刺梨果渣发酵饲料蛋白的工艺研究

以刺梨果渣为原料发酵生产饲料蛋白。研究以发酵产物中蛋白含量为指标,通过混合菌种进行发酵,筛选出最佳菌种比例,并通过单因素试验和正交试验得到混合菌发酵的最佳工艺条件。结果显示,最佳菌种组合为白地霉/康宁木霉/热带假丝酵母（2∶1∶2）,产物中蛋白质含量为14.87%;混合菌发酵的最佳工艺条件为尿素添加量2%,装料量50 g/250 m L,料液比1∶1（g∶m L）,接种量17%,发酵温度30℃,发酵时间5 d。发酵产物中蛋白质含量较未发酵果渣提高了175.8%,游离氨基酸含量提高了56.3%,可溶性膳食纤维提高了37.34%,适口性得到改善,同时具有刺梨的特殊香味,适合作为饲料添加剂。     

纳豆杆菌固态发酵花生粕的工艺条件研究

以纳豆杆菌固态发酵花生粕产物对DPPH自由基的清除率为指标,考察底物配比、接菌量、料液比、发酵温度和发酵时间对发酵效果的影响,并通过响应面实验确定最佳发酵工艺条件。结果表明最佳发酵条件为:底物配比m(花生粕)∶m(大豆粕)∶m(麸皮)=7∶1.5∶1.5,接菌量0.3%,料液比10∶3,发酵温度37℃,发酵时间48.7 h。在最佳条件下发酵,上清液40倍稀释液对DPPH自由基清除率达到74.7%,10倍稀释液对羟自由基清除率高达85.2%,表明该条件下制备的发酵产物具有较高的抗氧化活性。     

发酵法制备刺梨果渣可溶膳食纤维的工艺优化

为研究刺梨果渣可溶性膳食纤维的发酵工艺,该文以保加利亚乳酸杆菌与嗜热链球菌1:1混合菌种为发酵剂,在接种量、发酵时间、发酵温度、pH和料液比5个单因素实验的基础上,利用正交实验对可溶性膳食纤维的制备工艺进行优化。结果表明:该法制备刺梨果渣可溶性膳食纤维的最佳工艺条件为:接种量12%、pH6.0、发酵时间48 h、料液比1:25、发酵温度40℃。在此条件下明显提高了刺梨果渣可溶性膳食纤维的比例,其得率为16.81%,经发酵法制备的刺梨果渣膳食纤维持水力和膨胀力均高于刺梨果渣。     

发酵法制取蓝莓果渣可溶性膳食纤维工艺优化及其特性分析

以蓝莓果渣为原料,乳酸菌作为发酵菌种,研究微生物发酵法从蓝莓果渣中提取可溶性膳食纤维的加工工艺及其理化性质的研究。结果表明乳酸菌发酵法制备蓝莓果渣可溶性膳食纤维的最佳工艺是:接种量12%、料液比1∶6(g/mL)、发酵温度34℃、发酵时间48 h以及pH 6.0;此条件下蓝莓果渣可溶性膳食纤维的的率为15.92%。发酵法得到的膳食纤维膨胀力、持水力以及对油脂、葡萄糖以及亚硝酸盐的吸附能力均比原果渣有所提高。     

发酵条件对余甘果乳酸发酵饮料品质的影响

研究了余甘果乳酸发酵饮料的加工工艺技术,并通过正交试验设计研究了乳酸菌接种量等发酵条件对余甘果乳酸发酵饮料的感官品质等的影响。试验结果表明:复合稳定剂组成为0.25%羧甲基纤维素钠盐、0.15%蔗糖酯、0.01%果胶酶,蔗糖为8%,25%余甘果汁与10%脱脂奶的配比为3∶1,发酵条件为菌种比(保加利亚乳杆菌∶嗜热链球菌)1∶1、接种量5%、发酵温度42℃、发酵时间36h时,余甘果乳酸发酵饮料的稳定性最佳,感官品质最好。     

