薇菜干氨基酸组成分析与营养价值评价

为了对薇菜干中氨基酸进行综合分析评价,以6-氨基喹啉基-N-羟基琥珀酰亚氨基甲酸酯作为衍生剂,采用超高效液相色谱法对薇菜干中17种氨基酸进行分析测定,采用分光光度法对其色氨酸进行定量分析,再结合氨基酸比值系数法、模糊识别法,对薇菜干蛋白质的营养价值进行综合评价。结果表明:薇菜干中含18种氨基酸,总氨基酸含量达697.93 mg/g·蛋白质,必需氨基酸总量/氨基酸总量为0.45,必需氨基酸总量/非必需氨基酸总量为0.83,高于FAO/WHO所推荐的理想蛋白标准。薇菜干中粗蛋白含量为12.09%。鲜味氨基酸、甜味氨基酸、芳香族氨基酸及药效氨基酸分别占氨基酸总量的23.99%,22.16%,12.46%,63.97%。8种必需氨基酸均衡性良好,与FAO/WHO标准氨基酸模式贴近。在各种必需氨基酸中,第一限制性氨基酸为异亮氨酸。     

不同类型腐乳氨基酸组成分析与营养价值评价

采用氨基酸分析仪测定三种不同类型腐乳(白腐乳、红腐乳和臭腐乳)样品的氨基酸种类和含量,并应用氨基酸比值系数法,以WHO/FAO氨基酸参考模式为评价标准,对必需氨基酸的组成进行了评价。结果表明:三种不同类型腐乳的必需氨基酸组成及含量基本相同,亮氨酸是腐乳中主要的必需氨基酸成分,蛋氨酸和缬氨酸是含量较低的必需氨基酸。依据WHO/FAO必需氨基酸参考模式,在其各种必需氨基酸中,三种不同类型腐乳第一限制氨基酸均为缬氨酸。根据氨基酸比值系数分(SRC)的高低,不同腐乳类型其蛋白质营养价值高低的顺序为:白腐乳(SRC=53.40)>红腐乳(SRC=52.39)>臭腐乳(SRC=43.17)。     

基于FAO/WHO相对氨基酸新评分模式的建立及其应用探讨

从理论上讲,氨基酸在人体内的吸收是以其配比及其在必需氨基酸中所占的比例进行的,传统的按照每克评价蛋白质中某种必需氨基酸的含量与FAO/WHO参考蛋白的该氨基酸模数(每克参考蛋白中某种必需氨基酸的含量)的比忽视其相互的协同作用,为此提出基于FAO/WHO的氨基酸模数的相对含量,建立一种新的相对法评分模式,并就其进行应用性探讨,为营养配方奠定了便捷的理论基础.     

澳洲坚果粕营养成分测定与氨基酸组成评价

目的:研究分析澳洲坚果粕营养成分的含量与组成。方法:采用氨基酸自动分析仪、凯氏定氮法及蒽酮-硫酸法等方法对澳洲坚果粕中的氨基酸、蛋白质、碳水化合物等营养成分进行了测定。应用氨基酸比值系数法,以WHO/FAO氨基酸参考模式为评价标准,对必需氨基酸的组成进行了评价。结果:澳洲坚果粕含脂肪17.22%、蛋白质24.90%、碳水化合物24.78%、氨基酸17种,总量为17.84%。其必需氨基酸的构成比例基本符合食品法典委员会(FAO/WHO)的标准,氨基酸的比值系数分(SRC)为86.95。结论:澳洲坚果粕营养丰富,人体必需氨基酸种类齐全,配比均衡,是有利于人体氨基酸营养平衡的优质食品原料。     

白斑狗鱼肌肉氨基酸含量测定及其营养评价

分别采用酸水解法与碱水解法测定白斑狗鱼(Esox lucius)的肌肉氨基酸含量,分析其氨基酸的种类与比例,并对其营养成分进行评价。结果表明：白斑狗鱼蛋白质中含有18 种氨基酸,总含量(以干质量计)为82.65g/100g,其中8 种为人体必需氨基酸,总含量43.58g/100g,占氨基酸总含量的53%;其必需氨基酸的构成比例基本符合食品法典委员会(FAO/WHO)的标准,氨基酸比值系数分为86.41,4 种鲜味氨基酸总含量为30.51g/100g。     

15种坚果果仁氨基酸组成及含量差异分析

目的分析15种市售坚果中氨基酸组成,比较不同品种坚果间必需氨基酸、非必需氨基酸含量的差异。方法使用氨基酸分析仪对样品中氨基酸的组成及含量进行分析,用最小显著性差异法(least-significant difference,LSD)进行多重比较。结果纸皮核桃中的必需氨基酸含量最高,为6.264 g/100 g,花生中总氨基酸含量最高,为22.622 g/100 g。使用模糊辨识法对贴近度进行计算得出,FAO/WHO模式蛋白质贴近度为0.840-0.933。结论坚果中必需氨基酸和总氨基酸含量的差异显著。限制氨基酸均为蛋氨酸和胱氨酸。东北松子的FAO/WHO模式蛋白质贴近度最高,最贴近人体所需蛋白质的模式。     

