植酸酶的激活及其催化植酸钠水解提取肌醇

以脱脂米糠为原料提取肌醇,用离子交换树脂吸附植酸,再用NaOH洗脱,得到植酸钠溶液,采用植酸酶阳离子激活提高酶活后催化植酸钠水解,水解液最后用CaCO3溶液破坏水解平衡的原理辅助水解,从而制得得率高达11.5％的肌醇.     

植酸酶的激活及其催化植酸钠水解提取肌醇

以脱脂米糠为原料提取肌醇,用离子交换树脂吸附植酸,再用NaOH洗脱,得到植酸钠溶液,采用植酸酶阳离子激活提高酶活后催化植酸钠水解,水解液最后用CaCO3溶液破坏水解平衡的原理辅助水解,从而制得得率高达11.5%的肌醇。     

微波辐射水解植酸快速制备肌醇的研究

采用微波辐射法水解植酸制备肌醇，缩短了水解时间和获得了较好的产率。用正交实验法确定了制备肌醇的最佳水解条件。提出了分析水解度的方法和探讨了植酸微波水解机理。     

用沉淀法减少植酸钙的含杂量

用沉淀法减少植酸钙的含杂量王小华　（苏州吴越粮油化工有限公司２１５１２８）１引言肌醇是粮油工业综合利用重要产品之一。目前国内肌醇生产的传统工艺是先从米糠制得植酸钙，再由植酸钙经水解而制得肌醇。植酸钙作为肌醇生产的中间产品，其质量对肌醇生产的影响很大，...     

高质量高效率肌醇生产新方法

高质量高效率肌醇生产新方法周秀琴肌醇是国际上热门的健康食品添加剂，又是营养辅助食品和养殖鱼用的饲料添加剂，仅美国年需８００吨。以往肌醇制造一般以米糠等为原料，用酸抽提植酸，将植酸沉淀、分离、加压水解精制、浓缩、结晶而成，但该法得到的植酸纯度低、植酸沉...     

肌醇生产中离子交换树脂净化工艺的研究

在以脱脂米糠为原料提取肌醇的工艺中,用离子交换树脂吸附植酸,再用Na OH溶液洗脱,得到植酸钠溶液,采用植酸酶阳离子激活提高酶活后催化植酸钠水解,获得肌醇溶液。对肌醇溶液采用离子交换树脂净化,既可淡化产品颜色,又能有效去除各种杂质离子。研究表明,用阶梯式阳、阴、阴、混合树脂柱进行离子交换,净化效果理想,树脂再生易行。交换液的流速为300~400 m L/min。     

三磷酸肌醇抗油脂氧化性的研究

三磷酸肌醇(IP3)既可以用肌醇经一系列化学反应而合成，也可由植酸经不完全水解后分离而制得。但化学合成方法所得产品成本太高，故一般采用植酸水解法。本文欲研究用微波辐射使植酸水解生产IP3。通过在微波条件下，控制水解条件，当水解度达到50%，将水解混合物通过装有717型强阴离子树脂柱，并用0．05～0．7M盐酸进行线性梯度洗脱，洗脱物分别取样消化，     

用沉淀法减少植酸钙含杂量

<正>肌醇是粮油工业综合利用重要产品之一.目前国内肌醇生产的传统工艺是先从米糠制得植酸钙,再由植酸钙经水解而制得肌醇.植酸钙作为肌醇生产的中间产品,其质量对肌醇生产的影响很大,特别是杂质的含量对肌醇的收得率来说更是至关重要的因素.植酸钙生产工艺是先用一定浓度的盐酸(或硫酸)溶液来浸泡米糠,使米糠中的植酸     

植酸水解制取肌醇的条件与机理

在常压及高沸点溶剂多元醇存在下,新工艺植酸催化水解制取肌醇的反应条件是:植酸浓度(水酯比)55—65％(W/W,下同),温度130—150℃,水解时间3—4小时,水解平衡转化率可达96％。并对反应机理进行了分析。     

提高植酸钙、肌醇得率方法的初步探讨

提高植酸钙、肌醇得率方法的初步探讨郑启阶植酸钙也称菲汀，是植酸与钙镁形成的一种复盐，广泛存在于植物种子的糊粉层中，尤以米糠中含量最丰富，国内报道米糠中含植酸钙多为１０～１１％，日本报道高的有９．５～１４．５％。肌醇是菲汀水解后的产物，菲汀中一般含有２...     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.