3种青稞糌粑分级粉性质差异及相关性分析

以3种不同品种的青稞为原料,炒制后采用分层磨粉的方法分别获得由青稞籽粒外层至内层的糌粑分级粉Ⅰ~Ⅵ,探究各分级粉的β-葡聚糖含量、糊化特性及风味特征,分析不同糌粑分级粉之间的差异和相关性。结果表明:随着获得的糌粑分级粉道次由外层至内层变化,藏青320、藏青2000和勾芒最外层糌粑分级粉的β-葡聚糖含量均显著低于最内层的,初始及最终黏度增大。采用气相色谱法研究不同糌粑粉的风味特征,发现各品种糌粑分级粉由外层至内层出现峰面积减少、风味减弱的趋势,同时紫皮青稞勾芒糌粑粉的皮层呈现出比藏青320和藏青2000更好的风味特征。研究表明,藏青320、藏青2000和勾芒3品种的糌粑分级粉之间β-葡聚糖含量、黏度及风味物质的差异较为显著。     

炒制对青稞糌粑粉品质及贮藏稳定性的影响

为探究炒制对青稞全谷物品质的影响以及糌粑粉在贮藏期间的品质稳定性变化，该研究对不同炒制条件下青稞糌粑粉及炒制前后青稞粉原料与糌粑粉产品的品质进行检测，并测定糌粑粉在加速贮藏条件下氧化指标的变化。研究发现，炒制功率为1 300 W、炒制时间为6 min、水分含量为20%时，糌粑粉的综合评分最高；与青稞粉相比，经高温炒制后，糌粑粉的脂肪、淀粉、粗纤维及抗氧化物质含量均显著减少，脂肪酸值、过氧化值、酶活性均降低，丙二醛值增加；风味物质中醛类和杂环类化合物含量明显增加，酮类和烯烃类含量明显减少。加速贮藏期间，糌粑粉的脂肪含量下降，过氧化值上升，脂肪酸值、丙二醛值和酶活性均呈先上升后下降的趋势；糌粑粉在加速贮藏15 d(相当于常温贮藏120 d)后出现氧化劣变。该研究明确了糌粑粉在炒制及贮藏期间的品质变化情况，为实现糌粑粉的工业化生产提供了理论参考。     

不同碾减率青稞营养成分及糊化特性对比分析

以青稞为主要研究对象,通过对不同碾减率青稞的营养成分及糊化特性进行对比分析,研究不同碾磨程度对青稞营养特性和糊化特性的影响。研究发现,随着碾减率的提高,青稞米的粒型减小,淀粉含量上升,蛋白质、脂肪、灰分和总膳食纤维的含量均逐渐减小,β-葡聚糖由于主要分布在胚乳细胞壁中,所以其含量也增加。碾磨处理后的青稞米其糊化特性和糊化时间得到明显改善,通过碾磨处理可以有效改善青稞米的食用方便性。     

脱皮率对青稞粉的品质及面团特性的影响

为提高青稞粉在食品中添加量并且改善制品的色泽及口感等,将不同脱皮率的青稞粉作为研究对象,通过测定各样品的基本组分、色泽、糊化特性及降落数值,探讨青稞粉品质的变化;通过测定青稞复配粉面筋及面团的性质,研究脱皮率对于面团特性的影响。结果表明:随着脱皮率的增加,青稞粉的水分、灰分、粗蛋白、粗脂肪、膳食纤维含量均呈现减少的趋势,而淀粉含量由51.01%显著增加至60.38%;青稞粉的色泽与糊化特性也随着脱皮率的增加而有所改善,降落数值由297 s增加至489 s,发生了显著变化;面筋含量并未产生显著变化,但其面筋指数显著增加;随脱皮率的增加,青稞面团的吸水率无显著性变化,形成时间、稳定时间均随脱皮率增加有不同程度地增加,弱化度整体呈下降趋势;拉伸曲线面积有所降低,拉伸阻力增加,延伸度呈降低的趋势,拉伸比例有一定程度的增加。青稞粉经脱皮后营养组分含量有所下降,但理化特性与面团特性均有所改善。     

