蕨根保健酒发酵工艺研究

以蕨根、高粱为主要发酵原料,酵母菌为发酵菌种,糖化酶为糖化剂,通过液态发酵生产蕨根保健酒.优化的发酵工艺条件为m(蕨根):m(高粱)=1:2,料液比为1:4(m/V),发酵温度为30℃,发酵时间为15 d,酵母接种量为8%.     

酵母菌ZJ16酿造枣酒工艺研究

以内黄大枣为原料,用从枣园土壤中分离到得一株适宜枣酒酿造的优异酵母菌ZJ16进行枣酒发酵研究。分别对料液比、酵母接种量、发酵温度、初始糖度进行了单因素实验,并通过单因素实验选取四个因素的合适水平进行四因素三水平的正交实验,以感官评分为指标对正交实验结果进行极差分析,得出枣酒的最佳发酵工艺条件为料液比为1∶6,酵母接种量...     

麸曲酱香酒醅中酵母菌的分离、筛选及应用

以麸曲酱香型白酒酒醅为菌种来源,通过平板分离纯化得到7株酵母菌。将各菌株分别制曲后测定酶活力及发酵力,筛选出5株酶活力高、发酵力强的酵母菌,并通过正交试验确定酱香酒的最佳工艺条件。结果表明,在发酵时间为21d,发酵温度为20℃,曲料比为1：1．1,接种量为13％的条件下,酒的酱香味突出,酒质最好。     

菊芋叶酵素的制备

以新鲜菊芋叶、菊芋为原料,白砂糖、苹果液为辅料。研制菊芋叶酵素的发酵工艺。结果表明,苹果液加入量2%、白砂糖加入量20%、发酵时间100 d、发酵温度30℃。在此条件下,所得产品口感清香、酸甜适口、有菊芋叶特有的清香气味。     

彩色甜糯玉米甜酒酿罐装食品的研制

对彩色甜糯玉米甜酒酿罐装食品的发酵工艺和产品的内容物配比进行试验研究.以发酵温度为25℃、料液比为1:0.8进行发酵试验,考察不同甜酒曲用量、不同发酵时间的发酵效果.再以发酵后的甜酒醪进行调配试验,找出适宜的稀释比和加糖量.试验结果表明:在发酵温度为25℃、料液比为1:0.8的条件下,彩色甜糯玉米甜酒酿发酵时甜酒曲最佳用量为1.5%、发酵最佳时间为72h.彩色甜糯玉米甜酒酿罐装食品内容物最佳配比为:甜酒醪:水为1:2,加糖量9%.产品可溶性固形物为9.4%,酒精度≤1.50.     

山楂酒饮料的加工工艺

研究以山楂为原料,比较了不同料液比、不同浸提温度、不同浸提时间对山楂成分的影响,以及酵母菌添加量、二氧化硫添加量、发酵温度、发酵液初始p H对发酵结果的影响,通过单因素和正交试验,得出山楂果酒的发酵优化条件:酵母接种量为0.02%,发酵温度为23℃,发酵液初始p H为3.5。此条件下发酵山楂酒的酒精度为10.9%,感官评分为88。最后探讨了澄清降酸处理对山楂酒品质的影响。     

辣木醋酿造工艺的研究

以辣木叶粉、红糖为原料,采用半固态发酵方法,通过正交试验,确定原料液酶解、酒精发酵和醋酸发酵的最佳工艺条件。辣木醋原料液酶解的最佳工艺参数为:辣木叶粉与水的质量比为1∶10,复合酶由纤维素酶、木聚糖酶和β-葡聚糖酶组成,复合酶的添加量为0.4g/L,酶解温度为50℃,时间为1.5h。酒精发酵的最佳工艺参数为:酵母菌接种量0.3%,发酵温度30℃,发酵时间7天。醋酸发酵的最佳工艺条件为:醋酸菌接种量10%,初始酒精度9%,发酵温度29℃,发酵时间6天。     

红茶菌饮料的研制

以茶液为主要原料,经酵母菌、醋酸菌、乳酸菌共同发酵制成红茶菌发酵液,再调配成红茶菌饮料,对茶液浸提、发酵的适宜工艺条件及红茶菌饮料的配方进行了探讨.通过单冈素和正交试验对反应条件的优化,结合感官评价,得出本次试验最佳的工艺条件:对比红茶,以绿茶为发酵摹液效果较佳,而绿茶的茶水比为1:120,100%浸提20min;接入酵母菌、醋酸菌、乳酸菌量分别为3%、1%、3%,加糖量为5%,30℃培养60h;红茶菌饮料pH值为3.0～3.5,含糖量为11%.     

酵母液态发酵法生产复合型柿子酒的研究

研究了以柿子、苹果、山楂为原料制成复合果浆,采用单株酵母发酵酿造技术,对2株酵母菌株在复合果浆中的发酵性能进行测定,确定了1450酵母比较适合复合柿子酒的酿造。以该菌株为生产菌种,对发酵工艺进行优化实验,最佳发酵工艺条件为：温度为28℃、SO2添加量为80mg/L、果胶酶添加量0.6mL/L、接种量10%。通过正交试验优选出复合柿子酒原料的调配方案为：柿子、苹果、山楂用量比为7：3：1。以此酿造而成的柿子酒,酒体金黄,具有果香及酒香,口感协调。     

蓝莓酵素复合菌种发酵工艺优化及品质分析

该研究以蓝莓为主要原料,以酵母菌、植物乳杆菌(Lactobacillus plantarum)、干酪乳杆菌(Lactobacillus casei)为发酵菌种制备蓝莓酵素,以超氧化物歧化酶(SOD)酶活性为考察指标,首先通过均匀设计试验确定复合菌种的最佳接种量;其次通过单因素试验,考察发酵时间、发酵温度、初始总可溶性固形物含量及料液比对SOD活力的影响;最后通过响应面试验获得最佳发酵工艺条件。结果表明,酵母菌、植物乳杆菌、干酪乳杆菌三种菌株的最佳接种量分别为0.1%、2%、0.47%,蓝莓酵素的最佳发酵工艺条件为发酵时间41.5 h,发酵温度31℃,初始总可溶性固形物含量12°Bx,料液比1∶5(g:m L),在此优化条件下,蓝莓酵素的pH值为3.14,酒精度为0.2%vol,总酚含量为3.14 mg/mL,花色苷含量为26.06 mg/mL,乳酸菌活菌数为1.01×10⁷CFU/m L,SOD酶活性为103.01 U/m L。     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.