皮裸燕麦胚乳淀粉形态结构及理化性质的比较

燕麦作为血糖生成指数较低的食品,被广泛应用于食品、医药工业。为比较皮、裸燕麦胚乳淀粉理化性质的差异,探究皮、裸燕麦在食品等加工利用方面的不同,以2个裸燕麦品种(白燕2号,坝燕18)以及2个皮燕麦品种(蒙燕1号,塔娜)为材料,通过扫描电镜观察燕麦胚乳淀粉颗粒的形态,采用X-射线衍射分析(XRD)、傅里叶变换远红外光谱、以及¹³C固体核磁共振等方法研究淀粉的理化性质,同时测定其支链淀粉链长和淀粉的消化速率。研究结果表明,燕麦胚乳中淀粉同时以复粒淀粉和单颗粒淀粉形式存在,复粒淀粉在淀粉提取中易破裂,形成不规则的多面体颗粒,粒径多在5～8μm。4个燕麦品种胚乳的淀粉均为A型晶体,但膨胀势和溶解度存在差异,裸燕麦坝燕18膨胀势最高,溶解度最低。皮、裸燕麦在淀粉晶体结构方面存在差异,皮燕麦淀粉较裸燕麦有更高的结晶度和表层有序度,裸燕麦淀粉无定形比例和表观直链淀粉含量更高,导致皮、裸燕麦在食品加工方面的差异。皮、裸燕麦支链淀粉链长分布不同,裸燕麦的长支链分布少,慢速消化淀粉(SDS)含量高,尤其坝燕18的SDS含量明显高于其他三个品种,更适合作为减肥食品。     

芒果采后炭疽菌Colletotrichum asianum鉴定及生物学特性研究

采用组织块分离法从采后发病芒果果肉中分离病原菌,通过形态学观察、r DNA-ITS序列和系统发育树分析对其进行鉴定,并初步研究其生物学特性。结果表明:从发病芒果中分离到的病菌T0408鉴定为Colletotrichum asianum Prihastuti,L.CaiK.D.Hyde。该菌菌丝生长的适宜温度为20~30℃、适宜pH值为5~8;环境湿度在75%~98%范围内,湿度越大,菌丝生长速度越快,在3 000 lx日光灯的光照强度下连续光照有利于菌丝的生长和产孢;孢子萌发的适宜温度为25~30℃、适宜pH值为6~8,环境湿度为75%~98%,湿度越大、在3 000 lx日光灯的光照强度下连续光照有利于孢子的萌发。     

不同直链淀粉含量小麦淀粉理化性质与消化特性研究

为深入理解小麦直链淀粉含量与淀粉理化性质及消化特性之间的关系,以4份直链淀粉含量差异较大的小麦品种为材料,分析了其淀粉理化性质以及消化特性方面的差异。结果表明,随着直链淀粉含量的增加,回生值呈增加趋势;在体外消化前期,4个小麦品种的淀粉消化速率差异显著,西农836最慢,陕糯1号最快。这种差异与直链淀粉含量及回生值密切相关,说明直链淀粉比支链淀粉更易于回生,糊化后的冷却过程中更容易发生分子间部分重排和再结晶,重新组装成有序的聚集体,导致供试材料之间快速消化淀粉含量及总体消化程度不同。直链淀粉含量高的品种具有更多的B型小淀粉粒,但是大量B型小淀粉粒的存在并没有导致淀粉消化速率以及淀粉总体消化程度的提高,说明淀粉充分糊化后,粒度的差异并不改变淀粉消化特性。     

不同生态环境对四川小麦品种(系)籽粒淀粉含量及理化特性的影响

为了明确不同生态点对不同小麦品种籽粒淀粉含量及理化特性的影响,对四川省27个小麦品种(系)在四个生态点(温江、西昌、崇州、仁寿)3年的籽粒淀粉总含量、直链/支链淀粉比例(直/支比)以及小麦淀粉糊化温度等参数进行了分析。结果表明,同一个生态点的小麦淀粉品质指标在不同年份间没有显著差异;同一性状在不同生态点间存在一定的差异,仁寿地区的小麦淀粉直/支比和直链淀粉含量显著高于其他三个生态点,总淀粉含量显著高于崇州点;仁寿和崇州地区的小麦淀粉糊化初始温度显著高于其他两个生态点,且仁寿地区的小麦淀粉糊化峰值温度和结束温度均显著高于温江地区。淀粉组成对淀粉的糊化特性有一定影响,且总淀粉含量、直链淀粉含量、直/支比与淀粉的糊化特性之间均存在显著正相关关系。不同气象因子对小麦淀粉不同品质指标影响程度不同,其中,降雨量、温度和光照时间对大多数淀粉品质指标有显著影响。     

