红茶菌在谷物原料发酵制醋中的应用

为了研究红茶菌在谷物原料发酵制醋中的应用,以玉米粉、豆粕、米糠粕为原料,总酸、不挥发酸及氨基酸态氮含量为评价指标,考察不同原料比例、不同酶制剂添加量对谷物醋发酵的影响。结果表明,采用玉米粉∶豆粕∶米糠粕=50∶45∶5质量比发酵14 d,糖化酶对成品总酸含量有显著性影响（P＜0.05）,中性蛋白酶对成品中氨基酸态氮含量有显著性影响（P＜0.05）。各种酶制剂的添加量为：α-淀粉酶0.4%、糖化酶0.3%、中性蛋白酶1%、酸性蛋白酶0.3%（第一次添加量）,在此最佳酶添加量条件下,接种5%红茶菌发酵,制备谷物醋中总酸、氨基酸态氮含量和不挥发酸含量分别为47.90 g/L、6.62 g/L和0.72 g/L。结果说明红茶菌在谷物原料发酵制醋中的应用是可行的。     

固态发酵豆粕的研究

利用米曲霉、酵母菌、乳酸菌混合菌固态发酵豆粕。研究了发酵时间、接种菌配比、接种量及发酵温度等对发酵豆粕的影响,得到了最佳工艺条件为豆粕∶水=1∶1,起始pH值自然,米曲霉∶酵母菌=2∶1,接种量4g/100g,好氧发酵温度30℃,发酵周期36h,乳酸菌培养液6mL/100g,厌氧发酵温度35℃,发酵周期72h。并对该条件下发酵后的豆粕营养成分及抗营养因子进行了分析。     

葛根黄酒发酵工艺研究

以荆门地区糯米和葛根粉为原料,利用麦曲和黄酒活性干酵母进行发酵。选取葛根与糯米质量比、料水比、麦曲添加量、黄酒酵母添加量为主要影响因素,以酒精度、黄酮含量及感官评定为测量指标,采用单因素试验和正交试验对葛根黄酒发酵工艺进行优化。结果表明,葛根黄酒最佳发酵条件为:葛根与糯米质量比为1∶3.3,料水比为1∶2(g/m L),麦曲添加量为8%,黄酒酵母添加量为0.08%。     

响应面法优化罗非鱼干制汤汁速酿鱼露工艺

以罗非鱼干制余留的鱼汤为主要原料,采用快速发酵法研究其鱼露发酵工艺,并按响应面试验设计方法优化其发酵工艺。结果表明,最佳发酵工艺条件为发酵温度42 ℃、加盐量10%、大豆固体曲添加量22%、还原糖添加量3%（木糖∶葡萄糖=1∶4）、料液比1∶1（g∶mL）、发酵时间9 d,最优工艺条件下所得样品中氨基酸态氮含量为0.763 g/100 mL。     

罗非鱼副产物对米曲霉产酶及蛋白质转化的影响

针对鱼肉、鱼排为主要氮源制曲存在的工艺复杂、制曲酶活力低等问题,在传统的豆粕制曲基础上,添加罗非鱼鱼排替代部分豆粕氮源,进行混合氮源制曲,研究鱼排的添加对米曲霉生长产酶活力的影响,以及对发酵制品呈味氨基态氮的影响。研究结果显示,鱼排(干基)替代豆粕量在1/3以内时,对米曲霉产中性、酸性蛋白酶活力影响不显著。通过优化,鱼排(干基)、豆粕、麸皮、小麦按2∶4∶3∶1添加,润水量为原料的40%,米曲霉种曲孢子接种量为3×106 CFU/100g,制曲时间为72h时,可达到较优的酶活力。通过比较混合制曲、豆粕制曲及鱼排后期添加3种发酵工艺,发现鱼、豆混合制曲进行低盐固态发酵比另外两种工艺的氨基酸态氮,蛋白水解率都要高,铵盐比豆粕制曲鱼排后期添加低,说明鱼、豆混合制曲发酵可加快原料蛋白水解,提高原料利用率和鱼酱油品质。     

响应面法优化豆粕发酵产共轭亚油酸条件

为寻求以豆粕为主要基质产共轭亚油酸最佳发酵条件,采用响应面法优化其发酵条件.在单因素试验基础上,选择不同接种量、油脂添加量、发酵时间为自变量,共轭亚油酸产量为响应值,利用Box-Benhnken中心组合方法进行3因素3水平的试验设计,并做响应面分析,建立回归模型.结果表明,回归方程拟合性好,发酵最优条件为:接种量3.2％,油脂添加量1.93 g·(50 g豆粕)-1,初始pH6.0,在37℃发酵80 h.在此条件下,发酵豆粕中共轭亚油酸产量可达700.32 μg/g.这为生物发酵法生产共轭亚油酸提供研究基础.     

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。     

燕麦拿铁饮料的研制及稳定性研究

以咖啡、燕麦为主要原料开发燕麦拿铁饮料,通过单因素试验和正交试验设计,以感官评分为评价指标确定原料最佳配比,并探讨不同稳定剂组合对目视浮油感官评分、离心沉淀率、粒径分布、LUMiFuge快速稳定性表征的影响确定最佳稳定剂组合方案。结果表明,燕麦拿铁饮料的最佳配比为冻干咖啡粉添加量为1.6%、酶解燕麦粉添加量为11%、亚麻籽油添加量为0.5%、白砂糖添加量为4%(均为质量分数);最佳稳定剂组合方案为m(微晶纤维素)∶m(单、双甘油脂肪酸酯)∶m(硬脂酰乳酸钠)∶m(卡拉胶)=3∶2∶2∶1(添加量为0.4%),在此条件下所得制品兼具咖啡、燕麦的风味,感官评分高,具备良好的贮藏稳定性,对燕麦拿铁饮料相关理化指标进行测定,可溶性固形物为(15.09±0.04) g/100g,蛋白质含量为(1.51±0.16) g/100g,脂肪含量为(1.27±0.09) g/100g,膳食纤维含量为(1.87±0.07) g/100g,β-葡聚糖含量为(486.75±0.49) mg/100g,咖啡因含量为(358±0.21) mg/kg,卫生指标符合国家相关标准。     

椰子酸奶发酵工艺

以椰浆和全脂奶粉为主要原料,通过原料配比、菌种、发酵温度和时间、蔗糖添加量等单因素试验和正交组合试验设计方法,确定了椰子酸奶的工艺条件:全脂奶粉和椰浆比例为1∶2(即全脂奶粉添加量5%)、蔗糖添加量为8%,采用SH-470乳酸菌植物性发酵剂(按其说明接种量):嗜热链球菌和植物乳杆菌发酵,发酵温度43℃,发酵时间6 h。     

风味白鲢鱼肉干香肠的关键工艺研究

以白鲢鱼为原料,研究干制鱼肉水分含量、肉料配比、发酵菌种配比、发酵剂添加量和发酵温度对发酵香肠品质的影响。结果表明:当干鱼肉水分含量在45%、香肠肉料配比为鱼糜∶干制鱼肉∶猪背膘∶蛋清=100∶30∶20∶11(m/m)时,混合发酵菌种采用戊糖片球菌10196∶植物乳杆菌6001∶干酪乳杆菌6002∶汉逊酵母=2∶3∶1∶1、菌种发酵液最佳添加量为3%,30℃下发酵33 h,制得的风味白鲢鱼肉干香肠品质最佳。     

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.     

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.