燕麦品种的品质性状及聚类分析

收集我国2012年31个裸燕麦品种,对燕麦品种间营养与加工品质的差异进行分析;通过聚类分析初步筛选出营养品质较高的燕麦品种,并对糊化特性为主的加工品质进行品种分类。结果表明:营养品质中直链淀粉、粗脂肪、β-葡聚糖、总酚等营养指标品种变异性较大(CV15%)。加工品质中脂肪酶活(CV:32.56%)和糊化特性(CV15%)品种变异性较大,白度差异较小(CV:4.57%)。通过聚类分析最终初步筛选出甘肃定莜5号(高蛋白)、吉林白燕2号(高β-葡聚糖)、山西晋燕8号(高赖氨酸)及山西坝莜3号(高亚油酸)等营养品质较高的燕麦品种。按糊化特性初步将燕麦品种分为3类,适宜不同类型燕麦产品加工。相关研究旨在为燕麦育种和加工人员提供燕麦品质的基础理论数据。     

热处理对谷物粉物化性质及淀粉体外消化性的影响

为了研究热处理对谷物粉物化性质和淀粉体外消化性的影响,测定燕麦、小米和玉米3种谷物粉经蒸汽和烘烤热处理前、后糊化特性、膨胀势、吸水性和不同淀粉组成含量的变化。结果表明:热处理使燕麦粉的糊化温度显著降低、小米粉和玉米粉显著升高(P<0.05),燕麦粉和小米粉的回生值显著升高、玉米粉显著降低(P<0.05),玉米粉峰值黏度和崩解值显著降低(P<0.05)、燕麦粉和小米粉的变化不同;蒸汽和烘烤处理使燕麦粉膨胀势分别降低32%和12%,吸水性指数升高20%以上,但是小米粉和玉米粉变化较小;热处理使3种谷物粉水溶性指数降低28%~55%;热处理使3种谷物粉中快消化淀粉含量降低10%~20%,慢消化淀粉含量升高3%~30%,抗性淀粉含量升高20%,尤其热处理对燕麦淀粉组成含量影响最大。扫描电镜观察燕麦、小米和玉米淀粉颗粒直径分别为5,10,15 μm,经热处理后淀粉发生团聚和黏结现象,尤其燕麦淀粉团聚和黏结程度最大。结论:适当的预热处理可以改变谷物粉的物化特性,进而改善其加工性能。热处理改变了谷物淀粉的构成,减缓了淀粉的消化性,提高了其功能特性。     

不同品种绿豆淀粉的功能特性比较研究

以9个品种绿豆淀粉为研究对象,研究了绿豆淀粉的化学组成及糊化特性、溶解度、膨胀度和冻融稳定性等功能特性,并分析了直链淀粉含量与功能特性的相关性。结果表明,不同品种绿豆淀粉直链淀粉含量不同,其分布范围为33.10%~44.08%;不同品种淀粉糊化特性参数间有明显差异;潍绿4号和中绿1号绿豆淀粉峰值粘度显著高于其他品种(p0.05),安绿8号具有最低破损值(p0.05),毛绿豆和安绿092具有较低的回生值。绿豆淀粉的溶解度和膨胀度与温度有关,均随温度的增加而增大。不同品种绿豆淀粉糊经一次冻融后析水率均较高,随冻融循环次数的增加,析水率均逐渐增大。相关性分析表明,直链淀粉含量与淀粉糊的最终粘度和回生值之间存在显著正相关(r=0.674,r=0.725;p0.05),与膨胀度之间具有极显著负相关关系(r=-0.805,p0.01)。     

制粉方式对燕麦粉理化及面团特性的影响

以坝莜1号燕麦籽粒为原料,分别制粉获得炒制燕麦粉、燕麦片磨粉、超微燕麦粉3种燕麦面粉,并以实验室粉碎获得燕麦粉为对照,系统比较了不同处理获得燕麦粉的出粉率、理化指标以及面团特性。表明:炒制燕麦粉、燕麦片磨粉、超微燕麦粉的出粉率分别为79.4%、85.0%及95.0%。与对照燕麦粉相比,3种处理燕麦粉的脂肪含量均增加,而蛋白质含量、β-葡聚糖含量和灰分含量均减小。超微燕麦粉破损淀粉含量高;燕麦片磨粉色泽L值和a值最高,炒制燕麦粉的b值最大。峰值黏度、DSC热焓值从高到低依次为燕麦片磨粉、炒制燕麦粉和超微燕麦粉,且差异显著(P0.05)。扫描电镜观察发现燕麦片磨粉淀粉颗粒保留完整。3种燕麦粉的吸水率、峰值黏度、回生值、稳定时间都差异显著(P0.05),其中,炒制燕麦粉和超微燕麦粉吸水率高。总体而言,炒制燕麦粉各项指标较优。     

不同品种糙米营养品质与糊化特性分析

收集我国2013年籼型和粳型共24个品种的糙米,分析比较糙米品种间的营养品质和以糊化特性为主的加工品质的差异性。结果表明:营养品质中蛋白质、脂肪、直链淀粉、氨基酸含量、游离酚等指标品种间变异系数较大(CV15%);糊化特性中低谷黏度、最终黏度、破损值和回生值品种间差异性较大(CV15%);籼型和粳型糙米的蛋白质、直链淀粉、总淀粉的含量均影响糊化特性,且粳型糙米的糊化特性与脂肪、游离酚相关。采用聚类分析初步筛选出武运粳21(高游离酚),曲阜香稻、北旱1号(高蛋白、高赖氨酸),圣稻735(高游离酚、蛋白质和赖氨酸较高)等高营养品种。旨在为糙米育种、加工和糙米食品的开发提供基础数据。     

