菊芋预处理及菊糖提取工艺优化的研究

菊芋茎块中含有非常丰富菊糖,菊糖是具有重要的保健功能,近年来其功效被人们所认知。本研究为工业化大生产提供理论依据,寻求适合工业化生产的工艺条件。以菊芋茎块为原料,确定了热烫灭酶65℃烘干的预处理工艺;采用单因素试验设计和正交试验设计方法,对提取温度、提取时间、料液比、提取次数4个因素进行研究。结果表明:菊芋菊糖热水浸提的最佳提取工艺条件为:温度60℃、料液比1∶25、浸提时间60min、提取次数为1次。     

菊芋苦荞山药复合功能膏的制备与工艺流程

研究菊芋苦荞山药复合功能膏的制备方法与工艺流程。将菊芋、苦荞和山药在一定条件下烘干、粉碎、过滤成粉,将菊芋粉放在一定条件下提取菊糖,提取方法采取温度、时间、料液比三因素正交试验,并将菊糖溶液与苦荞、山药按照一定比例混合。然后在菊芋苦荞山药复合溶液里添加一定浓度的果糖、果胶和CaCl_2,并控制一定的pH值。菊芋烘干温度80℃、时间10 h,过40目;山药烘干温度60℃、时间8 h,过100目;苦荞烘干温度60℃、时间8 h,过100目,最后制备的复合膏口感质地最好;采用热水浸提法对菊糖进行提取,通过正交试验确定了提取菊糖的最佳条件为:料水比1:40(g/mL),温度80℃,提取时间50 min,菊糖提取率为75.32%;添加果糖终浓度15%,低脂果胶1.2%,添加CaCl_20.06%;终pH控制在6.4,制备的复合膏的质感和口感达到理想状态。菊芋苦荞山药粉化后,以每100 mL菊糖液中加入0.4%山药粉、0.1%苦荞粉的比例混合,经果胶调制可以制备口感质感优良的多功能复合膏。     

菊芋菊糖的超声波提取、纯化及HPLC法纯度检测

重点研究了菊芋菊糖的超声波提取、纯化工艺和利用高效液相色谱技术进行纯度检测.其中,超声波提取菊芋菊糖最佳工艺条件为:超声功率112W,提取温度70℃,提取时间20min,料液比1:20,菊糖得率为57.3%.菊糖提取液经石灰乳法和醇沉法除杂,再经S-8大孔吸附树脂脱色处理后色泽澄清,真空冷冻干燥得白色粉末,经高效液相色谱法检测,其纯度为96.2%.     

盐碱滩涂菊芋菊糖的提取纯化及其聚合度分布

对来自江苏盐城盐碱滩涂上生长的菊芋中菊糖的提取纯化与聚合度分布进行研究。经过菊芋成分分析可知,来自盐碱滩涂的菊芋灰分含量较高;通过考察不同提取条件,确定最优提取条件为90℃水浴、料液比(g/mL)1:15、提取时间40min、提取两次后提取率可达89.56%。与传统的磷酸-石灰乳法纯化相比,采用截留分子质量为10kD的有机膜可去除大分子蛋白质及果胶,蛋白质去除率及菊糖得率分别提高了27.12%和13.41%。采用不同截留分子质量的超滤膜对提取液中菊糖的聚合度分布进行分析,其聚合度主要分布在16～60之间,占总菊糖成分的76.1%。确定了活性炭脱色的最佳条件为活性炭用量5g/L、60℃脱色20min,脱色率达92.87%,菊糖得率91.63%。超滤纯化方法简便、快速,大大减少了纯化工序,便于工业化应用。     

