鲜食糯玉米贮藏过程中可溶性糖含量变化的研究

以垦糯1号为研究对象,利用高效液相色谱法测定不同贮藏温度(5℃、15℃、25℃)下的鲜食玉米在48h内可溶性糖含量的变化。结果表明,可溶性糖含量随着温度的升高、贮藏时间的延长呈下降趋势,且下降主要是由蔗糖引起的(5℃下降97%、15℃下降98%、25℃下降94%);低温可以延缓可溶性糖含量的下降,与15℃和25℃相比,5℃条件下可溶性糖含量降低幅度最小(5℃下降34%、15℃下降49%、25℃下降55%),是鲜食玉米贮藏的理想温度。     

降温方法对鸭梨冰温贮藏过程中可溶性糖的影响

该文通过缓慢降温和急速降温方法对早、中、晚3种不同成熟度的鸭梨进行处理并于冰温（0℃～1℃）下贮藏,应用高效液相色谱法（high performance liquid chromatography,HPLC）对鸭梨中可溶性糖含量进行测定。结果表明,鸭梨果肉和果皮的可溶性糖由果糖、葡萄糖和蔗糖组成,果糖含量最多,果肉中果糖含量高于果皮。鸭梨在冰温贮藏过程中果肉、果皮的果糖、葡萄糖和蔗糖含量均呈现下降趋势。早采和中采缓慢降温处理果的可溶性糖含量普遍高于急速降温处理果,到贮藏末期,中采缓慢降温处理果可溶性糖含量适中。因此,中采鸭梨结合缓慢降温能够更好地保持果实中可溶性糖含量和鸭梨的品质。     

液相色谱示差折光法测定酒中的总糖和还原糖

目的建立高效液相色谱-示差折光检测法(high performance liquid chromatogram-refractive index detection method,HPLC-RID)测定酒的总糖和还原糖的分析方法。方法根据不同酒的类别和含糖量进行其相应倍数的稀释,过滤后利用HPLC-RID法测定酒样中的4种糖,其总和为其总糖量,而果糖、葡萄糖和麦芽糖的含量之和,为该酒样还原糖量。结果本方法在15 min内完成4种目标化合物的分离分析。酒样的4种糖在1、2、4 g/L添加水平的回收率为94.1%~99.9%,相对标准偏差最高为2.34%,方法检出限约为0.1 g/L,定量限约为0.4 g/L。结论该方法快速、简便、准确,适用于大多数酒类样品的总糖与还原糖测定。     

鲜玉米中可溶性糖含量的测定

采用高效液相色谱法对鲜玉米中可溶性糖含量进行检测。色谱柱为Agilent Zorbax carbohydrate柱(4.6mm×250mm,5μm),流动相为75%乙腈,柱温25℃,流速1mL/min。相关系数r在0.99839～0.99995(n=5)之间;精密度实验RSD为0.90%～3.80%(n=5);平均回收率在95.28%～101.02%之间。该方法准确、可靠,可以快速准确的对鲜玉米中可溶性糖进行定性定量分析。     

基于不同检测器高效液相色谱法测定食品中糖醇的研究

分析比较了口香糖、饮料样品中3种糖醇的2种测定方法。样品经水直接提取后一分为二,一份用配有示差折光检测器的高效液相色谱法检测,另一份用配有蒸发光散射检测器的高效液相色谱法检测。高效液相色谱法—示差折光检测法(HPLC-DRID)测定的木糖醇、山梨醇和麦芽糖醇的检出限(RSN=3)均为0.037 5g/100g,相关系数为0.999 21～0.999 29,加标回收率为91.5%～97.3%;高效液相色谱法—蒸发光散射检测法(HPLC-ELSD)测定的木糖醇、山梨醇和麦芽糖醇的检出限(RSN=3)为0.009 5～0.027 5g/100g,相关系数为0.999 3～0.999 6,加标回收率为91.2%～96.3%。结果表明:2种高效液相色谱法均能满足样品中3种糖醇的检测要求,而高效液相色谱法—蒸发光散射检测法的灵敏度要明显优于高效液相色谱法—示差折光检测法的,更适用于糖醇含量低的样品检测。     

