Physical property improvement of fluid shortening using peanut oil-based diacylglycerols and their applications in sponge cake

Fluid shortening is an important ingredient in the production of sponge cake. Peanut oil with 0, 43% and 85% of diacylglycerol content was used as the base oil. Different emulsifiers, such as glycerol monostearate, soy lecithin and sucrose ester, and their respective amounts, were investigated. It was found that the addition of emulsifiers had a positive effect on water-absorbing capacity, air-absorbing capacity and viscosity of the oils. Glycerol monostearate was the preferred emulsifier for fluid shortening with a recommended addition of 1.5%. The effects of different diacylglycerol content on fluid shortening and their impact on sponge cake production was also investigated. The onset oxidation temperature of the oil could be increased from 253.21 ℃ for PO-TAG-based fluid shortening to 263.70 ℃ for PO-DAG85-based fluid shortening. And the increase in diacylglycerol content leading to a lower specific gravity of the batter, which was 1.06 g/mL, 1.02 g/mL and 0.98 g/mL prepared by PO-DAG, PO-DAG43 and PO-DAG85 shortening, respectively. The results showed that diacylglycerols can be used as base oils in fluid shortening to improve the crystal network and stability of fluid shortenings, thereby reducing the specific gravity of the batter and improving the structural properties of the cake. This will extend the potential applications of diacylglycerols and increase the variety of base oils available for fluid shortening preparation.

The in vitro digestion fates of diacylglycerol under different intestinal conditions:a potential lipid source for lipid indigestion patients

The in vitro digestion models mimicking the gastrointestinal(GI)tract of general population and lipid indigestion patients(with lower levels of bile salts or pancreatic lipase)were selected to investigate whether diacylglycerols(DAGs)are potential good lipid sources for these patients.Linseed oil-based DAG(LD)and linseed oil(LT)were selected.LD-based emulsion((83.74±1.23)%)had higher lipolysis degree than LT-based emulsion((74.47±1.16)%)when monitoring the GI tract of normal population as previously reported.Indigestion conditions seriously decreased the digestive degree of LT-based emulsion((40.23±2.48)%-(66.50±3.70)%)while showed less influence on LD-based emulsion((64.18±2.41)%-(81.85±3.45)%).As opposed to LT-based emulsion,LD-based emulsion exhibited preference for releasing unsaturated fatty acids(especially oleic acid andα-linolenic acid)due to their different glycerolipid compositions.LD-based emulsion showed potential for providing lipids and nutrients(including essential fatty acids)for lipid indigestion patients.

向日葵HaDGAT3基因的生物信息学和表达分析

利用生物信息学分析向日葵HaDGAT3编码蛋白,预测HaDGAT3编码蛋白是碱性和亲水性蛋白,二级结构以a螺旋为主(47.11%),亚细胞定位预测显示定位于细胞核。系统进化结果表明,HaDGAT3与小蓬草(Erigeron canadensis L.)DGAT3亲缘关系最近,序列相似性为68%。荧光定量PCR结果表明,HaDGAT3在向日葵各组织部位表达量表现为管状花>叶>种子,在茎、舌状花、根中未见表达。HaDGAT3在种子发育中后期(开花后22~37 d)表达量明显高于种子发育前期(开花后7~17 d),在开花后37 d最高。HaDGAT3基因表达量与种子油分和脂肪酸含量的相关性分析结果表明,HaDGAT3基因表达量与种子含油量呈显著正相关,推测HaDGAT3是与向日葵种子油分积累相关的重要基因。

Enzymatic preparation of mono-and diacylglycerols:A review

Monoacylglycerols(MAGs) and diacylglycerols(DAGs) are partial glycerides widely used in food industry. They are safe and non-toxic food emulsifiers, especially for MAGs. MAGs account for approximately 75% of the total emulsifiers in food industry worldwide. DAGs are recognized as functional cooking oils, they can suppress body fat accumulation and postprandial serum triacylglycerols(TAGs) level. The traditional production of MAGs and DAGs is based on the chemical method, which requires high reaction temperature usually up to 200–260 ℃. Such high temperature is not suitable for oil containing heat sensitive polyunsaturated fatty acids. Enzymatic approach has been received increasing attentions. Enzymatic production of partial glycerides to replace chemical processes has been in industry, particularly for DAGs production as the products have been claimed as a functional and nutritional oil. Enzyme technology for the processing of oils and fats has been moved to industry step by step and case by case during the last 20 years. More and more applications are particularly moving into bulky oils and fats processing. At the same time, the cost of enzymes as a commercial product is reducing steadily. This review summarized the recent 15 years advances on the the enzymatic preparation of MAGs and DAGs. The critical process parameters under different reaction routes were presented and emphasized. The reaction media not only increased the homogeneity of the reaction system, but also shifted the reaction equilibrium towards the target product generation, and this part was stated in detail. In addition, the patent evaluation was included, and the application of MAGs and DAGs was covered.

