寸更細(xì)小,網(wǎng)絡(luò)結(jié)構(gòu)更緊致,填充度較高。(3)1,3-PO,1,3-OO和1,3-PP的同質(zhì)多晶型均表現(xiàn)為β型,其滑動熔點(diǎn)分別為37.6℃、22.1℃和68.7℃。通過結(jié)晶和熔化DSC曲線構(gòu)建的動力學(xué)相圖均表明二元體系1,3-PO/1,3-OO和1,3-PP/1,3-PO存在共晶現(xiàn)象,1,3-PP/1,3-OO則表現(xiàn)為偏晶行為。1,3-PO/1,3-OO和1,3-PP/1,3-PO的液相邊界模擬分析結(jié)果表明,在1℃/min和10℃/min兩種冷卻速率條件下,當(dāng)0≤X_(1,3-PP)≤X_e時(shí),體系的非線性參數(shù)ρ均為負(fù)值,意味著異分子間的相互作用占優(yōu)勢,趨向于形成1,3-PO-1,3-OO和1,3-PP-1,3-PO體系。1,3-PO/1,3-OO,1,3-PP/1,3-OO和1,3-PP/1,3-PO的微觀晶體結(jié)構(gòu)的研究表明,添加的組分對其微觀晶體形態(tài)影響顯著,尤其是在接近共晶點(diǎn)附近尤為明顯。(4)與原油體系相比,二元體系PO-DAGE/POL-DAGE和PO-DAGE/PS-DAGE的相容性較得到了顯著的改善,并伴有微弱的共晶作用,熔化和結(jié)晶性質(zhì)差異極其顯著,富含DAG油脂的二元體系結(jié)晶速率更為迅速,且在結(jié)晶過程中無球形晶體生長,形成的晶體網(wǎng)絡(luò)結(jié)構(gòu)更為致密有序。三元體系PO-/POL-/RSO-DAGE、PO-/PS-/RSO-DAGE、PO-/PS-/POL-DAGE均具有良好的相容性。最后通過相容性、SFC以及同質(zhì)多晶型的研究確定了比較適用于典型焙烤起酥油的基料油配方分別為:PO-/POL-/RSO-DAGE(45:45:10)、PO-/PS-/POL-DAGE(45:10:45)、PO-/PS-/POL-DAGE(10:10:80)、PO-DAGE/POL-DAGE(90:10)、PO-DAGE/POL-DAGE(70:30)、PO-DAGE/PS-DAGE(90:10)。(5)在恒溫和波動溫度兩種條件下貯藏3個月,無論是PDAGE-起酥油還是其對照組以及市售起酥油的POV值和甘油酯組分均未發(fā)生明顯改變(P0.05)。與其相應(yīng)的原油對照組相比,PDAGE-起酥油A和B的SFC對溫度的敏感度明顯較低,而且硬度下降較為平緩。在貯藏期間,PDAGE-起酥油A和B粘彈性較為穩(wěn)定,對溫度和時(shí)間變化的敏感度較低,且變化幅度明顯較弱。恒溫5℃存儲時(shí),時(shí)間對PDAGE-起酥油A和B的焓值影響不顯著,恒溫貯藏溫度升高,時(shí)間對二者焓值影響相對顯著。波動溫度貯藏時(shí),時(shí)間對PDAGE-起酥油A和B的焓值影響比在恒溫時(shí)顯著,但是對溫度和時(shí)間的敏感程度均明顯弱于其對照A和對照B以及市售起酥油。PDAGE-起酥油A和PDAGE-起酥油B的晶型衍變速率比其相應(yīng)的對照A和B以及市售起酥油明顯緩慢,在貯藏3個月后,樣品依然存在一部分β′型晶體。而且在貯藏過程中富含DAG油脂的起酥油晶體的生長和遷移聚集過程較為緩慢,不及其棕櫚原油對照樣品明顯,且不易聚集生成較大的顆粒狀晶體或大脂肪塊。
[Abstract]:Diethylene glycerol (DAG) lipids not only have the physiological functions of reducing body weight and postprandial blood lipids, but also have unique physical and chemical properties, which have attracted much attention. Using these properties, DAG-rich fats can be processed into various types of plastic fat products with weight-reducing effect. Extracts (PMF), palm oil (PO), palm soft fat (POL) and low erucic acid rapeseed oil (RSO) were used to study the molecular composition, melting and crystallization properties, crystal morphology, rheological properties and texture characteristics of different palm oil-based DAG oils. The crystallization mechanism of palm oil-based DAG and the interaction between different DAG-rich oils were also studied. The main results are as follows: (1) Lipozyme TL IM was selected as the immobilized lipase for lipase immobilization. As a catalyst, glycerolysis was carried out in tert-butanol system. The addition of lipase was 5% (w/w) of substrate oil, and the reaction temperature was 70 ~C. The volume ratio of tert-butanol to substrate oil of palm oil was 4:1, the molar concentration ratio of substrate to glycerol was 1:2, the reaction time of PMF and PO glycerolysis was 36 h, PS and POL was 24 h, RSO was tert-butanol. The ratio of DAG to substrate oil was 3:1, the molar concentration ratio of substrate to glycerol was 1:3, and the reaction time was 36 h. Under these conditions, the conversion of TAG was higher and the content of DAG was higher. After purification by molecular distillation, the content of DAG in PS, PMF, PO, POL and RSO was 89.45%, 92.61%, 