软饮料中糖的测定

应用高效液相色谱法测定了国外8种软饮料中的果糖、葡萄糖、蔗糖、麦芽糖和异麦芽糖的含量。测定时，将折光检测器与质量检测器串接联用，以折光检测器测定含量高的糖，以质量检测器测定含量低的糖。异麦芽糖的检出可以证实该软饮料以玉米糖浆作甜味剂。     

浓缩果汁中游离糖的组成分析

建立高效液相色谱分析浓缩果汁中游离糖的成分及含量的方法。该方法采用AgilentZORBAX Carbohydrate色谱柱(4.6mm×150mm,5μm)进行分离,以乙腈-水(75∶25)为流动相进行等度洗脱,示差折光检测器检测浓缩果汁中游离糖的成分及含量。结果表明,在0.5mg/mL^20mg/mL范围内,木糖、果糖、葡萄糖、蔗糖、麦芽糖和乳糖的色谱峰面积与其质量浓度呈良好的线性关系(R2>0.9990),相对标准偏差为0.77%~4.54%,加标回收率为87.20%~105.22%。     

基于高效液相色谱法分析不同品种马铃薯中可溶性糖含量

建立一种对不同品种马铃薯中4种可溶性糖含量进行测定分析的方法,明确山西省17种马铃薯中可溶性糖的含量,以期为山西省马铃薯的加工利用提供理论依据。结果表明：在色谱柱为Zorbax Carbohydrate（4.6 mm×250 mm,5 μm）,流动相为乙腈和水（70∶30,体积比）,流速 0.9 mL/min,进样量 20 μL,柱温 35 ℃的条件下这 4 种可溶性糖在15 min内达到良好的分离。其标准曲线的相关系数均大于0.999,且重复率、稳定性、精密度、回收率的相对标准偏差（relative standard deviation,RSD）均在5%以内,说明该测定方法良好。17种马铃薯可溶性糖含量为370.95 mg/100 g～4 497.24 mg/100 g,还原糖含量为 63.09 mg/100 g～2 727.03 mg/100 g,果糖含量为 63.09 mg/100 g～1 272.67 mg/100 g,葡萄糖含量为 33.11 mg/100 g～1 409.66 mg/100 g,麦芽糖含量为 40.29 mg/100 g～147.28 mg/100 g,蔗糖含量为 25.11 mg/100 g～1 770.21 mg/100 g。不同品种马铃薯中可溶性糖组分相似,但其含量差异较大。     

HPLC-RID法测定蜂蜜中果糖、葡萄糖、蔗糖、麦芽糖及乳糖含量

建立了高效液相色谱-示差折光检测法(High Performance Liquid Chromatography Differential Refractive Detector,HPLC-RID)测定蜂蜜中果糖、葡萄糖、蔗糖、麦芽糖及乳糖5种还原糖含量的分析方法.蜂蜜试样用水提取,摇匀过滤后,经Kromasil 10...     

高效液相色谱法测定烟草及烟草制品中的三种水溶性糖

建立了高效液相色谱(HPLC)/示差折光检测器(RID)测定烟草和烟草制品中葡萄糖、果糖和蔗糖的方法。样品用0.01 mol/L 氢氧化钠溶液振荡提取60 min,以高度交联的铅型磺化苯乙烯-二乙烯苯(SDVB)树脂为填料的阳离子交换色谱柱为分离柱,用纯水作流动相进行等梯度洗脱,外标法定量。方法线性良好,相关系数均大于0.999。方法回收率98.9%～101.8%,精密度0.44%～0.90%。方法测定值与离子色谱法的检定结果一致。方法适用于各种烟草和烟草制品中葡萄糖、果糖和蔗糖的分析测定。     

Changes in inulin and soluble sugar concentration in artichokes (Cynara scolymus L.) during storage

BACKGROUND: The artichoke (Cynara scolymus L.) accumulates about 50–70 g kg^?1 of its fresh weight as inulin‐type fructan. Inulin fermentation increases gas production and thereby provokes intestinal discomfort in some people. The present research focuses on the changes in carbohydrate composition occurring in artichoke heads during storage under different conditions (18 °C, 4 °C and 4 °C under polypropylene film packing). RESULTS: Carbohydrate content and composition were determined by anion‐exchange high‐performance liquid chromatography with pulsed amperometric detection. Storage time caused a decrease in inulin content and an average degree of polymerization, accompanied by an increase of free fructose and sucrose due to depolymerization of inulin. CONCLUSION: Higher‐temperature storage and storage without packing induce strong carbohydrate changes. Thereby, eating stored artichoke leads to consumption of an inulin quantity that does not provoke unwanted symptoms related to gas production but sufficient to have a prebiotic effect. Copyright © 2010 Society of Chemical Industry     