DAG和LML型结构脂质的热力学及煎炸应用特性研究

以功能性健康油脂甘油二酯(Diacylglycerol,DAG)和长-中-长(Long-Medium-Long,LML)型结构脂质为研究对象,大豆油为对照,研究50%DAG、90%DAG和LML型结构脂质的理化性质、热力学特性及煎炸应用特性。结果表明:50%DAG、90%DAG和LML型结构脂质与大豆油的黏度、密度和过氧化值(POV)基本保持一致,且三者的茴香胺值(AnV)均高于大豆油;与大豆油相比,50%DAG、90%DAG和LML型结构脂质中的甘油酯组成和脂肪酸组成仅有由结构与引入脂肪酸的不同而引起的差异,没有发生其他明显变化;50%DAG和90%DAG中的—OH及LML型结构脂质中的中链脂肪酸均会引起油脂失重起始温度降低,且50%DAG和90%DAG均会出现温度跨度较大的熔融曲线;50%DAG、90%DAG和LML型结构脂质在3470 cm^(-1)、1400~1100 cm^(-1)、722 cm^(-1)等处均出现由结构不同引起的吸收峰差异;连续高温煎炸后,50%DAG、90%DAG和LML型结构脂质的AV、POV、色度、水分含量、AnV和甘油酯组成及被煎炸土豆条的质构特性均体现出良好的稳定性。总之,50%DAG、90%DAG和LML型结构脂质在高温连续煎炸中能保持良好稳定性,满足国家煎炸用油标准,可作为日常煎炸用油使用。

DGAT1在腮腺腺淋巴瘤组织中的表达及其临床意义

目的 探讨二酰甘油O-酰基转移酶1 (DGAT1)在腮腺腺淋巴瘤组织中的表达及其临床意义。方法 回顾性分析山东大学齐鲁医院德州医院2012年1月—2021年12月腮腺腺淋巴瘤患者的临床资料,包括年龄、性别、单双侧发病、有无吸烟史、肿瘤位置、肿瘤直径和血脂水平。分别选取腮腺腺淋巴瘤、多形性腺瘤和正常腮腺的组织标本各5例,通过逆转录定量聚合酶链式反应(RT-qPCR)、蛋白质印迹法检测DGAT1在各组织中的表达情况。选取30例患者的病理切片免疫组织化学染色,检测DGAT1在腮腺腺淋巴瘤和正常腮腺组织中的表达差异。结果 111例腮腺腺淋巴瘤患者的年龄为25~84岁,平均年龄为(62.08±10.61)岁;男性92例(82.9%);有吸烟史者79例(71.2%),吸烟时间8~50年;单侧发病者103例(92.8%);肿瘤位于腮腺尾部者62例(55.9%);肿瘤直径为0.5~6.2 cm,平均直径为(2.998±1.083) cm,肿瘤直径为2.0~4.0 cm者76例(68.5%)。RT-qPCR、蛋白质印迹法结果显示DGAT1在腮腺腺淋巴瘤表达显著高于多形性腺瘤和正常腮腺组织。免疫组织化学结果显示DGAT1在腮腺腺淋巴瘤中高表达。结论 腮腺腺淋巴瘤多发于吸烟的中老年男性,病变位于腮腺后下极居多,肿瘤直径多为2.0~4.0 cm。DGAT1在腮腺腺淋巴瘤中高表达,显著高于正常腺体组织,提示DGAT1高表达与腮腺腺淋巴瘤发生密切相关,有望成为腮腺腺淋巴瘤诊断的新型标志物。