基于转录组的芒果MYB家族基因的鉴定及分析

MYB家族作为植物中较大的转录因子家族之一,参与调控植物的多种生理活动。本研究基于芒果果实转录组测序结果,鉴定出71个MYB家族蛋白,其中包含1个4R-MYB蛋白、3个R1R2R3-MYB蛋白、60个R2R3-MYB蛋白和7个MYB相关蛋白。进化树及基序分析表明:除个别蛋白外,相同类型的MYB蛋白均聚在一起,且相近分支的MYB蛋白具有相同或相似的基序。60个全长MYB家族蛋白中,大部分为不稳定蛋白,且均为不含跨膜结构和信号肽的亲水性蛋白,亚细胞定位分析均定位于细胞核。进化树分析发现芒果R2R3-MYB蛋白与拟南芥有较高的保守性。R2R3-MYB蛋白保守域分析发现,R2和R3结构域均有多个氨基酸保守不变。GO分析发现芒果R2R3-MYB蛋白共注释到生物学过程、细胞组分和分子功能3大类功能的15个亚类。     

花后干旱对小麦胚乳淀粉粒发育和理化特性的影响

我国小麦主产区在籽粒灌浆期往往频发干旱,常导致小麦产量下降和品质变劣。为了解花后干旱对小麦籽粒淀粉粒发育及淀粉理化特性的影响,以中强筋小麦新冬20号和新冬23号为供试材料,在花后干旱胁迫下对小麦籽粒灌浆过程中淀粉粒形态、粒径、淀粉降解酶活性以及淀粉相对结晶度、持水力、膨胀势、溶解度和破损淀粉粒含量进行了研究。结果表明,花后干旱处理下两个参试小麦品种的淀粉粒基本形态未发生明显变化。对比新冬20号,花后干旱对新冬23号淀粉粒的形成、发育影响更大。花后干旱处理下,新冬20号和新冬23号胚乳中的淀粉降解酶活性均在灌浆后期达到峰值,花后35 d时,籽粒淀粉降解酶活性均明显高于同时期的对照。花后干旱未改变参试小麦品种淀粉粒的结晶类型,但降低了其相对结晶度。花后干旱处理的新冬23号籽粒中淀粉粒的持水力和破损淀粉含量显著低于对照。试验说明花后干旱胁迫影响了小麦籽粒灌浆过程中淀粉降解酶活性,进而作用于淀粉粒的表观结构,最终对淀粉粒的理化特性产生影响,影响程度与参试小麦品种的遗传特性有关,干旱敏感型品种受其影响更为明显。     

玉米可溶性淀粉合成酶研究进展

玉米淀粉是优良的饲料和工业原料,具有重要的经济价值。从影响玉米淀粉生物合成的酶出发,讨论玉米可溶性淀粉合成酶的主要理化性质、催化机理、分子机理等方面取得的研究进展,并提出了今后需要进一步研究的方向。     

Blue Maize: Morphology and Starch Synthase Characterization of Starch Granule

The use of pigmented maize varieties has increased due to their high anthocyanins content, but very few studies are reported about the starch properties of these grains. The aim of this work was to isolate the starch granules from pigmented blue maize and carry out the morphological, physicochemical, and biochemical characterization studies. The proximate composition of starch granules showed high protein contents, after purification, the blue maize starch presented lower protein amount than starch from white maize (control). Although the purity of starch granules was increased, the damaged starch (determined for the Maltase cross absence) was also increased. Scanning electron microscopy showed the presence of some pores and channels in the blue maize starch. The electrophoretic protein profiles showed differences in the bands that correspond to the enzymes involved in the starch biosynthesis; these differences could explain the variation in morphological characteristics of blue maize starches against starch from white maize.     

