阳荷红色素的提取及稳定性研究

在单因素试验基础上用正交试验对阳荷红色素的提取工艺条件进行筛选，得出最优提取条件为：在60℃下，用150倍于阳荷粉的pH1的70％乙醇，恒温提取50min。同时研究自然光照、糖类、防腐剂、氧化剂和金属离子对色素稳定性的影响，结果表明，阳荷红色素除在防腐剂苯甲酸钠和山梨酸钾、强氧化剂H2O2及铁离子环境中稳定性较差外，在其他条件下均具有良好的稳定性。     

荔枝核棕色素提取及稳定性研究

对荔枝核棕色素的提取工艺及其稳定性进行了研究,结果表明:以70%乙醇溶剂作为提取剂,料液配比为1∶10,温度为80℃,提取时间为2 h是最佳提取工艺条件;荔枝核棕色素在光照、酸性、温度低于80℃、有还原剂(Na2SO3)的加入下稳定,但在强碱、高温及氧化剂(H2O2)下不稳定。     

黑液预煮KP法蔗渣浆的OOP漂白

对用黑液预煮的两段改良蔗渣KP浆的氧气和H2O2漂白进行了研究。结果表明，使用OP两段漂白，在H2O2用量低于1．2％的条件下白度很难达到80％SBD。而采用OOP三段漂白，在H2O2用量1．0%的条件下，白度可达80．1％SBD，浆的粘度较高(达752mL／g)。在两段氧气漂白中，NaOH用量3％和H2O2用量1．0％时，提高H2O2漂白温度至86℃，可得到80．9％SBD的漂白浆，浆的粘度达782mL/g。研究认为，两段改良KP浆较常规KP浆具有更好的漂白性能，漂白浆的粘度也较高。     

脱墨浆H2O2漂白工艺条件的优化

在浆浓为10％、温度为80℃的条件下，研究了脱墨浆H2O2漂白的几种主要影响因素。研究结果表明：脱墨浆采用H2O2漂白时，其最佳工艺条件为H202用量2％，NaOH用量1．2％，H2O2用量与NaOH用量之比为1：0．6，Na2SiO，用量4．0％，漂白时间1h，助漂剂用量0．5％，在此工艺条件下所得漂白浆白度完全能够满足配抄较高白度新闻纸的需要。     

微波辅助麦草浆HP漂白

研究了麦草浆在微波辐射下的HP两段漂白工艺,探讨了漂白过程中微波功率、处理时间、NaClO及H2O2用量对漂白浆性能的影响.结果表明,漂白的最佳工艺条件H段微波功率320 W,微波处理时间2 min,NaClO用量8%;P段微波功率320 W,微波处理时间1.5 min,H2O2用量1.5%.在最佳漂白条件下,麦草浆白度可以达到80%以上,白度稳定性较好,可降低能耗50%左右.     

金莲花天然色素的提取方法与稳定性研究

对水提取金莲花色素的温度、pH、提取次数进行单因子试验与正交实验；研究了丙酮提取时不同温度和次数的影响；比较了不同的提取方式；探讨了色素的理化稳定性。试验条件下，水提取最佳条件为95℃～100℃下，pH7．0，1次提取30min丙酮宜用54℃水浴，1次浸提；先水后丙酮的提取方式花瓣几近无色，明显优于先酮后水或单一溶剂；常温下、pH3．0—7．0、蔗糖介质中色素稳定，食品加工用盐量、低浓度钙、镁离子对色素影响不大，铁离子、自然强光、H2O2破坏、降解色素。     

刺参体壁超氧化物歧化酶提取及酶学性质的研究

以刺参体壁为原料,提取制备超氧化物歧化酶(SOD),并分析了SOD的pH稳定性,热稳定性,以及H2O2和金属离子对刺参体壁SOD活力的影响,研究结果表明刺参体壁SOD的最佳提取条件为:提取液pH为4.0,浓度50 mmol/L,料液比1:4,提取时间6 h,硫酸铵饱和浓度80%~100%;3%H2O2直接导致SOD活力完全丧失;同时该酶具有较好的耐热性,在酸性条件下SOD具有较好的pH稳定性;Na+、K+、Mg2+、Cu2+对SOD基本无影响;Zn2+、Ca2+对SOD具有激活作用;Fe2+在相同浓度条件引起SOD活力的全部丧失。对刺参体壁SOD的研究,为其生产加工应用、以及丰富刺参自溶机制提供基础的理论依据。     

酸模叶蓼果实红色素的稳定性研究

目的:研究了不同环境条件对酸模叶蓼果实红色素在可见光区的稳定性的影响。方法:采用pH2的80%乙醇作为提取溶剂,对色素提取液在400～700nm进行紫外扫描,而后分别探讨温度、pH、H2O2、VC、金属离子以及蔗糖对色素在紫外和可见光区的稳定性的影响。结果:该色素的四个吸收峰波长分别为444、475、519、665nm;酸模叶蓼果红色素可耐受一定高温,pH对其影响很大,应在低酸性条件下使用;H2O2可使其褪色,VC对其影响不大;大多数金属离子对其无影响,Fe3+等少数金属离子对色素有影响。     

不同黏均分子量壳聚糖制备及在染整中的应用

研究了壳聚糖在中性条件下用H2O2进行氧化降解的情况，讨论了反应温度和H2O2浓度对氧化降解反应的影响。结果表明，用H2O2使壳聚糖在中性条件下氧化降解是制备低分子量壳聚糖的一种简便易行的方法，以分子量为4.5万左右的壳聚糖预处理的棉织物，对活性染料染色增深效果最明显。     

微波辅助提取紫马铃薯花色苷及其稳定性的研究

研究微波辅助提取紫马铃薯花色苷的工艺条件和稳定性。用pH示差法对紫马铃薯中的花色苷含量进行测定。正交实验结果表明:微波辅助提取的优化条件:提取时间40s,微波功率480W,料液比1:70,提取溶剂酸度0.11%盐酸水溶液,提取液花色苷含量达到3.649mg/鲜紫马铃薯(g)。稳定性研究表明紫马铃薯花色苷具有较差的光稳定性和热稳定性,应避免光照和高温;氧化剂H2O2对其稳定性有较大的影响;在酸性条件下稳定性较好;金属离子和常用食品添加剂对紫马铃薯花色苷色素稳定性的影响较小。     

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.     

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.     

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