大豆分离蛋白种类及取代量对冰淇淋品质的影响

研究了不同来源的大豆分离蛋白Ⅰ、Ⅱ、Ⅲ、Ⅳ的起泡性、泡沫稳定性、乳化性及乳化稳定性,并以20％ ～50％的取代率替代全脂乳粉生产冰淇淋,通过测定冰淇淋浆料粘度、硬度、膨胀率等指标,研究大豆分离蛋白来源与取代度对冰淇淋品质的影响.结果表明,冰淇淋浆料粘度及硬度均随四种来源的大豆分离蛋白取代率的增加而显著提高；不同来源的大豆分离蛋白,其取代率对冰淇淋膨胀率影响不同,膨胀率随着大豆分离蛋白Ⅰ取代率的增加而提高,随着大豆分离蛋白Ⅳ取代率的提高而降低；大豆分离蛋白来源不同,其取代率对冰淇淋融化率影响趋势基本一致,随着取代率的增加,融化率略有升高然后快速下降；大豆分离蛋白冰淇淋感官评价综合指标随着取代率的增加先升高后降低.而且研究结果还表明,大豆分离蛋白冰淇淋的膨胀率与起泡性无相关性；皮尔逊相关性分析表明在一定粘度范围内,膨胀率与大豆分离蛋白乳化性呈正相关.     

乳化型大豆分离蛋白对冰淇淋质构的影响及工艺优化

主要研究了乳化型大豆分离蛋白(ESPI)以40%~80%的添加量替代全脂乳粉在冰淇淋中的应用,通过测定冰淇淋浆料黏度、膨胀率、融化率等指标,研究ESPI的添加量对冰淇淋品质的影响。单因素实验表明,冰淇淋浆料粘度及硬度均随ESPI取代率的增加而显著提高;冰淇淋的膨胀率随着ESPI添加量的增加而提高;随着ESPI添加量的增加,冰淇淋的融化率有升高的趋势,达到60%的添加量时,融化率开始下降;ESPI冰淇淋感官评价综合指标随着添加量的增加先升高后降低。结果还表明,跟其他大豆分离蛋白相比,这种乳化型大豆分离蛋白的替代量处于较高的水平。大豆分离蛋白冰淇淋的品质与加工过程中的ESPI替代量、CMC-Na添加量、单甘酯添加量以及水的添加量有很大关系,4个因素对ESPI冰淇淋感官评定的影响大小顺序为:单甘酯添加量(C)CMC-Na添加量(B)水的添加量(D)ESPI替代量(A)。结合冰淇淋的膨胀率、融化率以及感官评定的结果,其最佳组合为:ESPI替代量为60%,CMC-Na添加量为0.3%,单甘酯添加量为0.2%,水的添加量为60%。     

改性大豆分离蛋白-磷脂复合物对冰淇淋品质的影响

针对大豆分离蛋白(SPI)取代部分乳粉生产冰淇淋,产品膨胀率低、易融化、口感较硬和有豆腥味等问题,本实验采用超高压改性大豆分离蛋白(USPI)、大豆分离蛋白-磷脂复合物(SPI-PLW)和超高压均质改性大豆分离蛋白-磷脂复合物(USPI-PLW)分别替代乳粉生产冰淇淋,研究了不同改性条件的大豆蛋白对冰淇淋浆料的静态流变学、膨胀率、融化率、硬度和微观结构的影响。通过对比研究得出,以USPI-PLW为原料制作成的冰淇淋的各项标准都优于其它类型的大豆分离蛋白冰淇淋。USPI-PLW冰淇淋融化率为33.17%,膨胀率可达86.86%,较传统低脂冰淇淋融化率降低26.86%,膨胀率提高了94.84%,且储藏硬化后无较大冰晶,相对于传统冰淇淋口感更绵软。     

酶改性大豆分离蛋白冰淇淋工艺研究

利用Alcalase碱性蛋白酶对大豆分离蛋白进行适度酶水解改性,并将改性后的大豆蛋白以不同比例替代奶粉应用于冰淇淋中,对生产的大豆分离蛋白冰淇淋与普通冰淇淋的质构特性、膨胀率、融化率及感官进行比较分析,最终确定了最佳的改性分离蛋白替代量为30%,产品的各项指标令人满意。     