Physicochemical Composition and Characterization of Bioactive Compounds of Mulberry (Morus indica L.) Fruit During Ontogeny

Plant Foods for Human Nutrition - Mulberry fruit is well recognized as one of the richest sources of bioactive compounds. We investigated the physicochemical composition and characterized the...     

芒果实生资源遗传多样性的SSR分析

利用18对SSR多态性引物对来自中国4个省份的116份芒果种质资源进行SSR-PCR扩增,共扩增出202条条带,其中多态性条带193条,多态性比率为95.54％,PIC平均值为0.57.UPGMA树状聚类图表明,109份芒果实生材料具有丰富的遗传多样性,相似系数在0.6～1.0之间,可分为4个地域性群组,分别是广东和海南土芒、广西百色土芒、广西南宁土芒以及云南小鸡芒.     

国外16个杧果品种的引进观察

对从澳大利亚引进广东湛江的16个杧果品种的果实经济性状(包括果实形状、果形指数、果实颜色、单果重、可食率、可溶性固形物、可溶性总糖、可滴定酸等)、生长结果习性(包括花期、株抽穗率、两性花比率、果实发育天数、产量等)进行系统观察和分析。结果表明,引进的16个品种中,除维伦西亚和奥奴外,其余14个品种均具有较好的品质性状。综合品质和产量等指标,晚熟品种吉莱特(Zillate)综合表现较好,产量和品质性状俱佳,可作为我国晚熟品种的有益补充,在我国其它产区进一步试种推广;马丽卡(mallika)具有比其亲本椰香杧(Deshehari)更佳的综合性状,作为椰香杧的更新换代品种推广的潜力较大;其它品种则需在我国其它产区作进一步试种观察。     

Evaluation of selected food characteristics of three advanced lines of Nigerian soybean (Glycine max (L.) Merr.)

The seeds of three promising advanced lines of soybeans (TGx 923-2^EN, TGx 1019-2^EN and TGx 1497-1^D) which were part of a larger collection evaluated in agronomic field trials in Nigeria were selected for characterization of physicochemical properties, chemical composition, water absorption, cooking time and cooked texture as a function of soaking and cooking. Seed density, leached solids, swelling capacity and seed coat percentage were within a range of 1.15 to 1.26 g per ml, 1.00 to 1.26 g per 100 g, 80.25 to 84.35 g per 100 g and 6.6 to 10.1% w/w of dry beans, respectively. The total polyphenol content of the cream colored beans was similar (0.75 to 0.76 mg/g) but higher than the amount (0.60 mg/g) found in the white beans. Cooking times varied between 71 and 96 min without soaking and were reduced by about 32.0% following a presoaking treatment in water for 12 hours at room temperature (28±1°C). Small seeds absorbed higher amounts of water during soaking and required less cooking time than larger seeds. Unsoaked beans required 40 min of cooking to achieve the same degree of cooked texture as the soaked beans cooked for 20 min, suggesting that cooking times and cooked texture for all lines were improved through soaking.     

Functional Properties and Dietary Fiber Characterization of Mango Processing By-products (Mangifera indica L., cv Ataulfo and Tommy Atkins)

Several reports have focused on utilization of post-harvest residues of crops, while neglecting those residues produced by mango processing. These residues represent a waste of nutrients and a source of environmental contaminants. Such by-products could be valuable sources of dietary fiber (DF), antioxidant compounds, and single carbohydrates. The aim of this study was to evaluate some functional properties (FP), and the content of DF and polyphenols (PP) of the peel and coarse material obtained from residues during the industrial processing of Ataulfo and Tommy Atkins mangoes. The total dietary fiber (TDF) content was about 225 mg/g and 387 mg/g (dry weight) for the coarse material and the peel, respectively, from which soluble dietary fiber represented 23 and 42 %, respectively. The main neutral sugar identified was rhamnose, especially in peels; the klason lignin (KL) content was 92 mg/g, which highlights the Ataulfo peel (Ataulfo-P) and the Tommy Atkins peel (Tommy Atkins-P). The extractable PP content in Ataulfo-P was higher than in Tommy-Atkins-P, and interesting data for non-extractable PP were obtained in the residues. FP as swelling, water holding, oil holding, and glucose absorption in the residues was studied, obtaining better functional properties when compared to cellulose fiber. The results show that mango industrial by-products, mainly from the Ataulfo-P variety, could be used as ingredients in food products because of their functional properties as well as their DF and PP content.     