发酵法从西番莲果渣中制备膳食纤维的研究

以生产西番莲果汁的副产物为原料,保加利亚乳杆菌和嗜热链球菌混合菌种为发酵菌种,探讨微生物发酵法从西番莲果渣中提取膳食纤维的工艺,同时对膳食纤维的物化性质进行研究。结果表明发酵法制备西番莲果渣膳食纤维的最佳工艺条件为:接种量5%、固液比1:10、33℃发酵21h。在此条件下制备的西番莲果渣膳食纤维中可溶性膳食纤维的含量为(29.01±0.41)%,高于采用化学法制备的可溶性膳食纤维的含量。发酵法制备的西番莲果渣膳食纤维的持水力优于化学法,但溶胀性变化不明显。     

固态发酵生产复合纳豆芽孢杆菌制剂

为了探索复合益生菌剂多菌种混合发酵条件,作者以活菌数为指标,采用固态发酵技术,研究了接种比例、接种量、培养基初始pH值、含水量、发酵温度和时间对固态发酵的影响,并通过L9(34)正交试验确定了纳豆芽孢杆菌和啤酒酵母混合固态发酵最佳条件.结果表明:培养基初始含水量70 %、pH 6.5、纳豆芽孢杆菌和啤酒酵母接种比例为1∶1、接种体积分数10%、发酵温度34 ℃、发酵5 d的效果最好.在此条件下发酵后,纳豆芽孢杆菌数为1.96×1010 cfu/g,啤酒酵母数为1.68×109 cfu/g.     

棕榈纤维制浆技术与装备研究

采用棕榈空果串纤维制浆在世界上是一项首创的技术,经过实验室试验和大型工业试验。文章提出了一套适合棕榈空果串纤维制浆的独有的设备及工艺技术,系统介绍了棕榈空果串纤维制浆的生产方法及棕榈空果串制浆设备的特点、要求和工艺条件。图1表4参5     

利用自提菌种固态发酵棕榈粕的研究

利用从棕榈粕堆和腐叶处提取筛选的两种高效降解纤维素菌株F1和F2(初步鉴定为米曲霉和黑曲霉),配合酿酒酵母和枯草芽孢杆菌进行棕榈粕固态发酵最佳工艺参数的研究,结果显示:固态发酵棕榈粕的最优菌种组合为“F2+酿酒酵母”,其最适配比比例为1∶1,最佳接种量为8％,麸皮最佳添加量为20％,硫酸铵最适添加量为4％,通过响应面优化的最佳含水量、发酵温度和发酵时间分别为1.48 ml/g、35.06℃和7.34d.在不灭菌条件下,以最佳工艺参数发酵棕榈粕,发酵产物中的粗蛋白质质量分数达33.49％,增加了58.20％.对比发酵前后培养基的营养性能后发现,固态发酵能够显著改善棕榈粕的营养性能.     

益生菌发酵猕猴桃果渣饮料及其营养品质与风味分析

为减少猕猴桃果渣资源浪费,采用植物乳杆菌发酵猕猴桃果渣以制备果饮。通过单因素实验考察料液比、接种量、初始（total soluble solid,TSS）、发酵时间对产品感官评分与活菌数的影响,据此以感官评分为响应值对发酵工艺进行响应面试验优化,进一步分析该产品发酵期间的营养品质、抗氧化活性及风味的变化。结果表明,猕猴桃果渣果饮的最佳发酵工艺为:初始TSS 12.4%、接种量3.3%、发酵时间36 h,所得产品感官评分87.17分;营养品质分析表明:随着发酵时间延长,活菌数、可溶性蛋白和总酸含量升高,总酚含量先降后升,类黄酮含量无明显变化,总糖、抗坏血酸含量降低;最佳工艺下ABTS+·清除率、DPPH·清除率和铁还原力比未发酵时分别增高9.59%、6.89%、4.08%。发酵36 h产品综合营养品质达到最佳。此外,顶空气相色谱-离子迁移谱（HS-GC-IMS）分析表明发酵的前24 h是风味物质转变阶段,发酵36 h为产品风味形成重要节点,而发酵48 h会积累不愉悦气味物质。其中,酮类、酯类物质相对含量升高,醛类、醇类物质相对含量降低。进一步研究发现发酵促使果香与焦甜香先降后升,发酵香增加,特征香和生青香降低;发酵36 h时嗅香评分（31.00）最高,主体香气由生青香转变为发酵香。综上,采用最佳工艺（发酵36 h）得到的产品感官优良、营养丰富、风味馥郁;但其发酵进程对产品整体品质影响较大,需严格控制。     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.