90.43%, 89.87%, 92.67% respectively. The composition of fatty acids remained unchanged, the content of each component remained unchanged, the sliding melting point increased, the plastic range widened, and the crystalline form changed from beta'-type to beta-type. The results of oscillatory rheology show that the | G * | and | delta curves of palm oil-based DAG oils reach equilibrium with a shorter time span and a steeper change trend. The network structure is composed of fine acicular crystals. Compared with the corresponding crude oil, the crystal size is smaller, the network structure is more compact, and the filling degree is higher. Phase diagrams show that the binary system 1,3-PO/1,3-OO and 1,3-PP/1,3-PO have eutectic phenomena, while 1,3-PP/1,3-OO exhibit monotectic behavior. The liquid-phase boundary simulation results of 1,3-PO/1,3-OO and 1,3-PP/1,3-PO show that the nonlinear parameters of the system are negative when the cooling rates are 0 < X_ (1,3-PP) < X_e at 1,3-PP/min and 10 < X_e. It means that the intermolecular interactions are predominant, and tend to form 1,3-PO-1,3-OO and 1,3-PP-1,3-PO systems. The compatibility of the binary system PO-DAGE/POL-DAGE and PO-DAGE/PS-DAGE was improved remarkably, accompanied by weak eutectic effect. The difference of melting and crystallization properties between the binary system was extremely significant. The binary system rich in DAG oil had a faster crystallization rate, and no spherical crystals grew during the crystallization process. The crystal network structure was more compact. The ternary systems PO-/POL-/RSO-DAGE, PO-/PS-/RSO-DAGE, PO-/PS-/POL-DAGE, PO-/PS-/POL-DAGE have good compatibility. Finally, through compatibility, SFC and homogeneous polymorphism, the formulations of base oils suitable for typical baking shortening are PO-/POL-/RSO-DAGE (45:45:10), PO-/PS-/POL-DAGE (45:10:45), PO-/PS-/POL-DAGE (1:1:45), PO-/PS-/POL-DAGE (1:1:1). PO-DAGE/POL-DAGE (90:10), PO-DAGE/POL-DAGE (70:30), PO-DAGE/PS-DAGE (90:10). (5) The POV value and glyceride composition of PDAGE-shortening, its control group and commercial shortening did not change significantly (P 0.05) after 3 months storage at constant and fluctuating temperatures. During storage, PDAGE-shortening A and B were more stable in viscoelasticity, less sensitive to temperature and time changes, and the range of change was significantly weaker. The effect of storage time on the enthalpy values of PDAGE-shortening A and B is more significant than that of isothermal storage, but the sensitivity to temperature and time is weaker than that of control A and control B, and the crystal type derivative ratio of PDAGE-shortening A and PDAGE-shortening B. The corresponding control A and B as well as the commercial butter were obviously slow. After 3 months storage, there were still some beta'-type crystals in the samples, and the growth, migration and aggregation process of the butter crystals rich in DAG oil during storage was slower than that of the palm crude oil, and it was not easy to aggregate into larger granules. Crystals or large fat blocks.