Stabilization of Tarom and Domesiah cultivars rice bran: Physicochemical,functional and nutritional properties

Extrusion is a multi-step thermal process which has been extensively utilized in food preparations. Effects of temperature, moisture content and speed screw on the stabilization of rice bran were optimized using response surface methodology. Furthermore, the effect of extrusion processing on the physicochemical, nutritional and functional properties of Tarom and Domesiah cultivars stabilized rice bran (SRB) were studied. The colour of rice bran was improved by extrusion processing, but the protein content was reduced, which can be related to the denaturation of protein. Extrusion had also a reduction significant effect on the phyitic acid and vitamin E in stabilized rice bran. However, the content of vitamins B₂, B₃, B₅ and folic acid were remained unchanged, but the dietary fibre was enhanced which has beneficial health effect. In comparison with raw rice bran, water holding capacity was enhanced, but the oil absorption capacity was reduced. Foaming capacity and foaming stability of SRB was more than that of untreated rice bran. Although, they were less than that of rice bran protein concentrate/isolate. As a result, extrusion process improves some functional and nutritional properties of rice bran which are valuable for industrial applications and have potential as food ingredient to improve consumer health.     

杧果皮萃取物的生物活性及其化学成分分析

对杧果皮乙醇提取的乙酸乙酯萃取物进行抑菌性测定。离体抑菌活性测定结果表明,乙酸乙酯萃取物对小麦纹枯和水稻纹枯等病原菌具有很强的抑菌活性;硅胶柱层析及生物活性测定结果表明,正己烷∶乙酸乙酯∶无水甲醇为 60∶40∶20（v∶v∶v）时对抑菌成分的分离效果最好;化学定性分析结果表明,对水稻纹枯病菌抑菌最强的（11~13）组段的化学成分主要为酚类、黄酮类和有机酸等物质,但具体是那一类物质起作用还需要进一步分离纯化和鉴定。     

Proximate Composition and Functional Properties of Fullfat and Defatted Beniseed (Sesamum Indicum L.) Flour

The proximate composition and functional properties of fullfat and defatted beniseed (Sesamum indicum L.) flour were evaluated. Functional properties studied were foam capacity and stability, water and oil absorption, bulk density, emulsion capacity and nitrogen solubility. Defatting increased the crude protein, ash, crude fiber, carbohydrate and mineral contents. Defatted flour showed comparatively better foam capacity and stability, water absorption and emulsion capacities but diminished bulk density and oil absorption capacity. Nitrogen solubility was pH dependent with a minimum at pH 4 and maximum at pH 8. Maximum nitrogen solubility (95%) was recorded for defatted flour while that for the fullfat flour was 60%. The proximate composition and functional properties of the samples suggest that beniseed flour would have useful application in fabricated foods.     

Physicochemical and functional properties of 11S globulin from chan (Hyptis suaveolens L. poit) seeds

The 11S globulin is one of the most abundant and important storage proteins of the chan seed (Hs11S). Therefore, we investigated its physicochemical and functional properties. Studying parameters related to emulsifying properties, a critical micelle concentration (CMC) at 0.6 mg/mL and a surface activity until 55.5 mN/m were determined using a DuNouy tensiometer. Zeta potential revealed isoelectric points (pI) with a clear NaCl influence (without NaCl pI = 3.5, at 0.05 M NaCl pI = 3, at 0.5 M NaCl pI = 2.5) and electrostatic potential dependent upon the pH. The Hs11S was highly soluble at pH 7.6 (≥94.5%) with salt variations (0–0.4 M). The thermostability of Hs11S by dynamic light scattering showed that it organizes in oligomeric forms: trimer, tetramer, hexamer, octamer, dodecamer and aggregates. Oscillatory rheology studies indicate the onset for the heat-induced gelation of Hs11S which occurred around 74–76 °C, developing strong gels with an elasticity of ∼10³ Pa, while a denaturation temperature of 94.1 °C and an enthalpy of 44.49 kJ/mol were found by differential scanning calorimetry. According to ΔH_expTm/ΔH_vHTm and ΔT_1/2 data, the Hs11S denaturation is not a cooperative process. Our results indicate that Hs11S might be used as potential thermostable ingredient in food systems.     