不同贮藏时间的莲子蛋白质提取及其理化特性研究

为研究莲子在陈化过程中蛋白质变化规律,本文首先通过正交实验对莲子蛋白质提取条件进行优化,再利用优化的条件,分别以不同贮藏时间的莲子为材料,提取获得莲子蛋白。采用SDS-PAGE电泳和氨基酸分析仪,研究提取蛋白质的相对分子量（Mr）组成及氨基酸组成。结果表明:莲子蛋白的优化提取条件为:p H11,料液比1∶30,提取时间2h,提取率达60.11%;随着贮藏时间的增加,莲子蛋白组成发生了一定变化,Mr在26⁴3ku的蛋白质含量逐渐变少;当年莲子蛋白的总氨基酸含量最高,但随着陈化过程的进行,含硫氨基酸中蛋氨酸含量下降。贮藏过程中莲子蛋白质结构等的变化是莲子陈化的主要原因之一。      

Effects of blanching and storage conditions on soluble sugar contents in vegetable soybean

Vegetable soybean is becoming increasingly popular in the U.S. because of its rich source of isoflavones, folic acid, and other nutrients. The objective of this study was to investigate various blanching and storage conditions in order to identify the proper post-harvest management strategy in preserving sugar composition of vegetable soybean during storage. Fresh soybean pods of two vegetable soybean genotypes were stored at 4 °C for 30 days or 25 °C for 8-12 days in fresh air or nitrogen atmosphere. Shelled seeds and intact pods were blanched in boiling water or steamed at 100 °C for 10 min. All blanched soybean was stored at −20 °C and sampled monthly for 6 months for sugar analysis. Glucose, fructose and sucrose decreased gradually in fresh soybean when stored at 4 °C in air or nitrogen atmosphere for 28 days. Soybean stored at 25 °C in open air showed a rapid decrease of sucrose in the first 24 h, and then followed by a gradual increase; whereas oligosaccharides accumulated significantly during storage. Significant degradation in all sugars was found in soybean stored in nitrogen atmosphere at 25 °C. Soluble sugars decreased from leaching during the water blanching and cooling treatment of vegetable soybean seeds. Steam blanching and the presence of pod effectively retained soluble sugars in vegetable soybean during thermal treatment.     

冻干甜椒贮藏过程中抗坏血酸及还原糖的变化

以冻干甜椒为材料,研究其在不同贮藏温度下抗坏血酸及还原糖含量的变化,揭示其品质变化的情况。分别采用斐林试剂比色法、固蓝盐B分光光度法测定抗坏血酸及还原糖的含量。结果表明,在贮藏期间,冻干甜椒中的抗坏血酸和还原糖含量逐渐减少,并且随储藏温度上升减少的速率增大。     

冷藏条件下带蓬鲜莲优势腐败菌鉴定及其消长规律研究

通过稀释平板法分离4℃条件贮藏18d的带蓬鲜莲腐败菌,提取筛选菌株DNA后进行PCR扩增,采用细菌16SrDNA菌种鉴定法对优势腐败菌进行鉴定,并分析其4℃冷藏过程中的消长规律。结果表明,带蓬鲜莲4℃冷藏过程中的优势腐败菌主要为分散泛菌(Pantoea dispersa)、表皮葡萄球菌(Staphylococcus epidermidis)、巴氏葡萄球菌(Staphylococcus pasteuri)、成团泛菌(Pantoea agglomerans)。且4℃贮藏期间,分散泛菌、表皮葡萄球菌、巴氏葡萄球菌的变化趋势大体相同,适应期后呈增长趋势,成团泛菌变化规律不明显。     

莲藕贮藏期间褐变生理的比较研究

莲藕是我国出口创汇的重要蔬菜之一,而褐变是莲藕贮藏和加工过程中限制其品质的关键问题.研究莲藕贮藏期间不同温度条件下可溶性蛋白质、还原糖等褐变相关成分,以及多酚氧化酶活性、呼吸强度等生理生化指标,从各指标的变化规律出发,探讨两类指标与褐变的相互关系.研究结果表明:莲藕采后贮藏期间,褐变度和PPO活性均呈上升趋势,可溶性蛋白质含量呈先上升后下降的趋势,还原糖含量在不同温度下变化差异显著.与室温贮藏相比,冷藏条件下的莲藕褐变度和PPO活性较低,而可溶性蛋白质和还原糖含量较高.室温和冷藏贮藏下莲藕的呼吸强度高峰分别出现在采后的第4天和第15天.莲藕褐变度与PPO活性之间、还原糖含量与呼吸强度之间存在很大的相关性.     

