蛹虫草固态发酵联产多糖和纤溶酶的工艺优化

以玉米粉作为主要原料,利用蛹虫草固态发酵同时生产多糖和纤溶酶。以多糖含量和纤溶酶活力为指标,通过单因素和正交试验优化了蛹虫草固态发酵培养基和培养条件。结果表明:培养基由玉米粉和麸皮构成,比例为18:2（g/g）,料水比例1:1（m/V）,接入6%（V/m）蛹虫草液体菌种,23℃发酵时间3 d。在优化条件下获得浸提液中的胞外多糖含量为3.23 mg/mL,纤溶酶在血纤维蛋白平板上形成的溶圈面积为169.34 mm2。研究结果为生产蛹虫草功能食品基料提供了基础。     

羊肚菌液体深层发酵条件

以羊肚菌为材料，研究了发酵过程中碳源、氮源、无机盐、培养条件对菌丝体生物量、胞外多糖的影响，以及发酵过程中菌丝体生物量、胞外多糖、总糖及还原糖质量浓度、培养基PH值的动态变化，并在此基础上确定了羊肚菌液体深层发酵的最佳条件。结果表明：羊肚菌液体深层发酵的最优培养基配比为：玉米粉4．0g／dL、葡萄糖1．0g／dL、黄豆粉2．0g／dL、酵母粉0．3g／dL、KH2PO4 0．2g／dL、MgSO4 0．1g／dL、CaSO4 0．1g／dL；最优培养条件为：24℃，起始pH5．8，250mL的摇瓶装液量为100mL，接种量10mL，摇瓶转速140r／min，发酵时间为108h。     

大米主料蛹虫草固体发酵生产纤溶酶的研究

以大米为主要原料,通过固态发酵的方法生产蛹虫草纤溶酶。运用单因素试验初步优化发酵的培养基组成及培养条件,用正交试验方法对蛹虫草固态发酵的无机盐添加量进行了细致探索。结果表明,试验范围内蛹虫草菌固态发酵生产纤溶酶的适合培养基主料为麸皮和大米,二者质量比为1︰1,培养基加水量75 g/100 mL,无机盐CaCl_2和(NH_4)_2SO_4的添加量分别为0.1 g/100 mL和2 g/100 mL,培养基初始pH自然,接种量25 g/100 mL,培养时间5 d,固体发酵物的纤溶酶浸提时间为4 h。优化条件下的固体发酵纤溶酶活力达167±1 U/mL。     

银耳芽孢多糖发酵培养基配方、发酵条件的优化及其放大发酵试验

为开发银耳芽孢高产胞外多糖深层液态发酵培养基,提高银耳芽孢多糖的发酵产量以及实现规模化生产应用,本研究采用单因素实验探索不同来源的碳氮源及营养元素对银耳多糖产量的影响,并结合Plackett-Burman和Box-Behnken响应面设计,得到高产胞外多糖的发酵培养基配方和发酵条件,进一步使用50 L发酵罐进行了发酵工艺的验证。结果表明:优化后得到银耳芽孢高产胞外多糖发酵培养基配方为:葡萄糖35 g/L,NaCl 0.6 g/L,复合氮源（酵母浸膏和玉米浆干粉1:1）3.6 g/L,MgSO₄ 0.5 g/L,KH₂PO₄ 1 g/L;最适发酵条件为:发酵温度27 ℃,发酵初始pH5,发酵时间6 d,接种量3%（v/v）,摇床转速150 r/min。优化完后银耳芽孢胞外多糖产量为214.45 mg/100 mL,在摇瓶发酵阶段达到了较高的产量水平。50 L发酵罐放大发酵中验证多糖得率为258.78 mg/100 mL,比摇瓶实验得率提高了21.03%。本次优化显著促进了银耳芽孢胞外多糖的产量,为其规模化工业生产提供理论支持。     

