响应面法优化超临界CO2萃取火龙果籽油工艺

采用响应面法优化超临界二氧化碳萃取工艺提取火龙果籽油,用Design Expert软件对试验数据进行分析,并用气相色谱-质谱法对萃取所得火龙果籽油进行成分分析。结果表明:萃取时间、萃取压力、萃取温度对火龙果籽油超临界CO2萃取工艺影响显著,其最佳提取工艺参数为萃取压力25MPa、萃取温度40℃、萃取时间3.5h,火龙果籽油萃取得率为30.21%。火龙果籽油中脂肪酸主要成分以不饱和脂肪酸为主,占总脂肪酸含量的74.64%,其中亚油酸及其异构体为46.91%,油酸及其异构体为25.36%;饱和脂肪酸以棕榈酸为主,棕榈酸及其异构体占总脂肪酸含量的21.10%。火龙果籽油可以作为一种食品保健油进行开发。     

溶剂法提取火龙果籽油工艺优化及其理化性质

以火龙果籽(H.polyrhizus)为原料,采用索氏抽提法提取火龙果籽油,通过单因素实验研究了抽提溶剂、干燥时间、液料比、抽提温度、抽提时间等因素对油脂提取率的影响,响应面优化实验确定了溶剂抽提火龙果籽油的最佳工艺条件,并分析了火龙果籽油的理化性质及其脂肪酸组成.结果表明,石油醚抽提法提取火龙果籽油的最佳条件为:液料比7∶1 (mL∶g),抽提温度78℃,抽提时间3h,在此条件下油脂提取率31.47％;火龙果籽油的酸值、过氧化值等指标达到食用油脂的国家标准;GC-MS分析结果表明火龙果籽油中含8种脂肪酸,主要为亚油酸(47.98％)、油酸(28.13％)、棕榈酸(16.77％)、硬脂酸(5.02％);通过面积归一化法计算可知其不饱和脂肪酸占油脂总量的77.58％,因而是一种具有较高的开发潜力的营养油脂.     

红心火龙果营养果醋加工工艺研究

以红心火龙果为原料,通过单因素试验和正交试验,探讨火龙果果醋生产的最佳工艺条件。经实验结果证明:其最佳酒精发酵工艺条件为发酵温度28℃,酵母接种量8%,发酵时间6天;醋酸发酵工艺条件为温度33℃,恒温发酵6天,起始酒精度6%,醋酸菌接种量10%。在此工艺条件下能生产出色泽棕红、风味突出、果香浓郁、酸味柔和的火龙果果醋。     

人工神经网络优化火龙果籽油的超临界CO_2萃取工艺

采用超临界CO2萃取火龙果籽油,通过单因素试验研究了干燥时间、原料粒度、CO2流量等因素对油脂得率的影响,利用JMP 7.0软件中的人工神经网络平台,建立了超临界CO2萃取火龙果籽油的人工神经网络模型,并优化了萃取过程的工艺条件。试验结果表明:火龙果籽晒干后经(80±1)℃干燥1 h,稍粉碎过40目筛,CO2流量为20 L/h,萃取压力30 MPa,萃取温度55℃,萃取时间3 h,油脂得率达31%以上;超临界CO2萃取的火龙果籽油酸值、过氧化值都较低,不饱和程度较高,是一种具有较高的开发潜力的植物油脂。     

红心火龙果柚子复合果醋发酵工艺条件优化

以红心火龙果和柚子为原料,以醋酸产量为指标,在单因素试验的基础上利用Box-Benhnken设计响应面试验,优化了红心火龙果柚子复合醋的发酵工艺。试验结果表明:红心火龙果柚子复合果醋发酵的最佳工艺条件为初始酒精度7.24%、发酵温度35.48℃、果醋菌接种量572.4 mg/L,此条件下醋酸的理论产率最大,为0.94 mol/L。     