Nutritional composition of Zizyphus lotus L. seeds

BACKGROUND: Zizyphus lotus seeds are an unutilized source of vegetable oil and protein and nothing has been reported on their physicochemical characteristics which would indicate the potential uses of these seeds. RESULTS: The percentage composition of the Zizyphus lotus seeds is (on a dry‐weight basis): ash 1.05%, oil 32.92%, protein 19.11%, total carbohydrate 40.87% and moisture 6.05%. Calcium, potassium and magnesium constitute the major minerals of Zizyphus lotus seeds. The seed proteins are rich in threonine, glutamic acid, leucine, arginine and aspartic acid (26.73%, 17.28%, 13.11%, 9.47% and 7.76%, respectively). The main fatty acids of the oil are oleic (61.93%), linoleic (18.31%) and palmitic (9.14%) acids. Glycerol trioleate (OOO; O: oleic acid) was the most abundant triacylglycerol, representing 26.48% of the total triacyglycerols. β‐Tocopherol was the major tocopherol (130.47 mg 100 g^?1). This oil was rich in Δ7‐campestrol and β‐sitosterol (147.82 and 82.10 mg 100 g^?1 oil), respectively. CONCLUSION: Zizyphus lotus seeds are rich in fat and protein which are of potential industrial significance. In addition, Zizyphus lotus L. seed oil contained many bioactive compounds. This fact is of great economic interest owing to several applications of Zizyphus lotus L. seeds in the food, cosmetics and medicinal industries. Copyright © 2011 Society of Chemical Industry     

不同品种莲子对纯莲蓉馅料加工品质影响作用的研究

以湘莲、泰莲、野生湖莲、红莲为研究对象,选取吸水率、膨胀度分析评判莲子颗粒在糊化过程中的吸水润涨特性;选取感官、比容和油水析出率分析评判由莲子制作出的纯莲蓉馅料在4℃冷藏存放1个月后的品质稳定性,并试图探讨它们之间的相关性用于传统馅料企业的生产实践中.结果表明:吸水率高、膨胀度大的湘莲加工出的馅料质地细腻、油润嫩滑,比...     

莲藕圆子及低脂藕片加工与保藏

研究了莲藕圆子和低脂藕片的水分含量、水分活度、脂肪含量以及贮藏过程中制品的脂肪氧化值.结果表明:油炸莲藕圆子及低脂藕片的水分活度都在0.9～0.94之间,脂肪含量在22%以下,且低脂藕片的脂肪含量较一般油炸制品的低20%左右.复合铝箔袋包装能减缓脂肪的氧化.上述制品的保鲜期以二个月较为适宜.     

Kinetic studies on soluble sugar profile in rice during storage: Derivation using the Laplace transform

Soluble sugar is an important parameter to evaluate rice quality during storage. In this study, the changes of soluble sugars (fructose, glucose, maltose and sucrose) in rice during 11 months of storage at 0 °C, 10 °C and room temperature (25 °C) were studied. Laplace transform was applied to solve the models expressed as differential equations based on kinetic changes of soluble sugars during long-term storage. Results showed that the contents of sucrose and maltose in rice decreased whereas fructose and glucose increased over storage time. The soluble sugars in rice showed the best fit to a first-order kinetic model. Furthermore, the rate constants of the soluble sugars at 0 °C were lower than those at 10 °C and room temperature, indicating temperature affected the inter-conversion and degradation of the four soluble sugars, and storage at 0 °C could better delay changes of these sugars in rice during storage.Industrial relevanceKinetic studies on soluble sugars in rice during storage are pretty meaningful due to the complexity of inter-conversion and degradation reactions of the sugars. The present work showed that the developed kinetic model provided a better understanding of the mechanisms of these reactions, and could be used to predict the content changes of soluble sugars in rice during storage.