山东引种果桑果实氨基酸组分测定及营养评价

本文测定13个果桑品种果实中氨基酸组分。对比了不同样品间的氨基酸组成差异,采用RAA、RC、SRC等氨基酸评价指标进行营养综合评价。研究结果表明:13种果桑均含有丰富的氨基酸,冰糖椹总氨基酸高于其他12种果桑,通过与WHO/FAO氨基酸模式谱(%)的比较得出,果桑果实中缬氨酸和亮氨酸这两种必需氨基酸符合FAO模式,其中韩国大白珍珠的必需氨基酸除蛋氨酸+胱氨酸和赖氨酸以外,均符合WHO/FAO氨基酸模式要求。果桑果实氨基酸评分评定可知蛋氨酸为第一限制氨基酸,赖氨酸为第二限制氨基酸。冰糖椹、韩国大白珍珠2个品种从氨基酸营养角度值得关注。本文的研究结论为果桑的深层次食用开发提供了参考依据。     

柱前衍生化HPLC法测定叶游离氨基酸成分及风味评价

建立柱前衍生化HPLC法测定柊叶游离氨基酸的方法，对其营养价值和风味进行评价。柱前衍生化HPLC法以异硫氰酸苯酯为衍生试剂，色谱条件为:C₁₈色谱柱（4.6 mm×250 mm，5μm），醋酸钠缓冲液-乙腈（93:7）和乙腈-水（4:1）为流动相，进行梯度洗脱，流速为1.0 mL/min，柱温40℃，检测波长为254 nm。结果表明，18种氨基酸均呈现良好的线性关系（R2>0.9990），柊叶游离氨基酸的平均回收率分别为98.3%~105.6%（RSD为0.63%~3.11%，n=6）。所建立的方法稳定、灵敏、重现性好，可用于柊叶游离氨基酸的定量分析。柊叶含有18种氨基酸及8种人体必需氨基酸，必需氨基酸总量为38.85%，接近于WHO/FAO模式值（40.0%），各种必需氨基酸组分达到WHO/FAO氨基酸成人模式的需求；鲜味氨基酸和甜味氨基酸的含量分别为10.73和5.20 mg/g，占呈味氨基酸总含量的22.58%和46.59%；鲜味氨基酸Asp和甜味氨基酸Thr的含量较高，分别为3.75 mg/g和3.33 mg/g，鲜味氨基酸Asp和芳香族氨基酸Cys的RCT值分别为125.00和20.50，对风味贡献最高。总之柊叶氨基酸种类齐全，比例合理，呈味氨基酸含量丰富，具有极大开发价值。     

红萍叶蛋白氨基酸成分分析及营养价值评价研究

为了探究红萍作为食品开发利用的可行性,以酸化加热法提取的红萍(卡州萍3001(A.caroliniana Wild.3001)为代表)叶蛋白为材料,运用氨基酸自动分析仪对红萍叶蛋白进行氨基酸含量的测定,采用模糊识别法和氨基酸比值系数法对红萍叶蛋白中氨基酸展开分析讨论,并与WHO/FAO推荐的人体必需氨基酸模式进行对比,结果显示:红萍叶蛋白测定了17种氨基酸,氨基酸总量为41.38%,必需氨基酸含量占氨基酸总含量的42.18%,必需氨基酸与非必需氨基酸含量的比值为0.72,分别高于WHO/FAO标准规定的40%和0.6。红萍叶蛋白相对于鸡蛋蛋白(标准蛋白)的贴近度为0.81,SRC值为81.87,均高于苜蓿叶蛋白和四翅滨藜叶蛋白,与花生叶蛋白相当。     

樟芝菌粉的氨基酸测定及营养评价

建立了柱前衍生化高效液相色谱(HPLC)测定樟芝菌粉中氨基酸含量的方法,并进行营养评价分析。样品以邻苯二甲醛(OPA)为衍生化试剂衍生后进行HPLC分析,色谱条件为:Thermo Hypersil GOLD Dim色谱柱(150mm×4.6mm,3μm),流动相A为20mmol/L醋酸钠∶0.3%四氢呋喃∶0.02%三乙胺(p H7.2),流动相B为100mmol/L醋酸钠∶甲醇∶乙腈(200∶450∶350),流速为1m L/min,检测波长为338.1nm;采用氨基酸比值系数法对樟芝菌粉进行营养评价。结果表明:樟芝菌粉中含有20种游离氨基酸、18种结合氨基酸,氨基酸的种类和含量丰富;菌粉中除苯丙氨酸+酪氨酸外,其余几种必需氨基酸均低于WHO/FAO模式谱,氨基酸配比合理性不高,菌粉中第一限制性氨基酸为蛋氨酸+半胱氨酸,樟芝菌粉含有γ-氨基丁酸,含量为1.57mg/g。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.