红心火龙果醋发酵工艺的研究

以贵州省关岭县红心火龙果为研究对象,探讨红心火龙果醋的发酵工艺。结果表明,果醋最佳发酵工艺为初始酒精度8%vol,初始pH 4.0,醋酸菌种LB1接种量10%,发酵温度30 ℃,180 r/min恒温发酵7 d。在此条件下,红心火龙果醋酸度可达5.30 g/100 mL,果醋呈淡琥珀色、澄清透明、有清淡的火龙果香味、酸甜爽口、柔和无异味。为实现工业生产,采用自吸式供氧方式进行30 L果醋发酵罐放大试验,最终酸度达6.34 g/100 mL,增加了1.04 g/100 mL。     

喀斯特环境火龙果真空冷冻干燥工艺研究

研究火龙果真空冷冻干燥工艺条件,探索火龙果真空冷冻干燥的工艺参数,提高火龙果附加值。分别对3个影响真空冷冻干燥的因素设计正交试验,研究不同切片厚度、升华温度、解析温度对火龙果感官品质及内在品质的影响。结果表明:感官评分优化的最佳工艺参数为:厚度8 mm、升华温度25℃、解析温度50℃;VC含量评分优化的最佳工艺参数为:厚度10 mm、升华温度25℃、解析温度40℃;蛋白质含量优化的最佳工艺参数为:厚度8 mm、升华温度15℃、解析温度45℃。总膳食纤维含量优化的最佳工艺参数为:厚度10 mm、升华温度15℃、解析温度45℃;糖酸比优化的最佳工艺参数为:厚度10 mm、升华温度20℃、解析温度50℃。综合分析得出火龙果最佳干燥工艺条件为:厚度10 mm、升华温度25℃、解析温度50℃,所得火龙果感官得分95、VC含量74 mg/100 g、蛋白质含量9 g/100 g、总膳食纤维含量22.5 g/100 g、糖酸比64.37。     

红心火龙果酒酿造工艺研究

以贵州关岭县红心火龙果为原料,探讨火龙果酒的最佳酿造工艺。通过单因素试验和正交试验,研究酵母接种量、果胶酶添加量、初始糖度、发酵温度对果酒品质的影响。结果表明,火龙果酒最佳酿造工艺参数为酵母接种量0.03%,果胶酶添加量0.4%,初始糖度26%,发酵温度22 ℃。此最佳酿造工艺条件下,发酵的果酒酒精度13.5%vol,感官评分为89分,果酒呈深红色、澄清透明,具有浓郁、宜人的酒香和火龙果香气,各项指标符合国标GB 15037—2006《葡萄酒》的要求。     

火龙果籽油抑制癌细胞增殖作用的研究

采用气相-质谱联用仪(GC-MS)分析了火龙果籽油的脂肪酸组成;利用噻唑蓝(MTT)法,检测了火龙果籽油抑制Hep G-2、HT-29人体癌细胞的增殖,并绘制了火龙果籽油对这些癌细胞生长曲线的影响。结果表明:火龙果籽油中主要含有亚油酸(41.28%)、油酸(26.17%)、棕榈酸(20.76%)等组分,不饱和脂肪酸高达72.10%;MTT法显示火龙果籽油呈剂量(1、3、5 mg/m L)和时间(24、48、72、96 h)依赖方式抑制Hep G-2、HT-29等细胞增殖,作用48 h细胞抑制率分别可达到24.76%、38.92%、48.18%和35.47%、46.11%、53.78%,火龙果籽油对这些癌细胞的生长具有显著性、持续性的抑制作用。     

红心火龙果百香果复合果酒发酵工艺优化

该研究以红心火龙果和百香果为主要原料制备红心火龙果百香果复合果酒，以酒精度及感官评分为评价指标，利用单因素试验及响应面法对发酵工艺进行优化，并对其理化指标及发酵过程中颜色参数、甜菜红素含量及1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除率进行测定。结果表明，最优发酵条件为发酵温度22℃，初始糖度22%、火龙果与百香果质量比100∶10。红心火龙果百香果复合果酒的理化指标为：总酸3.73 g/L、pH 3.8、总糖54.94 g/L、酒精度11.87%vol、甲醇102.17 mg/L、甜菜红素105.98 mg/L,DPPH自由基清除率为61.03%，感官评分为84.72分。在发酵过程中，甜菜红素含量、a^*值、b^*值及DPPH自由基清除率均呈下降趋势，而L^*值的变化趋势不明显。     

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.