燕麦粉挤压膨化工艺参数研究

为了研究挤压工艺参数对纯燕麦粉挤压膨化产品特性的影响并初步优化工艺参数,以纯燕麦粉为原料,采用DSE-25型双螺杆挤压设备,分析挤压温度、物料含水率、喂料速度和螺杆转速对燕麦挤压膨化产品口感、表观、气味、膨化率和综合评价的影响。结果表明:不同工艺参数对纯燕麦粉挤压膨化产品的口感得分、表观得分、膨化率和综合评分影响显著,对气味得分影响不显著。随着挤压温度、物料含水率、喂料速度和螺杆转速的增加,燕麦挤压膨化产品的质量先改善,后趋于下降。综合考虑燕麦挤压膨化产品特性,初步认为纯燕麦粉挤压膨化的较优工艺为:挤压温度160℃,物料含水率18%~20%,喂料速度40 g/min,螺杆转速160~180 r/min。     

挤压膨化对绿茶茶渣中没食子酸影响实验研究

利用DS30-III型双螺杆挤压膨化机对绿茶茶渣进行挤压膨化加工,在单因素试验的基础上,选取了物料含水量、喂料速度、螺杆转速、套筒温度为影响因子,以绿茶茶渣中没食子酸为响应面值,应用响应面设计方法建立数学模型,进行响应面分析。结论表明,获得高没食子酸含量的最佳工艺参数为:物料含水量70%,喂料速度58 r/min,螺杆转速60 r/min,套筒温度60℃。挤压膨化参数对没食子酸含量影响的大小依次为:物料含水量螺杆转速套筒温度喂料速度。经过最佳挤压膨化参数处理的绿茶茶渣中没食子酸含量为3.57 mg/g,与原料相比,没食子酸含量增加2.69 mg/g。     

线性插值优化多指标芦荟—玉米粉挤压膨化工艺

针对芦荟加工过程副产物利用率较低的问题,提出将芦荟叶皮干燥制粉后,加入玉米粉中进行挤压膨化试验,制备芦荟—玉米功能膨化食品。采用单因素及五因素四水平正交试验方法,研究了芦荟添加量、物料含水率、螺杆转速、喂料速度以及膨化温度等工艺参数对膨化产品品质的影响规律;采用线性插值法对芦荟—玉米粉挤压膨化产品指标进行综合评价,得出添加芦荟超微粉体后的混合物料挤压膨化最优工艺参数为:喂料速度30r/min,螺杆转速115r/min,水分含量14%,芦荟含量4%,膨化温度150℃。     

挤压膨化技术在玉米胚浸出提油中的应用研究

探讨了玉米胚经挤压膨化后对浸出提油的影响,通过响应面分析方法对玉米胚挤压膨化的参数(喂料含水率、模孔直径、套筒温度、螺杆转速)进行优化,建立回归模型,优化得到最佳工艺条件为:喂料含水率11.27%、模孔直径6 mm,套筒温度102.6℃、螺杆转速170 r/min,此条件下残油率最小为0.342%。     

挤压工艺参数对膨化杂粮粉感官品质的影响

利用DS32-I双螺杆挤压机,以小米粉、糯玉米粉、黄豆粉、小麦粉、燕麦粉、糙米粉、麦麸为膨化杂粮粉原料,研究物料水分、机筒温度、螺杆转速和喂料转速对挤压膨化杂粮粉感官品质的影响。结果表明:影响膨化杂粮粉产品感官品质的因素为物料水分>机筒温度>喂料转速>螺杆转速,膨化杂粮粉在物料水分16%、螺杆转速150r/min、机筒三段温度80℃-145℃-165℃、喂料转速20r/min时,膨化杂粮粉的感官品质较好,有淡淡的谷香味,色泽为浅黄色,口感较细腻,入水易成糊状,无结团和沉淀,水溶分散性好,感官综合评分达到7.86。     

挤压膨化对白汤酱油成曲糖化酶活力的影响

以面粉为原料进行挤压膨化,以成曲糖化酶活力为评价指标,研究挤压膨化参数对白汤酱油成曲糖化酶活力的影响。通过单因素试验分别研究了面粉含水率、螺杆转速、喂料速度和套筒温度对糖化酶活力的影响。在单因素的基础上进行响应面试验,对挤压膨化参数进行优化。结果表明,最佳的挤压膨化参数为面粉含水率45%,螺杆转速100 r/min,喂料速度10 kg/h,套筒温度80℃,在此条件下,糖化酶活力为1 293.49 U/g。利用高糖化酶活力的成曲,采用低盐固态发酵方式进行白汤酱油酿造,测得白汤酱油的氨基酸态氮含量为0.65 g/d L,还原糖含量为243.25 mg/m L,酱油口味清甜,酱香浓郁。     

挤压膨化对杏鲍菇深加工残渣中可溶性膳食纤维影响

试验探讨了挤压膨化技术对杏鲍菇深加工残渣中可溶性膳食纤维的影响。在单因素试验的基础上,选取了物料含水量、喂料速度、螺杆转速以及套筒温度为试验因子,以可溶性膳食纤维含量为响应面值,通过响应面试验设计方法来构造数学模型并进行数据分析。研究结果表明,获得较高可溶性膳食纤维含量的工艺参数为:物料含水量25%,喂料速度29 Hz,螺杆转速97 r/min,套筒温度103℃。在该工艺参数下,杏鲍菇深加工残渣中可溶性膳食纤维含量为1.33%,与挤压膨化前原料相比,可溶性膳食纤维含量提高了46%。     

双螺杆挤压膨化大豆模头压力对粕残油率的影响

以单因素试验为基础,采用响应曲面设计的试验方法研究了挤压膨化工艺参数(物料含水率、套筒温度、轴头间隙、螺杆转速)对挤压机模头压力和粕残油率的影响规律。用SAS 9.1软件对试验数据进行处理并建立数学模型,并运用SPSS 17.0分析软件对所得数据进行分析,获得模头压力与粕残油率之间的相关性。结果表明:挤压膨化工艺参数对模头压力的影响程度依次为:轴头间隙、螺杆转速、物料含水率、套筒温度。对粕残油率的影响程度依次为:轴头间隙、物料含水率、套筒温度、螺杆转速。模头压力越高物料被挤出的油脂量就越多,膨化物含油率也就越低,致使浸出粕的残油率越低。     

膨化亚麻籽模头压力的变化规律研究

采用SLG67-18.5双螺杆挤压机优化亚麻籽挤压膨化工艺.通过二次正交旋转组合设计试验,研究了温度、含水率、螺杆转速、喂料速度对模头压力的影响.研究结果表明,影响性能指标模头压力的因素主次关系为含水率、喂料速度、螺杆转速、温度,其中温度影响不显著.在实际生产中,需要着重考虑含水率和喂料速度、温度和含水率、温度和螺杆转速、温度和喂料速度的交互作用对模头压力的交互作用.     

淡水鱼糜挤压膨化技术研究

本实验研究了不同加工温度、物料含水量、螺杆转速、喂料速度对挤压膨化产品系统参数扭矩、4区压力、5区压力、两区压力差的影响。研究表明:加工温度、物料含水量、螺杆转速、喂料速度对挤压膨化产品系统参数的影响,只有螺杆转速对两区压力差不显著,其余都达到极显著水平;随着加工温度、物料含水量、螺杆转速升高,扭矩、4区压力、5区压力、两区压力差呈大致降低趋势;随着喂料速度升高,扭矩、4区压力、5区压力、两区压力差呈现大致升高的趋势。     

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