不同类型稳定剂和乳化剂对冰淇淋品质特性的影响

本文研究了不同类型的稳定剂和乳化剂在冰淇淋中的作用,以三种代表性的不同类型的稳定剂:卡拉胶（离子型多糖）、瓜尔豆胶（非离子型多糖）和明胶（蛋白质）,以及具有不同亲水亲油性的乳化剂:单硬脂肪酸甘油酯（Glyceryl Monostearate, MG,HLB=3.8）和吐温80（HLB=15）作为研究对象,以冰淇淋的物理特性（粘度、膨胀率与融化率）和感官（粘稠度、顺滑性、口融性与颗粒感）为指标,讨论了稳定剂和乳化剂对冰淇淋品质的影响。结果表明,与吐温80相比,加入MG的冰淇淋膨胀率更高,抗融性更好,二者对浆料粘度的作用无显著性差异（P<0.05）;三种稳定剂均可增大冰淇淋浆料的粘度,其中,卡拉胶较瓜尔豆胶和明胶对浆料粘度的影响差异显著（P<0.05）,抗融性最强,瓜尔豆胶对膨胀率影响最大。其中MG与卡拉胶复配所得浆料粘度和抗融性最佳,分别为898.35 cp,融化率4.74%;与瓜尔豆胶复配所得冰淇淋膨胀率最高为66.95%。在此基础上,以MG作为乳化剂,复配瓜尔豆胶和卡拉胶,研究不同复配比例的稳定剂在冰淇淋中的作用。结果表明,稳定剂总添加量为0.25%时,卡拉胶与瓜尔豆胶的质量比为1:1.5,冰淇淋的浆料粘度可达1036.5 cp,融化率为17.4%,感官评分最高。     

超高压处理对冰淇淋浆料及其成品品质的影响

该研究主要探究超高压（ultra-high pressure,UHP）处理对分别以卡拉胶、黄原胶和塔拉胶为稳定剂制得的冰淇淋浆料及其成品品质的影响。以稳定剂添加量0.15%,分别经50、100、150、200 MPa处理60 min为处理组,以老化处理（2℃下静置24 h）为对照组,测定冰淇淋浆料的乳化性、乳化稳定性、混料粘度、粒径,分析荧光强度分布趋势,测定冰淇淋成品的硬度、膨胀率和融化率。结果表明,浆料经超高压处理后,其乳化性呈先升高后降低的趋势,当压力为150 MPa时乳化稳定性最高;内源荧光光谱扫描结果显示浆料中酪蛋白分子发生去折叠现象;该条件下以卡拉胶为稳定剂制得的冰淇淋成品的硬度、膨胀率和融化率最好。由此可知,由卡拉胶为稳定剂制得冰淇淋浆料在150 MPa处理后能在一定程度上改善冰淇淋的成品品质。     

以果胶为基质的脂肪替代品对冰淇淋品质的影响

以果胶为基质的脂肪替代品替代冰淇淋中的脂肪,随着脂肪替代率的增加,冰淇淋浆料黏度和膨胀率增大,抗融化率下降,硬度增大.不同替代比例制得的低脂冰淇淋的各项感官指标均与中脂冰淇淋无显著差异;当替代全部脂肪时,所制得的无脂冰淇淋也有较好的感官接受性.     

稳定剂对软冰淇淋品质的影响

对软冰淇淋浆料的粘度及软冰淇淋的硬度、膨胀率、抗融性等指标进行测试来观察黄原胶、刺槐豆胶和卡拉胶对软冰淇淋品质的影响.结果表明：在没有乳化剂存在的前提下,刺槐豆胶的抗融性最好,卡拉胶次之,黄原胶较差,但刺槐豆胶对软冰淇淋膨胀率的影响不稳定,当添加量为0.2%～0.4%时能显著提高软冰淇淋的膨胀率,其他用量时膨胀率则反而降低,黄原胶可提高产品的膨胀率,卡拉胶则降低膨胀率;在粘度方面,三者均有增稠作用,作用大小依次为黄原胶、刺槐豆胶和卡拉胶;三者均有降低产品硬度的趋势,刺槐豆胶的降低程度大于卡拉胶和黄原胶.     

以乳清蛋白为基质的脂肪替代品对冰淇淋品质的影响

以乳清蛋白WPC-80为基质制备脂肪替代品,替代中脂冰淇淋中25%的脂肪。随着脂肪替代率的增加,冰淇淋浆料黏度和膨胀率增大,抗融化率和硬度下降,制得的低脂冰淇淋的各项感官指标均与中脂冰淇淋相当。当替代全部脂肪时,所制得的无脂冰淇淋也有较好的感官接受性。     

添加磷脂大豆分离蛋白复合物对冰淇淋品质的影响

将大豆分离蛋白与磷脂复合物添加到冰淇淋中,以膨胀率、融化率、硬度和感官评价等为衡量指标,研究其对冰淇淋品质的影响。在单因素的基础上,运用响应面优化磷脂大豆分离蛋白复合物冰淇淋的最佳工艺条件。结果显示,当磷脂大豆分离蛋白复合物添加20%、大豆分离蛋白与磷脂比例3∶1、乳化剂添加量为0.15%时,膨胀率达到72.12%,比普通冰淇淋提高了22.17%。感官评价研究表明,感官评价良好。     

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