Safety Evaluation of Diacylglycerol Microemulsion in Rats/Mice

The objective of the present study was to evaluate potential adverse effects of diacylglycerol microemulsion （DAGM） in rats/mice. Acute safety evaluation was carried out by giving intragastrically with 20 mL 25% DAG kg-1 body weight of DAGM or water with two groups of mice. Chronic safety evaluation with 40 male and 40 female Sprague-Dawley rats was carried out by setting a control group and 3 different dose groups （n=10 male＋10 female） administered with DAGM with 6.7, 10 and 20 mL kg-1 body weight per day. Relevant parameters of liver and kidney function and biochemistry were determined by standard methods at end point. Acute toxicity study revealed the maximum tolerated dose （MTD） of DAGM was 20 mL kg-1 body weight in mice. No death was observed at the dose of 20 mL kg-1 body weight per day. Chronic safety evaluation did not show significant changes on hematological, histopathologic, clinical, and biochemical tests when administered at levels of 6.7, 10 and 20 mL kg-1 body weight per day to rats for 30 d. No significant body weight changes were observed in different dosages in both male and female rats. Our results suggested that acute and chronic adverse effects were not observed in histology and clinical parameters in both mice and rats. The results suggested that DAGM is safe at the experimental levels.

Pharmacological inhibition of diacylglycerol acyltransferase-1 and insights into postprandial gut peptide secretion

AIM To examine the role that enzyme Acyl-CoA:diacylglycerol acyltransferase-1(DGAT1) plays in postprandial gut peptide secretion and signaling.METHODS The standard experimental paradigm utilized to evaluate the incretin response was a lipid challenge.Following a lipid challenge,plasma was collected via cardiac puncture at each time point from a cohort of 5-8 mice per group from baseline at time zero to 10 h.Incretin hormones [glucagon like peptide-1(GLP-1),peptide tyrosine-tyrosine(PYY) and glucose dependent insulinotropic polypeptide(GIP)] were then quantitated.The impact of pharmacological inhibition of DGAT1 on the incretin effect was evaluated in WT mice.Additionally,a comparison of loss of DGAT1 function either by genetic ablation or pharmacological inhibition.To further elucidate the pathways and mechanisms involved in the incretin response to DGAT1 inhibition,other interventions [inhibitors of dipeptidyl peptidase-IV(sitagliptin),pancreatic lipase(Orlistat),GPR119 knockout mice] were evaluated.RESULTS DGAT1 deficient mice and wildtype C57/BL6J mice werelipid challenged and levels of both active and total GLP-1 in the plasma were increased.This response was further augmented with DGAT1 inhibitor PF-04620110 treated wildtype mice.Furthermore,PF-04620110 was able to dose responsively increase GLP-1 and PYY,but blunt GIP at all doses of PF-04620110 during lipid challenge.Combination treatment of PF-04620110 and Sitagliptin in wildtype mice during a lipid challenge synergistically enhanced postprandial levels of active GLP-1.In contrast,in a combination study with Orlistat,the ability of PF-04620110 to elicit an enhanced incretin response was abrogated.To further explore this observation,GPR119 knockout mice were evaluated.In response to a lipid challenge,GPR119 knockout mice exhibited no increase in active or total GLP-1 and PYY.However,PF-04620110 was able to increase total GLP-1 and PYY in GPR119 knockout mice as compared to vehicle treated wildtype mice.CONCLUSION Collectively,these data provide some insight into the mechanism by which inhibition of DGAT1 enhances intestinal hormone release.

Perspectives on diacylglycerol-induced improvement of insulin sensitivity in type 2 diabetes

Diacylglycerol(DAG)-based edible oils have attracted increasing research interest owing to their healthpromoting properties.Recent animal and human studies showed that an increased 1,2-DAG content in the liver and skeletal muscle may cause insulin resistance.However,earlier studies using animal models or humans reported that dietary DAGs with a 1,2-DAGs to 1,3-D AGs ratio of approximately 3:7 could improve insulin sensitivity in type 2 diabetic patients.This conflict raises the question of whether there is a link between the ingested DAGs and endogenous DAGs during their metabolism.To make a contribution to this field,this review provides an overview of the metabolic pathways of ingested DAGs and biological roles of DAGs(ingested and endogenous)in the change of insulin sensitivity.Accordingly,strategies for further investigations on the metabolism of DAGs are proposed.