燕麦浆的酶解工艺研究及感官评价分析

为优化出最佳的燕麦浆酶解工艺条件,以燕麦粉为原料,在单因素实验的基础上,利用四因素三水平正交试验对酶解温度、酶解时间、酶添加量和糊化温度4个单因素对燕麦浆的酶解工艺条件进行研究。结果表明:燕麦浆最佳酶解工艺条件为酶解液稳定性最好的酶解条件为A_2B_3C_1D_2,即酶解温度80℃,酶解时间70min,酶添加量120U/g,糊化温度80℃,此条件下离心沉淀率为20.04%,燕麦浆稳定性比较好。经雷达感官图分析得出:粘稠度适宜,口感细腻、爽滑,不油腻,口味适中,麦香味醇厚突出,完全无分层现象,上下均一且稳定,研究中燕麦浆整体上优于市售的燕麦饮料。以上研究为燕麦浆的进一步研究提供了一定的理论依据。     

5种杂粮粉的粉质特性研究

对燕麦、青稞、苦荞、甜荞和藜麦的粉质特性进行了分析,包括破损淀粉及直链淀粉含量、粒径分布、面团流变学特性和水合特性。结果表明,苦荞粉的直链淀粉含量最高,为23.46%;燕麦和藜麦的破损淀粉含量均在20%以上;青稞的膳食纤维含量最高,为20.94%,且青稞粉的粒径最大(D_(50)=41.12μm)。青稞和燕麦的吸水率较高,回生值低,面团韧性强,糊化时间短,易蒸煮;苦荞的吸水率较小,面团形成时间和稳定时间较长,面团结合力强,糊化时间短,淀粉糊化特性和热稳定性较好,面团黏度较高;甜荞的糊化特性和糊化热稳定性较好,但吸水能力较差,回生值高。藜麦的吸水率较低,蛋白弱化程度大,糊化时间较长,面团流变学特性较差,不适于制作面条。燕麦的持水力和溶胀性最弱,但水溶性最低,说明其制品蒸煮损失最少;苦荞的持水力和溶胀性最佳,青稞和藜麦的次之;当温度为25,100℃时,甜荞的水溶性为5种杂粮中的最大值,预示其面制品的蒸煮损失最高。     

酶解改性对燕麦粉中淀粉含量及消化性的影响

为研究酶解对燕麦粉的淀粉含量和消化性的影响,本文采用双波长法测定天然燕麦粉、焙烤燕麦粉、酶解燕麦粉中直链淀粉、支链淀粉及总淀粉含量,并测定其快速消化淀粉、慢速消化淀粉和抗性淀粉含量以评价其消化性,利用红外光谱仪及电镜对其结构和颗粒形貌进行分析。结果表明,与天然燕麦粉相比,焙烤燕麦粉中直链淀粉、支链淀粉及总淀粉含量没有显著变化(p>0.05),但酶解改性燕麦粉变化极显著(p<0.01),分别下降了77.97%、43.55%、46.19%;焙烤燕麦粉中快速消化淀粉、慢速消化淀粉和抗性淀粉含量没有显著变化(p>0.05),但酶解改性燕麦粉变化极显著(p<0.01),分别下降了82.29%、57.06%、33.48%;经淀粉的红外光谱及1047/1022、1022/995 cm-1特征吸收比值没有显著变化(p>0.05)。经焙烤和酶解改性的燕麦粉中大淀粉颗粒表面出现较多的凹陷,而酶解改性后的淀粉中含有的小颗粒较少,且表面的凹陷程度不同。酶解改性极显著降低了燕麦粉的直链淀粉、支链淀粉、总淀粉、快速消化淀粉、慢速消化淀粉及抗性淀粉含量(p<0.01),会对燕麦粉加工性能及营养价值产生影响。     

大米淀粉物化特性与糊化曲线的相关性研究

以不同品种的大米淀粉为原料，采用快速黏度分析仪（RVA）研究不同品种大米淀粉的糊化曲线的差异，碘兰值和酶解力等物化特性对糊化特性的影响。结果表明，不同品种大米淀粉的碘兰值、酶解力存在差异，以籼米淀粉的碘兰值最大，其次是粳米淀粉和糯米淀粉。粳米淀粉和糯米淀粉酶解力相对较大。糊化温度、最终黏度、最低黏度、回升值与碘兰值均呈不同程度的正相关。峰值黏度、最低黏度、最终黏度、回升值、糊化温度与酶解力呈不同程度的负相关。采用碘兰值、酶解力的指数模型描述大米淀粉的糊化特性可达到很高的拟合精度。     

普鲁兰酶酶解处理红薯淀粉及其性质研究

以红薯淀粉为研究对象,分析普鲁兰酶酶解处理对红薯淀粉性质的影响。结果显示采用普鲁兰酶酶解脱支处理后,红薯直链淀粉质量分数增加了8.57%。对酶解前后淀粉的理化性质、微观颗粒形态、糊化和老化特性以及凝胶特性等进行分析比较,发现酶解后淀粉颗粒表面出现空穴,呈现出不规则的多边形,增加了反应位点;酶解后淀粉溶解度、膨润力降低,淀粉颗粒内部键结合力增强,透光率增加显著,凝沉性增强;酶解后淀粉糊化特性和凝胶特性发生变化,淀粉稳定性增强,高温下耐剪切力增强,硬度增大;淀粉热力学性质:起始糊化温度由63.70℃增加到71.75℃、峰值糊化温度由72.35℃增加到76.20℃、终止糊化温度和糊化焓都升高;还发现酶解后淀粉老化度有增加。粉丝品质会受到原料直链淀粉含量的影响,酶解红薯淀粉在提升红薯粉丝品质方面具有应用前景。     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

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