猴头菇-青稞预糊化粉的添加对桃酥品质的影响

针对传统桃酥营养成分单一、直接外源添加菇粉造成适口性差等问题,本研究利用双螺杆挤压膨化机处理猴头菇粉与青稞粉制得糊化度为86.13%预糊化粉,分析挤压前后混合粉的营养成分、微观结构及糊化特性,并添加不同比例预糊化粉制作桃酥,以营养、物理特性、感官评价及消化特性为指标,分析其对桃酥品质的影响。结果表明,预糊化粉的营养成分改善,糊化温度降低,稳定性提升。桃酥中K、Mg等矿物质、蛋白质和膳食纤维含量与预糊化粉添加量呈正比,碳水化合物含量、热量及血糖生成指数预测值与预糊化粉添加量呈反比,纯猴头菇-青稞酥氨基酸组成更接近FAO/WHO理想蛋白质条件。猴头菇-青稞预糊化粉的占比超过50%后,对桃酥的物理特性及口感造成负面影响。本研究为食用菌复合谷物产品的研发提供理论依据。     

青稞棒挤压膨化工艺优化及其品质特性的研究

为了开发青稞新产品,以青海纯青稞粉为原料,采用挤压膨化探索青稞棒最佳工艺条件,并研究挤压膨化对青稞粉理化指标、糊化特性和质构特性的影响。结果表明,青稞棒挤压膨化的最佳工艺条件为:加水量为18%,Ⅳ区挤压温度为180℃,螺杆转速为377 r/min,喂料速度为40 Hz;4个因素对产品品质影响的主次顺序为:加水量挤压温度喂料速率螺杆转速;青稞经挤压后水分、脂肪、蛋白质、淀粉含量分别减少40%,53%,13.5%,12.2%,膳食纤维含量增加27.1%;挤压前后对青稞粉糊化特性分析表明,其峰值黏度、谷值黏度、最终黏度、回生值和峰值时间均有不同程度下降,淀粉稳定性增强;质构特性分析表明,挤压膨化处理后,青稞硬度、黏着性、弹性、咀嚼性下降,回复性增加。挤压膨化青稞棒不仅具有良好的感官品质,其理化特性和加工品质也有所提高。     

青稞复配体系与馒头品质研究

探究在高筋小麦粉中以不同比例添加青稞全粉(QF)与青稞精粉(TPF)后,各复配粉的糊化特性、理化指标、面团流变特性及馒头的感官品质和质构特性.结果表明:QF与TPF添加量增加,对糊化特性产生负面影响,使得面粉更难糊化.QF复配粉的降落数值由370.5 s降至300.5 s,TPF复配粉的降落数值呈先降低后升高的趋势;Q...     

添加木薯淀粉和谷朊粉对保湿熟面条品质的影响

为探究木薯淀粉和谷朊粉对保湿熟面条品质的影响,本实验分别研究了木薯淀粉和谷朊粉对混合粉湿面筋含量、糊化特性和析水率的影响。通过单因素实验,以面条质构特性和感官评价为依据,得到了木薯淀粉和谷朊粉的最优配比。结果表明:适量添加木薯淀粉可以降低混合粉的湿面筋含量和析水率,提高糊化特性,改善面条品质;适量添加谷朊粉会提高其湿面筋含量,改善面条品质,但对析水率和糊化特性的影响较小;当木薯淀粉和谷朊粉添加量分别为5%和2%时,面条质构特性和感官评分(90分)最优。     

不同稳定化处理方式对4％剥皮率青稞粉营养组分与理化特性的影响研究

利用5种稳定化方式处理4％剥皮率青稞籽粒,处理后磨粉过80 mm孔径筛,以研究不同稳定化处理对4％剥皮率青稞粉的营养组分含量、基本理化特性、糊化特性及热力学性质的影响.结果 表明:稳定化处理可明显提高4％剥皮率青稞粉的品质,减少灰分含量,同时对蛋白质、脂肪、总膳食纤维及β-葡聚糖的含量无影响;不同稳定化处理方式对淀粉颗...     

不同焙炒程度对复配糙米粉的品质影响

目的 研究焙炒过程中复配糙米粉理化性质及风味的变化。方法 将糙米粉与粳米粉以8：2比例混合，在200±5℃条件下分别进行轻度、中度、重度焙炒。研究不同焙炒程度下复配糙米粉的基本营养成分、糊化特性、糊化度、色度、流变学特性等性质以及其风味变化，并确定复配糙米粉的最佳焙炒条件。结果 随着焙炒程度的增加，复配糙米粉的色泽逐渐加深，糊化度升高，直链淀粉含量、峰值粘度、回生值和衰减值降低。焙炒后复配糙米粉的挥发性风味物质显著增加，主要增加了13种吡嗪类物质和10种醛类物质，在重度焙炒条件下生成糠醛、异辛醇等刺激性风味物质。结论 中度焙炒时复配糙米粉的理化性质和风味最佳。     

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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