二次正交旋转组合设计优化水酶法提取猕猴桃籽油的工艺

以猕猴桃籽为原料,采用水酶法提取猕猴桃籽油。在单因素试验的基础上,采用二次正交旋转组合试验对猕猴桃籽油的提取工艺进行优化,建立了各主要影响因素与猕猴桃籽出油率之间的回归模型。试验结果表明:各因素对猕猴桃籽出油率影响的顺序为液料比>酶解pH>酶添加量>酶解温度,水酶法提取猕猴桃籽油的最优工艺参数为液料比10,酶解温度50℃,酶添加量2.5%,酶解pH 9.0。在此条件下,提取二次总出油率为27.17%,萃取率达86.75%。所建立的数学回归模型能够较准确预测猕猴桃籽油的出油率。     

水酶法提取茶叶籽油工艺条件研究

采用水酶法提取茶叶籽油,通过单因素实验和正交实验优化提取工艺条件。结果表明,水酶法提取茶叶籽油优化工艺条件为:纤维素酶用量1.1%、果胶酶用量2.0%、蛋白酶用量0.2%,料液比1:6,酶解温度45℃、酶解pH值5.0、酶解时间8h,茶叶籽油得率28.64%。     

响应面优化超声波辅助水酶法提取茶叶籽油工艺

利用响应面法(RSM)优化超声波辅助水酶法提取茶叶籽油工艺条件,在单因素试验基础上,选取复合酶用量、酶解pH、酶解温度、酶解时间为影响因子,茶叶籽油得率为响应值,应用Box-behnken中心组合试验设计建立数学模型,进行响应面分析。结果表明,超声波辅助水酶法提取茶叶籽油工艺优化条件为:高压蒸煮20min,超声处理20min,超声温度60℃,料液比1:5、复合酶用量1.75%,酶解pH4.6,酶解温度44℃,酶解时间6.9h。茶叶籽油得率为29.88%。     

水相法提取牡丹籽油及破乳工艺的研究

采用水相法提取牡丹籽油,碱提形成稳定乳状液后,用酶和乙醇进行破乳。选择料液比、酶活添加量、酶解时间、酶解温度作为试验的四个因素,在单因素试验的基础上,进行四因素三水平的正交试验优化提油工艺。通过极差分析可看出,四个因素对牡丹籽出油的影响大小为:料液比酶活添加量酶解温度酶解时间。通过正交工艺优化,得出最佳的提油工艺为:料液比1︰6(g/m L)、酶活添加量600 U/g、酶解时间2.5 h、酶解温度60℃。在此优化条件下,牡丹籽出油率可达到17.13%。提油率为62.29%。     

茶叶籽饼粕中茶皂素提取工艺研究

本实验研究了茶叶籽饼粕中茶皂素的浸出工艺。在分析比较不同提取溶剂提取能力的基础上,选择95％乙醇为浸出溶剂,考察了浸提温度、浸提时间、液料比和茶叶籽饼粕粉碎粒度等因素对茶皂素得率的影响。正交试验结果表明,茶皂素提取的较优工艺条件为浸提温度60℃、浸提时间2h、液料比13：1、粒度40目,此时茶皂素得率为8．85％,粗产品茶皂素纯度为54．2％。     

超声波辅助酶法提取茶叶籽油及其脂肪酸组成分析

以湖南怀化地区茶叶籽为原料,在单因素试验的基础上,通过正交试验优化超声波辅助酶法提取茶叶籽油的工艺条件,并采用气相色谱-质谱联用分析茶叶籽油的脂肪酸组成。结果表明:超声波辅助酶法提取茶叶籽油最佳工艺条件为料液比1∶5、植物提取复合酶添加量0.6%、p H 5.8、超声酶解温度55℃、超声酶解时间90 min、超声功率300 W,在此条件下,茶叶籽出油率为(52.61±0.11)%;茶叶籽油中共鉴定出17种脂肪酸,主要含油酸(47.67%)、亚油酸(24.32%)、亚麻酸(4.26%)等不饱和脂肪酸。     

水酶法提取石榴籽油工艺研究

以石榴籽为原料,利用水酶法提取石榴籽油.通过单因素及二次回归旋转组合实验研究了料液比、石榴籽粒度、酶的种类、酶解温度、提取时间、离心时间、pH以及酶的添加量等因素对出油率的影响,确定了水酶法提取石榴籽油的最佳工艺条件.结果表明,酶解最佳工艺参数为:用Alcalase蛋白酶添加量为1.0%(mL/g),原料粒度40目,料液比1:5(g/mL),提取温度50℃,提取时间6h,pH8.0,离心时间25min,在该工艺条件下石榴籽油出油率达18.2%.     

火棘籽油提取工艺优化

研究火棘籽油最佳提取工艺条件.采用有机溶剂提取法提取火棘籽油,以石油醚为提取溶剂,通过L9(33)正交试验,并以出油率作为评价指标,对提取温度、提取时间、料液比等提取工艺条件进行优化研究.影响火棘籽油出油率的主要因素次序为提取温度＞料液比＞提取时间,最佳提取工艺为提取温度60℃、提取时间8h、料液比1:6(W:V).在此工艺条件下火棘籽的出油率为7.45%.     

水酶法提取海滨锦葵籽仁油工艺条件优化

以海滨锦葵籽仁为原料,利用水酶法提取海滨锦葵籽仁油。通过单因素实验及中心组合实验研究了固液比、提取温度、酶用量、提取时间等因素对油脂出油率的影响,确定了水酶法提取海滨锦葵籽仁油的工艺条件。结果表明,在实验范围内各影响因素对海滨锦葵籽仁油提取率作用的大小依次为:酶用量>提取温度>固液比>提取时间。水酶法提取海滨锦葵籽仁油的优化工艺参数为:酶用量0.024 mL/g,提取温度63℃,固液比1∶6,提取时间230 min,在该工艺条件下海滨锦葵籽仁油提取率达到24.281%。     

响应面分析水酶法提取茶叶籽油工艺优化研究

茶叶籽作为茶叶生产副产物,富含油脂及茶皂素等成分.试验采用中性蛋白酶进行水酶法提取茶叶籽油工艺研究,单因素试验探索酶量、作用温度、作用时间、料液比等对油得率影响,并对副产物茶皂素得率进行测定;在此基础上开展中心组合试验,进行响应面分析对油脂提取工艺进行优化.研究结果表明回归方程为:Y=-65.950+3.011X1+1.522X2+10.167X3+5.685X4+0.167X1X3-0.108X1X4+0.0433X2X4-0.300X3X4-0.166X12-0.0157X22-1.059X32-0.797X42,最佳提取条件为酶量10.83 mL、酶解温度53℃、料液比1∶5.19、酶解时间3.30 h,验证试验油得率为26.053％,为茶叶籽资源开发提供了理论指导.     

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.