芒果乙烯响应转录因子MiERF113基因的克隆及表达分析

芒果（Mangnifera indica L.）是著名的热带水果,深受消费者的喜爱。我国是世界第二大芒果生产国,其中广西为全国最大的芒果产区。芒果是典型的呼吸跃变型水果,其果实在采摘后因乙烯大量释放容易软化腐烂,导致货架期短,影响产业的发展。乙烯响应转录因子（ethylene response factor, ERF）是乙烯信号通路中的关键基因,参与果实内源乙烯合成的信号转导。为了探究ERF在芒果果实采后成熟调控的作用机制,以‘台农1号’芒果为研究对象,依据前期完成的芒果转录组数据结果,筛选并克隆得到1个ERF基因（MiERF113）,利用生物信息学方法分析MiERF113的基本理化特征、保守结构域、蛋白质结构、进化关系等;利用实时荧光定量PCR（qPCR）技术对MiERF113基因在芒果采后不同贮藏时期的特异性表达进行分析。结果表明：MiERF113基因的开放阅读框（ORF）长度为681 bp,编码227个氨基酸,预测蛋白质分子量为25.61 kDa,理论等电点（pI）为6.07,总平均亲水性为-0.883,有32个磷酸化位点,无跨膜螺旋结构,无信号肽。蛋白质结构域预测MiERF113蛋白仅含有1个保守的AP2结构域,且该结构域中第14和19位氨基酸分别为丙氨酸和天冬氨酸,符合ERF亚家族的典型结构特征。将芒果与拟南芥、猕猴桃、阿月浑子、苹果、柑橘和茶树的ERF氨基酸序列进行进化分析,发现MiERF113与阿月浑子ERF113的同源性较高,亲缘关系最近。利用qPCR检测MiERF113基因在芒果采后不同贮藏时间果皮和果肉部位的表达情况,结果显示,MiERF113基因在果皮和果肉中均有表达,且随着果实不断成熟其表达量在逐渐增加,在采后贮藏12 d时表达量达到最高。本研究为揭示MiERF113基因在芒果采后成熟过程中的调控作用提供理论依据。     

Effects of heat,drought and their combined effects on morphological structure and physicochemical properties of rice (Oryza sativa L.) starch

High temperature (HT) and drought stress (WS) severely affect rice quality by altering the starch structure in rice. The morphological and physicochemical properties of starches isolated from two rice varieties grown under three stress treatment (HT, WS and WS + HT) during the grain filling stage were investigated. The results showed that WS increased amylose content (AC%) and the proportion of large starch granules (LSG) and made the surface of the starch granule smooth and flat. As a result, a lower relative crystallinity, surface order, swelling power, setback viscosity and gelatinization enthalpy were caused. HT decreased AC% and milled rice rate, but increased chalky rice rate, the number of LSG and the large air space and pits on the surface of the starch granules. As a result, a higher relative crystallinity, surface order, swelling power, setback viscosity and gelatinization enthalpy were caused. Similar results were observed under the treatment of WS + HT, indicating that there is a mild antagonistic effect on rice starch when the HT and WS occur simultaneously.     

种植密度与施氮水平对高淀粉玉米郑单18淀粉含量的影响

在四种种植密度和四种氮肥水平下研究了种植密度和氮肥对高淀粉玉米品种郑单18子粒淀粉含量的影响.随种植密度增加,玉米(郑单18)子粒淀粉含量增加;随施氮量增加,玉米子粒淀粉含量的变化不显著;不同种植密度条件下,玉米子粒淀粉含量与单株产量、千粒重均呈显著负相关,与子粒蛋白质含量、脂肪含量亦均呈显著负相关.