白灵菇产胞外多糖液体培养条件优化

以菌丝体生物量及发酵液中胞外多糖(exopolysaccharides,EPS)含量为指标对白灵菇产胞外多糖的液体培养基组成和发酵条件进行了优化。结果表明,最适碳源是麦芽糖,最适氮源是酵母膏。正交实验确定最佳培养基组成为麸皮200g/L,麦芽糖25g/L,酵母膏3g/L,KH2PO41g/L,MgSO·47H2O1g/L。最佳发酵条件为起始pH8.0,培养温度25℃,摇床转速160r/min,装液量100mL/250mL,接种量0.50cm2菌种块,发酵时间4d。在此条件下,白灵菇菌丝体生物量(0.413g/100mL)及胞外多糖含量(2403.2mg/L)分别是对照(0.177g/100mL和664.533mg/L)的2.3倍和3.6倍。     

冬虫夏草液体发酵产胞外多糖的研究

本文以冬虫夏草菌丝体产胞外多糖为参考指标，对冬虫夏草液体发酵所采用的培养基成分和发酵条件进行了研究，确定了培养基的合理配比为蔗糖3％、玉米粉5％、豆饼粉4％、MgSO4．7H2O0．05％、KH2PO40．1％、VBI0．01％，22℃、pH6．5，120转／min摇床，摇瓶培养7天，冬虫夏草胞外粗多糖产量为5．86g／L。     

废蜜原料液体发酵蛹虫草菌丝体和多糖的条件

废蜜（糖蜜）是制糖工业的主要副产物之一,含有很多微生物可利用的成分,是一种廉价的生产原料.以甜菜糖蜜为原料,通过液体发酵方法生产蛹虫草菌丝体.以蛹虫草菌丝体生物量为主要指标,发酵液中胞外多糖做为次要指标,运用单因素对比试验和正交实验,对蛹虫草液体培养基中的氮源以及培养条件进行优化.结果表明：有机氮源比无机氮源更有利于蛹虫草液体发酵;大豆分离蛋白与蛋白胨以4：1的比例混合,不仅能降低生产成本,还能促进菌丝生物量及胞外多糖的积累;发酵的最适培养条件为：摇床转速180r/min、装液量50/250ml、培养温度23℃、接种量8％ （v/v）,优化条件下蛹虫草液体培养生物量达到42.71 mg/ml,培养液中多糖含量达到5.97mg/ml.     

响应面法优化蛹虫草菌固体发酵五味子药渣发酵条件

将五味子药渣用作蛹虫草菌发酵培养基且不添加其他任何营养物质,并以水料比、基质重量、接种量、发酵温度为考察因子,在单因素实验基础上,结合响应面法以发酵产物中虫草素含量为响应值对发酵条件进行优化。响应面法分析得出蛹虫草菌发酵五味子药渣最佳条件:水料比为2mL/g,基质重量为37g,接种量为23%,发酵温度为26℃。在此条件下发酵15d,发酵产物中虫草素含量高达5.1202mg/g;多糖含量为2.87%,相比发酵前五味子药渣中多糖含量提高了24.97%。结果说明,以五味子药渣作为蛹虫草菌发酵培养基,不仅可以提高五味子药渣的利用价值,而且可以降低发酵蛹虫草菌生产虫草素的成本。     

搅拌转速和通气量对灰树花深层发酵培养的影响

采用15L搅拌式发酵罐研究灰树花的扩大培养条件，主要考察了搅拌转速和通气量对灰树花菌丝量、胞外多糖产率、溶氧、菌丝形态以及发酵液粘度的影响．研究结果表明搅拌转速和通气量能显著影响灰树花的生长，并且通过对灰树花菌丝球的大小、形态以及胞外多糖的分泌影响发酵液的粘度．并得出较为优化的培养条件为：温度25℃，通气量0．75vvm，搅拌转速80r／min，装液量60％；在此条件下，发酵10d后，灰树花菌丝体最大得率为22．95g／L，胞外多糖的得率为1．521g／L。     

蓝光对蛹虫草多糖含量的影响

蛹虫草菌种在两种不同的液体培养基(其中一种添加奶粉)中经摇发酵培养后,再在静置培养过程中以蓝光照射蛹虫草菌丝体,研究蓝光照射对其产生胞内和胞外多糖含量的影响。结果表明,在不含有奶粉的液体培养基表面生长蛹虫草菌丝体,其胞外多糖和胞内多糖含量受蓝光照射的影响而降低;而在培养基中加入奶粉以后,蓝光照射时也可降低胞内多糖的相对含量,但使蛹虫草胞外多糖含量稍有增加。     

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