菊芋多糖提取过程中的pH控制策略研究

采用未漂洗和漂洗过的菊芋做原料,在pH5.0～9.0,85℃、固液比1:10下提取,并在60～120min每隔10min取样分析,得出如下结论:pH越低,提取液中的还原糖含量越高;pH越高,提取液中的蛋白质的含量越高;菊糖含量在100min左右达到最高值。考虑还原糖及蛋白质等杂质、脱色及菊糖的含量,未漂洗的原料最佳提取条件为pH7.0,提取110min,其菊糖含量为88.43g/L,菊糖提取率为76.46%;漂洗过的原料最佳提取条件则是pH7.0,提取100min,其菊糖含量为86.10g/L,菊糖提取率为72.65%。     

微波辅助法提取牛蒡根中菊糖的研究

本实验采用微波辅助热水提取法以牛蒡根为原料制备具有良好生物活性的菊糖。微波辅助提取法和传统的热水提取法的菊糖提取率分别为58.18%和50.19%,表明采用微波辅助法可以将菊糖的提取率提高15.92%,效果显著。利用单因素试验分别考察了料液质量比、微波提取时间、水提取温度、热水提取时间在不同水平下对菊糖提取率的影响程度。通过正交试验结果显示影响因素从大到小依次为:热水提取时间>微波提取时间>水提取温度>料液质量比。最佳提取条件为:料液质量比1:20、微波提取时间240s、水提取温度70℃、热水提取时间1.5h,在此条件下菊糖的提取率可达到91.40%。产品外观呈微黄色絮状固体、易吸湿、易结块、微甜、无臭、易溶于水、热稳定性好,有着良好的应用前景。     

超声波辅助复合酶提取菊糖工艺优化

以菊芋块茎为原料,采用超声波辅助复合酶酶解法进行菊糖提取工艺研究。首先通过单因素试验和Plackett-Burman筛选试验确定菊糖提取工艺中影响显著的3 个因素--超声温度、超声时间和加酶量,再利用Box-Behnken试验及响应面分析法优化最佳提取工艺条件。结果表明：最佳提取工艺条件为料液比1∶20（g/mL）、超声温度51 ℃、加酶量120 μg/g（m（果胶酶）∶m（纤维素酶）=1∶4）、超声时间25 min、pH 5.5,优化后菊糖得率为72.2%。     

超声强化提取菊芋中菊糖的研究

为了探讨超声对菊芋中菊糖提取的影响,试验采用单因素试验和响应曲面法对其提取工艺进行了研究,建立并分析了各主要影响因子与菊糖提取率关系的数学模型.单因素试验结果表明,超声功率、超声辐照时间和料液比对菊糖提取率影响显著,而提取温度影响不明显.通过RSM响应曲面法的进一步分析显示,回归方程p=0.002028＜0.01,决定系数R2为97.33%,说明所建模型与试验值的拟合度很好.超声提取菊糖的优化工艺为:总提取时间为10min,超声辐照方式为15s/6s,超声功率为750W,料液比(w/v)为1 :29.24,提取温度为40℃,在此条件下菊糖的提取率为94.23%.超声波强化提取法与热水浸提法相比较,具有工艺简单、提取时间短、提取温度低、提取率高等优点.     

牛蒡菊糖的提取及其分离纯化

以水提醇沉工艺,采用单因素实验和正交实验设计方法研究料液比、提取温度、提取时间以及提取次数对牛蒡菊糖提取率的影响,得到牛蒡菊糖提取的最佳因素组合：料液比1∶15（g∶mL）,提取温度80℃,提取时间90 min,提取2次,提取率为90.86%。比较不同的脱色、脱蛋白方法,得到纯度较高的均一多糖。     

超声波辅助提取菊芋中菊粉的工艺研究

以菊芋中菊粉为研究对象,采用单因素分组实验法对菊芋中菊粉超声波辅助提取工艺进行了初步探讨,比较了提取温度、料液比、提取时间、超声波功率等因素对菊粉得率的影响。实验结果表明:超声波提取的影响因素顺序为提取温度>超声波功率>料液比>提取时间,其最佳工艺条件为提取温度70℃,料液比1:20,时间30min,超声波功率160W,此条件下菊粉得率为63.37%。超声波法与传统热水法相比,菊粉得率提高20.97%。     

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.     

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.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.