Increased Seizure Susceptibility in a Mouse with Diacylglycerol Kinase <i>β</i>Deficiency

Diacylglycerol kinase (DGK) is an enzyme that converts diacylglycerol to phosphatidic acid. Several DGK isoforms have been implicated in the pathogenesis of seizure, but the role of DGKβ in seizure is unknown. In the present study, we investigated the involvement of DGKβ in seizure using DGKβ knockout (KO) mice. Seizures were more severe in DGKβ KO mice than in wild-type (WT) mice after pentylenetetrazol (PTZ) treatment and after kainic acid treatment, but there were no differences in latency to seizure. The expression levels of DGKβ in the hippocampal CA1, CA3, or DG areas did not differ between PTZ (60 mg/kg) treatment and saline treatment. There were fewer parvalbumin-positive interneurons in the hippocampal CA3 area in DGKβ KO mice than in control WT mice, which might partly account for the increased seizure susceptibility displayed by DGKβ KO mice. These results suggest that DGKβ may play a pivotal role in the development of the relevant interneurons, and that on inherent deficiency of DGKβ increases the animal’s sensitivity to seizure-inducing stimuli.

Diacylglycerol-enriched Oil from Hydrolysis of Soybean Oil with Rhizopus Oryzae Lipase Against High-fat Diet-induced Obesity in Mice

The present work aimed to investigate the impact of intake of diacylglycerol(DAG) from soybean oil on the reduction of fat accumulation and the long-term effects of dietary intake of DAG and triacylglycerol(TAG) with similar fatty acid compositions on the development of obesity. Kuming mice were used to compare the effects of low-dose TAG(2.5 g/kg BW), low-dose DAG(2.5 g/kg BW), high-dose TAG(10 g/kg BW), and high-dose DAG(10 g/kg BW) on the induced obesity. The results showed that the body weight and serum triglyceride concentration decreased significantly in both DAG-treated groups compared with the TAG-treated groups(P < 0.01, P < 0.05, respectively). However, the plasma glucose concentration was significantly lower in the DAG-treated groups than the TAG-treated groups(P < 0.05); the weight and morphology of the liver and kidney in DAG-treated groups were similar to those in the control group, there were no significant differences within each group. The present results indicated the anti-obesity and lipid-lowering effects of dietary DAG oil in mice and its potential use as a functional food for humans.

Physicochemical Properties, Baking Performance and Sensory Evaluation of Bakery Shortening Enriched with Diacylglycerol

The purpose of this study was to investigate the suitability of palm diacylglycerol （PDAG）-enriched formulations for bakery shortening. Three types of palm diacylglycerol olein （PDAGOL） at different degree of unsaturation （PDAGOL1V56, PDAGOLIV62 and PDAGOLIV64） were used as main raw materials blended with palm stearin （PS）. The blending compositions ranged from 30% to 70% of PDAGOLIV56/PS, PDAGOLIV62/PS and PDAGOLIV64/PS, respectively. The physicochemical properties of all binary blend systems were characterized for fatty acid composition （FAC）, slip melting point （SMP） and solid fat content （SFC）. The selected bakery shortening formulations were further characterised for polymorphic form of fat crystal and thermal behavior, using X-ray diffractometer （XRD） and differential scanning calorimetry （DSC）. Bakery shortening enriched with diacylglycerol that were produced from 40DS56 （40% PDAGOLIV56/60% PS）, 40DS62 （40% PDAGOL1V62/60% PS） and 40DS64 （40% PDAGOLIV64/60% PS） had 45%-50% unsaturated fatty acid and crystallized in β ＋ β polymorphs; thus they were suitable for shortening system. Based on product＇s baking performance, it could be found that all Madeira cakes prepared from bakery shortening enriched with diacylglycerol had higher specific cake volume as compared to commercial shortening （CS）. In customer acceptance test, Madeira cake made from 40DS56 shortening scored the highest rating for all sensory attributes, including overall customer acceptability. It had given an indication that 40DS56 shortening formulation was the most suitable fat blends to be used as bakery shortening.