【學(xué)位授予單位】：江南大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TS221
，
本文編號：2233987
[Abstract]:Diethylene glycerol (DAG) lipids not only have the physiological functions of reducing body weight and postprandial blood lipids, but also have unique physical and chemical properties, which have attracted much attention. Using these properties, DAG-rich fats can be processed into various types of plastic fat products with weight-reducing effect. Extracts (PMF), palm oil (PO), palm soft fat (POL) and low erucic acid rapeseed oil (RSO) were used to study the molecular composition, melting and crystallization properties, crystal morphology, rheological properties and texture characteristics of different palm oil-based DAG oils. The crystallization mechanism of palm oil-based DAG and the interaction between different DAG-rich oils were also studied. The main results are as follows: (1) Lipozyme TL IM was selected as the immobilized lipase for lipase immobilization. As a catalyst, glycerolysis was carried out in tert-butanol system. The addition of lipase was 5% (w/w) of substrate oil, and the reaction temperature was 70 ~C. The volume ratio of tert-butanol to substrate oil of palm oil was 4:1, the molar concentration ratio of substrate to glycerol was 1:2, the reaction time of PMF and PO glycerolysis was 36 h, PS and POL was 24 h, RSO was tert-butanol. The ratio of DAG to substrate oil was 3:1, the molar concentration ratio of substrate to glycerol was 1:3, and the reaction time was 36 h. Under these conditions, the conversion of TAG was higher and the content of DAG was higher. After purification by molecular distillation, the content of DAG in PS, PMF, PO, POL and RSO was 89.45%, 92.61%, 90.43%, 89.87%, 92.67% respectively. The composition of fatty acids remained unchanged, the content of each component remained unchanged, the sliding melting point increased, the plastic range widened, and the crystalline form changed from beta'-type to beta-type. The results of oscillatory rheology show that the | G * | and | delta curves of palm oil-based DAG oils reach equilibrium with a shorter time span and a steeper change trend. The network structure is composed of fine acicular crystals. Compared with the corresponding crude oil, the crystal size is smaller, the network structure is more compact, and the filling degree is higher. Phase diagrams show that the binary system 1,3-PO/1,3-OO and 1,3-PP/1,3-PO have eutectic phenomena, while 1,3-PP/1,3-OO exhibit monotectic behavior. The liquid-phase boundary simulation results of 1,3-PO/1,3-OO and 1,3-PP/1,3-PO show that the nonlinear parameters of the system are negative when the cooling rates are 0 < X_ (1,3-PP) < X_e at 1,3-PP/min and 10 < X_e. It means that the intermolecular interactions are predominant, and tend to form 1,3-PO-1,3-OO and 1,3-PP-1,3-PO systems. The compatibility of the binary system PO-DAGE/POL-DAGE and PO-DAGE/PS-DAGE was improved remarkably, accompanied by weak eutectic effect. The difference of melting and crystallization properties between the binary system was extremely significant. The binary system rich in DAG oil had a faster crystallization rate, and no spherical crystals grew during the crystallization process. The crystal network structure was more compact. The ternary systems PO-/POL-/RSO-DAGE, PO-/PS-/RSO-DAGE, PO-/PS-/POL-DAGE, PO-/PS-/POL-DAGE have good compatibility. Finally, through compatibility, SFC and homogeneous polymorphism, the formulations of base oils suitable for typical baking shortening are PO-/POL-/RSO-DAGE (45:45:10), PO-/PS-/POL-DAGE (45:10:45), PO-/PS-/POL-DAGE (1:1:45), PO-/PS-/POL-DAGE (1:1:1). PO-DAGE/POL-DAGE (90:10), PO-DAGE/POL-DAGE (70:30), PO-DAGE/PS-DAGE (90:10). (5) The POV value and glyceride composition of PDAGE-shortening, its control group and commercial shortening did not change significantly (P 0.05) after 3 months storage at constant and fluctuating temperatures. During storage, PDAGE-shortening A and B were more stable in viscoelasticity, less sensitive to temperature and time changes, and the range of change was significantly weaker. The effect of storage time on the enthalpy values of PDAGE-shortening A and B is more significant than that of isothermal storage, but the sensitivity to temperature and time is weaker than that of control A and control B, and the crystal type derivative ratio of PDAGE-shortening A and PDAGE-shortening B. The corresponding control A and B as well as the commercial butter were obviously slow. After 3 months storage, there were still some beta'-type crystals in the samples, and the growth, migration and aggregation process of the butter crystals rich in DAG oil during storage was slower than that of the palm crude oil, and it was not easy to aggregate into larger granules. Crystals or large fat blocks.
【學(xué)位授予單位】：江南大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TS221
，
本文編號：2233987
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