无花果风味酸奶的研制

本文以牛乳为主要原料,无花果为辅料,制作无花果风味的凝固型酸奶。以感官评分为评价指标,通过无花果汁添加量、蔗糖添加量、发酵剂接种量和发酵时间4个单因素实验和响应面分析确定最佳工艺。结果表明,8%无花果汁添加量、5%蔗糖添加量、0.03%发酵接种量、4 h发酵时间条件下生产的无花果风味酸奶质地细腻,酸甜可口,具有清新甜香的无花果香味,感官评定评分最高,可达到89.8分。     

刺梨凝固型酸奶的发酵工艺研究

研究了刺梨及蜂蜜制备的凝固型酸奶的发酵工艺,考察刺梨汁添加量、发酵温度、蜂蜜添加量、乳酸菌接种量及发酵时间对刺梨酸奶感官品质的影响。在单因素试验的基础上采用正交试验优化刺梨凝固型酸奶的发酵工艺。结果表明,刺梨凝固型酸奶最佳发酵条件为：刺梨汁添加量30%、蜂蜜添加量10%、乳酸菌接种量0.15%、发酵温度42 ℃和发酵时间9 h。在此条件下,所得刺梨凝固型酸奶感官评分为92.5分,质地均匀、凝结状态良好、口感细腻,且有浓郁的乳香味和刺梨风味。     

金银花凝固型酸奶制作工艺研究

为充分发挥金银花的保健功效,以金银花汁与全脂乳粉为主要原料,研究了金银花凝固型酸奶制作工艺。试验结果表明:金银花汁浸提条件为:95℃,40 min;金银花凝固型酸奶最佳工艺参数:金银花汁添加量8%,白砂糖添加量9%,发酵剂接种量5%,发酵时间4 h。     

搅拌型龙眼酸奶的研制

以龙眼汁和奶粉为主要原料研制一种复合型发酵酸奶。从产品感官质量和稳定性入手,应用正交实验法,确定了合理的配方和适宜的发酵工艺条件。结果表明,龙眼酸奶的主要原料最佳配比为奶粉与水质量之比为1∶8,龙眼汁添加量7.5%,复合稳定剂为淀粉0.10% 果胶0.025% CMC0.05%,最佳的发酵工艺条件为接种量5%,发酵温度为42℃,发酵时间为2.5h,将得到保健功效的搅拌型龙眼酸奶。     

Box-Behnken模型响应面法优化口蘑酸奶发酵工艺

以口蘑和乳粉为原料,研究口蘑酸奶的发酵工艺。在口蘑汁添加量、发酵剂添加量、白糖添加量为单因素实验的基础上,以感官评定为指标,利用响应面Box-Behnken模型对口蘑酸奶发酵工艺进行优化。最终确定了口蘑酸奶最佳发酵工艺参数:蘑汁添加量12.3%(体积分数),白砂糖添加量64 g/L,发酵剂添加量33 g/L,此条件下,口蘑酸奶感官评定分值为(88.93±0.37)分,与预测值接近。     

复合型凝固酸奶工艺条件的响应面法优化

试验以高蛋白脱脂高钙奶粉为原料,南瓜汁和苦瓜汁为配料制备的复合凝固型酸奶。研究了奶粉、糖、南瓜汁以及苦瓜汁的不同添加量对复合凝固型酸奶感官品质的影响。利用响应面分析法优化工艺参数,最后确定出凝固型酸奶的最佳生产工艺条件为:发酵温度43℃,发酵时间6.5h,发酵剂添加量1%。此时生产出的凝固型酸奶质地细腻,酸味清爽。     

酒味果蔬复合搅拌型酸奶的研制

将酵母菌发酵剂接入南瓜苹果混合果汁中发酵,通过单因素、正交试验,得出发酵果汁的最佳工艺为:m(南瓜汁):m(苹果汁)=1:3,酵母菌接种量8%,发酵天数3d,糖度8Brix;将鲜牛奶中添加稳定剂、糖,接种乳酸菌发酵,得最佳工艺为:稳定剂添加量0.25%,稳定剂添加比例为:m(变性淀粉):m(海藻酸钠):m(果胶)=2:1:0.5,均质温度70℃。在中速搅拌的条件下,将发酵果汁按10%的添加量加入酸奶中,得到一种新型的果蔬复合搅拌型酸奶。     

马铃薯酸奶研制及贮藏期间的品质变化

以奶粉和马铃薯为原料研制马铃薯酸奶。研究了发酵时间、发酵温度、菌种添加量对酸奶发酵工艺的影响,以及搅拌速度、搅拌时间、马铃薯浆添加量对搅拌工艺的影响进行研究,并对贮藏期间马铃薯酸奶水分含量、pH、酸度、持水力、质构、流变的变化进行研究。结果表明:马铃薯酸奶的最佳发酵工艺为菌粉添加量0.02%,发酵温度41℃,发酵时间4.5h;最佳搅拌工艺为马铃薯浆添加量25.5%,搅拌速度90r/min,搅拌时间25min;在贮藏期间,马铃薯酸奶各项指标均有一定程度的增减,但与空白组相比变化幅度更小,说明品质更稳定。     

冬枣酸奶加工工艺研究

以鲜乳为原料,经乳酸菌发酵制成凝固型酸牛奶后,添加一定比例的冬枣汁搅拌、冷却罐装,即得风味清香、口感好、营养价值丰富的合格的搅拌型冬枣汁酸奶.经研究得:接种菌种为保加利亚乳杆菌和嗜热链球菌(按1:1比例),接种量为3%～5%,发酵温度和发酵时间的最佳组合为41℃～42℃、3 h～4h.     

响应面法优化金银花枸杞风味酸奶的发酵工艺

以金银花、枸杞、全脂奶粉为原料,采用单因素试验研究了金银花汁添加量、枸杞汁添加量、白砂糖添加量、发酵温度、发酵时间、发酵剂接种量对金银花枸杞风味酸奶发酵的影响。以感官评分为响应值,采用响应面法对金银花枸杞风味酸奶的发酵工艺条件进行优化。结果表明,金银花枸杞风味酸奶的最佳发酵工艺条件为金银花汁添加量5%、枸杞汁添加量6%、白砂糖添加量8%,发酵剂接种量10%,发酵温度43 ℃,发酵时间5.1 h。在此优化工艺条件下,发酵的金银花枸杞风味酸奶组织细腻,酸甜可口,具有独特的中药香,感官评分为91分。     

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