Comparison of Oxidative Stability of Monogalactosyl Diacylglycerol, Digalactosyl Diacylglycerol, and Triacylglycerol Containing Polyunsaturated Fatty Acids

Oxidative stability of three different lipid classes, namely, monogalactosyl diacylglycerol (MGDG) and digalactosyl diacylglycerol (DGDG) from spinach and edible brown seaweed (Akamoku) and triacylglycerol (TAG) of linseed oil was compared. Analysis of oxygen consumption and polyunsaturated fatty acid (PUFA) composition demonstrated that spinach DGDG had the highest oxidative stability, followed by Akamoku DGDG, Akamoku MGDG, spinach MGDG, and linseed TAG. These results disagree with the order of oxidative stability expected from the average number of bis-allylic positions of each lipid. Additionally, DGDG constituents of both spinach and Akamoku showed higher oxidative stability than their MGDG constituents. The unusual oxidative stability of MGDG and DGDG could be conferred by the protection of bis-allylic positions of the PUFA against oxidative attack by the galactosyl moiety of the GL.

Characterization of a broad substrates specificity acyl-CoA:diacylglycerol acyltransferase 1 from the green tide alga Ulva prolifera

Triacylglycerols(triglycerides,TAGs)are the major carbon and energy storage forms in various organisms,and important components of cellular membranes and signaling molecules;they have essential functions in multiple physiological processes and stress regulation.Acyl-CoA:diacylglycerol acyltransferase(DGAT)catalyzes the final and only committed acylation step in the synthesis of TAGs in eukaryotes.The present work identified and isolated a novel gene,UpDGAT1,from the green tide alga Ulva prolifera.The activity of UpDGAT1 was confirmed by heterologous expression in a Saccharomyces cerevisiae TAG-deficient quadruple mutant.Results of thin-layer chromatography and BODIPY staining indicated that UpDGAT1 was able to restore TAG synthesis and lipid body formation in the yeast.Lipid analysis of yeast cells revealed that UpDGAT1 showed broad substrate specificity,accepting saturated as well as mono-and polyunsaturated acyl-CoAs as substrates.High salinity and high temperature stresses increased UpDGAT1 expression and TAG accumulation in U.prolifera.The present study provides clues to the functions of UpDGAT1 in TAG accumulation in,and stress adaptation of,U.prolifera.

畜禽动物油甘油二酯的酶法制备及应用研究进展

1,3-甘油二酯(diacylglycerol,DAG)是公认的安全食品,在人体中的代谢途径不同于甘油三酯,具有提高人体新陈代谢水平以及预防肥胖和心血管疾病等功效。然而,天然DAG在食用油中的质量分数不及10%,因此,近年来高纯度DAG的制备受到了广泛关注。与化学法相比,酶法因绿色、安全、选择性高等优点成为了油脂工业制备DAG的首选。畜禽动物油具有特殊的风味和一定的营养价值,但其高饱和脂肪、高胆固醇和高熔点等理化特征致使其在食品工业的利用受到了极大限制。鉴于此,合成畜禽动物油DAG成为了实现畜禽动物油高值化利用的一种有效途径。本文综述了酶法制备畜禽动物油DAG的研究现状及其潜在的应用价值,以期为畜禽动物油DAG的酶法加工及高值化利用提供一定的思路。

Gomparative analysis of DGAT3（diacylglycerol acyltraiisferase 3） gene from different peanut （Arachis hypogaea L.） varieties

Cultivated peanut is one of the primary sources of vegetable oil and protein in developing countries. DG〉A73 family in peanut cotyledons has no membrane-bound regions suggesting that cytosol is one of the sites for triacylglycerol （TAG） biosynthesis in oilseeds. According to functional annotation and classification of 5 cDNA libraries, 12 unigenes were found with relation of peanut DGAT3 in different organs. Three clones of unigenes, OCP- contig168t OCPcontig12101-3 and OCPcontigl2388-1 were selected for sequencing. Full length sequence of DGAT3 was obtained, showing over 98% sequence similarity with peanut DGAT3 gene AY875644 or EU183333. Upon cluster analysis, DGAT3 of 40 culti- vars were divided into 3 types, namely AhDGATS-1, AhDGAT3-2 and AhDGAT3-3. Coding regions are 1023, 1038 and 1026 base pairs which encoded proteins with 340-, 345- and 341-amino acids, respectively. DGAT3-3 might be a novel gene type among the DGAT3 family which provides great help for studying DGAT3 gene evolution in peanut.

