果胶原料(柠檬皮)预处理方法的研究

以新鲜柠檬皮为原料,通过组织捣碎、研磨,反复冻融、急热骤冷及复合磷酸盐处理五种组织细胞破碎方法对果胶提取率的影响效果对比,结果表明,复合磷酸盐是最佳的组织细胞破碎方法,有效地提高了果胶的提取率。其最佳作用条件:温度90℃,静置24h,复合磷酸盐配比为3%磷酸钠,0.9%磷酸氢二钠,0.3%焦磷酸钠,0.6%六偏磷酸钠(其中百分比为原料用量的质量百分比)。     

果胶原料(橘子皮)预处理方法研究

为探究果胶原料预处理的最佳方法,以干橘子皮为原料,对组织捣碎、反复冻融、急热骤冷及复合磷酸盐处理四种组织细胞破碎方法进行对比,结果表明,复合磷酸盐处理是最佳的组织细胞破碎方法,其最佳作用条件:温度90℃,静置24h,复合磷酸盐配比为3%磷酸钠,0.9%磷酸氢二钠,0.3%焦磷酸钠,0.6%六偏磷酸钠(其中百分比为原料用量的质量百分比)     

不同提取方法对马铃薯果胶多糖组成特性的影响

以马铃薯渣为原料,采用酶法脱除淀粉和蛋白质,分别以盐酸法、柠檬酸法、碱性磷酸盐法和复合盐法从马铃薯渣中提取果胶,经超滤、乙醇沉淀和冷冻干燥得到4种马铃薯果胶多糖。研究不同的提取方法对马铃薯果胶多糖提取率、组成特性的影响。结果表明,碱性磷酸盐法和复合盐法提取果胶得率高(分别为29.89%和21.01%)、半乳糖醛酸含量高(分别为29.71%和31.57%)。碱性磷酸盐法提取果胶的中灰分含量(22.38%)显著高于其他3种果胶多糖(2.09%~2.48%)。4种工艺提取得马铃薯果胶是低甲氧基果胶;蛋白质含量低于3.0%,没有显著差异;中性单糖组成主要包括半乳糖,及少量的阿拉伯糖、鼠李糖和葡萄糖。马铃薯果胶多糖的峰值分子质量在1.65×10~4~1.17×10~6u左右,为非均一多糖,4种方法提取得马铃薯果胶均具有果胶的特征官能团。     

超声波辅助提取夏橙皮渣果胶研究

以干燥的夏橙皮渣为原料,先用复合磷酸盐碱性溶液浸泡24 h,采用超声波辅助提取法对果胶进行了提取。以果胶提取率为考察指标,研究了盐酸浓度、液料比、水解温度、水解时间、超声波处理时间对果胶提取的影响。结果表明,盐酸浓度为0.15 mol/L、液料比为30 m L/g、水解温度为70℃、水解时间为30 min、超声波处理时间为40 min时,果胶提取率高达20.67%,试验重现性好。     

复合磷酸盐法预处理西瓜皮制备低酯果胶工艺优化

以西瓜皮为原料,研究复合磷酸盐法预处理西瓜皮制备低酯果胶的工艺条件。实验结果表明从西瓜皮中提取低酯果胶的最佳条件：质量分数2% 的磷酸钠、质量分数0.9% 的磷酸氢二钠、质量分数0.3% 的焦磷酸钠、质量分数0.6% 的六偏磷酸钠配比的复合磷酸盐预处理,脱酯pH10、脱酯温度15℃、脱酯时间0.5h。在此条件下,低酯果胶得率5.07%,甲氧基含量4.49%,脱酯效果较好。     

超声波辅助提取火龙果皮中的果胶

探索不同提取条件对火龙果皮中果胶提取率的影响,以获得果胶的最佳提取条件和提取率。以干燥后的火龙果皮为原料,采用超声波辅助提取火龙果皮中的果胶,以果胶提取率作为测定指标,通过单因素实验和正交试验,确定提取果胶的最佳工艺。结果表明用超声波提取火龙果皮中果胶的最佳提取工艺为:料液比为1∶20、超声波功率为180W、提取时间为60min、提取温度为50℃。在最佳提取工艺下,果胶的提取率高达12.65%,为火龙果皮果胶的开发应用提供了理论依据。     

南瓜皮果胶的提取工艺及其品质分析

研究南瓜皮果胶超声波辅助半纤维素酶提取最佳工艺条件,并对果胶的品质进行分析。以南瓜皮为原料,果胶提取率为考察指标,在单因素试验基础上通过正交试验确定最佳提取工艺条件;参照QB 2484-2000对其果胶进行品质分析。结果表明:在半纤维素酶溶液浓度为0.7%,料液比(m∶V)为1∶20,浸提温度为50℃,浸提时间为90 min,超声时间为10 min,超声功率为240 W的条件下,果胶的提取率高达11.21%。所得果胶为高甲氧基果胶。     

西瓜皮中果胶的提取工艺研究

以新鲜西瓜皮为原料,采用酸提醇沉的方法提取果胶。通过正交试验研究pH、果皮量、加热温度和提取时间4个因素对果胶提取率的影响,得出提取果胶的最佳工艺条件为:果皮量5g、pH3、加热温度70℃、加热时间90min,该工艺条件下果胶的提取率为0.764%。     

纤维素酶辅助提取橘皮中果胶类化合物

本文以橘皮为原料,研究用纤维素酶辅助提取橘皮中果胶的工艺,分别讨论了温度、pH值、时间、料液比、纤维素酶用量等因素对果胶提取率的影响,通过单因素及L16(45)正交实验,获得了橘皮中提取果胶的最佳条件,即温度55℃,pH7.0,提取时间2.5h,料液比1∶20,纤维素酶用量0.25%,在此条件下果胶提取率可达17.31%。     

响应面试验优化兔肉滚揉腌制工艺

在单因素试验基础上,研究滚揉里程、液肉百分比、复合磷酸盐添加量对腌制液吸收百分比和出品率的影响。通过Box-Behnken试验设计和响应面分析法确定兔肉真空滚揉腌制的最佳工艺。结果表明：兔肉最佳滚揉腌制工艺为滚揉里程351 m、液肉百分比38%、复合磷酸盐添加量0.37%,在此条件下得到腌制液吸收百分比为31.97%,出品率为98.83%。     

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.