超高压处理芝麻蛋白制备甘油二酯乳液及其消化和氧化特性研究

植物油粕中所含蛋白的溶解性较差,难以直接作为乳化剂用于食品乳液体系.本文通过超高压处理,改善芝麻蛋白的功能特性,用于以甘油二酯为油相的O/W乳液体系,研究其体外消化和氧化特性.结果发现,在不同消化阶段,300 MPa超高压处理芝麻蛋白所得两种乳液的粒径均较小,脂肪酸释放率较高.经14 d储存后,初级、次级油脂氧化产物的含量均升高,300 MPa处理芝麻蛋白制备的乳液较易氧化.同甘油三酯乳液相比,甘油二酯乳液体系呈现更高的消化和氧化特性.

固定化脂肪酶Lipase G 50催化合成甘油二酯的研究

以D380、CAT600、AB-8三种大孔树脂为载体,采用物理吸附法,对偏甘油酯脂肪酶LipaseG50进行了固定化,并利用其催化脂肪酸和甘油酯化合成甘油二酯。结果表明,采用D380固定的脂肪酶酶活最高,用此固定化酶催化反应的最佳条件为:甘油和脂肪酸的摩尔比5∶1,固定化酶酶加量为底物总质量的7.5%,反应温度35℃,在此条件下经过96h的反应,酯化率为76.39%,甘油二酯的含量为43.89%,没有甘油三酯生成。固定化酶重复使用5个批次后酯化率可达65.76%,甘油二酯的含量达到38.45%,具有良好的重复使用稳定性。

Lipid phosphorylation by a diacylglycerol kinase suppresses ABA biosynthesis to regulate plant stress responses

Lipid phosphorylation by diacylglycerol kinase(DGK)that produces phosphatidic acid(PA)plays important roles in various biological processes,including stress responses,but the underlying mechanisms remain elusive.Here,we show that DGK5 and its lipid product PA suppress ABA biosynthesis by interacting withABA-DEFICIENT2(ABA2),a key ABA biosynthesis enzyme,to negatively modulate plant responseto abiotic stress tested in Arabidopsis thaliana.Loss of DGK5 function rendered plants less damaged,whereas overexpression(OE)of DGK5 enhanced plant damage to water and salt stress.The dgk5 mutant plants exhibited decreased total cellular and nuclear levels of PA with increased levels of diacylglycerol,whereas DGK5-OE plants displayed the opposite effect.Interestingly,we found that both DGK5 and PA bind to the ABA-synthesizing enzyme ABA2 and suppress its enzymatic activity.Consistently,the dgk5 mutant plants exhibited increased levels of ABA,while DGK5-OE plants showed reduced ABA levels.In addition,we showed that both DGK5 and ABA2 are detected in and outside the nuclei,and loss of DGK5 function decreased the nuclear association of ABA2.We found that both DGK5 activity and PA promote nuclear association of ABA2.Taken together,these results indicate that both DGK5 and PA interact with ABA2 to inhibit its enzymatic activity and promote its nuclear sequestration,thereby sup-pressing ABA production in response to abiotic stress.Our study reveals a sophisticated mechanism by which DGK5 and PA regulate plant stress responses.

甘油二酯对面团特性及面包品质的影响

为探究甘油二酯对面团特性和面包品质的影响,通过质构、扫描电子显微镜、X射线衍射、傅里叶变换红外光谱等技术研究分析了甘油二酯对面团质构特性、发酵特性、微观结构,以及对面包纹理结构和感官特性的影响。结果表明,70%甘油二酯会提高面团的硬度和湿面筋含量,并且面团的发酵体积增大4.02%,发酵速度加快20 min。微观结构观察发现,面团的面筋蛋白的断面更光滑。X射线衍射和傅里叶变换红外光谱检测表明,淀粉结构不变,相对结晶度下降,面团蛋白质的二级结构α-螺旋、β-转角占比分别下降4.21%、2.47%;70%甘油二酯面包的烘焙损失减少、脂肪含量降低,硬度增加,面包芯的黄度增加。纹理结构中,孔密度增加22.50个/cm^(2),孔占比增加19.71%。同时,面包的感官评价总分没有显著性差异。综合考虑,甘油二酯部分替代甘油三酯制备面包得到低脂面包的同时不会显著降低面包的品质。研究结果可为甘油二酯在面包中的应用提供一定的参考。